Resistance Training
for the Prevention
and Treatment of
Chronic Disease
Edited by
Joseph T. Ciccolo
William J. Kraemer
Resistance Training
for the Prevention
and Treatment of
Chronic Disease
Resistance Training
for the Prevention
and Treatment of
Chronic Disease
Edited by
Joseph T. Ciccolo
William J. Kraemer
Boca Raton London New York
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Contents
Preface......................................................................................................................vii
Acknowledgments......................................................................................................ix
Editors........................................................................................................................xi
Contributors............................................................................................................ xiii
Chapter 1
Introduction........................................................................................... 1
Joseph T. Ciccolo and William J. Kraemer
Chapter 2
Resistance Training Program Variables and Guidelines......................5
Nicholas A. Ratamess
Chapter 3
Resistance Training for Cardiovascular Disease................................ 23
Randy W. Braith and Joseph C. Avery
Chapter 4
Resistance Exercise Interventions across the Cancer Control
Continuum........................................................................................... 45
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
Chapter 5
Effects of Resistance Training on Insulin Sensitivity and
Glycemic Control: Potential Role in the Prevention of Type 2
Diabetes............................................................................................... 65
Christian K. Roberts
Chapter 6
Resistance Training in Chronic Renal Failure.................................... 81
Birinder S. Cheema and Danwin Chan
Chapter 7
Beneficial Effects of Progressive Resistance Training in
Multiple Sclerosis.............................................................................. 103
Lara A. Pilutti and Robert W. Motl
Chapter 8
Resistance Training for Parkinson’s Disease.................................... 117
Brian K. Schilling and Kelley G. Hammond
v
vi
Chapter 9
Contents
Resistance Training for Fibromyalgia............................................... 131
J. Derek Kingsley
Chapter 10 Resistance Training after Stroke....................................................... 149
Richard W. Bohannon
Chapter 11 Effects of Resistance Training on Depression and Anxiety............. 165
Shawn M. Arent and Brandon L. Alderman
Chapter 12 Progressive Resistance Training for Individuals with Chronic
Obstructive Pulmonary Disease........................................................ 181
Simone D. O’Shea and Nicholas F. Taylor
Chapter 13 Benefits of Resistance Training for HIV/AIDS.................................209
Jacob J. van den Berg and Joseph T. Ciccolo
Chapter 14 Resistance Training for Individuals with Orthopedic Disease
and Disability.................................................................................... 219
Mark D. Faries
Chapter 15 Resistance Training for Older Adults................................................ 239
Michael G. Bemben, Christopher A. Fahs, Jeremy P. Loenneke,
Lindy M. Rossow, and Robert S. Thiebaud
Chapter 16 Resistance Training for Children and Adolescents........................... 261
Avery D. Faigenbaum
Preface
There is currently a sufficient amount of evidence to support the use of resistance training (i.e., strength training or weight training) as a method to prevent,
treat, and potentially reverse the impact of numerous chronic diseases. Indeed,
­adhering to a properly designed progressive program can significantly enhance the
­physical and mental health of both apparently healthy and known disease populations. The importance of resistance training for maintaining health is now widely
recognized by numerous organizations, including the World Health Organization,
Centers for Disease Control and Prevention, American Heart Association, American
Association of Cardiovascular and Pulmonary Rehabilitation, American College of
Sports Medicine, National Strength and Conditioning Association, and it is part of
the U.S. National Physical Activity Plan. Despite the support of these organizations,
a majority of the books describing the relationship between physical activity and
chronic disease do not provide an in-depth analysis of the independent and positive
effects that can result from resistance training. There is an obvious imbalance favoring the promotion of aerobic activities given that the bulk of research on physical
activity has maintained a focus on the benefits of aerobic exercise. Over the past
decade, however, resistance training has quickly become increasingly more popular
worldwide, and its distinct effects are undeniable given the most recent research
­findings. It is now clear that resistance training has an independent and valuable
impact on disease prevention, and it can uniquely contribute to the treatment of
numerous medical conditions.
As the use of exercise in medicine grows, there is a need for an evidence-based
guide that will provide a detailed account of the research on resistance training,
particularly one that can offer direction and guidance to conduct future ­studies. The
purpose of this book is to fulfill that need by providing the scientific and ­public health
community with the most up-to-date and comprehensive resource on r­esistance
training research available.
This book is written for physical activity, public health and medical researchers,
allied health professionals, health educators, and college students. Each chapter provides the reader with a detailed description of the benefits of resistance training for
a specific clinical population and includes guidelines on how to construct a tailored
resistance training prescription for that population when appropriate. The chapters
of this book are written by some of the world’s leading exercise physiologists and
resistance training researchers and experts. Although resistance training research is
discussed in complex detail, an advanced knowledge of the field is not needed.
vii
Acknowledgments
We thank the authors of each chapter for their long hours of hard work and ­enduring
commitment to creating this book with us. It has been an honor and privilege to work
with them.
ix
Editors
Joseph T. Ciccolo, PhD, is an assistant professor and researcher in the Department of
Biobehavioral Sciences and director of the Applied Exercise Psychology Laboratory
in Teachers College at Columbia University in New York. He has received over
$2 million in funding from the National Institutes of Health and private f­ oundations
for his research investigating the physiological and psychological effects of resistance training for apparently healthy and known disease populations. Dr. Ciccolo is
a member of the American College of Sports Medicine and the National Strength
and Conditioning Association, and he has authored or coauthored over 35 papers in
the areas of physical activity, public health, and resistance training. He is currently
an associate editor for the Journal of Strength and Conditioning Research and a
Certified Strength and Conditioning Specialist.
William J. Kraemer, PhD, is a full professor in the Department of Kinesiology,
working in the Human Performance Laboratory at the University of Connecticut,
Storrs, Connecticut. He also holds joint appointments as a full professor in the
Department of Physiology and Neurobiology and as a professor of medicine at the
UConn Health School of Medicine. Dr. Kraemer is a fellow in the American College
of Sports Medicine and the National Strength and Conditioning Association. He has
authored and coauthored over 400 peer-reviewed manuscripts related to resistance
training, sports medicine, exercise endocrinology, and sport science. In addition, he
has authored or coauthored 10 books in the areas of strength training and physiology of exercise. He was awarded the University of Connecticut’s Research Medal in
2005 and the UConn Alumni Association’s Research Excellence Award in Sciences
for UConn faculty in 2009.
xi
Contributors
Brandon L. Alderman
Department of Exercise Science and
Sport Studies
Rutgers University
New Brunswick, New Jersey
Shawn M. Arent
Department of Exercise Science and
Sport Studies
Rutgers University
New Brunswick, New Jersey
Joseph C. Avery
Department of Applied Physiology and
Kinesiology
University of Florida
Gainesville, Florida
Michael G. Bemben
Department of Health and Exercise
Science
University of Oklahoma
Norman, Oklahoma
Richard W. Bohannon
Department of Kinesiology
Program in Physical Therapy
University of Connecticut in Storrs
Storrs, Connecticut
Randy W. Braith
Department of Applied Physiology and
Kinesiology
Division of Cardiovascular Medicine
College of Medicine
University of Florida
Gainesville, Florida
Danwin Chan
School of Science and Health
University of Western Sydney
Penrith, New South Wales, Australia
Birinder S. Cheema
School of Science and Health
University of Western Sydney
Penrith, New South Wales, Australia
Joseph T. Ciccolo
Department of Biobehavioral Sciences
Columbia University
New York, New York
Steven K. Clinton
Department of Kinesiology
Comprehensive Cancer Center
The Ohio State University
Columbus, Ohio
Christopher A. Fahs
Department of Health and Exercise
Science
University of Oklahoma
Norman, Oklahoma
Avery D. Faigenbaum
Department of Health and Exercise
Science
The College of New Jersey
Ewing, New Jersey
Mark D. Faries
Department of Kinesiology and Health
Science
Stephen F. Austin State University
Nacogdoches, Texas
xiii
xiv
Brian C. Focht
Department of Kinesiology
Comprehensive Cancer Center
The Ohio State University
Columbus, Ohio
Kelley G. Hammond
Department of Health and Sport
Sciences
The University of Memphis
Memphis, Tennessee
J. Derek Kingsley
Department of Exercise Physiology
Kent State University
Kent, Ohio
William J. Kraemer
Human Performance Laboratory
Department of Kinesiology
University of Connecticut in Storrs
Storrs, Connecticut
Jeremy P. Loenneke
Department of Health and Exercise
Science
University of Oklahoma
Norman, Oklahoma
Alexander R. Lucas
Department of Kinesiology
Comprehensive Cancer Center
The Ohio State University
Columbus, Ohio
Robert W. Motl
Department of Kinesiology and
Community Health
University of Illinois at
Urbana-Champaign
Urbana, Illinois
Simone D. O’Shea
Physiotherapy Program
School of Community Health
Charles Sturt University
Albury, Australia
Contributors
Lara A. Pilutti
Department of Kinesiology and
Community Health
University of Illinois at
Urbana-Champaign
Urbana, Illinois
Nicholas A. Ratamess
Department of Health and Exercise Science
The College of New Jersey
Ewing, New Jersey
Christian K. Roberts
Exercise and Metabolic Disease
Research Laboratory
School of Nursing
University of California
Los Angeles, California
Lindy M. Rossow
Department of Health and Exercise
Science
University of Oklahoma
Norman, Oklahoma
Brian K. Schilling
Department of Health and Sport
Sciences
The University of Memphis
Memphis, Tennessee
Nicholas F. Taylor
Department of Physiotherapy
La Trobe University
Melbourne, Australia
Robert S. Thiebaud
Department of Health and Exercise Science
University of Oklahoma
Norman, Oklahoma
Jacob J. van den Berg
Department of Medicine
Brown University AIDS Program
Alpert Medical School of Brown
University
Providence, Rhode Island
1
Introduction
Joseph T. Ciccolo and William J. Kraemer
CONTENT
References................................................................................................................... 3
Worldwide, the majority of deaths each year are now caused by chronic ­disease.1
Although certain risks, like tobacco smoking and exposure to secondhand smoke,
have remained constant, the risks for developing a chronic disease that are a­ ttributable
to physical inactivity have significantly increased over the past 20 years.2 In fact,
physical inactivity is now the fourth leading risk factor for global mortality.1
In an effort to promote the primary prevention of noncommunicable diseases
through physical activity at the population level, the World Health Organization
released the Global Recommendations on Physical Activity for Health in 2010.3 These
recommendations duplicate the guidelines released by the United States Department
of Health and Human Services (USDHHS) in 2008, which were c­ onstructed in an
attempt to provide science-based information and guidance on the type and amount
of physical activity needed to maintain good health and reduce the risk of chronic
disease.4 Currently, the majority of American adults do not meet the recommended
levels5 and physical inactivity remains one of the leading preventable causes of early
death and disability related to chronic disease in the United States.6 The four 2008
USDHHS guidelines for physical activity for adults aged 18–64 are as follows:
1. All adults should avoid inactivity. Some physical activity is better than
none, and adults who participate in any amount of physical activity gain
health benefits.
2. For substantial health benefits, adults should do at least 150 min/week of
moderate-intensity or 75 min/week of vigorous-intensity aerobic physical
activity, or an equivalent combination of moderate- and vigorous-intensity
aerobic activity. Aerobic activity should be performed in episodes of at least
10 minutes and, preferably, it should be spread throughout the week.
3. For additional and more extensive health benefits, adults should increase their
aerobic physical activity to 300 min/week of moderate-intensity or 150 min/week
of vigorous-intensity aerobic physical activity, or an ­equivalent combination
of moderate- and vigorous-intensity activity. Additional health benefits are
gained by engaging in physical activity beyond these amounts.
4. Adults should also do muscle-strengthening activities that are of moderate
or high intensity and involve all major muscle groups on 2 or more days a
week, as these activities provide additional health benefits.
1
2
Introduction
Using these guidelines as the goal for a level of participation, there are a variety
of worldwide initiatives promoting physical activity using behavioral, community,
environmental, and policy approaches. Over the past decade the surveillance of global
physical activity levels has increased, and data collected from 122 countries are now
available (see the study by Hallal et al.2). In the United States, a number of nationaland state-based surveys collect information on physical activity, including the National
Health Information Survey (NHIS). The NHIS is one of the principal data collection
programs of the National Center for Health Statistics (NCHS), which is part of the
Centers for Disease Control and Prevention (CDC). The NHIS is a continuous crosssectional survey of U.S. households using in-person interviews. It is the primary source
of information on the health of the United States’ noninstitutionalized, civilian population, and it provides comprehensive annual estimates of the levels of physical activity
participation. Results from the 2011 survey indicate that 48.4% of American adults
aged 18 and over met the 2008 guidelines for aerobic exercise; 24.1% met the guidelines
for resistance training (i.e., muscle-strengthening activities); and 20.6% met the full
guidelines, completing the recommended amounts of both types of exercise.5 These
estimates are similar to the 2010 rates of 46.9% for aerobic exercise, 24.1% for resistance training, and 20.4% for both.7
Although these data highlight the low percentage of Americans meeting the full
guidelines, the significant difference between the rates of those meeting the recommended level of aerobic exercise (48.4%) and those meeting the recommended level
of resistance training (24.1%) is disturbing. More specifically, over the past decade
an increasing number of individuals have been participating in aerobic exercise without a parallel rise in resistance training.5,7–9 This is not particularly surprising, given
the enormous efforts devoted to the research and promotion of aerobic exercise and
meeting the guidelines of at least 150 minutes of activity per week.10,11 Certainly,
the promotion of aerobic exercise should not be scaled back, as it has been shown
to reduce the risk of all cause mortality and is associated with reductions in cardiovascular disease, type 2 diabetes, certain types of cancer, and improved mental
health12–14; however, these relationships also exist with resistance training.15 Despite
the common promotion of resistance training simply having an additive, rather than
an independent, effect on disease risks,3,4,16,17 regular resistance training can dramatically and significantly influence the disease course of numerous illnesses.15
The purpose of this book is to call attention to the body of resistance t­raining
research conducted to date, and to highlight the numerous benefits a properly
designed program can have on the prevention and treatment of chronic disease. As
outlined by the American College of Sports Medicine (ACSM) “Position Stand on
Progression Models in Resistance Training for Healthy Adults,”18 it is essential to take
a sophisticated approach to resistance training, one that is individualized and uses the
­appropriate equipment, program design, and exercise techniques. This will ensure
that the r­esistance training routine will effectively stimulate the physiological and
­psychological changes necessary to achieve enhanced health. Indeed, when ­correctly
prescribed, resistance training can significantly increase muscle mass, strength,
power, and endurance.18 Such changes can have profound effects on health and have
been shown to be inversely and independently associated with all-cause mortality,
even after adjusting for cardiorespiratory fitness and other potential confounders.19–21
Joseph T. Ciccolo and William J. Kraemer
3
In the following chapters of this book, the changes that can result from participating in a resistance ­training–only program are described. It should be acknowledged
that while there is evidence to ­support the benefits, efficacy, and/or use of aerobic
exercise, or a combined ­aerobic and ­resistance training program, the aim of this book
is to focus on the specific effects of resistance training. This does not suggest that
a resistance training–only exercise prescription is superior to other programs, but
instead that it can be highly effective on its own, especially when it is the preferred or
more practical mode of exercise. In addition, although many of the chronic diseases
examined in this book are related and several occur comorbidly within the general
population, each chapter is devoted to a single illness to more accurately describe
the effects that resistance training can have on the prevention and treatment of that
particular disease.
REFERENCES
1. World Health Organization. 2005.Preventing Chronic Diseases: A Vital Investment:
WHO Global Report. Available from http://www.who.int/chp/chronic_disease_report/en.
Accessed December 6, 2013.
2. Hallal PC, Andersen LB, Bull FC, Guthold R, Haskell W, Ekelund U, Lancet Physical
Activity Series Working Group. Global physical activity levels: surveillance progress,
pitfalls, and prospects. Lancet. 2012;380:247–57.
3. World Health Organization. Global Recommendations on Physical Activity for Health.
Geneva, World Health Organization, 2010.
4. U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans.
2008. Available from http://www.health.gov/paguidelines. Accessed December 6, 2013.
5. U.S. Department of Health and Human Services. Summary health statistics for U.S.
adults: National Health Interview Survey, 2011. National Center for Health Statistics.
Vital Health Stat. 2012;10:256.
6. Centers for Disease Control and Prevention. Chronic Disease Prevention and Health
Promotion. 2012. Available from http://www.cdc.gov/chronicdisease/overview/index.
htm Accessed December 6, 2013.
7. Schiller JS, Lucas JW, Ward BW, Peregoy JA. Summary health statistics for U.S.
adults: National Health Interview Survey, 2010. National Center for Health Statistics.
Vital Health. 2012; 10:252.
8. Centers for Disease Control and Prevention (CDC). Vital signs: walking among adults—
United States, 2005 and 2010. MMWR Morb Mortal Wkly Rep. 2012;61:595–601.
9. Centers for Disease Control and Prevention (CDC). Trends in strength training—United
States, 1998–2004. MMWR Morb Mortal Wkly Rep. 2006;55:769–72.
10. Kohl HW 3rd, Craig CL, Lambert EV, Inoue S, Alkandari JR, Leetongin G, Kahlmeier S,
Lancet Physical Activity Series Working Group. The pandemic of physical inactivity:
global action for public health. Lancet. 2012;380(9838):294–305.
11. Blair SN, Kohl HW, Gordon NF, Paffenbarger RS Jr. How much physical activity is
good for health? Annu Rev Public Health. 1992;13:99–126.
12. Murtagh EM, Murphy MH, Boone-Heinonen J. Walking, the first steps in ­cardiovascular
disease prevention. Curr Opin Cardiol. 2010;25:490–6.
13. Kokkinos P, Sheriff H, Kheirbek R. Physical inactivity and mortality. Cardiol Res Pract.
2011;2011:924–45.
14. Lee DC, Artero EG, Sui X, Blair SN. Mortality trends in the general population: the
importance of cardiorespiratory fitness. J Psychopharmacol. 2010;24(4 Suppl):27–35.
4
Introduction
15. Ciccolo JT, Carr LJ, Krupel KL, Longval JL. The role of resistance training for the
­prevention and treatment of chronic disease. Am J Lifestyle Med. 2010;4:293–308.
16. U.S. Department of Health and Human Services. Physical Activity and Health: A Report
of the Surgeon General. Atlanta (GA): U.S. Department of Health and Human Services,
Centers for Disease Control and Prevention, National Center for Chronic Disease
Prevention and Health Promotion. 1999. Available from http://www.cdc.gov/nccdphp/
sgr/pdf/sgrfull.pdf. Accessed December 6, 2012.
17. Pate RR, Pratt M, Blair SN et al. Physical activity and public health. A ­recommendation
from the Centers for Disease Control and Prevention and the American College of Sports
Medicine. JAMA.1995;273:402–7.
18. American College of Sports Medicine. American College of Sports Medicine ­position
stand. Progression models in resistance training for healthy adults. Med Sci Sports
Exerc. 2009;41:687–708.
19. Ruiz JR, Sui X, Lobelo F, Morrow JR Jr, Jackson AW, Sjöström M, Blair SN. Association
between muscular strength and mortality in men: prospective cohort study. BMJ.
2008;337:a439.
20. Katzmarzyk PT, Craig CL. Musculoskeletal fitness and risk of mortality. Med Sci Sports
Exerc. 2002;34:740–4.
21. Artero EG, Lee DC, Lavie CJ, España-Romero V, Sui X, Church TS, Blair SN. Effects
of muscular strength on cardiovascular risk factors and prognosis. J Cardiopulm Rehabil
Prev. 2012;32:351–8.
2
Resistance Training
Program Variables
and Guidelines
Nicholas A. Ratamess
CONTENTS
Introduction................................................................................................................. 5
Basic Principles of Resistance Training...................................................................... 7
Prescreening and the Needs Analysis......................................................................... 7
Other Preresistance Training Special Considerations................................................. 9
Resistance Training Program Design........................................................................ 10
Muscle Actions..................................................................................................... 10
Exercise Selection................................................................................................ 11
Workout Structure and Exercise Sequence.......................................................... 12
Intensity................................................................................................................ 13
Methods of Prescribing Resistance Exercise Intensity........................................ 14
Training Volume/Volume Load............................................................................ 16
Set Structures for Multiple-Set Programs............................................................ 16
Rest Intervals........................................................................................................ 17
Repetition Velocity............................................................................................... 17
Frequency............................................................................................................. 18
Progression........................................................................................................... 19
Summary................................................................................................................... 19
References................................................................................................................. 19
INTRODUCTION
Resistance training is a modality of exercise known for increasing muscular strength,
power, speed, hypertrophy, endurance, balance, coordination, motor performance,
and reducing the percentage of body fat.1,2 Theoretically, any object can be used
for resistance training. Often, resistance training is performed using free weights
and associated equipment, machines, medicine balls, stability balls and other balance and vibration devices, implements, elastic bands, sandbags, ropes, water, and
one’s body weight.2 The source of resistance can vary based on the needs of an individual. For example, the buoyancy force of water (during an aquatic exercise) not
only provides resistance but also enables the individual to exercise in a non-weightbearing environment, which could benefit some special populations such as those
1
2
Resistance Training Program Variables and Guidelines
with neuromuscular/orthopedic disabilities or obesity. Machines provide added stability to users, which could initially benefit individuals with balance and coordination deficiencies. However, free weights, medicine/stability balls, and related balance
equipment can be used during progression to enhance neuromuscular function. Body
weight provides the most basic source of resistance and may be used in a variety of
ways to gradually increase complexity (intensity) based on biomechanics. Multiplanar
body weight exercises are highly functional and often similar in motion to performance of activities of daily living. Elastic bands provide multiplanar resistance and
have a variety of uses that enable numerous therapeutic exercises. Inspiratory devices
with resistive and threshold loading have been used for specific respiratory muscle
strength and endurance training primarily in chronic obstructive pulmonary disease
patients.3 Thus, the type of resistance used provides training variability and can be
easily adapted to meet the needs of any healthy or special population.
In addition to its numerous performance-enhancing benefits, resistance training
has been shown to have several health-promoting benefits4 and has been recommended by national health organizations, such as the American College of Sports
Medicine (ACSM), American Heart Association, and the American Association
for Cardiovascular and Pulmonary Rehabilitation, in conjunction with aerobic and
­flexibility training for the maintenance and improvement of health and performance.
Table 2.1 depicts some health-promoting benefits of resistance training. Resistance
training reduces several risk factors for disease/physical ailments and improves the
quality of life by improving functional capacity and performance of activities of
daily living.
The critical component of resistance training is the design of the program.
A ­resistance training program involves the interaction among several variables,
including muscle actions utilized, exercise selection and sequence of performance,
TABLE 2.1
Health-Promoting Benefits of Resistance Training
• Increased muscle strength, power, and
endurance
• Increased lean body mass
• Reduced body fat
• Increased basal metabolic rate
• Decreased blood pressure
• Increased left ventricular and septal wall
thickness
• Decreased cardiovascular demands to activity
• Improved blood lipid profiles, increased
HDLs, decreased LDLs and triglycerides
• Improved glucose tolerance and insulin
sensitivity
• Decreased risk of sarcopenia
• Increased bone mineral density and reduced
the risk of osteoporosis
• Increased tendon and ligament strength
• Improved flexibility
• Increased cardiorespiratory fitness
• Prevention and management of low back pain
• Maintained long-term independence and
functional capacity
• Increased balance, coordination, and
functional ability
• Reduced risk of falling
• Improved psychological well-being
Note: HDL = high-density lipoprotein and LDL = low-density lipoprotein.
Nicholas A. Ratamess
3
intensity, volume, rest intervals, lifting velocity, and frequency, all aimed at targeting specific goals and adaptations. The manipulation of these variables is critical to
minimizing potential boredom and increasing adherence, reducing training plateaus,
and allowing the individual to progress at a gradual rate. Resistance training guidelines have been established for healthy children, adult, and elderly populations5,6 and
modifications have been used for special populations. Specific guidelines for each
population are discussed in Chapters 3 through 16 of this book. This chapter overviews the general process of resistance training program design and to discuss and
define the acute program variables that comprise resistance training.
BASIC PRINCIPLES OF RESISTANCE TRAINING
There is a multitude of methods to design resistance training programs. However, any
resistance training program can be effective as long as it adheres to established scientific guidelines and includes strategies for “progressive overload,” “specificity,” and
“variation.” Progressive overload is the gradual increase of stress placed on a body during training. Without progressive overload, there is no need for the human body to adapt
positively. The gradual increase in workload is required to meet higher physiological
demands. Specificity entails all responses and adaptations that are specific to the training stimulus, for example, muscle actions involved, velocity of movement, exercise
range of motion, muscle groups trained, uni- versus bilateral exercises, energy systems
involved, and the intensity and volume of training.2 The most effective resistance training programs are designed individually to bring about specific adaptations. Variation
is the systematic alteration of the program variables over time to allow training to
remain optimal. It has been shown that systematic program variation is most effective
for long-term progression.1 Gains in performance that are only seen during training
can be decreased during training cessation or during a large decrease in frequency.
“Reversibility,” or detraining, results when the training stimulus becomes suboptimal.
PRESCREENING AND THE NEEDS ANALYSIS
It is recommended that all participants be prescreened prior to participation in resistance training. Self-guided screening is initiated by the individual, and it is recommended that inactive men over the age of 40, inactive women over the age of 50,
and those at high risk for cardiovascular disease consult a physician for medical
clearance.7 Professionally guided screening is conducted by an exercise specialist
and involves obtaining pertinent information from the individual prior to program
design and implementation. Critical is the use and/or development of an accurate and
informative medical history document. All participants should complete medical
history documentation prior to beginning a program. Several documents have been
effectively used for this purpose. As recommended by the ACSM,7 a medical history
document should ascertain information related to the following:
• Medical diagnoses
• Previous physical examination results
• History of symptoms
4
Resistance Training Program Variables and Guidelines
•
•
•
•
•
Recent illnesses, injuries, surgical procedures, and hospitalizations
Orthopedic problems
Allergies
Medications and supplement use
Other habits such as recreational drug use, tobacco use, and caffeine and
alcohol intake
• Exercise and work history
• Family history of disease
Analysis of the medical history document enables risk classification. Recommendations for medical examinations, exercise, fitness testing, and physician supervision
are based on risk stratifications. Often, the ACSM risk stratification categories are
used. Risk is determined by the summation of the number of present positive risk
factors or symptoms observed7 based on the following:
• Age (men ≥ 45 years, women ≥ 55 years)
• Family history of myocardial infarction, coronary revascularization, or
sudden death of a relative under 55 years for men and 65 years for women
• Cigarettes smoked in last 6 months
• Sedentary lifestyle (<30 minutes at least 3 day·week−1)
• Body mass index ≥ 30 kg·m2 or waist girth > 102 cm for men and >88 cm
for women
• Blood pressure ≥ 140/90 or taking hypertensive medications
• Total cholesterol ≥ 200 mg·dL−1; LDL-C ≥ 130 mg·dL−1, HDL-C < 40 mg·dL−1
• Fasting blood glucose ≥ 100 mg·dL−1
• Negative risk factor = HDL-C ≥ 60 mg·dL−1
Individuals are classified as “low risk” (asymptomatic with ≤1 risk factor),
“moderate risk” (asymptomatic with ≥2 risk factors), or “high risk” (one or more
symptoms of cardiopulmonary or metabolic disease) for cardiovascular disease. The
individuals at low risk may pursue vigorous exercise. The individuals at moderate
risk can participate in light to moderate training, but it is advisable to seek medical clearance for high-intensity training. The individuals at high risk should receive
medical clearance prior to resistance training at any intensity.7
Upon health appraisal, the goals of training are elucidated. The most effective resistance training programs are those designed to meet the specific needs
of an i­ndividual. The goals of training are elucidated via conducting the “needs
­analysis.” The needs analysis consists of answering questions based on goals and
desired ­outcomes, assessments, access to equipment, time constraints, physician
­recommendations, and health. Such questions may include the following:
• Are there health/injury concerns that may limit the exercises performed or
the exercise intensity/volume?
• What special needs (e.g., use of medications, inhalers, and snacks to prevent
hypoglycemia) do you have during resistance exercise?
• What type of equipment do you have access to?
Nicholas A. Ratamess
5
• Do you have any preferences for specific types of equipment?
• What is the targeted training frequency?
• What time of day will the workouts occur, and are there any time constraints that may affect the workout duration?
• What muscle groups/areas of the body require special attention?
• What are your goals of resistance training? Which health- and skill-related
fitness components do you want to improve?
• Will other modalities of exercise (i.e., cardiovascular, flexibility) be performed in addition to resistance exercise?
Information regarding the health status and current medication use of the
i­ndividual is paramount prior to program design. A trainer must know the individual’s health concerns as these will affect the exercises selected, intensity,
­volume, frequency, rest intervals, and velocity of resistance exercise. For example,
a patient with knee osteoarthritis may only be able to perform exercises at a low
or moderate intensity that do not exacerbate the pain. Patients with lower back
pain may avoid exercises that highly stress the lumbar vertebrae or provide significant compressive loading such as sit-ups or some exercises that require lumbar flexion from a standing position. Obese individuals must use caution when
performing weight-bearing exercises that require balance and strength even if a
limited range of motion is used. Exercises that require little motion may be more
appropriate initially. Some medications may cause fatigue (or other undesirable
side effects), so the trainer may adjust the workout length and schedule to accommodate medicinal intake. Thus, trainers must design programs based on patients’
needs and limitations.
OTHER PRERESISTANCE TRAINING SPECIAL CONSIDERATIONS
Resistance training program design involves proper instruction. Although it is
beyond the scope of this chapter to discuss the safety and technical aspects of the
majority of exercises that can be performed, a few general considerations need to be
mentioned:
• Proper breathing: trainees should be instructed to breathe properly ­during
each repetition of every set. Proper breathing entails inhaling during the
negative (eccentric or yielding) phase of each repetition and exhaling during
the positive (concentric or lifting) phase. It is important to avoid voluntary
breath holding, or a “Valsalva maneuver.” Air cannot escape the lungs and
the glottis is closed, thereby increasing the cardiovascular demand to resistance exercise. Although a Valsalva maneuver increases intra-­abdominal
pressure and torso rigidity, it is generally advisable to avoid Valsalva
maneuvers during most circumstances.
• Proper technique: each exercise should be performed in a fully prescribed
range of motion to ensure maximal benefits. Trainees should be taught
proper execution of the exercise, and initial loading should be light to allow
for learning the proper technique.
6
Resistance Training Program Variables and Guidelines
• Supervision: special populations should be closely monitored during
­resistance training by qualified staff, for example, individuals with degrees
in an exercise-related field and certifications by reputable organizations
such as the ACSM and the National Strength and Conditioning Association.
Depending on the population, special monitoring may be needed, such as,
blood pressure measurement or blood glucose monitoring. Trained individuals should always be present. Studies show that supervised resistance
training is safer and results in higher rates of progress and proper load
selection.8,9
• Evaluation: testing and evaluation are critical to comprehensive resistance
training. Testing can identify strengths and weaknesses, and the program
can be designed, in part, to correct weaknesses. Testing can be used to
evaluate progress or health status. Routine health checks, for example,
checking blood pressure, body weight, blood glucose, triglycerides, and
cholesterol, can accompany a resistance training program to assess health
improvements. Testing can be used to evaluate progress from training and,
in some programs, may be used to identify training loads. Thus, health and
performance evaluation provides several benefits to the trainee.
RESISTANCE TRAINING PROGRAM DESIGN
The resistance training program is a composite of several variables, such as muscle
actions used, exercises selected, exercise sequencing and workout structure, intensity, volume, rest intervals between sets and exercises, repetition velocity, and training frequency. Altering one or several of these variables will affect the training
stimulus and subsequent adaptations.
Muscle Actions
All resistance exercises consist of concentric (CON; muscle shortening), eccentric
(ECC; muscle lengthening), and/or isometric (ISOM; static) muscle actions. Each
dynamic repetition consists of ECC and CON, and may include ISOM muscle actions
at the beginning or end of the repetition. Muscle strength, hypertrophy, and damage
are greatest when loaded ECC actions are utilized.10 All dynamic motion consists
of CON and ECC muscle actions. ECC muscle actions should be controlled by the
individual to maximize the benefits of the resistance exercise. CON muscle action
velocity varies depending on the goals and loading utilized. ISOM muscle actions
exist in many forms during resistance exercise including stabilizer muscles’ contraction to maintain posture and stability, ISOM actions between ECC and CON actions
for agonist muscles, and in gripping tasks, and they may serve as the primary mode
of exercise in a specific area of the range of motion (ROM). Exercises such as the
quadruped and plank are predominantly ISOM once the final position is attained.
Strong contraction of the trunk is needed to offset the effects of gravity. These exercises are often used as corrective exercises to increase postural stability and reduce
the risk of injury/illness, such as low back pain. It is recommended that all three
types of muscle actions be emphasized during resistance training.5
Nicholas A. Ratamess
7
Exercise Selection
Exercise selection is critical to resistance training program design. Exercises should
be selected that stress all muscle groups to increase strength, size, power, and endurance throughout the body and provide balance among opposing and contralateral
muscle groups. There are numerous exercises that can be performed using a variety of equipment or body weights. In addition, exercises can be combined into one
general movement (“combination exercises”) to increase the metabolic response
and balance and coordination requirement. Two general types of exercises may be
selected: (1) “single joint” and (2) “multiple joint.” Single-joint exercises (leg curl,
arm curl) stress one joint or major muscle group, whereas multiple-joint exercises
(chest press, lat pulldown) stress more than one joint or major muscle group. Both
types are effective for increasing muscle strength. Single-joint exercises are used to
target specific muscle groups and may pose a lesser risk of injury due to the reduced
level of skill and technique involved. Multiple-joint exercises are more complex and
are regarded most effective for increasing strength because of the use of a larger
amount of weight. Because many muscle groups must work together in collaboration, multiple-joint exercises are effective for improving balance and coordination.
They are more specific to performance of activities of daily living, for example,
ascending/descending steps, rising from a chair, cleaning, and lifting of household
objects. In addition, the magnitude of muscle mass involvement of an exercise is an
important consideration. Exercises stressing multiple or large muscle groups produce the greatest acute metabolic responses.11 Energy expenditure is an important
consideration for weight loss when designing programs for obese populations.
Exercises can be varied in a number of ways to target specific goals. Alterations
in body posture, grip, and hand width/foot stance and position change muscle activation to some degree and alter the exercise. For example, Saeterbakken and Fimland12
have recently shown that rectus abdominis muscle activity is greater during standing
versus seated shoulder press exercise. Differences in muscle activation and exercise
kinematics occur when comparing exercises of varying posture (i.e., decline, flat, or
incline bench press) and grip/stance width.13–15
Performing an exercise with different equipment varies the exercise. For example,
performing an exercise with a free weight (barbell, dumbbell) or machine varies
the stimulus. Free weight training leads to greater improvements in free weight test
performance and machine training results in greater performance on machine tests,16
although free weight training increases machine-based maximal strength and vice
versa. When a neutral testing device is used, the strength improvements from free
weights and machines are similar.16 In general, machines are safe; easy to learn;
enable performance of some exercises that are difficult using free weights; and can
provide some unique training qualities depending on the machine, for example, variable resistance, isokinetic lifting velocities, and multiplanar loading. However, they
may hinder the development of coordination as stabilizer muscle activity is limited. Free weights are safe but require a longer learning phase; enable performance
of several exercises with very few pieces of equipment; enable greater movement
potential and variability for exercise performance per foot/hand placement, position,
and posture; require the individual to control all aspects of the exercise; and enable
8
Resistance Training Program Variables and Guidelines
greater bar velocity.2 In addition, muscle activation and performance will vary when
an exercise is performed in a stable versus an unstable environment, that is, stability
ball, Airex pads, BOSU ball, or some other balance device.17
Corrective exercises are single- or multiple-joint dynamic and ISOM exercises
used to correct neuromuscular dysfunction. The primary objective is to enhance
posture by restoring muscle strength and length balance to the weakened areas of
the body. Often corrective exercises are used in conjunction with other modalities
including myofascial release and flexibility exercises to increase muscle strength and
endurance and restore function and balance to a problem area.18 For example, exercises such as quadrupeds, back bridges, and planks have been used successfully
(among others) to increase the strength and endurance of trunk muscles in healthy
and special populations.
Performing an exercise with one or two limbs affects the neuromuscular adaptations to resistance training. Training one limb has been shown to increase strength in
both trained and untrained limbs.19 In addition, force production can vary based on
unilateral or bilateral muscular contractions.20 Unilateral exercises require greater
balance and stability. For example, performing a one-arm shoulder press (with
only one dumbbell) requires the trunk muscles (external obliques) to contract more
intensely to offset the torque produced by unilateral loading compared to a bilateral
shoulder press.12 Unilateral training may be particularly attractive for the populations targeting balance improvements, trunk muscle strength, or those with limitations to one area of the body. Numerous studies examining special populations have
utilized single- and multiple-joint resistance exercises during resistance training.21–23
Thus, it is recommended that unilateral and bilateral single- and multiple-joint (free
weight and machine) exercises be included in resistance training programs targeting
muscle strength, size, and endurance.5 Modifications should be made based on the
population’s needs and limitations. Most studies examining special populations have
utilized approximately 5–12 exercises per workout.21,23,24
Workout Structure and Exercise Sequence
Workout structure refers to the number of muscle groups trained per session.
Structures include total-body workouts, upper/lower body split (exercises for upper
body are performed during one session and lower body during another session)
workouts, or muscle group splits (only one or two muscle groups are trained per session). The majority of studies examining special populations have utilized total-body
workouts consisting of one to two exercises for each major muscle group, although
any of these structures can be effective for improving fitness provided other program
variables are correctly prescribed. The advantages of total-body workouts include
activation of a large muscle mass per workout, less residual fatigue from previous
exercises (stressing similar muscle groups), high efficiency especially when sequencing exercises that stress different muscle groups, and their ease of being structured
into a 2 to 3 day·week−1 training program.
Exercise sequence can be determined upon selection of the workout structure.
Exercise sequence affects acute lifting performance, and the rate of strength increases
during resistance training. Exercises performed early in a workout generate higher
Nicholas A. Ratamess
9
repetition numbers and weights lifted because less fatigue is present. Multiple-joint
exercise performance declines when these exercises are performed later in a workout rather than earlier.25 Considering that multiple-joint exercises are effective for
increasing strength and power and have high transference to performance of activities of daily living, it is recommended that they be performed early in a workout.5
It is important to note that numerous sequencing strategies can be effectively used
for muscle endurance and hypertrophy training. Depending on training goals, the
following general sequencing strategies have been recommended for strength training in healthy populations,2,5 although they have been applied to special populations
as well:
• Large muscle exercises should be performed before smaller muscle
exercises.
• Multiple-joint exercises should be performed before single-joint exercises.
• When practical, rotation of upper and lower body exercises or opposing
(agonist–antagonist relationship) exercises can be employed.
• Some exercises targeting different muscle groups can be staggered in
between sets of other exercises to increase workout efficiency.
• When applicable, exercises of higher intensity could be performed before
those of lower intensity.
Intensity
Intensity describes the amount of weight lifted and in some cases the effort taken
by the individual during a resistance exercise. Intensity prescription is dependent
on exercise order, volume, frequency, repetition speed, rest interval length, and the
health status of the individual. Intensities range from low (60% and less of maximal
capacity) to moderate (70%–80% of maximal capacity) to high (>85% of maximal
capacity). In untrained populations, low intensities of 45%–50% of one-repetition
maximum (1RM) increase muscular strength.1 Light loading is typically prescribed
initially to stress proper form and technique, and it is recommended that novice
trainees start light and progress gradually over time.5 A meta-analysis examining numerous resistance training studies has shown that 60% of 1RM produces
the largest strength effects in untrained individuals.26 Moderate to high intensities
(≥80%–85% of 1RM) are needed to increase maximal strength as one progresses to
advanced training. The majority of studies examining resistance training in special
populations effectively used tolerable intensity ranges of 50%–80% of 1RM21–22,27
with some utilizing loads as low as 30% of 1RM24 and some loads as high as 90% of
1RM.23 Most of these studies utilized previously untrained individuals and designed
training studies based on recommendations for novice-to-intermediate training.
There is an inverse relationship between the amount of weight lifted and the
number of repetitions completed. Light to moderate loading elicits high (12–15
and higher) repetition numbers. This loading/repetition range has been used successfully for strength and hypertrophy training in untrained individuals and special populations,21,22 but it is most specific to increasing local muscular endurance.
Moderate to heavy loading elicits moderate repetition numbers (6–12). This range
10
Resistance Training Program Variables and Guidelines
is multifunctional (and most commonly used), leading to increased strength,
­hypertrophy, and muscular endurance. The interaction of load and volume in this range
appears to adequately train multiple fitness components sufficiently. The majority of
studies examining special populations have targeted an 8–15 ­repetition range21,23,27
with some ­studies utilizing six repetition maximum loading.24 Heavyweights yield
low repetition numbers (1–6). This range is most specific to increasing maximal
strength. Muscle hypertrophy also increases, but endurance improvements are
­minimal. Although each training zone has its advantages, it is recommended that an
individual use cyclically multiple zones rather than only using one depending on the
training goals. For strength and hypertrophy training, the ACSM recommends that
novice-to-intermediate individuals train with loads corresponding to 60%–70% of
1RM for 8–12 repetitions and loads of 80%–100% of 1RM with advanced training
to maximize muscular strength.5 Intensity prescription is exercise dependent. Some
exercises, for example, multiple-joint structural exercises, benefit from high-intensity
training. However, other exercises (i.e., corrective exercises) may have other goals
associated with them. For novice and intermediate muscle endurance training, it is
recommended that relatively light loads be used with moderate to high repetitions
(10–15 repetitions or more).5
Unique to resistance training program design in special populations has been the
inclusion of power training, primarily in the elderly population. Power training is
the multifaceted stressing of both the force and the velocity contractile properties of
the neuromuscular system. Although power training has been viewed primarily as a
modality of training for athletes, modifications have been appropriately prescribed
for older adults. Power training in special populations typically involves performing
a free weight- or machine-based exercise with a light weight (30%–60% of 1RM)
but at a fast velocity (primarily the CON action of the repetition). Studies have shown
power training to be feasible and effective for improving performance and, in some
cases, offering greater advantages than traditional strength training.28 Interestingly,
maximal strength increases have been shown to be similar between power training and traditional strength training, whereas velocity-specific task performance
is augmented to a greater extent with power training.29 Thus, it appears that more
comprehensive neuromuscular performance increases may take place when power
training elements are incorporated into a traditional resistance training program in
older adults.30
Methods of Prescribing Resistance Exercise Intensity
Resistance exercise intensity can be prescribed in a few ways. All the methods
described in the following section have been shown to be effective and may mostly
be up to the personal preferences of the trainee or the trainer. If a 1RM or an estimated 1RM value is known for a particular exercise, a relative percentage can be
prescribed. For example, 70% of 1RM can be prescribed for 10–12 repetitions. The
individual can simply multiply their maximal strength value by 0.70 to determine
the load lifted. The advantage is that relative intensity can be accurately prescribed
based on a known quantity. It is important to note that each exercise is specific and
muscle mass involvement is critical. Thus, 75% of 1RM could yield 10 repetitions
Nicholas A. Ratamess
11
for an exercise such as the bench press but more repetitions for a large muscle mass
exercise such as the leg press. The disadvantage is that the 1RM value must be determined directly or estimated via multiple RM testing. Strength testing is most feasible
for only a few exercises rather than all of the exercises performed in a program.
Multiple RM testing can be performed to determine the maximal number of repetitions that a weight can be lifted for a specific exercise. For example, a load can
be prescribed that yields eight repetitions. One popular method of progression is
to perform three sets of the exercise for eight repetitions. When the individual can
successfully complete each set for 8 repetitions over the course of two workouts,
repetitions can be added until the individual can successfully perform 12 with that
load. Upon the successful completion of 12 repetitions per set over the course of two
workouts, the load can be increased during the next workout to yield 8 repetitions.
This system implies that each set is performed to muscular failure or near muscular
failure. It is important to note that every set does not need to be performed until muscular failure. The rationale for training to failure is to maximize motor unit activity
and muscular adaptations. It is thought to maximize muscle strength, hypertrophy,
and endurance. However, sets performed to failure cause a higher level of fatigue,
so it is unclear how many sets in a workout (if any) should be performed to failure.
Some studies show that training to failure is superior,31 whereas others show similar
strength increases between training to failure and terminating a set prior to muscular
failure.32 Training to failure may be appropriate under certain conditions, especially
to enhance or maximize muscle hypertrophy and endurance. However, the challenge
is to designate the proper proportion of the total sets performed to failure based on
the population.
The most practical way to prescribe intensity is through a “trial and error”
method. A load (initially light to moderate) is selected and an individual performs
the required number of repetitions. If the load is too light, weight can be added to
subsequent sets or during the next one to two workouts. Absolute load increases
of 2.5 to 10 lb are common depending on the exercise. This method is practical
because maximal strength does not need to be known. Rather, a starting weight
is selected and progressed upon with training. The rate of progression depends on
the goals of training and the health status of the individual. Some trainers prefer to
use “ratings of perceived exertion” as a tool to monitor resistance exercise intensity
and/or physical exertion during progression. Often, a 10-point CR-1033 or OMNIRES34 scale is used; but some have used the original 15-point Borg scale, which is
commonly used during aerobic exercise. The scales (Table 2.2) consist of 10 numbers displayed on a continuum, representing rest to maximal levels of exertion. The
OMNI-RES scale also includes pictorials (not shown) to assist trainees in determining an accurate number. The scale is presented to the trainee during the set, and the
trainee is asked to provide a number estimating subjectively the perceived exertion
or the difficulty associated with the set. The rated perceived exertion (RPE) scale
can be used to represent intensity during low-volume sets. However, research indicates that RPE scale use during a resistance exercise may be more reflective of
fatigue rate than intensity per se35, especially with increasing repetition numbers or
shortened rest intervals. Thus, a trainer can modify load selection based on the RPE
input from a trainee.
12
Resistance Training Program Variables and Guidelines
TABLE 2.2
CR-10 and OMNI-RES 10-Point RPE Scales
CR-10
Rating
0
1
2
3
4
5
6
7
8
9
10
OMNI-RES
Descriptor
Rating
Descriptor
Rest
Very, very easy
Easy
Moderate
Somewhat hard
Hard
Hard
Very hard
Very hard
Very hard
Maximal
0
1
2
3
4
5
6
7
8
9
10
Extremely easy
Extremely easy
Easy
Easy
Somewhat easy
Somewhat easy
Somewhat hard
Somewhat hard
Hard
Hard
Extremely hard
Training Volume/Volume Load
Training volume is the summation of the number of sets and repetitions. “Volume
load” is calculated by multiplying the load lifted by the number of sets and repetitions and is more indicative of the workload than the volume alone. Training volume
can be manipulated by changing the number of exercises performed per session, the
number of repetitions performed per set, the number of sets per exercise, and loading
(volume load). There is an inverse relationship between volume and intensity such
that volume should be reduced if major increases in intensity are prescribed. Strength
training is synonymous with low to moderate training volume, whereas hypertrophy and muscle endurance training are synonymous with low to moderately-high
intensity and moderate to high volume. Training volume is dependent on training
experience, frequency, intensity, nutrition, and recovery factors. Few studies directly
compare resistance training programs of varying total sets. Most volume-related
studies have compared single- and multiple-set training programs. These studies
show that untrained individuals respond well to single and multiple sets. However,
multiple sets are needed for higher rates of progression in advancing training status.5
The majority of studies examining resistance training in special populations utilized
one to four sets per exercise21,24 with most utilizing two to three sets.24 Thus, one to
three sets are recommended for novice trainees, whereas multiple sets are recommended with progression.5 Not all exercises need to be performed with the same
number of sets as variation in set number per exercise is common depending on the
specific goals of an exercise. A dramatic increase in volume is not recommended.
Set Structures for Multiple-Set Programs
The structure, that is, the pattern of loading and volume prescription from one set to
the next, needs to be determined for multiple-set programs. The intensity and volume of each set during an exercise can increase, decrease, or stay the same. Three
Nicholas A. Ratamess
13
basic structures (as well as many integrated systems) can be used. All are effective,
so their use is left to the personal preference of the trainee. A “constant load/repetition system” utilizes loading and repetition numbers that remain constant across
all sets. A “light to heavy system” is one in which load is increased in each set
while repetitions remain the same or decrease. A “heavy to light system” is one in
which load is decreased with each set and repetition number is either maintained
or increased. Integrated and/or undulating models (that are based on constant load/
repetition, heavy to light, and light to heavy systems) have been used effectively in
multiple populations. Integrated models combine two or more of these systems. It
is important to note that variation can exist in set-structuring systems based on the
exercise, for example, some exercises may utilize a light to heavy approach, whereas
others may utilize a constant load/repetition approach.
Rest Intervals
The rest interval length between sets and exercises depends on training intensity,
goals, fitness level, and targeted energy system utilization. Rest intervals between
exercises are affected by the muscle groups trained, equipment availability, and the
time needed to change and relocate weights to another bench, machine, platform, and
so on. The amount of rest between sets and exercises affects the metabolic, hormonal,
and cardiovascular responses to an acute bout of resistance exercise, as well as performance of subsequent sets and training adaptations.1,36 Acute strength and power
performance is compromised with short rest intervals,37 although short rest intervals
are beneficial for hypertrophy and muscle endurance training. Short rest intervals
compromise performance, whereas long rest intervals help to maintain intensity/volume load,36 and the reductions may be more prominent in men compared to women
and in individuals with higher levels of muscle strength.37 Several training studies
show a higher rate of strength gain with long (2–3 minutes) versus short (30–40 seconds) rest intervals between sets.38,39 The rest interval length will vary based on the
goals of that particular exercise (not every exercise will use the same rest interval).
General recommendations for rest interval length prescription include the following5:
• For strength and power training, at least 2–3 minutes of rest intervals for
structural exercises using heavy loads and 1–2 minutes of rest for other
exercises can be used.
• For hypertrophy training, rest intervals similar to strength training or
shorter rest intervals can be effectively used.
• For muscular endurance training, it is recommended that short rest intervals be used, for example, 1–2 minutes for high-repetition sets (15–20 repetitions or more) and less than 1 minute for moderate (10–15 repetitions) sets.
Repetition Velocity
Repetition velocity refers to how fast the CON and ECC phases of repetitions are
performed. With light to moderately heavy loading during a dynamic resistance
exercise, the trainee has the ability to control the lifting velocity under nonfatigued
14
Resistance Training Program Variables and Guidelines
situations. Thus, the choice of velocities affects the neural, hypertrophic, and metabolic responses to training.5 There are two types of slow-velocity contractions: unintentional and intentional. Unintentional slow velocities are used during high-intensity
repetitions in which either the loading or the fatigue is responsible for the velocities.
Intentional slow-velocity repetitions are used with submaximal weights where the
individual has direct control over the velocities. These velocities have been used, in
part, to increase muscular time under tension. Force and power production is lower
for an intentionally slow velocity compared to a moderate or fast velocity with a corresponding lower level of muscle fiber activation40,41 and forces the trainee to reduce
the load or will result in fewer repetitions performed per load.41 In addition, strength
increases at a larger rate when fast velocities are used compared to slow ones.42,43
Compared to slow velocities (>3 second CON:>3 second ECC), moderate (1 to
2 ­second CON:1 to 2 second ECC) and fast (<1 second CON:1 second ECC) velocities are more effective for enhanced muscular performance, for example, number of
repetitions performed, work and power output, and volume. Intentionally slow velocities are most useful for muscular endurance training. They can be initially beneficial
in training when the individual is learning proper technique. Recommendations for
selecting repetition velocities include the following5:
• Slow and moderate velocities for untrained individuals and moderate
velocities for intermediately trained individuals whose goals are focused on
muscle strength and hypertrophy.
• Fast velocities (<1 second CON:<1 second ECC) are recommended for
power training.
• Muscle endurance training requires a spectrum of velocities with various
loading strategies leading to prolonged set durations utilizing moderate
repetition numbers using an intentionally slow velocity and high repetition numbers using moderate to fast velocities. Intentionally slow velocities
are recommended for moderate repetitions (10–15), and moderate to fast
velocities are recommended when performing a large number of repetitions
(15–25 or more).
Frequency
Frequency refers to the number of training sessions performed during a specific
period of time and is dependent on several factors such as volume and intensity,
exercise selection, level of conditioning and/or training status, recoverability,
nutritional intake, and training goals. Intense resistance training increases the
­recovery time needed prior to subsequent training sessions. The majority of studies e­ xamining untrained individuals or special populations have used frequencies
of 2 to 3 a­ lternating days per week.21–24,27 Meta-analysis data show that training
specific muscle groups 3 day·week−1 produces the highest effect size in untrained
­individuals and 2 day·week−1 produces the highest effect size in trained individuals.26 When total-body workouts are used, a frequency of 2 to 3 alternating days per
week is recommended.5 An increase in training experience does not necessitate a
change in frequency for training each muscle group but may be more dependent on
Nicholas A. Ratamess
15
alterations in other acute variables such as exercise selection, volume, and intensity. Increasing frequency may enable greater exercise selection and volume per
muscle group.
Progression
Resistance training progression should take place at a gradual rate. Program design
reflects the progression from initial general design to greater specificity as one
continues to improve. The largest rates of fitness improvement occur in untrained
individuals as the window of adaptation is highest at this point. Numerous studies
have shown significant strength, power, and endurance increases in novice trainees
despite the program used.1,2 Many studies examining special populations were only
6–26 weeks in duration,21 so long-term progression strategies have not been studied.
Thus, it is recommended that a general or simple program design be used initially
while the trainee is learning proper technique and eliciting positive adaptations to
training. As progression becomes more difficult with advancing status, specificity,
and variation, progressive overload is needed to a greater extent and the individual
may benefit from cyclical changes in the training program. Systematically altering
the training stimulus is referred to as “periodization.” Periodized resistance training
involves the planned manipulation of program variables. This is most commonly
implemented by the use of specific training cycles that target few fitness components.
Although any variable can be manipulated to some degree to target a fitness component, often volume, intensity, and exercise selections are manipulated. Various
models of periodization have been investigated, and studies have consistently shown
periodized training to be superior to nonperiodized training especially in populations with resistance training experience.1,2
SUMMARY
Resistance training is a modality of exercise recommended by major health organizations for the inclusion for healthy and special populations. The benefits of resistance
training extend beyond performance but include several benefits known to improve
health. The key element of successful resistance training is the program prescribed.
The program consists of several acute variables that can be systematically altered to
target specific health- and skill-related components of fitness. Resistance training
programs can be effective provided they adhere to established guidelines and foster
the principles of specificity, progressive overload, and variation.
REFERENCES
1. Kraemer WJ, Ratamess NA. Fundamentals of resistance training: progression and
­exercise prescription. Med Sci Sport Exerc. 2004; 36: 674–678.
2. Ratamess NA. 2012. The ACSM’s Foundations of Strength Training and Conditioning.
Philadelphia, PA: Lippincott Williams and Wilkins.
3. Gosselink R, de Vos J, van den Heavel SP, Segers J, Decramer M, Kwakkel G. Impact
of inspiratory muscle training in patients with COPD: what is the evidence? Eur Resp J.
2011; 37: 416–425.
16
Resistance Training Program Variables and Guidelines
4. Kraemer WJ, Ratamess NA, French DN. Resistance training for health and p­ erformance.
Curr Sport Med Rep. 2002; 1: 165–171.
5. Ratamess NA, Alvar BA, Evetovich TK et al. American College of Sports Medicine
position stand: progression models in resistance training for healthy adults. Med Sci
Sport Exerc. 2009; 41: 687–708.
6. Faigenbaum AD, Kraemer WJ, Blimkie CJ et al. Youth resistance training: updated
position statement paper from the National Strength and Conditioning Association.
J Strength Cond Res. 2009; 23: S60–S79.
7. American College of Sports Medicine. 2010. ACSM’s Guidelines for Exercise Testing
and Prescription. 8th ed. In Thompson WR, Gordon NF, Pescatello LS (Eds.).
Philadelphia, PA: Lippincott Williams and Wilkins, pp. 18–59.
8. Mazzetti, SA, Kraemer WJ, Volek JS et al. The influence of direct supervision of
­resistance training on strength performance. Med Sci Sport Exerc. 2000; 32: 1175–1184.
9. Ratamess NA, Faigenbaum AD, Hoffman JR, Kang J. Self-selected resistance training
intensity in healthy women: the influence of a personal trainer. J Strength Cond Res.
2008; 22: 103–111.
10. Dudley GA, Tesch PA, Miller BJ, Buchanan MD. Importance of eccentric actions in
performance adaptations to resistance training. Aviat Space and Environ Med. 1991; 62:
543–550.
11. Ballor DL, Becque MD, Katch VL. Metabolic responses during hydraulic resistance
exercise. Med Sci Sport Exerc. 1987; 19: 363–367.
12. Saeterbakken AH, Fimland MS. Effects of body position and loading modality on muscle activity and strength in shoulder presses. J Strength Cond Res. 2012.
13. Barnett C, Kippers V, Turner P. Effects of variations of the bench press exercise on the
EMG activity of five shoulder muscles. J Strength Cond Res. 1995; 9: 222–227.
14. Escamilla RF, Fleisig GS, Lowry TM, Barrentine SM, Andrews JR. 2001. A threedimensional biomechanical analysis of the squat during varying stance widths. Med Sci
Sport Exerc. 2001; 33: 984–998.
15. Signorile JF, Zink AJ, Szwed SP. A comparative electromyographical investigation
of muscle utilization patterns using various hand positions during the lat pulldown.
J Strength Cond Res. 2002; 16: 539–546.
16. Langford GA, McCurdy KW, Ernest JW, Doscher MW, Walters SD. Specificity of
machine, barbell, and water-filled log bench press resistance training on measures of
strength. J Strength Cond Res. 2007; 21: 1061–1066.
17. Behm DG, Leonard Am, Young WB, Bonsey WA, MacKinnon SN. Trunk muscle
­electromyographic activity with unstable and unilateral exercises. J Strength Cond Res.
2005; 19: 193–201.
18. Clark MA, Lucett SC. 2011. NASM Essentials of Corrective Exercise Training.
Philadelphia, PA: Lippincott Williams and Wilkins.
19. Munn J, Herbert RD, Gandevia SC. Contralateral effects of unilateral resistance t­ raining:
a meta-analysis. J Appl Physiol. 2004; 96: 1861–1866.
20. Kuruganti U, Parker P, Rickards J, Tingley M, Sexsmith J. Bilateral isokinetic ­training
reduces the bilateral leg strength deficit for both old and young adults. Eur J Appl
Physiol. 2005; 94: 175–179.
21. Cramp F, James A, Lambert J. The effects of resistance training on quality of life in
cancer: a systematic literature review and meta-analysis. Support Care Cancer. 2010;
18: 1367–1376.
22. Ehrman JK, Gordon PM, Visich PS, Keteyian SJ. 2009. Clinical Exercise Physiology.
2nd ed. Champaign, IL: Human Kinetics.
23. O’Shea SD, Taylor NF, Paratz JD. Progressive resistance exercise improves muscle
strength and may improve elements of performance of daily activities for people with
COPD. Chest. 2009; 136: 1269–1283.
Nicholas A. Ratamess
17
24. De Backer IC, Schep G, Backx FJ, Vreugdenhil G, Kuipers H. Resistance training in
cancer survivors: a systematic review. Int J Sport Med. 2009; 30: 703–712.
25. Simao R, Farinatti PTV, Polito MD, Maior AS, Fleck SJ. Influence of exercise order on
the number of repetitions performed and perceived exertion during resistive exercises.
J Strength Cond Res. 2005; 19: 152–156.
26. Rhea MR, Alvar BA, Burkett LN, Ball SD. A meta-analysis to determine the dose
response for strength development. Med Sci Sport Exerc. 2003; 35: 456–464.
27. Johansen KL. Exercise and chronic kidney disease: current recommendations. Sport
Med. 2005; 35: 485–499.
28. Tschopp M, Sattelmayer MK, Hillfiker R. Is power training or conventional resistance
training better for function in elderly persons? A meta-analysis. Age Ageing. 2011;
40: 549–556.
29. Sayers SP, Gibson K. A comparison of high-speed power training and traditional
­slow-speed resistance training in older men and women. J Strength Cond Res. 2010;
24: 3369–3380.
30. Sayers SP. High velocity power training in older adults. Curr Aging Sci. 2008; 1: 62–67.
31. Drinkwater EJ, Lawton TW, Lindsell RP, Pyne DB, Hunt PH, McKenna MJ. Training
leading to repetition failure enhances bench press strength gains in elite junior athletes.
J Strength Cond Res. 2005; 19: 382–388.
32. Izquierdo M, Ibanez J, Gonzalez-Badillo JJ et al. Differential effects of strength ­training
leading to failure versus not to failure on hormonal responses, strength, and muscle
power gains. J Appl Physiol. 2006; 100: 1647–1656.
33. Egan AD, Winchester JB, Foster C, McGuigan MR. Using session RPE to monitor
­different methods of resistance exercise. J Sport Sci Med. 2006; 5: 289–295.
34. Lagally KM, Amorose AJ, Rock B. Selection of resistance exercise intensity using
ratings of perceived exertion from the OMNI-RES. Percept Mot Skills. 2009; 108:
573–586.
35. Hardee JP, Lawrence MM, Utter AC, Triplett NT, Zwetsloot KA, McBride JM. Effect
of inter-repetition rest on ratings of perceived exertion during multiple sets of the power
clean. Eur J Appl Physiol. 2012; 112: 3141–3147.
36. Ratamess NA, Falvo MJ, Mangine GT, Hoffman JR, Faigenbaum AD, Kang J. The
effect of rest interval length on metabolic responses to the bench press exercise. Eur J
Appl Physiol. 2007; 100: 1–17.
37. Ratamess NA, Chiarello CM, Sacco AJ et al. The effects of rest interval length on acute
bench press performance: the influence of gender and muscle strength. J Strength Cond
Res. 2012; 26: 1817–1826.
38. Pincivero DM, Lephart SM, Karunakara RG. Effects of rest interval on isokinetic
strength and functional performance after short-term high intensity training. Br J Sport
Med. 1997; 31: 229–234.
39. Robinson JM, Stone MH, Johnson RL, Penland CM, Warren BJ, Lewis RD. Effects of
different weight training exercise/rest intervals on strength, power, and high intensity
exercise endurance. J Strength Cond Res. 1995; 9: 216–221.
40. Keogh JWL, Wilson GJ, Weatherby RP. A cross-sectional comparison of d­ ifferent
resistance training techniques in the bench press. J Strength Cond Res. 1999;
­
13: 247–258.
41. Hatfield DL, Kraemer WJ, Spiering BA et al. The impact of velocity of movement on
performance factors in resistance exercise. J Strength Cond Res. 2006; 20: 760–766.
42. Munn J, Herbert RD, Hancock MJ, Gandevia SC. Resistance training for strength: effect
of number of sets and contraction speed. Med Sci Sport Exerc. 2005; 37: 1622–1626.
43. Rana SR, Chleboun GS, Gilders RM et al. Comparison of early phase adaptations for
traditional strength and endurance, and low velocity resistance training programs in
college-aged women. J Strength Cond Res. 2008; 22: 119–127.
3
Resistance Training for
Cardiovascular Disease
Randy W. Braith and Joseph C. Avery
CONTENTS
Introduction............................................................................................................... 23
Inclusion Criteria..................................................................................................24
Resistance Training and Hypertension......................................................................25
Systemic Blood Pressure......................................................................................25
Resistance Training and Hypertension Control...................................................25
Resistance Training in Prehypertension...............................................................26
Resistance Training and Arterial Stiffness................................................................26
Young and Middle-Aged Adults without Cardiovascular Disease....................... 27
Older Men and Women without Cardiovascular Disease..................................... 29
Mechanisms for Change in Arterial Compliance................................................. 30
Resistance Training and Blood Flow Patterns................................................. 30
Resistance Training, Inflammation, and Proinflammatory Cytokines...................... 31
C-Reactive Protein............................................................................................... 31
Resistance Training, Redox Status, and Oxidative Stress......................................... 33
Resistance Training and Antioxidative Capacity in Type 2 Diabetes.................. 36
Resistance Training and Dyslipidemia..................................................................... 37
Recent Advances in the Measurement of Low-Density Lipoprotein................... 38
Resistance Training and Obesity............................................................................... 38
Obesity Prevention............................................................................................... 38
Visceral Adipose Tissue.................................................................................. 39
Obesity Reduction........................................................................................... 39
Summary...................................................................................................................40
References.................................................................................................................40
INTRODUCTION
The most recent statistics show that cardiovascular disease (CVD) accounted for
32.8% of all deaths, or one out of every three deaths, in 2008 in the United States.1
Consequently, it is not surprising that CVD is a significant economic burden costing
more than $298 billion annually in the United States alone.1 One mechanism used
to explain the high mortality rate associated with patients with CVD is their lack of
physical activity. For example, Myers et al.2 showed that a metabolic equivalent (or
a unit of energy expenditure) increase in aerobic fitness was associated with a 12%
19
20
Resistance Training for Cardiovascular Disease
Homocysteine
lip
No
ve
ids
itio
na
l li
Hypertension
pid
Diabetes
I
BM
vel
Diabetes
BMI
No
Tr
ad
Homocysteine
l li
pid
s
s
Unknown factors
40%
Traditional lipids
Unknown factors
65%
Hemostatic factors
Hypertension
Hemostatic
inflammatory factors
(a)
(b)
FIGURE 3.1 Although exercise training decreases cardiovascular risk factors, mitigation of traditional cardiovascular risk factors can explain only approximately 35% of the
beneficial effects of exercise in coronary artery disease (a) and only approximately 60%
of the exercise benefits in all-cause cardiovascular disease (b). (Adapted from Mora et al.,
Circulation,116, 2110–8, 2007. With permission.)
increase in survival rate for individuals with a history of CVD. Regrettably, such
precise associations between exercise benefits and disease are not always forthcoming. Rather, we now recognize that mitigation of traditional cardiovascular
risk factors explains only approximately 60% of the beneficial effects of aerobic
exercise in all-cause CVD and only approximately 35% of the exercise benefits
in coronary artery disease (CAD)3 (Figure 3.1). Thus, a substantial portion of the
protective mechanistic effects of exercise in preventing CVD and CAD remains
unknown.
Numerous recent human studies have focused on the direct mechanical effects
of resistance training (RT) on arterial function, inflammation, oxidative stress, and
dyslipidemia, where RT could explain some of the cardiovascular protective benefits
of exercise. In this chapter, the authors present novel insights into training adaptations that may further corroborate the recommendations by the American Heart
Association (AHA)4 and the American College of Sports Medicine (ACSM)5 that RT
helps to prevent CVD and/or the clustering of cardiovascular risk factors associated
with metabolic syndrome.4
Inclusion Criteria
In an attempt to capture what may be described as chronic adaptations to training,
only longitudinal studies over a minimum of 6 weeks in duration and examining RT
as the sole intervention and its effects are included in the chapter. When the effects
of RT were confounded by other factors such as aerobic exercise programs, dietary
modification, or pharmacological interventions, studies were excluded.
Randy W. Braith and Joseph C. Avery
21
RESISTANCE TRAINING AND HYPERTENSION
Adopting a healthy lifestyle is critical for the prevention of high blood pressure
(BP) and is an indispensable part of the treatment of hypertension. The AHA4 and
the ACSM5 have each endorsed moderate-intensity RT as a complement to aerobic
­exercise programs in the prevention, treatment, and control of hypertension.
Systemic Blood Pressure
The rationale for RT as an adjunct to aerobic exercise for controlling BP stems from
multiple studies. Two meta-analyses of RT and hypertension are perhaps the most noteworthy with respect to helping us to interpret the data from a large body of research.6,7
Inclusion criteria, consistent across both reviews, were as follows: (1) trials included a
randomized nonexercise control group, (2) RT was the only intervention, (3) training
was a minimum of 4 weeks, and (4) participants were sedentary normotensive and/
or hypertensive adults with no other concomitant disease. Kelley and Kelley7 examined the effects of RT on resting BP in studies published between January 1966 and
December 1998. A total of 11 studies met the inclusion criteria and represented initial
and final BP assessments in 182 RT subjects and 138 controls. Decreases (p ≤ .05)
of approximately 3 mmHg were found for both systolic blood pressure (SBP) and
diastolic blood pressure (DBP) across all BP categories as the result of RT. These
changes represented a 2% decrease for resting SBP and 4% for resting DBP. No differences were found for changes in resting BP between ­studies that used conventional
RT regimens and those that used a circuit RT protocol. A ­conventional RT regimen
generally consists of lifting heavier weights with longer rest periods, whereas a circuit
RT protocol consists of lifting lighter weights with shorter rest periods between exercises. By moving quickly between exercises and by using lighter weights with higher
repetitions, circuit training introduces an aerobic component to the workout.
In a more recent meta-analysis, Cornelissen and Fagard6 pooled data from studies
published between 1996 and 2003 that included nine randomized controlled trials,
involving 341 participants. The overall effect of RT was a decrease of 3.2 mmHg
(p = .10) in SBP and a decrease of 3.5 mmHg in DBP (p ≤ .05). The results from
these meta-analyses are consistent with the conclusions generated by narrative
reviews. Although these reductions seem modest, an SBP reduction of 3 mmHg in
average populations has been estimated to reduce cardiac morbidity by 5%–9%,
stroke by 8%–14%, and all-cause mortality by 4%.6
Resistance Training and Hypertension Control
Control of BP is very important in individuals who already have hypertension. Although
there is general agreement that endurance training lowers resting BP in patients with
mild to severe hypertension, there is a paucity of data on the effects of RT alone on BP
in individuals with hypertension. Only 20% of the outcomes in the two meta-analysis
reviews were based on a mean initial resting SBP > 140 mmHg, whereas only 13% had
a mean initial resting DBP > 90 mmHg. Although any reduction in BP is desirable, the
available studies do not answer the question regarding the independent benefit of RT in
persons initially classified as being hypertensive.
22
Resistance Training for Cardiovascular Disease
Resistance Training in Prehypertension
According to the report from the Joint National Committee on Prevention, Detection,
Evaluation, and Treatment of High Blood Pressure (JNC7), prehypertension is not a
disease category per se, and individuals with prehypertension are not candidates for
drug therapy.8 Rather, the JNC7 recommends physical activity as the cornerstone for
the treatment of prehypertension. Despite these recommendations, the efficacy of RT
in reducing BP in young prehypertensives remains nearly uninvestigated.
Recently, Beck et al.9 conducted a prospective randomized and controlled study to
examine the independent effects of RT on SBP in young prehypertensives. Forty-three
unmedicated prehypertensive (SBP = 120–139 mmHg; DBP = 80–90 mmHg) but
other­wise healthy men and women and 15 normotensive matched time-control subjects
between 18 and 35 years of age were randomly assigned to an RT (n = 15), an endurance training (n = 13), or a control group (n = 15). The treatment groups performed
the exercise 3 days per week for 8 weeks. RT resulted in reductions in resting SBP and
DBP by 8 and 6 mmHg, respectively. Interestingly, the antihypertensive benefits of RT
were nearly identical to endurance training. Endurance training resulted in reductions
in resting SBP and DBP by 10 and 6 mmHg, respectively. The authors attribute the
benefits of RT to significant improvements in endothelial function as determined by
brachial artery flow–mediated dilation (+30%), increased nitric oxide (NO) bioavailability (+19%), and reduced plasma levels of endothelin-1 (−16%). These data support
the JNC7 recommendation that RT may be used prophylactically to prevent progression toward adult essential hypertension in young individuals with prehypertension.
RESISTANCE TRAINING AND ARTERIAL STIFFNESS
Recent epidemiological studies confirm that central arterial stiffness, determined by
aortic pulse wave velocity (PWV) or beta stiffness of the common carotid artery, is an
important determinant of cardiovascular risk and an independent predictor of cardiovascular events and mortality.10 Although arterial stiffening was once considered an
inevitable consequence of normal aging, it is now considered to be a clinically relevant
process to be treated in older adults or prevented in younger adults. One clinical consequence of arterial stiffening is augmented cardiac afterload, which causes left ventricular hypertrophy and may be associated with the high prevalence of heart failure
with preserved ejection fraction in the older population.10
Several conditions, such as diabetes, obesity, hyperlipidemia, and hypertension,
are reported to accelerate stiffness by stimulating the development of collagen crosslinking in the arterial wall. In contrast, long-term endurance exercise attenuates
stiffness and masters aerobic athletes have “younger” aortas than their sedentary
peers.11 There is also evidence from interventional studies that short-term aerobic
exercise training reduces arterial stiffness and central pressure wave reflection in
healthy young individuals12 and middle-aged patients with CAD.13 Therefore, aerobic exercise training could be a potential strategy to treat central arterial ­stiffening,
although it has not yet been validated for this purpose.
Nonetheless, in elderly individuals in the seventh or eighth decade of life even
intensive aerobic exercise appears to be inadequate to improve central arterial
23
Randy W. Braith and Joseph C. Avery
s­ tiffening.11 Thus, it is possible that while accumulation of extracellular cross-linked
collagen or degeneration of the elastin matrix can be prevented by lifelong aerobic
training, once established it is hard to reverse these processes by exercise alone.
To date, much less is known about the independent effects of RT on arterial stiffness.
Outcomes from studies that focused specifically on RT and arterial function in both
younger healthy adults and older adults are presented in the following subsections.
Young and Middle-Aged Adults Without Cardiovascular Disease
Early cross-sectional studies suggested that chronic, high-intensity, high-volume RT
reduces arterial compliance (i.e., increased stiffness) in both young and middle-aged
men.14,15 More recent interventional studies, on the other hand, have yielded conflicting results regarding the effects of RT on arterial function. A comparison of arterial
stiffness outcomes from RT studies that used similar laboratory measurement techniques can be found in Table 3.1B.
A pair of early short-term training studies from the same laboratory, utilizing
­modern noninvasive technology to assess arterial stiffness, reported that RT increased
arterial stiffness in healthy young adults.16,17 Miyachi et al.17 reported that RT
3 day·week−1 for 4 months decreased carotid arterial compliance by 19% (p < .05) in
TABLE 3.1A
Subject Characteristics, Training Duration, and Protocol in Studies That
Measured Arterial Stiffness
Study
Bertovic et al.14
Miyachi et al.15
Miyachi et al.17
Cortez-Cooper
et al.16
Rakobowchuk
et al.23
Casey et al.18
Kingsley and
Figueroa21
Total Subjects + RT Group
Characteristics
38 Males
n = 19 (26 ± 4 years,
BMI = 26.9 ± 0.8 kg·m−2)
62 Males
n = 16 Young (29 ± 1 years)
n = 14 Middle-aged (51 ± 2 years)
28 Males
n = 14 (22 ± 1 years,
BMI = 22.9 ± 0.7 kg·m−2)
33 Females
n = 23 (29 ± 1 years,
BMI < 30 kg·m−2)
28 Males
n = 28 (23 ± 4 years,
BMI = 25.8 ± 0.78 kg·m−2)
42 Males/females
n = 24 (21 ± 0.5 years,
BMI 23.3 ± 0.7 kg·m−2)
24 Females
n = 24 (44 ± 1 years,
BMI = 28.5 ± 0.64 kg·m−2)
Duration
RT Intervention
1 year
Previously
trained
5–21 years
Previously
trained
16 weeks
Noninterventional
11 weeks
12 exercises, 3–6 sets, 5–10 reps,
4×/week
12 weeks
14 exercises, 2–3 sets, 5–12 reps,
≥80% 1RM, 5×/week
12 weeks
7 exercises, 2 sets, 8–12 reps,
3×/week
12 weeks
5 exercises, 3 sets, 10 reps,
50–60% 1RM, 2×/week
Noninterventional
6 Exercises, 3 sets, 8–12 reps,
80% 1RM, 3×/week
24
Resistance Training for Cardiovascular Disease
TABLE 3.1B
Indexes of Arterial Stiffness before and after RT
Study
Bertovic et al.14
Central PWV
(m·s−1)
Arm/Leg PWV
(m·s−1)
Carotid–femoral
Pre: 6.6 ± 0.2
Post: 6.5 ± 0.2
p Value: NS
Femoral–dorsalis
pedis
Pre: 8.1 ± 0.3
Post: 9.2 ± 0.3+
p Value < .01
Arm
Young
Pre: 12.2 ± 0.53
Post: 11.39 ± 0.55
Middle-aged
Pre: 13.10 ± 0.44
Post: 12.40 ± 0.49
p Value: NS
Miyachi et al.15
Carotid–femoral
Pre: 7.91 ± 0.88
Post: 8.33 ±
0.96*
p Value: < 0.05
Heart–femoral
Pre: 6.52 ± 0.46
Post: 6.65 ± 0.58
p Value: NS
Femoral-Ankle
Pre: 8.71 ± 0.88
Post: 8.62 ± 1.06
p Value: NS
Pre: −1 ± 14
Post: −8 ± 13*
p Value < .05
Kingsley and
Figueroa21
Pre: ~1.45 ± ~0.1
Post: ~1.83 ±
~0.1*
p Value <.05
Pre: ~37 ± ~2.0
Post: ~40 ± ~3.0
p Value: NS
Rakobowchuk
et al.23
Casey et al.18
β Index
Pre: 3.8 ± 0.4
Post: 4.6 ± 0.2*
p Value < .05
Pre: −18 ± 3.0
Post: −13 ± 3.0
p Value: NS
Miyachi et al.17
Cortez-Cooper
et al.16
Carotid
Augmentation Index
Carotid–femoral
Pre: ~6.3 ±
~0.05
Post: ~6.3 ±
~0.05
p Value: NS
Carotid–radial
Pre: ~8.75 ± ~0.1
Post: ~8.0 ± ~0.1
p Value: NS
Femoral–distal
Pre: ~9.75 ± ~0.2
Post: ~9.75 ± ~0.2
p Value: NS
Pre: ~2.75 ± ~2.25
Post: ~5.0 ± ~1.75
p Value: NS
Pre: 27.6 ± 1.6
Post: 28.1 ± 1.2*
p Value < .05
Note: NS, not significant; *, p < .05 trained versus control; +, p < .01 trained versus control.
Randy W. Braith and Joseph C. Avery
25
young healthy males who were novice weight trainers. Cortez-Cooper et al.16 reported
that high-intensity RT for 4 day·week−1 for 3 months in young healthy women who
were novice weight trainers (n = 23; 29 ± 1 years; mean ± standard deviation [SD])
increased the carotid augmentation index (a measure of arterial wave reflection and
arterial stiffness) from −8% ± 13% to 1% ± 18% (p < .05) and carotid–femoral PWV
(p ≤ .05) from 791 ± 88 to 833 ± 96 cm·s−1. Paradoxically, neither study reported
increases in SBP or DBP secondary to RT.
Subsequent studies have been unable to establish a relationship between RT
and increased arterial stiffening. Rather, numerous independent investigators have
reported no change in arterial function after RT.18–23 Utilizing similar laboratory
technology to assess arterial function, all of the recent studies have concluded that
arterial stiffness (both central and peripheral) is unaltered after short-duration RT in
young and middle-aged adults without CVD (Table 3.1).
The discrepancy in outcomes between studies involving healthy young and
­middle-aged subjects may be explained by differences in RT protocols (Table 3.1).
The two pioneering studies that reported increased central arterial stiffness used
RT protocols consisting of high-intensity super sets and an extremely high volume
(up to six sets per exercise),16,17 both of which are not commonly recommended for
the majority of the population and are usually performed by competitive athletes.4,5
Conversely, the studies that reported no change in arterial stiffness used progressive
training protocols that increased the intensity but not the volume of exercise over time.
Older Men and Women Without Cardiovascular Disease
Large elastic artery stiffness increases with age in both men and women24 and menopause is a mitigating factor in women. The mechanism by which menopause exerts its
effect on arterial function may be related to changes in estrogen deficiency on endothelial function, vascular smooth muscle phenotype, and elastin-/­collagen-related
stiffening of large elastic conduit arteries. Little is known about the effects of RT on
central aortic stiffness in healthy postmenopausal women. In a recent study, Casey
et al.18 randomized healthy normotensive postmenopausal women to either 18 weeks
(2 day·week−1) of RT (n = 13) or aerobic training (n = 10). RT consisted of one set of
12 repetitions on 10 variable-resistance machines that provided a whole-body training stimulus. Eighteen weeks of RT did not change central aortic pressure wave
reflection or brachial artery flow–mediated dilation.
Basal limb blood flow and vascular conductance decrease with advancing age even
in healthy adults. Daily aerobic exercise appears to be unable to attenuate or prevent the age-related reductions in basal limb blood flow and vascular conductance. In
contrast, there is some evidence that RT may be a promising intervention to prevent
age-related diminishment of limb perfusion. In a cross-sectional study, Miyachi et
al.25 measured basal whole-leg blood flow and vascular conductance in middle-aged
men (49 ± 2 years of age) who were either sedentary (n = 25) or had performed
vigorous RT for >2 years. Basal whole-leg blood flow, vascular ­conductance, and
common femoral artery lumen diameter were significantly higher (35%, 36%, and
9%, respectively; p < .05) in the RT men versus the sedentary men, and these findings
were independent of leg muscle mass. In a follow-up interventional study designed to
26
Resistance Training for Cardiovascular Disease
determine the effects of short-term whole-body RT on leg blood flow in middle-aged
adults, Anton et al.26 found that basal femoral blood flow and vascular conductance
increased by 55%–60% in older men and women (52 ± 2 years, 3 men and 10 women)
after 13 weeks of training. These data suggest that RT may be an effective lifestyle
intervention for minimizing the reductions in limb blood flow with advancing age.
Mechanisms for Change in Arterial Compliance
Studies reporting adverse effects of RT on the arterial system have only speculated about
mechanisms responsible for the changes.14–17 The elastic properties of the arterial wall
are determined by both structural components (e.g., relative composition of elastin and
collagen) and functional components (e.g., vasoconstrictor tone exerted by the vascular
smooth muscle cells). Because 3 to 4 months of RT is unlikely to cause marked structural
changes in the arterial wall, changes in the functional components of the arterial wall
need to be considered. One potential mechanism is endothelial dysfunction manifested
as a reduction in the bioavailability of NO. Recent evidence, however, indicates that 4
months of RT in healthy young men do not impair endothelial-­dependent vasodilation
in the brachial artery.27 Another mechanism for functional change in the arterial wall is
increased sympathetic tone. There is evidence that RT increases resting humoral norepinephrine levels, a surrogate marker of sympathetic nervous system (SNS) activity.
However, increased SNS vasoconstrictor tone is likely to be greater in peripheral muscular arteries than in central elastic arteries. Surprisingly, both studies reporting increases
in stiffness of central conduit arteries after RT did not show changes in peripheral muscular arteries.16,17 Results from narrative 4,5 and meta-analytical reviews6,7 do not support
the contention that RT increases vascular resistance. Moreover, these findings are compatible with the absence of hypertension observed among isometric and power athletes.28
Resistance Training and Blood Flow Patterns
Gurovich et al.29 recently completed an elegant study designed to characterize the
“real-time” blood flow patterns in vivo in femoral and brachial arteries during RT.
Femoral and brachial artery diameters and peak systolic and diastolic blood flow
velocities were measured using B-mode ultrasound imaging and echo Doppler,
respectively, during bilateral knee extension and bilateral biceps curl exercise
at 40% and 70% of one-repetition maximum (1RM) in eight young (21–32 years
of age) healthy men. Blood flow patterns including endothelial shear stress, flow
direction, and flow turbulence were determined. The relevant major findings of this
study were twofold: (1) endothelial shear stress increases with exercise intensity during RT in both antegrade and retrograde blood flows and (2) both antegrade and
retrograde blood flows become more turbulent with increasing RT intensity. It is
widely accepted that blood flow–induced endothelial shear stress during exercise can
regulate endothelial function. Gurovich et al.29 speculate that the direct mechanical
effects of RT-induced blood flow patterns on the vascular endothelium could be a
major mitigating factor in the prevention of CVD.
In summary, there is good evidence that RT has no deleterious effect on arterial function when performed in compliance with guidelines recommended by our
governing organizations, such as the ACSM and the AHA18,19,21–23 (Table 3.1). There
Randy W. Braith and Joseph C. Avery
27
is also some evidence that RT may improve arterial function in healthy middleaged and older adults22,26 and the underlying mechanism appears to be blood flow–
induced shear stimuli acting on vascular endothelial cells.29
RESISTANCE TRAINING, INFLAMMATION, AND
PROINFLAMMATORY CYTOKINES
Chronic low-grade systemic inflammation is implicated in the development of ather­
osclerosis and CVD. More than 50% of myocardial infarctions and strokes occur in
patients lacking hyperlipidemia, and 15%–20% occur in those who do not smoke or
present with hypertension.30 Consequently, in addition to conventional risk factors,
novel immunological risk factors are emerging as important screening markers that
have predictive insight into CVD risk.
In this section, we focus on the inflammatory biomarker high-sensitivity C-reactive
protein (CRP) and its systemic precursor interleukin-6 (IL-6). These markers were
selected for two reasons: (1) there is extensive evidence from clinical trials that CRP
and IL-6 are linked to the pathogenesis of CVDs and (2) CRP and IL-6 are the
most investigated indexes of immune system function in RT interventional studies
designed to measure inflammation.
High-sensitivity CRP is a serum biomarker of systemic inflammation that is synthesized and released by hepatocytes in response to the proinflammatory cytokine IL-6,
as part of acute-phase inflammatory response.30 The levels of these markers increase
as a result of local inflammation in response to an acute infection or trauma and then
decrease when the infection or trauma is resolved. In contrast, a low-level increase in
serum concentrations of these inflammatory markers is defined as low-grade or subclinical inflammation. Chronic low-grade inflammation is related to atherosclerosis,
which is characterized by the accumulation of lipid and fibrous elements in arteries.31
Atherosclerotic plaques attract inflammatory cells, which in turn produce reactive oxygen species (ROS) and inflammatory cytokines such as tumor necrosis factor alpha
(TNF-α) and monocyte chemoattractant protein 1 (MCP-1). These inflammatory
events exacerbate atherosclerosis and promote thrombosis.31 Therefore, intervention
strategies such as RT that may reduce CRP have important clinical implications.
C-Reactive Protein
Changes in serum CRP due to RT have been reported in a total of 10 studies
(Table 3.2). Six of them showed significant reductions in serum CRP levels after
RT intervention.32–37 Conversely, one uncontrolled study38 and two randomized
controlled trials39,40 showed no significant change in serum CRP after RT. Thus,
comparable studies examining RT effects on CRP using randomized controlled
experimental designs have arrived at disparate conclusions.
The reader should note that the largest randomized controlled trial to date, the
one that investigated the effect of exercise modality on CRP levels, found nonsignificant reductions in CRP.40 This multicenter trial, the recently completed Health
Benefits of Aerobic and Resistance Training in Individuals with Type-2 Diabetes
(HART-D) study, was a 9 month exercise study comparing the effects of aerobic
45 Males/females
n = 14 (73.2 ± 6.5 years, BMI 30.8 ± 5.3 kg·m−2)
102 Males/females
n = 35 (BMI 27.8 ± 3.9 kg·m−2)
21 Females
n = 21 (85.0 ± 4.5 years, BMI 21.2 ± 4.0 kg·m−2)
62 Males/females
n = 31 (66 ± 2 years, BMI 30.9 ± 1.1 kg·m−2)
28 Females
n = 16 (39 ± 5 years, BMI 26.9 ± 3.0 kg·m−2)
10 Females
n = 10 RT (47 ± 12 years, BMI 26 ± 7 kg·m−2)
12 Males
n = 12 (50.4 ± 2.3 years, BMI 33.6 ± 3.9 kg·m−2)
204 Males/females
n = 50 (58.7 ± 8 years, BMI 34.1 ± 5.4 kg·m−2)
Total Subjects + RT Group Characteristics
36 weeks
12 weeks
8 weeks
1 year
16 weeks
12 weeks
10 weeks
16 weeks
Duration
8 exercises, 1–3 sets, 8–15 reps, moderate
intensity, 3×/week
7 exercises, 2–4 sets, 8–10 reps, 70%–75%
1RM, periodized training
4 exercises, 1 to 2 sets, 10 reps, at least
1×/ week
5 exercises, 3 sets, 8 reps, 60%–80%
1RM, 3×/week
9 exercises, 3 sets, 6–12 reps, at least
2×/ week
3 exercises, 1 set, 6–15 reps, 50%–70%
1RM, 2×/week
17 exercises, 1+ sets, 12–15 reps,
60%–70% 1RM, 3×/week
8 exercises, 2–3 sets, 10–12 reps, 3×/week
RT Intervention
Note: hs-CRP, high sensitivity C-reactive protein; NS, nonsignificant; *, p < .05 trained versus control; +, p < .01 trained versus control.
Swift et al.40
Klimcakova et al.38
White et al.37
Olson et al.36
Brooks et al.32
Ogawa et al.35
Donges et al.33
Martins et al.34
Study
TABLE 3.2
Subject Characteristics, Training Duration and Protocol in Studies That Measured C-Reactive Protein
NS
Pre: 5.61 ± 4.12
Post: 5.02 ± 3.85
Pre: 3.57 ± 2.08
Post: 2.40 ± 2.03*
Pre: 2.44 ± 3.22
Post: 1.46 ± 2.22*
Pre: 3.5
Post: 2.8
Pre: ~3.25
Post: ~3.0*
Pre: 4.8 ± 1.7
Post: 3.4 ± 1.0+
Pre: 3.3 ± 2.2
Post: 2.9 ± 1.7
Pre: 5.2 ± 6.2
Post: 4.1 ± 4.5
NS
NS
<.01
<.05
NS
<.05
<.05
p Value
hs-CRP (mg/L)
28
Resistance Training for Cardiovascular Disease
Randy W. Braith and Joseph C. Avery
29
training (n = 50), RT (n = 58), or a combination (n = 59) of both training modalities
on hemoglobin-A1c and CRP in older (~58 ± 8 years of age) men and women with
type-2 diabetes. The RT regimen, consisting of two to three sets of nine exercises
performed to volitional fatigue within 10–12 repetitions, was consistent with the
recommendations of the ACSM for nonathletic healthy adults.5
Nonetheless, the HART-D trial did report a significant correlation between
a change in CRP and a change in fat mass.40 Thus, RT may be more effective in
­reducing CRP levels in overweight and obese populations compared to healthy
­subjects and these results may be related to higher baseline levels of CRP in
­overweight or obese subjects. Indeed, large cross-sectional studies have shown an
association between CRP concentration and adiposity.41 The replacement of muscle
mass with adipose tissue with age is likely one factor responsible for the increased
production of ­proinflammatory cytokines such as IL-6 and TNF-α seen in chronic
­low-grade inflammation. Interventional studies have consistently reported significant c­ orrelations between CRP levels and RT-induced changes in indexes of body
composition such as lean body mass,36 fat mass,40 muscle hypertrophy,35 waist
­circumference,34 and waist-to-hip ratio.33 It is important to note that aerobic ­exercise
intervention studies have arrived at the same conclusion regarding the relationship between exercise-induced changes in body composition and changes in CRP
­levels. For example, the Inflammation and Exercise (INFLAME) study, the largest
­prospective, randomized, controlled aerobic exercise trial to date in sedentary individuals with elevated levels of CRP, concluded that changes in CRP were associated
­primarily with reductions in total body fat and abdominal body fat.42
In summary, elevated CRP (high risk, >3.0 mg·L−1) is an independent predictor
for cardiovascular events and cardiovascular mortality. We do not presently have
good evidence that RT directly reduces inflammation, as assessed by changes in
serum IL-6 and CRP levels. However, there is increasing evidence that RT may have
some efficacy through indirect means, especially by reducing fat mass and increasing muscle mass. These outcomes are not surprising in light of the fact that the predominant chronic inflammatory state is known to be obesity. Adipocytes appear to
be the primary tissue-producing IL-6 in obese individuals, and obese individuals are
indeed characterized by increased levels of circulating IL-6. In turn, IL-6 is known
to be a major inducer of CRP in hepatocytes.30
RESISTANCE TRAINING, REDOX STATUS, AND OXIDATIVE STRESS
To date, there is a paucity of information regarding the potential capacity of RT to
mitigate the damaging effects of oxidative stress in humans. Oxidative stress occurs
when there is an imbalance between pro-oxidant production and endogenous antioxidant enzymes and pathways. An imbalance between radical oxygen species and
antioxidant enzymes can result in oxidative damage to all tissue components, including oxidations of amino acids in proteins, oxidations of fatty acids in lipids, and
oxidations of nucleic acids containing genetic instructions (DNA).
Recent data suggest that RT can lower oxidative stress in healthy adults, as
shown by reductions in lipid and DNA oxidation43–45 (Table 3.3). A reduction in
the baseline levels of two independent indexes of lipid peroxidation, peroxides
28 Males/females
n = 28 (68.5 ± 5.1 years)
12 Males
n = 12 (71.2 ± 6.5 years)
Parise et al.44
Total Subjects + RT Group
Characteristics
Parise et al.43
Study
12 weeks
14 weeks
Duration
2 exercises, 3 sets, 10 reps,
50%–80% 1RM, 3×/week
12 exercises, 1–3 sets, 10–12
reps, 50%–80% 1RM, 3×/week
RT Intervention
Creatinine (mg·mL–1)
Pre: 0.73 ± 0.48
Post: 0.83 ± 0.45
8-OHdG (ng·g creatinine−1)
Pre: 10,783 ± 5,856
Post: 8,897 ± 4,030*
CS (μmol·min−1·g wetwt−1)
Pre: 12.2 ± 2.8
Post: 13.2 ± 3.2*
Catalase (μmol·min−1·mg protein−1)
Pre: 8.2 ± 2.3
Post: 14.9 ± 7.6*
Total SOD (U·mg protein−1)
Pre: 12.9 ± 4.5
Post: 18.1 ± 6.3
CuZnSOD (U·mg protein−1)
Pre: 7.2 ± 4.2
Post: 12.6 ± 5.6*
MnSOD (U·mg protein−1)
Pre: 5.7 ± 3.2
Post: 5.5 ± 3.0
CS (μmol·min−1·g wet wt−1)
Pre: 13.1 ± 5.1
Post: 12.7 ± 4.1
Biomarker Activity
TABLE 3.3
Subject Characteristics, Training Duration and Protocol, and Indexes of Redox Balance
p Value
Catalase
p Value < .05
Total SOD
p Value: NS
CuZnSOD
p Value < .05
MnSOD
p Value: NS
CS
p Value: NS
Creatinine
p Value: NS
8-OHdG
p Value < .05
CS
p Value < .05
30
Resistance Training for Cardiovascular Disease
24 weeks
49 Males/females
n = 10 NW (70.19 ± 1.4
years, BMI 23.9 ± 0.5
kg·m−2)
n = 10 O/O (71.2 ± 2.1 years,
BMI 29.4 ± 0.7 kg·m−2)
Vincent et al.46
13 exercises, 1 set, 8–13 reps,
50%–80% 1RM, 3×/week
14 exercises, 3 sets, 8–13 reps,
50%–80% 1RM, 3×/week
XO (nmol·mL–1)
LEX pre: 0.25 ± 0.11
LEX post: 0.27 ± 0.11
HEX pre: 0.27 ± 0.12
HEX post: 0.24 ± 0.04
H2O2 (nmol·mL–1)
LEX pre: 0.43 ± 0.28
LEX post: 0.47 ± 0.25
HEX pre: 0.58 ± 0.46
HEX post: 0.68 ± 0.37
ADP-Fe2+ (nmol·mL–1)
LEX pre: 0.29 ± 0.06
LEX post: 0.29 ± 0.05
HEX pre: 0.32 ± 0.04
HEX post: 0.34 ± 0.04
PEROX (nmol·mL–1)
NW pre: ~0.85 ± ~0.2
NW post: ~0.33 ± ~0.05*
O/O pre: ~0.60 ± ~0.13
O/O post: ~0.40 ± ~0.1*
TBARS (nmol·mL–1)
NW pre: ~0.042 ± ~0.004
NW post: ~0.002 ± ~0.000*
O/O pre: ~0.035 ± ~0.04
O/O post: ~0.010 ± ~0.002*
XO
LEX p value:
NS
HEX p value:
NS
H2O2
LEX p value:
NS
HEX p value:
NS
ADP-Fe2+
LEX p value:
NS
HEX p value:
NS
PEROX
NW p value
< .05
O/O p value
< .05
TBARS
NW p value
< .05
O/O p value
< .05
Note: 8-OHdG, 8-oxo-2’-deoxyguanosine; MnSOD, manganese superoxide dismutase; total SOD, total superoxide dismutase; CuZnSOD, copper/zinc superoxide
dismutase; CS, citrate synthase; XO, xanthine oxidase; H2O2, hydrogen peroxide; ADP-Fe2+, ferric adenosine diphosphate; PEROX, lipid hydroperoxides; NW,
normal weight; O/O, overweight/obese; LEX, low-intensity exercise; HEX, high-intensity exercise; NS, nonsignificant; *, p < .05 trained versus control.
24 weeks
62 Males/females
n = 24 LEX (67.6 ± 6.0
years)
n = 22 HEX (66.6 ± 7.0
years)
Vincent et al.45
Randy W. Braith and Joseph C. Avery
31
32
Resistance Training for Cardiovascular Disease
(PEROXs) and thiobarbituric reactive acid substances (TBARSs) (index of lipid
peroxidation), was reported in healthy adults after 24 weeks of RT performed three
times per week.45 Similarly, Parise et al.43 reported that circuit RT for 14 weeks,
three times per week, reduced urinary levels of 8-hydroxy-2-deoxyguanosine
(a marker of DNA oxidation). However, the same laboratory reported that isolated
unilateral leg resistance exercise training for 12 weeks, three times per week, did
not alter the protein carbonyl content (a marker of protein oxidation) of exercised
skeletal muscle in adults.44
It is known that oxidative stress is acutely elevated after aerobic exercise in older
adults, especially in those who are overweight and obese (Table 3.3). Vincent et al.46
sought to determine whether chronic RT could reduce the acute oxidative stress
insult that occurs immediately after aerobic exercise (lipid p­ eroxidation ­levels) in
overweight/obese older adults compared with normal-weight ­age-matched older
adults. Second, the authors sought to determine whether RT could reduce plasma
homocysteine in this population. Homocysteine is a sulfhydryl-containing amino
acid that causes endothelial damage, generates oxygen radicals, and promotes
oxidative stress. In this study, 49 older adults (age range of 60–72 years) were
stratified by body mass index (BMI) (<25 kg·m−2 normal weight, >25 kg·m−2
overweight/obese) and then randomly assigned to either a control nonexercise
group (n = 20) or an RT group (n = 29). The RT group completed 6 months of
RT (one set to volitional fatigue; 13 variable-resistance machines; three times
per week). All subjects performed a maximal graded treadmill test (GXT) before
and after the 6 month study period, and blood samples were obtained before and
immediately after each GXT. Exercise-induced PEROXs and TBARs during the
GXTs were lower in both the overweight/obese and normal-weight RT groups
compared with control groups. Homocysteine levels were also lower in both the
overweight/obese and normal-weight RT groups compared with control groups.
These novel data show that RT reduces aerobic exercise–induced oxidative stress
and homocysteine regardless of adiposity, thereby affording protection against
cardiovascular risk factors.
Resistance Training and Antioxidative Capacity in Type 2 Diabetes
Chronic hyperglycemia in persons with type 2 diabetes mellitus (T2DM) causes
increased free radical production through the autoxidation of glucose and the
intensified formation of advanced glycation products, the increased activity of
nicotinamide adenine dinucleotide phosphate–oxidases, or an excess supply of
substrates at the ROS-producing mitochondrial respiratory chains.47 This is a
cause of great concern because studies performed on blood samples indicate
that T2DM patients also have decreased endogenous antioxidative defense
­capacity, thereby reducing their ability to effectively counteract free radicals and
reduce oxidative stress.48 Brinkmann et al.47 recently investigated RT-induced
alterations in oxidative stress and the antioxidative defense systems in biopsy
samples taken from the vastus lateralis muscle of untrained overweight/obese
men (n = 16, years = 61 ± 7) suffering from T2DM. Three months of RT (two
times per week) significantly upregulated cytosolic and mainly mitochondrial
Randy W. Braith and Joseph C. Avery
33
antioxidative defense mechanisms, including superoxide dismutase-2 (+65.9%),
glutathione peroxidase-1 (+62.4%), and peroxiredoxin isoform (+37.5%), when
compared to BMI-matched nondiabetic male control subjects. In contrast, RT for
21 weeks in healthy middle-aged untrained men appeared to have no effect on
antioxidant enzyme content or activity.49
In summary, there is some evidence that RT is effective in attenuating ROS in
older healthy adults.43–45 There is better evidence that RT may be most effective
in attenuating oxidative stress in overweight/obese persons. RT decreased oxidative stress in nondiabetic overweight/obese persons46 and upregulated skeletal
muscle cellular antioxidant defense mechanisms in older overweight/obese adults
with T2DM.
RESISTANCE TRAINING AND DYSLIPIDEMIA
One of the major risk factors for CVD in the United States is dyslipidemia, defined
as less-than-optimal lipid and lipoprotein levels. The independent effects of RT on
lipids and lipoproteins in adults are inconclusive and difficult to tease out, but they
appear to be related to beneficial changes in body composition. Conflicting findings
are reported with regard to total cholesterol (TC), high-density lipoprotein (HDL)
cholesterol, non-HDL cholesterol, low-density lipoprotein (LDL) cholesterol, and
triglycerides (TGs). At the center of the conflict is the fact that many interventional
studies have failed to adequately control normal variations in lipoproteins, lacked
proper dietary controls and/or statistical power, and investigated cholesterol changes
in study groups that had TC values ≤ 200 mg·DL−1 at study entry. Recently, however, Kelley and Kelley50 provided some clarity by using the meta-analytic approach
to examine the effects of RT on lipids and lipoproteins in adults. Of the 612 studies reviewed by the authors, a total of 31 exercise groups from 29 studies met the
inclusion criteria for the meta-analysis study and results were pooled for statistical
analysis: randomized controlled trials; training ≥ 4 weeks; adult humans ≥ 18 years
of age; and studies published between January 1, 1955, and July 12, 2007. Individual
data from 1329 men and women (676 RT and 653 controls) were included in the
analysis. Statistically significant improvements were found for TC (−2.7%), HDL
(1.4%), non-HDL (−5.6%), LDL (−4.6%), and TGs (−6.4%). Statistically significant
decreases were found for percentage body fat, whereas a statistically significant
increase in lean body mass was observed. No statistically significant changes were
found for body weight or BMI.
Based on previous research involving cardiovascular risk factors, the RT-induced
changes in lipid profile reported in the meta-analysis by Kelley and Kelly50 (mentioned in the previous paragraph) are equivalent to the following in relation to reducing the risk of coronary heart disease: a reduction of an average of 5% as a result
of decreases in TC50; a reduction of 21% in men as a result of reductions in TC/
HDL50; a reduction of approximately 5% in men and women as a result of decreases
in non-HDL50; a reduction of approximately 9% as a result of decreases in LDL50;
and a reduction of 3% in men and 7% in women as a result of reductions in TGs.50
The reductions in non-HDL are noteworthy since recent research has suggested that
non-HDL may be a better predictor of cardiovascular morbidity and mortality than
34
Resistance Training for Cardiovascular Disease
LDL.51 This seems plausible given that non-HDL contains all known lipid particles
considered to be atherogenic [LDL cholesterol, lipoprotein(a), intermediate-density
lipoprotein, and very low–density lipoprotein]. The improvements in LDL are also
especially relevant given that LDL is currently the primary target of lipid-lowering
therapy (i.e., statins) in adults.
Recent Advances in the Measurement of Low-Density Lipoprotein
With respect to cholesterol profile, the objective of any exercise program is to create
a favorable shift in LDL metabolism and enhance the removal of LDL from circulation. In a recent elegant study, da Silva et al.52 investigated whether RT accelerated
LDL clearance. The authors used an LDL mimetic nanoemulsion radiolabeled with14
C-cholesteryl ester and3 H-free cholesterol that could be injected intravenously. LDL
clearance was studied in 15 healthy men (age = 25 ± 5 years) who had performed
regular RT for 1–4 years and in 15 healthy sedentary men (age = 28 ± 7 years). The
two groups showed similar LDL and HDL cholesterol, but oxidized LDL was lower
in the RT group (30 ± 9 vs. 61 ± 19 U/L; p = .0005). Most importantly, in the RT
group, the clearance of both of the radiolabeled LDL mimics from circulation was
twice as fast when compared with the sedentary group. Future prospective studies
that collect LDL clearance data both before and after RT are encouraged to corroborate the initial findings and understand the mechanisms of those findings.
RESISTANCE TRAINING AND OBESITY
Obesity is an important risk factor for CVD left ventricular dysfunction, congestive heart failure, stroke, and cardiac arrhythmias.53 Weight loss in obese persons
can improve or prevent many of the obesity-related cardiovascular risk factors (i.e.,
insulin resistance and T2DM, dyslipidemia, hypertension, and inflammation) and
can improve diastolic heart function.53 The encouraging news is that these benefits
are often found after only modest weight loss (~5% of initial weight) and continue to
improve with increasing weight loss.53
Obesity Prevention
Epidemiological evidence supports the use of increased exercise in preventing ageassociated weight and fat gains. Regrettably, exercise recommendations to treat or
prevent obesity frequently focus only on aerobic activities. However, RT is a behaviorally feasible and efficacious alternative to endurance exercise for weight control. For
example, resting energy expenditure (REE) decreases with aging and this decrease
is closely correlated with losses in skeletal muscle mass. RT increases muscle mass
by a minimum of 1 to 2 kg in studies of sufficient duration. Theoretically, a gain of
1 kg in muscle mass should result in an REE increase of approximately 21 kcal·kg−1
of new muscle.54 In practice, RT intervention studies report REE increases in the
range of 28–218 kcal·kg−1 of muscle.54 Consequently, it is appropriate to extrapolate
that RT when sustained over years or decades will translate into clinically important
Randy W. Braith and Joseph C. Avery
35
differences in daily energy expenditure and age-associated fat gains. However, even
without a change in REE, the maintenance of muscle mass through midlife years
may prevent age-associated fat gains by promoting an active lifestyle.
Visceral Adipose Tissue
RT can reduce total body fat mass in men and women, independent of dietary caloric
restriction.54 However, regional distribution of fat may be more important to health
than the total amount of body fat. Excessive central obesity and especially visceral
adipose tissue has been linked with the development of hyperlipidemia, hypertension, insulin resistance and glucose intolerance, diabetes, and heart disease.54,55–58
Fat distributed in the arms and legs, however, appears to impose little or no risk.54
Although there may be a genetic predisposition for visceral adipose tissue, increasing age, high-fat diets, and a sedentary lifestyle are also important determinants.
Several studies have demonstrated decreases in visceral adipose tissue after RT
programs.54 Treuth and coworkers59 assessed body composition in older men using
dual energy x-ray absorptiometry and in older women using computed t­ omography60
and observed significant decreases in visceral fat following 16 weeks of RT. Ross
et al.61,62 used magnetic resonance imaging to measure regional fat losses after
­exercise combined with diet interventions. In their first study,61 both diet plus ­aerobic
exercise and diet plus RT elicited similar losses of visceral fat that were greater than
losses of whole-body subcutaneous fat. In a follow-up study,62 they isolated the effects
of endurance exercise training and RT by comparing the responses to diet alone and
diet combined with each training modality in middle-aged obese men. All three
groups lost significant amounts of total body fat, and all three groups e­ xperienced
a significantly greater visceral fat loss compared with whole-body s­ ubcutaneous fat
loss. The changes amounted to a 40% reduction in visceral fat in the RT and diet
group, 39% in the endurance training and diet group, and 32% in the diet-only group.
One study has raised the possibility of gender specificity in visceral fat reduction
in response to RT. Hunter et al.63 studied older women and men (aged 61–77 years)
after 25 weeks of supervised RT. Both sexes significantly increased muscle mass,
but men increased muscle more than women (2.8 and 1.0 kg, respectively). Similar
decreases in total body fat mass were found for the men (1.8 kg) and women
(1.7 kg). However, women lost a significant amount of visceral adipose tissue
(131–116 cm2), whereas the men did not (143–152 cm2). Similarly, women also lost
a significant amount of subcutaneous adipose tissue (254–239 cm2), but men did not
(165–165 cm2). Although more research is needed to clarify these possible genderspecific responses, the overall available body of literature supports the use of RT,
with or without aerobic exercise and with or without diet modification, as an effective intervention that contributes to the reduction of abdominal obesity.
Obesity Reduction
Studies of the efficacy of RT in the context of total body weight loss have given
mixed results. Studies utilizing more severe caloric intake restriction have not shown
gains in muscle mass,64,65 whereas RT studies with less severe caloric restriction have
shown muscle mass gains with only modest losses in body weight.60–62,66 RT studies that attempt to maintain caloric balance during the intervention typically do not
36
Resistance Training for Cardiovascular Disease
observe major changes in body weight in either gender, despite significant reductions
in fat mass and percent body fat.59,60,63 In essence, body weight does not change much
because loss of fat mass is generally offset by the gain in muscle mass. Conversely,
endurance training-induced decreases in fat mass are more likely to be associated
with reductions in body weight since there is no offsetting gain in muscle mass.
SUMMARY
In this chapter, the authors reviewed the most recent human studies that were
designed to focus on the direct mechanical effects of RT on arterial function, inflammation, oxidative stress, and dyslipidemia. Novel mechanistic insights from such
studies constitute a giant step forward in our continuing efforts to understand the
cardiovascular protective benefits of RT. For example, there is now evidence that RT
may improve arterial health in healthy middle-aged and older adults and the underlying mechanism appears to be blood flow–induced shear stimuli acting on vascular
endothelial cells. There is recent evidence that RT is effective in attenuating oxidative stress in overweight/obese persons as well as in older healthy adults. Modern
studies, properly controlled and standardized, have unequivocally demonstrated the
independent effects of RT on lipid profiles. Finally, RT-induced maintenance of skeletal muscle mass with age reduces the production of proinflammatory cytokines
such as CRP, IL-6, and TNF-α.
REFERENCES
1. Roger VL, Go AS, Lloyd-Jones DM et al. Heart disease and stroke statistics—2012
update: a report from the American Heart Association. Circulation 2012;125:e2–e220.
2. Myers J, Prakash M, Froelicher V, Do D, Partington S, Atwood JE. Exercise capacity and
mortality among men referred for exercise testing. N Engl J Med 2002;346:793–801.
3. Mora S, Cook N, Buring JE, Ridker PM, Lee IM. Physical activity and reduced risk of
cardiovascular events: potential mediating mechanisms. Circulation 2007;116:2110–8.
4. Pollock ML, Franklin BA, Balady GJ et al. AHA Science Advisory. Resistance ­exercise
in individuals with and without cardiovascular disease: benefits, rationale, safety,
and prescription. An advisory from the Committee on Exercise, Rehabilitation, and
Prevention, Council on Clinical Cardiology, American Heart Association; Position paper
endorsed by the American College of Sports Medicine. Circulation 2000;101:828–33.
5. Pescatello LS, Franklin BA, Fagard R, Farquhar WB, Kelley GA, Ray CA. American
College of Sports Medicine position stand. Exercise and hypertension. Med Sci Sports
Exerc 2004;36:533–53.
6. Cornelissen VA, Fagard RH. Effect of resistance training on resting blood pressure: a
meta-analysis of randomized controlled trials. J Hypertens 2005;23:251–9.
7. Kelley GA, Kelley KS. Progressive resistance exercise and resting blood pressure: a
meta-analysis of randomized controlled trials. Hypertension 2000;35:838–43.
8. Chobanian AV, Bakris GL, Black HR et al. The seventh report of the Joint National
Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure:
the JNC7 report. JAMA 2003;289:2560–72.
9. Beck DT, Martin JS, Emerson BD, Casey DP, Braith RW. Resistance and endurance
training improve endothelial function and vasoactive balance in young ­prehypertensives.
Med Sci Sports Exerc 2011;43:91,92.
Randy W. Braith and Joseph C. Avery
37
10. Vlachopoulos C, Aznaouridis K, Stefanadis C. Prediction of cardiovascular events and
all-cause mortality with arterial stiffness: a systematic review and meta-analysis. J Am
Coll Cardiol 2010;55:1318–27.
11. Shibata S, Levine BD. Effect of exercise training on biologic vascular age in healthy
seniors. Am J Physiol Heart Circ Physiol 2012;302:H1340–6.
12. Cameron JD, Dart AM. Exercise training increases total systemic arterial compliance in
humans. Am J Physiol 1994;266:H693–701.
13. Edwards DG, Schofield RS, Magyari PM, Nichols WW, Braith RW. Effect of ­exercise
training on central aortic pressure wave reflection in coronary artery disease. Am J
Hypertens 2004;17:540–3.
14. Bertovic DA, Waddell TK, Gatzka CD, Cameron JD, Dart AM, Kingwell BA. Muscular
strength training is associated with low arterial compliance and high pulse pressure.
Hypertension 1999;33:1385–91.
15. Miyachi M, Donato AJ, Yamamoto K et al. Greater age-related reductions in central
arterial compliance in resistance-trained men. Hypertension 2003;41:130–5.
16. Cortez-Cooper MY, DeVan AE, Anton MM et al. Effects of high intensity r­ esistance training on arterial stiffness and wave reflection in women. Am J Hypertens 2005;18:930–4.
17. Miyachi M, Kawano H, Sugawara J et al. Unfavorable effects of resistance training on central arterial compliance: a randomized intervention study. Circulation
2004;110:2858–63.
18. Casey DP, Beck DT, Braith RW. Progressive resistance training without volume increases
does not alter arterial stiffness and aortic wave reflection. Exp Biol Med (Maywood)
2007;232:1228–35.
19. Fjeldstad AS, Bemben MG, Bemben DA. Resistance training effects on arterial compliance in premenopausal women. Angiology 2009;60:750–6.
20. Heffernan KS, Fahs CA, Iwamoto GA et al. Resistance exercise training reduces central
blood pressure and improves microvascular function in African American and white
men. Atherosclerosis 2009;207:220–6.
21. Kingsley JD, Figueroa A. Effects of resistance exercise training on resting and postexercise forearm blood flow and wave reflection in overweight and obese women. J Hum
Hypertens 2011;26(11):684–90.
22. Olson TP, Dengel DR, Leon AS, Schmitz KH. Moderate resistance training and vascular
health in overweight women. Med Sci Sports Exerc 2006;38:1558–64.
23. Rakobowchuk M, McGowan CL, de Groot PC et al. Effect of whole body resistance
training on arterial compliance in young men. Exp Physiol 2005;90:645–51.
24. McEniery CM, Yasmin, Hall IR, Qasem A, Wilkinson IB, Cockcroft JR. Normal vascular aging: differential effects on wave reflection and aortic pulse wave velocity: the
Anglo-Cardiff Collaborative Trial (ACCT). J Am Coll Cardiol 2005;46:1753–60.
25. Miyachi M, Tanaka H, Kawano H, Okajima M, Tabata I. Lack of age-related
decreases in basal whole leg blood flow in resistance-trained men. J Appl Physiol
2005;99:1384–90.
26. Anton MM, Cortez-Cooper MY, DeVan AE, Neidre DB, Cook JN, Tanaka H. Resistance
training increases basal limb blood flow and vascular conductance in aging humans.
J Appl Physiol 2006;101:1351–5.
27. Rakobowchuk M, McGowan CL, de Groot PC, Hartman JW, Phillips SM, MacDonald
MJ. Endothelial function of young healthy males following whole body resistance
­training. J Appl Physiol 2005;98:2185–90.
28. Longhurst JC, Stebbins CL. The isometric athlete. Cardiol Clin 1992;10:281–94.
29. Gurovich AN, Braith RW. Analysis of both pulsatile and streamline blood flow patterns
during aerobic and resistance exercise. Eur J Appl Physiol 2012;112(11):3755–64.
30. Ridker PM. C-reactive protein: eighty years from discovery to emergence as a major risk
marker for cardiovascular disease. Clin Chem 2009;55:209–15.
38
Resistance Training for Cardiovascular Disease
31. Libby P, Ridker PM. Novel inflammatory markers of coronary risk: theory versus practice. Circulation 1999;100:1148–50.
32. Brooks N LJ, Gordon PL, Roubenoff R, Nelson ME. Strength training improves muscle
quality and insulin sensitivity in Hispanic older adults with type 2 diabetes. Int J Med
Sci 2007;4:19–27.
33. Donges CE, Duffield R, Drinkwater EJ. Effects of resistance or aerobic exercise training on interleukin-6, C-reactive protein, and body composition. Med Sci Sports Exerc
2010;42:304–13.
34. Martins RA, Neves AP, Coelho-Silva MJ, Verissimo MT, Teixeira AM. The effect of
aerobic versus strength-based training on high-sensitivity C-reactive protein in older
adults. Eur J Appl Physiol 2010;110:161–9.
35. Ogawa K, Sanada K, Machida S, Okutsu M, Suzuki K. Resistance exercise traininginduced muscle hypertrophy was associated with reduction of inflammatory markers in
elderly women. Mediators Inflamm 2010;2010:171023.
36. Olson TP, Dengel DR, Leon AS, Schmitz KH. Changes in inflammatory biomarkers
following one-year of moderate resistance training in overweight women. Int J Obes
(Lond) 2007;31:996–1003.
37. White LJ, Castellano V, Mc Coy SC. Cytokine responses to resistance training in people
with multiple sclerosis. J Sports Sci 2006;24:911–4.
38. Klimcakova E, Polak J, Moro C et al. Dynamic strength training improves insulin sensitivity without altering plasma levels and gene expression of adipokines in subcutaneous
adipose tissue in obese men. J Clin Endocrinol Metab 2006;91:5107–12.
39. Levinger I, Goodman C, Peake J et al. Inflammation, hepatic enzymes and resistance
training in individuals with metabolic risk factors. Diabet Med 2009;26:220–7.
40. Swift DL, Johannsen NM, Earnest CP, Blair SN, Church TS. Effect of different doses of
aerobic exercise training on total bilirubin levels. Med Sci Sports Exerc 2012;44:569–74.
41. Mora S, Lee IM, Buring JE, Ridker PM. Association of physical activity and body
mass index with novel and traditional cardiovascular biomarkers in women. JAMA
2006;295:1412–9.
42. Church TS, Earnest CP, Thompson AM et al. Exercise without weight loss does not
reduce C-reactive protein: the INFLAME study. Med Sci Sports Exerc 2010;42:708–16.
43. Parise G, Brose AN, Tarnopolsky MA. Resistance exercise training decreases oxidative
damage to DNA and increases cytochrome oxidase activity in older adults. Exp Gerontol
2005;40:173–80.
44. Parise G, Phillips SM, Kaczor JJ, Tarnopolsky MA. Antioxidant enzyme activity is upregulated after unilateral resistance exercise training in older adults. Free Radic Biol
Med 2005;39:289–95.
45. Vincent KR, Vincent HK, Braith RW, Lennon SL, Lowenthal DT. Resistance exercise
training attenuates exercise-induced lipid peroxidation in the elderly. Eur J Appl Physiol
2002;87:416–23.
46. Vincent HK, Bourguignon C, Vincent KR. Resistance training lowers exercise-induced
oxidative stress and homocysteine levels in overweight and obese older adults. Obesity
(Silver Spring) 2006;14:1921–30.
47. Brinkmann C, Chung N, Schmidt U et al. Training alters the skeletal muscle antioxi­
dative capacity in non-insulin-dependent type 2 diabetic men. Scand J Med Sci Sports
2011;22(4):462–70.
48. Bhatia S, Shukla R, Venkata Madhu S, Kaur Gambhir J, Madhava Prabhu K. Antioxidant
status, lipid peroxidation and nitric oxide end products in patients of type 2 diabetes
mellitus with nephropathy. Clinical biochemistry 2003;36:557–62.
49. Garcia-Lopez D, Hakkinen K, Cuevas MJ et al. Effects of strength and endurance training on antioxidant enzyme gene expression and activity in middle-aged men. Scand
J Med Sci Sports 2007;17:595–604.
Randy W. Braith and Joseph C. Avery
39
50. Kelley GA, Kelley KS. Impact of progressive resistance training on lipids and lipoproteins in adults: another look at a meta-analysis using prediction intervals. Prev Med
2009;49:473–5.
51. Pischon T, Girman CJ, Sacks FM, Rifai N, Stampfer MJ, Rimm EB. Non-high-density
lipoprotein cholesterol and apolipoprotein B in the prediction of coronary heart disease
in men. Circulation 2005;112:3375–83.
52. da Silva JL, Vinagre CG, Morikawa AT, Alves MJ, Mesquita CH, Maranhao RC.
Resistance training changes LDL metabolism in normolipidemic subjects: a study with
a nanoemulsion mimetic of LDL. Atherosclerosis 2011;219:532–7.
53. Klein S, Burke LE, Bray GA et al. Clinical implications of obesity with specific focus
on cardiovascular disease: a statement for professionals from the American Heart
Association Council on Nutrition, Physical Activity, and Metabolism: endorsed by the
American College of Cardiology Foundation. Circulation 2004;110:2952–67.
54. Braith RW, Stewart KJ. Resistance exercise training: its role in the prevention of
­cardiovascular disease. Circulation 2006;113:2642–50.
55. American College of Sports Medicine Position Stand. The recommended quantity and
quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Med Sci Sports Exerc 1998;30:975–91.
56. Hunter GR, Kekes-Szabo T, Snyder SW, Nicholson C, Nyikos I, Berland L. Fat distribution, physical activity, and cardiovascular risk factors. Med Sci Sports Exerc
1997;29:362–9.
57. Hurley BF, Roth SM. Strength training in the elderly: effects on risk factors for agerelated diseases. Sports Med 2000;30:249–68.
58. Williams MJ, Hunter GR, Kekes-Szabo T, Snyder S, Treuth MS. Regional fat distribution in women and risk of cardiovascular disease. Am J Clin Nutr 1997;65:855–60.
59. Treuth MS, Ryan AS, Pratley RE et al. Effects of strength training on total and regional
body composition in older men. J Appl Physiol 1994;77:614–20.
60. Treuth MS, Hunter GR, Kekes-Szabo T, Weinsier RL, Goran MI, Berland L. Reduction
in intra-abdominal adipose tissue after strength training in older women. J Appl Physiol
1995;78:1425–31.
61. Ross R, Rissanen J. Mobilization of visceral and subcutaneous adipose tissue in response
to energy restriction and exercise. Am J Clin Nutr 1994;60:695–703.
62. Ross R, Rissanen J, Pedwell H, Clifford J, Shragge P. Influence of diet and exercise on
skeletal muscle and visceral adipose tissue in men. J Appl Physiol 1996;81:2445–55.
63. Hunter GR, Bryan DR, Wetzstein CJ, Zuckerman PA, Bamman MM. Resistance training and intra-abdominal adipose tissue in older men and women. Med Sci Sports Exerc
2002;34:1023–8.
64. Donnelly JE, Jacobsen DJ, Jakicic JM, Whatley JE. Very low calorie diet with concurrent
versus delayed and sequential exercise. Int J Obes Relat Metab Disord 1994;18:469–75.
65. Wadden TA, Vogt RA, Andersen RE et al. Exercise in the treatment of obesity: effects of
four interventions on body composition, resting energy expenditure, appetite, and mood.
J Consult Clin Psychol 1997;65:269–77.
66. Marks BL, Ward A, Morris DH, Castellani J, Rippe JM. Fat-free mass is maintained
in women following a moderate diet and exercise program. Med Sci Sports Exerc
1995;27:1243–51.
4
Resistance Exercise
Interventions across
the Cancer Control
Continuum
Brian C. Focht, Alexander R. Lucas,
and Steven K. Clinton
CONTENTS
Resistance Exercise–Cancer Study Characteristics.................................................. 47
Feasibility of Resistance Exercise Interventions in Cancer
Patients and Survivors............................................................................................... 48
Efficacy of Resistance Exercise Interventions During and Following
Cancer Treatment...................................................................................................... 48
Resistance Exercise Interventions in Breast Cancer Patients and Survivors............ 48
Resistance Exercise Interventions in Prostate Cancer Patients Undergoing
Active Treatment....................................................................................................... 51
Resistance Exercise in Head and Neck Cancer Survivors........................................ 53
Resistance Exercise in Lung Cancer Survivors........................................................ 54
Resistance Exercise in Mixed Cancer Sample.......................................................... 55
Efficacy of Resistance Exercise During and Following Cancer Treatment:
Summary and Synthesis............................................................................................ 56
Evidence-Based Resistance Exercise Prescription Recommendations for
Cancer Patients and Survivors.................................................................................. 56
Variability in the Effects of Resistance Exercise across Health, Fitness, and
Quality of Life Outcomes.........................................................................................60
Considerations for Future Resistance Exercise Intervention Research During
and Following Cancer Treatment.............................................................................. 61
References................................................................................................................. 62
Regular resistance exercise (RE) participation consistently yields meaningful
improvements in muscular strength, hypertrophy, and endurance.1 In addition
to these well-established increases in muscular fitness outcomes, accumulating
­evidence s­ upports the therapeutic value of RE as an adjuvant treatment in a variety
of chronic disease conditions including cardiovascular disease, osteoarthritis, and
41
42
Resistance Exercise Interventions across the Cancer Control Continuum
diabetes.2 Collectively, these findings provide support for the potentially beneficial role of RE interventions in the management of a variety of prevalent chronic
diseases.
Given that cancer patients and survivors are at increased risk for developing
chronic diseases such as heart disease, diabetes, and osteoporosis,3 RE interventions may hold considerable promise as a supportive care intervention during and
following cancer treatment.4–7 Exercise has been linked with significant, clinically
meaningful improvements in fitness, health, and quality of life (QoL) outcomes in
cancer patients and survivors. Furthermore, recent exercise training guidelines8 suggest that aerobic, resistance, and flexibility exercises are safe exercise interventions
with documented feasibility and efficacy for implementing among cancer patients
and survivors.
Despite mounting evidence of the potential therapeutic value of RE, the majority
of extant exercise–cancer research has focused on the effects of aerobic forms of
exercise.6,9 Although there is presently considerably more empirical evidence supporting the beneficence of aerobic exercise relative to RE across the cancer control
continuum, the limited number of studies addressing RE suggest that it is a promising exercise intervention that results in meaningful improvements in a variety of
clinically relevant health and QoL of outcomes for cancer patients and survivors.
Notably, RE has been shown to be a potent behavioral intervention approach for
countering the adverse effects of chemotherapy and hormone therapy on both physiologic (muscle mass, muscle strength, bone density, and body composition) and QoL
outcomes (fatigue, pain) in cancer patients and survivors.4,5,7,10,11
Consistent with the emerging interest in the RE–cancer relationship, recent
reviews have addressed the efficacy of RE interventions in selected cancer populations (e.g., breast cancer)12 and phases of the cancer control continuum (e.g.,
survivorship).13 Publication of these reviews demonstrates increased recognition
by both researchers and clinicians of the potential utility of implementing RE as
an adjuvant behavioral intervention in comprehensive, multimodal cancer control
approaches. However, given the focus on specific cancer populations and phases of
treatment in these prior reviews, knowledge of the potential efficacy of RE across
the entire cancer control continuum for patients and/or survivors of various forms
of cancer remains limited. Additionally, syntheses of the RE–cancer relationship
have included studies that combined RE with aerobic exercise, which limits the
ability to appropriately delineate the independent benefits of RE alone from the
potentially synergistic effects of resistance and aerobic exercise for cancer patients
and survivors. Hence, a primary purpose of this chapter is to summarize knowledge of the independent effects of RE interventions in the treatment of cancer
patients and/or survivors. The overall objectives of this chapter are to (1) summarize the feasibility of implementing RE interventions during and following
cancer treatment; (2) synthesize and quantify the effects of RE interventions on
clinically relevant health, fitness, and QoL outcomes across the cancer control continuum through calculation of Cohen’s d effect sizes; (3) provide evidence-based
recommendations for RE prescription and program design to cancer patients and
survivors; and (4) highlight key considerations for future inquiry addressing the
RE–cancer relationship.
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
43
To achieve these purposes, we have adapted the methods, narrative study
s­ ummaries, and effect size calculations from our recent systematic review a­ ddressing
the effects of RE interventions during and following cancer treatment.14 We also
complemented this synthesis by providing recommendations for RE prescription and
identifying important areas of future inquiry in RE–cancer research. The methods
for study identification and inclusion have been summarized in detail in our prior
review.14 However, a brief summary is provided here as well. Studies were addressed
in the systematic review and present chapter, if they specifically examined an RE
alone as an exercise intervention in individuals during or following the completion
of cancer treatment.
Studies that used RE in combination with other exercise (i.e., aerobic exercise
or yoga), lifestyle, or behavioral interventions (i.e., diet or psychosocial counseling)
were excluded from the review. Studies targeting individuals diagnosed with cancer
prior to beginning treatment, cancer patients who were actively undergoing cancer
treatment, and individuals who had successfully completed cancer treatment with
curative intent were included irrespective of gender, tumor type, or type of cancer
treatment. Additionally, for the purposes of both the prior systematic review and this
chapter, RE was defined as regular participation in a structured, repetitive strength
training program over an extended period of time with the goal of improving select
desired health, fitness, and QoL outcomes.
RESISTANCE EXERCISE–CANCER STUDY CHARACTERISTICS
As reported previously,14 a total of 15 studies involving 1,077 participants met the
inclusion criteria for the systematic review. Six studies addressed RE interventions
during treatment.15–20 Based on Courneya and Friedenreich’s11 well-established
Framework Physical Exercise Across the Cancer Experience model for organizing and exploring the effects of exercise on cancer control outcomes (prevention,
detection, buffering, coping, rehabilitation, palliation, or health promotion) across
the pre- and postcancer diagnosis time frame, all of the RE intervention studies focused on the coping and rehabilitation phases of the cancer control continuum. Of the studies examining the effects of RE during active cancer treatment,
four were conducted during androgen deprivation therapy (ADT),16–19 one during
­chemotherapy,15 and two during radiation therapy.19,20 The remaining eight studies
focused on RE in participants following the completion of active cancer treatment with curative intent. Studies examined samples of individuals diagnosed with
breast cancer15,21–25 (n = 6), prostate cancer (PC; n = 4),16–19 head and neck cancer
(n = 3),20,26,27 lung cancer (LC; n = 1),28 and one study examined a mixed sample
comprised of individuals diagnosed with various types of cancer (i.e., bladder, cervical, endometrial, uterine, and melanoma).29 Sample sizes in the studies ranged
from 10 to 242 participants. Eleven studies implemented center-based, supervised,
progressive RE interventions. Four studies implemented RE interventions involving a combination of supervised and unsupervised RE.20,24,25,29 The RE intervention
characteristics included training loads ranging from 25% to 80% of one repetition
maximum, sets ranging from 1 to 3 per exercise, and the intervention duration
ranging from 12 weeks to 12 months.
44
Resistance Exercise Interventions across the Cancer Control Continuum
FEASIBILITY OF RESISTANCE EXERCISE INTERVENTIONS
IN CANCER PATIENTS AND SURVIVORS
To evaluate the feasibility of delivering RE interventions during and following ­cancer
treatment, we examined recruitment, retention, and adherence rates reported in each
study included in the systematic review.14 With regard to participant recruitment,
an average of 44% (range = 9%–83%) of individuals who were either determined
eligible or screened for inclusion participated in the studies. Calculation of retention values revealed that 85% (range = 67%–100%) of participants who initiated the
study completed postintervention follow-up assessments. Adherence to supervised
RE sessions was 84% (range = 68%–100%).
EFFICACY OF RESISTANCE EXERCISE INTERVENTIONS
DURING AND FOLLOWING CANCER TREATMENT
As adapted from our systematic review,14 a brief summary of each study’s sample,
outcome assessments, recruitment, retention, adherence information, and the effect
sizes accompanying changes in the physiologic and QoL outcomes, organized by cancer site, are provided in the following section of this chapter. Cohen’s d effect sizes30
accompanying changes in the outcomes were either obtained directly from the studies themselves when reported or calculated using statistical information p­ rovided in
the study. Cohen’s d effect sizes are classified as: small = 0.20; moderate = 0.50; and
large = 0.80. Due to the fact that four of the 15 studies were ­nonrandomized trials
that did not include a control or comparison group in the experimental design, effect
sizes were calculated by taking the difference of the mean values obtained at baseline and postintervention follow-up assessments and dividing by the pooled standard deviation. The sign of effect sizes was set so that only positive values indicate
improvement in that respective outcome. Thus, positive effect size values indicate
that RE resulted in improvement in an outcome whereas negative effect sizes reflect
unfavorable changes in an outcome.
RESISTANCE EXERCISE INTERVENTIONS IN BREAST
CANCER PATIENTS AND SURVIVORS
In a randomized, controlled crossover design trial, Schmitz et al.23 compared the
effects of a 6-month progressive RE intervention with those of a delayed t­ reatment
control group in a sample of 85 breast cancer survivors. Assessments of body
­composition were obtained at baseline as well as 6- and 12-month follow-up.
Muscular strength and QoL were assessed at baseline and 6-month follow-up. The
QoL outcomes were reported in a separate publication.31 Of 132 eligible participants for the study, 85 women (64%) were recruited into the study and completed
the baseline assessments. Approximately 91% of the women randomized into the
RE intervention completed the 6-month follow-up assessment and 80% completed
the 12-month follow-up. Average participant adherence, measured via attendance
at the supervised RE sessions, was 80% across the 6-month RE intervention.
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
45
There were four mild to moderate adverse events related to the RE intervention
­involving muscle and/or joint strains to the back, legs, and wrist. No serious adverse
events related to the RE intervention was reported. The RE intervention yielded
improvements in muscular strength (leg press: d = 1.70 at 6 months and chest press:
d = 2.45 at 6 months), body fat percentage (d = −0.87 at 6 months and d = −1.69
at 12 months), lean body mass (d = 1.14 at 6 months and d = 1.78 at 12 months),
and global (d = 0.34), physical (d = 0.34), and psychosocial (d = 0.31) indices of
QoL. Additionally, RE was not associated with an increase in arm swelling or
­self-reported lymphedema symptoms.
Courneya et al.15 conducted a multicenter randomized controlled trial comparing
the effects of RE, aerobic exercise, and usual care treatment approaches in a sample
of 242 BC patients undergoing adjuvant chemotherapy. Assessments of ­muscular
strength, aerobic capacity, and multiple indices of body composition (i.e., body fat
­percentage, lean body mass, and fat mass) were obtained at baseline and within
4 weeks following the completion of chemotherapy. Assessments of self-reported
outcomes including cancer-specific QoL (FACT-Anemia), fatigue, self-esteem,
­
depression, and anxiety were obtained at baseline, midpoint of chemotherapy, and
within 4 weeks of chemotherapy completion. A total of 242 of 736 eligible ­participants
(33%) were recruited into the trial. Of the 82 participants randomly assigned to the
RE intervention, approximately 92% completed both the midpoint and posttreatment
follow-up assessments. Additionally, women in the RE intervention completed 68%
of their assigned supervised RE sessions during the trial. No adverse events related
to the RE intervention were reported. Results revealed that RE resulted in moderate to large statistically significant improvements in leg press strength (d = 0.69)
and chest press strength (d = 0.98). Small improvements in lean body mass (d =
0.21) and fat mass (d = 0.06) were observed, and no change in body fat percentage
(d = 0.06) was documented. Small changes in self-esteem (midpoint d = −0.06 and
posttreatment d = 0.30), FACT-Anemia (midpoint d = 0.02 and posttreatment d =
0.36), fatigue (midpoint d = 0.11 and posttreatment d = 0.20), depression (midpoint
d = 0.12 and posttreatment d = 0.33), and anxiety (midpoint d = 0.41 and posttreatment d = 0.45) emerged with exposure to the RE intervention. It is also important to
acknowledge that women randomized to the RE intervention demonstrated superior
chemotherapy completion rates relative to both the aerobic exercise and usual care
treatment groups. Furthermore, RE was not associated with an increase in arm swelling or self-reported lymphedema symptoms.
In a randomized controlled trial, Schmitz et al.24 compared the effects of a 1-year
RE intervention with those of a no exercise control group in 154 breast cancer s­ urvivors
at risk for lymphedema. Assessments of muscular strength and multiple measures of
body composition (body fat percentage, lean body mass, and fat mass) were obtained
at baseline and 1-year follow-up. A total of 154 of 1,802 screened, eligible participants (9%) were randomized into the trial. Of the 77 participants ­randomly assigned
to the RE intervention, approximately 86% completed both the 1-year follow-up
assessment. Adherence, calculated as attendance at prescribed ­sessions, was 79% in
the RE intervention. No adverse events related to the RE ­intervention were reported.
Results revealed that RE resulted in large, statistically significant improvements in
leg press strength (d = 0.88) and chest press strength (d = 1.04). Conversely, small
46
Resistance Exercise Interventions across the Cancer Control Continuum
to negligible improvements in lean body mass (d = 0.08), fat mass (d = 0.11), and
body fat percentage (d = 0.06) were observed following RE. Importantly, women
participating in the progressive RE intervention did not experience an increase in risk
of onset of lymphedema or self-reported lymphedema symptoms relative to the no
exercise control group.
In a single-blinded, randomized controlled trial, Winters-Stone et al.25 examined
the effects of a 12-month RE intervention with those of a placebo exercise intervention involving stretching and relaxation techniques within a sample of 106 older,
postmenopausal breast cancer survivors. Assessments of muscular strength, grip
strength, physical function, and QoL were obtained at baseline as well as at 6- and
12-month follow-up. Body composition and bone mineral density were assessed at
baseline and 6- and 12-month follow-up. However, descriptive statistics for all outcomes were only provided for the baseline and 12-month assessments. The effects
of the RE intervention on the body composition and bone mineral density outcomes
were reported in a separate publication (2011). Of 246 eligible participants for the
study, 106 women (43%) were recruited into the study and completed the baseline
assessments. A total of 64% of the women randomized into the RE intervention completed the 6-month follow-up assessment and 69% completed the 12-month followup. Average participant adherence to the supervised RE sessions was 76% across
the 12-month RE intervention, while adherence to the unsupervised, home-based
RE sessions was 23%. No serious adverse events related to the RE intervention were
reported. The RE intervention resulted in improvements in muscular strength (leg
press: d = 0.68 and bench press: d = 0.50). Although not statistically significant,
improvements in performance (chair stand: d = 0.68) and self-reported (d = 0.25)
physical function emerged following RE. No improvements in fatigue (d = −0.04)
accompanied RE. Furthermore, no significant differences emerged for the body
composition (lean body mass: d = 0.09 and body fat percentage: d = 0.00) and bone
mineral density measures (hip: d = −0.03, spine: d = 0.03, trochanter: d = −0.03).
However, analyses of these outcomes did reveal that women in the RE demonstrated
superior preservation of bone mineral density and lean body mass relative to the
stretching control group across the 12-month trial. Additionally, RE was not associated with an increase in arm swelling or self-reported lymphedema symptoms.
Musanti21 conducted a four-arm randomized controlled trial comparing the effects
of RE alone with those aerobic exercise alone, flexibility training, and a combination
of RE and aerobic exercise in a sample of 42 BC survivors. Assessments of muscular
strength and endurance, aerobic capacity, body composition, physical self-esteem,
and select psychological and QoL outcomes were assessed prior to and following the
12-week home-based exercise interventions. A total of 314 breast cancer survivors
were screened for participation and 42 women (13%) were recruited into the study
and completed the baseline assessments. A total of 88% of the women randomized
into the study completed the follow-up assessments. Average participant adherence
within the RE intervention was 91%. No serious adverse events related to the RE
intervention were reported. The RE intervention resulted in large improvements in
muscular strength (chest press: d = 1.06 and bicep curl: d = 1.08). Small effect size
improvements were observed for aerobic fitness (d = 0.23) and fat mass (d = 0.23).
The RE intervention also yielded moderate to large effect size improvements in the
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
47
various physical self-esteem domains (d = 0.70–1.90). No significant improvements
in fatigue, depression, or anxiety were observed following the RE. However, those
participants reporting clinically significant elevations at baseline demonstrated large
improvements in fatigue (d = 1.50) and depression (d = 0.87) following the RE
intervention.
In a two-arm randomized trial, Schmidt et al.22 compared the effects of a
6-month gentle supervised RE intervention (low intensity, volume, and load)
with those of an exercise intervention involving chair- or floor-based exercise in
a sample of 38 BC survivors. Assessments of muscular strength, aerobic endurance, and QoL were obtained at baseline, 3- and 6-month follow-up. Of 60 participants screened for the study, 38 women (63%) were enrolled and completed the
baseline assessments. Approximately 86% of the women randomized into the RE
intervention completed the 6-month follow-up assessment. Adherence to the RE
intervention was not reported. No adverse events related to the RE intervention
were reported. No descriptive statistics were provided for the changes in muscular
strength or aerobic capacity. However, the RE intervention did yield improvements
in QoL (3 months: d = 0.44 and 6 months: d = 1.14) and fatigue (3 months: d =
0.82 and 6 months: d = 0.98).
Overall results from six randomized controlled trials demonstrate the feasibility
and efficacy of RE as an exercise intervention for BC patients undergoing chemotherapy and BC survivors following active cancer treatment. RE yielded moderate
to large improvements in muscular strength and small to moderate improvements
in selected dimensions of QoL. There was considerable variability in the effects of
RE on body composition measures across studies of BC patients and survivors with
effects ranging from virtually negligible change15,24 to large effect size improvements.23 It is particularly notable that RE participation did not increase the risk
of developing upper extremity lymphedema nor did it exacerbate arm swelling or
self-reported lymphedema symptoms. Thus, evidence from extant trials examining RE demonstrate that RE is a safe form of exercise for BC patients and survivors that results in clinically meaningful improvements in relevant physiologic and
QoL outcomes.
RESISTANCE EXERCISE INTERVENTIONS IN PROSTATE
CANCER PATIENTS UNDERGOING ACTIVE TREATMENT
In a randomized controlled trial, Segal et al.18 compared the effects of a 12-week
center-based, supervised RE intervention with those of a wait-list control group in a
sample of 155 PC patients on ADT. Assessments of muscular endurance and body
composition, fatigue (FACT-F), and cancer-specific QoL (FACT-P) were obtained at
baseline and 12-week follow-up. A total of 155 of 507 eligible patients (31%) were
randomized into the trial. Approximately 90% of participants in the RE intervention completed the 12-week follow-up assessment, and average attendance to the
prescribed RE sessions was 79% during the 12-week intervention. No adverse events
related to the RE intervention were reported. RE resulted in significant increases
in upper and lower body muscular endurance. However, information necessary to
calculate effect sizes for improvements in muscular endurance were not provided.
48
Resistance Exercise Interventions across the Cancer Control Continuum
No significant changes in body composition were observed. The descriptive statistics necessary to calculate the effect sizes for body composition were not provided.
However, RE resulted in statistically significant, moderate in magnitude improvements in fatigue (d = 0.52) and cancer-specific QoL (d = 0.55).
Galvao et al.16 conducted a single-arm, uncontrolled trial examining the effects
of a center-based, supervised 20-week progressive RE intervention in a sample of
10 men undergoing ADT. Assessments of muscular strength, muscular endurance,
body ­composition, bone mineral density, and physical function (6-min walk, 400-m
walk, balance, stair climb, and chair stand) were obtained at baseline and 20-week
follow-up. A total of 11 of 14 eligible men (79%) participated in the study. Ten participants (91%) completed the 20-week follow-up assessment. Adherence to the
prescribed RE sessions was not reported. No adverse events related to the RE intervention were reported. The RE intervention yielded improvements in upper (d = 1.82)
and lower body muscular strength (d = 1.56) and upper (d = 2.80) and lower body
muscular endurance (d = 2.90). Conversely, the RE intervention had negligible effects
on lean body mass (d = 0.03), fat mass (d = 0.09), body fat percentage (d = 0.01), and
bone mineral density (d = 0.03). RE also resulted in improvements in 6-min walk
(d = 0.82), 400-m walk (d = 0.29), stair climb (d = 0.21), and chair stand (d = 1.29,
and balance (d = 1.08) performance. It is also important to acknowledge that ancillary analyses of endocrine and immune responses during the trial demonstrated that
serum testosterone and prostate-specific antigen levels did not increase following the
progressive RE intervention. Thus, these findings indicate that a progressive, intensive
RE intervention does not undermine the therapeutic androgen ablation effect of ADT.
Segal et al.19 conducted a randomized controlled trial comparing the effects of
24-week, center-based, supervised RE, aerobic exercise, and usual care interventions
in a sample of 121 PC patients receiving radiation therapy and ADT (approximately
60% of the sample). Assessments of muscular strength, aerobic capacity, and body
composition (body fat percentage) were obtained at baseline and 6-month follow-up.
Assessments of cancer-specific QoL (FACT-P) and fatigue (FACT-F) were obtained
at baseline and 3- and 6-month follow-up. A total of 121 of 325 eligible patients
(37%) participated in the study. Approximately 83% of men randomized into the
RE intervention completed the 3- and 6-month follow-up assessments, and average adherence to the RE intervention was 88%. There was one mild to moderate
adverse event related to the RE intervention involving chest pain following exercise.
However, no serious adverse events related to the RE intervention were reported.
The RE intervention produced increases in upper body (d = 0.90) and lower body
(d = 0.74) muscular strength. However, RE resulted in negligible changes in aerobic
capacity (d = 0.13), body fat percentage (d = 0.06), or physical disability (3 months:
d = 0.16; 12 months: d = 0.26). The aerobic exercise intervention resulted in negligible changes in upper body strength (d = 0.23), lower body strength (d = 0.04), aerobic
capacity (d = 0.21), body fat percentage (d = 0.20), or physical disability (3 months:
d = 0.11; 12 months: d = 0.01).
Hansen et al.17 conducted a single-arm uncontrolled trial examining the effects
of a center-based, supervised 12-week RE intervention in a sample of 10 men on
(n = 5) or off (n = 5) ADT. Assessments of muscular strength, body composition
(muscle volume), physical function (6-min walk and timed up and go performance),
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
49
and fatigue (FACT-F) were obtained at baseline and 12-week follow-up. The total
number of eligible men prescreened for inclusion in the study was not reported. Of
the 16 men included in the study, 10 (63%) completed the 12-week follow-up assessment, and adherence to the supervised exercise sessions among the 10 participants
who completed the study was 100%. No adverse events related to the RE intervention
were reported. The RE intervention resulted in statistically significant improvements
in muscular strength (d = 0.57), 6-min walk performance (d = 0.41), and timed up
and go performance (d = 0.45). However, only negligible changes in muscle volume
(d = 0.11) and fatigue (d = 0.15) were observed following RE.
Collectively, findings from the four studies addressing the effects of RE in PC
patients undergoing active cancer treatment (e.g., ADT and/or radiation therapy)
revealed that RE is a safe, feasible exercise intervention approach that results in significant, clinically meaningful improvements in physiologic and QoL outcomes. The
adverse effects accompanying ADT (declines in muscular strength, lean body mass,
and physical function) and radiation therapy (fatigue) in PC patients are well established.10 Consequently, the significant improvements in these outcomes observed
following RE provides support the efficacy of this mode of exercise RE as a complementary therapy for countering the adverse effects frequently associated with PC
treatment.
RESISTANCE EXERCISE IN HEAD AND NECK CANCER SURVIVORS
McNeely et al.26 conducted a two-arm, randomized controlled pilot trial comparing the effects of a progressive RE intervention with those of a usual care range of
motion exercise/stretching therapy program in 20 head and neck cancer patients.
Assessments of self-reported shoulder function, pain, and disability (SPADI),32
­cancer-specific QoL (FACT-H&N), and shoulder joint range of motion were obtained
at baseline and 12-week follow-up during the pilot trial. A total of 20 of 25 (80%)
eligible patients were randomized into the study. Eight of the 10 participants (80%)
randomized to the RE intervention completed the 12-week follow-up assessment,
and adherence to prescribed RE sessions was 93%. There was one mild to moderate
adverse event related to the RE intervention involving nausea following exercise.
However, no serious adverse events related to the RE intervention were reported.
Results revealed significant improvements in the SPADI total score (d = 0.62),
SPADI pain score (d = 0.79), and external rotation range of motion (d = 1.43) of the
shoulder joint following RE. The RE intervention also resulted in a non-significant,
moderate magnitude decrease in the SPADI disability score (d = 0.47).
In a single-blind, two-arm randomized controlled trial, McNeely et al.27 compared a 12-week progressive RE with a standard of care physical therapy in a
sample of 52 head and neck cancer patients. Assessments of muscular strength,
SPADI, shoulder joint range of motion, and cancer-specific QoL (FACT-Anemia
and the Neck Dissection Impairment Index) were assessed at baseline and 12-week
follow-up. A total of 52 of 110 eligible patients (47%) were randomized into the
trial. Twenty-two of the 25 patients (88%) randomized into the RE intervention
completed the 12-week follow-up assessment, and adherence to prescribed RE
sessions was 95%. There was one mild to moderate adverse event related to the
50
Resistance Exercise Interventions across the Cancer Control Continuum
RE intervention involving a soft tissue injury to the back during exercise. However,
no serious adverse events related to the RE intervention were reported. Results
revealed that the RE intervention resulted in significant improvements in muscular
strength (chest press d = 0.37, seated row d = 0.42), muscular endurance (d = 0.66),
pain (d = 0.84), and disability (d = 0.77).
Rogers et al.20 conducted a two-arm, randomized controlled pilot trial examining
the preliminary efficacy of a progressive 12-week RE intervention (6 weeks supervised and 6 weeks of home-based RE) with those of a usual care approach among
15 head and neck cancer patients undergoing radiation therapy. Assessments of muscular strength, grip strength, body composition, physical function, and QoL were
obtained at baseline, 6- and 12-week follow-up. A total of 15 of 238 (16%) patients
who were assessed for eligibility were randomized into the trial. Approximately
87% of patients randomized to the RE intervention completed the 12-week followup assessment. Adherence to prescribed RE sessions was 83% during the supervised
phase and 53% during the home-based phase of the RE intervention. No adverse
events related to the RE intervention were reported. RE resulted in small to moderate effect size improvements in muscular strength (d = 0.15) and physical function
(d = 0.51) at 12-week follow-up. Examination of the effect sizes (d = −0.58 to 0.21)
accompanying changes in the body composition and QoL revealed no meaningful
improvement in any of these outcomes relative to baseline at 12-week follow-up.
Indeed, select outcomes such as lean body mass and general and disease-specific
QoL exhibited unfavorable changes from baseline. However, it should be noted that
moderate to large between-group effect sizes favoring the RE intervention were
observed for physical function, fatigue, and QoL. Thus, unfavorable changes in these
outcomes were significantly attenuated in participants assigned to the RE intervention relative to those which emerged in the usual care control group.
Together, these findings demonstrate that progressive RE is a safe feasible intervention to implement among postoperative head and neck cancer patients. Evidence
from the three trials support preliminary efficacy of RE for eliciting improvements
in pain, disability, QoL, muscular fitness, and range of motion outcomes relative to
standard of care physical therapy interventions.
RESISTANCE EXERCISE IN LUNG CANCER SURVIVORS
In the only study to examine the effects of RE in LC survivors, Peddle-McIntyre
et al.28 conducted a single-arm, feasibility and preliminary efficacy study of RE in
17 LC survivors. Assessments of muscular strength and endurance, physical f­ unction,
body composition, and QoL were obtained prior to and following 10 weeks of RE.
A total of 17 of 389 (13%) LC survivors who were assessed for eligibility were randomized into the pilot trial and 87% of participants completed the postintervention
follow-up assessment. Adherence during the RE intervention was 87%. Three adverse
events involving minor musculoskeletal injuries related to the RE intervention were
reported. Findings revealed that RE resulted in large effect size improvements in
muscular strength (chest press: d = 0.96; leg press: d = 1.00) and muscular endurance
(chest press: d = 1.55; leg press: d = 1.49; arm curls: d = 1.49). Moderate to large
effect size improvements were also observed in performance measures of physical
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
51
function including 6-min walk distance (d = 0.90), chair stand time (d = 1.21), and
up and go task time (d = 0.58). Modest improvements in lean body mass (d = −0.01),
body fat percentage (d = 0.00), or QoL (d = −0.28 to 0.44) were observed following
the RE intervention. The results provide preliminary support for the feasibility and
efficacy of implementing RE interventions in survivors following LC treatment.
RESISTANCE EXERCISE IN MIXED CANCER SAMPLE
Katz et al.29 conducted a single-arm, uncontrolled trial examining the effects of a
5-month progressive RE intervention in a sample of 10 survivors of various cancer types
(bladder, cervical, endometrial, melanoma, and uterine). The RE intervention involved
2 months of supervised RE and 3 months of unsupervised RE. Assessments of muscular
strength, body composition (body fat percentage and lean body mass), physical function
(6-min walk, 50-ft walk, and single-leg stand), and global QoL (SF-36) were obtained
at baseline and 2- and 5-month follow-up. A total of 10 of 12 eligible survivors (83%)
participated in the study. All 10 participants completed the 2­ - and 5-month follow-up
assessments, and average adherence to the supervised RE ­sessions was 91%. There was
two mild to moderate adverse events possibly related to the RE intervention involving the development of cellulitic infections. Results revealed that the RE intervention
resulted in small to moderate improvements in muscular strength (chest press: 2 months,
d = 0.28; 6 months, d = 0.64; leg press: 2 months, d = 0.24; 6 months d = 0.58), 6-min
walk (2 months d = 0.21; 6 months d = 0.64), 50-ft walk (2 months d = 0.47; 6 months
d = 0.73), and single-leg stand (2 months d = 0.33; 6 months d = 0.00), but negligible
changes in body fat percentage (2 months d = −0.13; 6 months d = 0.02) and lean
body mass (2 months d = 0.07; 6 months d = 0.05). There were no changes in QoL
following RE, but the effect sizes and descriptive statistics of this measure were not
reported. Although RE yielded moderate effect size improvements in muscular strength
and physical function, the observation of cellulitic infections in two of the participants
suggests that the safety and efficacy of RE in cancer survivors with lower limb lymphedema are unclear and require further investigation.
Taken collectively, our attempt to comprehensively review existing RE–cancer
studies, one of the first to directly determine the independent effects of RE interventions, suggests that RE alone yields statistically significant, clinically meaningful improvements in a variety of relevant health, fitness, and QoL outcomes during
and following cancer treatment. Although RE produced improvements in an array
of valuable outcomes among cancer patients and survivors, the magnitude of benefit
accompanying RE showed marked heterogeneity across outcomes. Notably, while
RE yielded large average effect size increases in muscular strength (d = 0.86; range
= 0.11–2.45) and muscular endurance (d = 1.88; range = 0.66–2.90) and moderate
effect size improvements in physical function (d = 0.66; range = 0.21–1.29), only
small effect size improvements in body composition (d = 0.28; range = −0.51 to
1.78) and QoL (d = 0.25; range = −0.72 to 1.14) emerged following RE. Despite
this variability, the feasibility outcomes clearly demonstrate that RE is safe, welltolerated exercise intervention for cancer patients and survivors. Additionally, the
effect sizes provide quantitative evidence for the preliminary efficacy of RE as a
valuable supportive care intervention during and following cancer treatment.
52
Resistance Exercise Interventions across the Cancer Control Continuum
EFFICACY OF RESISTANCE EXERCISE DURING AND FOLLOWING
CANCER TREATMENT: SUMMARY AND SYNTHESIS
Findings from the RE–cancer studies conducted to date underscore several promising aspects of implementing RE interventions during and following cancer treatment. First, with regard to safety and feasibility of RE interventions, relatively few
adverse events were reported and those that were documented were nonserious and
often not directly related to the RE intervention. The 44% recruitment rate and 86%
retention rate also provide evidence that it is a well-tolerated behavioral intervention that is feasible to implement during and after treatment for a variety of cancer
populations.
Evaluation of the study results also demonstrates that RE interventions consistently yielded statistically significant, clinically meaningful improvements in a variety of relevant health, fitness, and QoL outcomes for cancer patients and survivors.
RE produced physiologic training adaptations including large effect size improvements in muscular strength, moderate effect size improvements in physical function,
and small effect size improvements in body composition. RE also produced moderate effect size improvements in fatigue and small to moderate effect size improvements in various measures of QoL. These effect sizes are comparable in magnitude
to the effects of exercise interventions reported in prior comprehensive reviews of
the exercise–cancer literature that primarily focused on aerobic exercise7,33 and provides preliminary evidence that RE yields many similar health, fitness, and QoL
benefit as aerobic exercise in select samples cancer patients and survivors. Together,
these findings provide strong initial evidence of the efficacy of RE as a supportive
care intervention during and following cancer treatment.
EVIDENCE-BASED RESISTANCE EXERCISE PRESCRIPTION
RECOMMENDATIONS FOR CANCER PATIENTS AND SURVIVORS
Despite mounting evidence supporting the value of exercise as a therapeutic intervention during and following cancer treatment, widespread implementation of
exercise as an adjuvant or supportive care intervention for cancer patients and survivors has yet to be achieved. It can be contended that this is due, in part, to the
lack of established exercise guidelines specifically targeting cancer patients and/
or survivors. However, in recent years, efforts to generate widely recognized, safe,
efficacious exercise prescription guidelines for cancer patients and survivors have
received considerable attention. In 2009, the American College of Sports Medicine
(ACSM) convened an expert panel to achieve two primary objectives: (1) to evaluate the safety and benefits of exercise interventions for cancer survivors (survivors
being defined using the National Coalition of Cancer Survivorship recommendation as “from the time of diagnosis until the end of life”) and (2) to provide initial
guidelines for the implementation of exercise interventions across the cancer control
continuum. Findings of the ACSM expert panel concluded that exercise recommendations issued by the United States Department of Health and Human Services 2008
Physical Activity Guidelines for Americans (PAGA) are sufficiently safe and effective to be implemented within cancer control efforts. However, in their report, the
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
53
ACSM expert panel also highlighted select modifications to the PAGA guidelines
that would be prudent in implementing exercise interventions among cancer patients
and survivors.34 A brief summary of RE portion of the ACSM exercise guidelines for
cancer survivors is provided in the following section.
The U.S. PAGA RE guidelines recommend performance of muscle strengthening activities of moderate intensity at least 2 days per week for each of the major
muscle groups. In reviewing the RE–cancer literature, the expert panel concluded
that there was only sufficient evidence to issue recommendations for select types of
cancer.34 The basic RE guidelines forwarded by PAGA were recommended without modification for prostate and hematologic cancer survivors. Modifications of the
PAGA RE guidelines were proposed for implementing RE in breast cancer and colon
cancer survivors. Specifically, for breast cancer survivors, the expert panel recommended that RE programs should be initially implemented as supervised programs
and should incorporate gradual progression. It should also be recognized that while
upper-body RE has frequently been cited as a risk factor for arm lymphedema in
breast cancer patients and survivors, findings from multiple randomized controlled
trials15,23,24,31 refuted this position and clearly demonstrate the safety and efficacy of
RE for breast cancer patients and survivors. Expert panel recommendations for colon
cancer survivors are consistent with PAGA guidelines with the exception of patients
with stoma who are encouraged to use lighter loads and slower progression to reduce
the risk of herniation. Finally, the expert panel also cited that there is presently insufficient data regarding the safety/efficacy of RE for gynecologic cancer survivors with
lower limb lymphedema.
The recommendations of the ACSM expert panel on exercise guidelines for
cancer survivors suggest that the PAGA recommendations, with modest modifications for select cancer survivorship groups, represent a safe, efficacious approach to
RE prescription across the cancer control continuum. When combining the ACSM
expert panel recommendations with evidence from our recent systematic review14
addressed in this chapter, it is reasonable to suggest that there are additional relevant prescription considerations that also warrant attention. Inspection of Table 4.1
reveals that the characteristics of the RE interventions such as the frequency, load
(amount of weight), and volume (sets and repetitions per set) varied considerably
across studies. Due to the variability in intervention characteristics used in prior
studies and absence of studies directly comparing different doses of RE, the minimum frequency, load, and volume of RE that yields favorable changes in physiologic
and QoL outcomes during and following cancer treatment has yet to be adequately
delineated.
Given the physiological and functional challenges individuals experience during
and following cancer treatment, clarifying the minimum amount of RE necessary to
produce clinically meaningful improvements would be valuable in guiding and/or
refining exercise prescription for cancer patients and survivors. Defining the minimal or optimal amount of RE participation necessary to improve relevant outcomes
among cancer patients and survivors remains unknown and is an important topic
that warrants study in future randomized, controlled RE trials. However, in exploring the dose–response effects of RE interventions, it is important to acknowledge
that any single RE prescription is unlikely represent an optimal stimulus for all
Segal
et al.19
RCT
121
10
NR
42
RCT
155
106
RCT
MCRCT
154
RCT
38
242
MCRCT
Schmitz
et al.23
Courneya
et al.15
Schmitz
et al.24
WintersStone
et al.25
Musanti21
RCT
85
CORCT
Schmidt
et al.22
Segal
et al.18
Galvao
et al.16
Sample
Size
Design
Study
TABLE 4.1
Study Characteristics
PC patients
PC patients
PC patients
BC patients
BC survivors
BC survivors
BC Survivors
BC Patients
BC Survivors
Diagnosis/
Phase
24 Weeks of supervised RE; 2 sets of 8–12
repetitions at 60%–70% 1RM
6 Months of supervised RE; 1 set of 20
repetitions at 50% 1RM
12 Weeks of supervised RE; 3 sets of 8–12
repetitions at 70%–80% 1RM
20 Weeks of supervised RE; 3 sets of 8–12
repetitions at 80% 1RM
12 Weeks of unsupervised RE; 1 set of 12
repetitions at an RPE 4–8
6 Months of supervised RE; 3 sets of 8–10
repetitions at 70%–80% 1RM
Supervised RE for duration of chemotherapy; 2
sets of 8–12 repetitions at 60%–70% 1RM
12 Months of supervised and unsupervised RE; 3
sets of 10 repetitions at a symptom limited load
12 Months of supervised and unsupervised RE; 3
sets of 8–12 repetitions at 60%–80%1RM
Intervention Characteristics (Duration/
Supervision/Sets/Repetitions/Load)
Improvements in muscular strength, Muscular endurance,
and physical function. Small, nonsignificant changes in
body composition and bone mineral density
Improvements in muscular strength. Small, nonsignificant
changes in body composition, disability, and QoL
Improvements in muscular endurance, fatigue, and QoL
Improvements in muscular strength and endurance, body
composition, and QoL following RE
Improvements in muscular strength, body composition,
and select patient-reported outcomes following RE
Improvements in muscular strength. Small nonsignificant
changes in body composition
Improvements in muscular strength and physical
function. Small, nonsignificant changes in body
composition, bone mineral density, and fatigue.
Improvements in muscular strength and self-esteem.
Small, nonsignificant changes in aerobic fitness, body
composition, fatigue, and depression
Improvements in fatigue and QoL
Summary of Overall Findings
54
Resistance Exercise Interventions across the Cancer Control Continuum
10
NR
Mixed
survivors
LC survivors
H&N
survivors
H&N
survivors
H&N patients
PC patients
20 Weeks of supervised and unsupervised
RE; 2–3 sets of 10 repetitions at symptom
limited load
12 Weeks of supervised RE; 2 sets of 15–20
repetitions at self-determined RPE
12 Weeks of supervised RE; 2 sets of 10–15
repetitions at 60%–70% 1RM
12 Weeks of supervised and unsupervised RE; 1
set of 10 repetitions with light, moderate, heavy
resistance bands
10 Weeks of supervised RE; 3 sets of 12
repetitions at 60%–85% 1RM
12 Weeks of supervised RE; 3 sets of eccentric
RE at self-determined RPE
Improvements in muscular strength and physical
function. Small, nonsignificant changes in body
composition and fatigue
Improvements in patient-reported pain, function, and
disability
Improvements in muscular strength, muscular endurance,
and patient-reported pain and disability
Small improvements in muscular strength, physical
function, body composition, and patient-reported
outcomes
Improvements in muscular strength, muscular endurance,
physical function, and QoL. Small change in body
composition
Improvements in muscular strength, physical function.
Small, nonsignificant change in body composition
and QoL
Note: RCT = randomized controlled trial; NR = nonrandomized study; CORCT = crossover randomized controlled trial; MCRCT = multicenter randomized controlled trial;
RE = resistance exercise; BC = breast cancer; PC = prostate cancer; LC = lung cancer; H&N = head and neck cancer; RPE = rating of perceived exertion; 1RM = 1
repetition maximum; QoL = quality of life.
17
15
RCT
RCT
52
RCT
PeddleMcIntyre
et al.28
Katz
et al.29
20
RCT
McNeely
et al.26
McNeely
et al.27
Rogers
et al.20
10
NR
Hansen
et al.17
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
55
56
Resistance Exercise Interventions across the Cancer Control Continuum
patients or yield a uniform magnitude of improvement in all relevant outcomes of
interest. Consistent with this position, it has been proposed that subjective responses
to RE (e.g., affect, QoL, and mood) may exhibit a family of dose–response curves.35
It should also be recognized that participant’s tolerance, preference, and adaptation to any dose of RE will be influenced by individual differences that shape their
interpretation of the exercise prescription.36,37 Therefore, while it is of considerable importance to augment knowledge of the dose–response effects of RE during and following cancer treatment, flexible prescription strategies that personalize
the characteristics of the RE intervention to one’s fitness level, exercise tolerance,
and preferences should also be viewed as an important consideration in both the
design of future investigations attempting to define the dose–response relationship
of RE interventions and the implementation of RE as a supportive care intervention
for cancer.
VARIABILITY IN THE EFFECTS OF RESISTANCE EXERCISE ACROSS
HEALTH, FITNESS, AND QUALITY OF LIFE OUTCOMES
Studies of the RE–cancer relationship suggest that resistance training is a promising behavioral intervention for cancer patients and survivors. Nonetheless, notable
variability in the magnitude of improvements accompanying the RE interventions
was observed across outcomes. One of the most relevant examples of this heterogeneity in responses is the difference in effect size changes in body composition
relative to other relevant fitness or functional outcomes. Whereas moderate to large
effect size improvements in muscular strength and physical function were consistently observed following RE, only small effect size improvements emerged for
indices of body composition. Results from our systematic review14 revealed that
the overall effect size for body composition measures was 0.28. However, this averaged effect resulted from small effect sizes (range = −0.09 to 0.21) in several studies15–17,19,24,25,28,29 and large effect size changes (range = 0.87–1.78) obtained in one
study.23 Excess body weight and body fat are linked with increased risk for chronic
disease, metabolic syndrome, and cancer recurrence. Increases in body weight, body
fat percentage, fat mass, and decreases in muscle mass are frequently documented
during hormone therapy,38 ­chemotherapy,39 and in cancer survivors following the
completion of active treatment.40 Hence, harnessing exercise-related weight management and disease prevention benefits is likely one factor contributing to the mounting
interest in implementing exercise interventions as an adjuvant treatment during and
following cancer treatment. Given exercise is an integral component of weight management efforts, the effects of RE on body weight and/or body composition-related
outcomes addressed in this chapter warrants careful consideration.
Overall, RE yielded small effect sizes changes in body composition outcomes,
but there are several important factors to consider when interpreting the modest
effects of RE on these outcomes. First, findings from the RE studies summarized
in this chapter clearly demonstrated that cancer patients undergoing hormone
therapy,16–19 chemotherapy,15 and cancer survivors who had completed active
­treatment23,24,26,27,29 who received RE interventions did not experience unfavorable
shifts in body composition observed in prior observation studies or in nonexercising
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
57
control participants involved in randomized controlled RE studies. Thus, although
RE interventions did not consistently produce profound improvements in body
composition-related outcomes, RE participation appeared to attenuate the adverse
changes in body fat percentage, lean body mass, and fat mass that are reliably documented in cancer patients and survivors who are not exposed to RE interventions.
It is reasonable to suggest, therefore, that the body composition benefits of RE are
preventive in nature, protecting cancer patients and survivors from the deleterious
changes in body weight, fat, and composition. In interpreting these effects, it should
also be acknowledged that the duration and intensity of several RE interventions
conducted to date may have been insufficient to produce marked improvement in
body composition outcomes. What can be concluded is that RE appears to attenuate unfavorable changes in body composition that frequently observed during and
following cancer treatment and that RE holds promise for producing improvements
in these outcomes. Further research delineating the load, volume, and duration of
RE training necessary to produce clinically meaningful change in these important
outcomes is warranted.
CONSIDERATIONS FOR FUTURE RESISTANCE
EXERCISE INTERVENTION RESEARCH DURING
AND FOLLOWING CANCER TREATMENT
In this chapter and our prior systematic review,14 we focused on the pre- to post-RE
intervention effects on select health, fitness, and QoL outcomes. The comparable
efficacy of RE to attention control or comparison exercise interventions was not
directly evaluated. It is interesting to note that findings from two trials comparing
the effects of RE to aerobic exercise in breast cancer15 and PC patients19 revealed that
RE yielded superior improvements in fatigue and chemotherapy completion rates.
Clearly, results from two studies cannot be considered definitive, and these findings
require replication to verify the veracity and consistency of this beneficial effect.
Nonetheless, these favorable effects documented following RE, if replicated, may be
indicative of unique RE-related benefits that have potential for a particularly significant impact on morbidity and mortality risk in cancer treatment and survivorship. In
light of these findings, it is also reasonable to suggest that determining the feasibility
and potentially synergistic benefits of interventions combining RE and aerobic exercise training may be critical to advancing knowledge of optimal exercise intervention approaches during and following cancer treatment.
It is important to acknowledge the relatively narrow breadth of both types of
cancer studied and the phase of the cancer control continuum within which the
effects of RE interventions have been examined. Accordingly, the feasibility and
efficacy of implementing RE as a supportive care intervention for other presently
understudied cancer groups are yet to be determined. The RE intervention studies
conducted to date have focused on the time period during or shortly following active
cancer therapy. Due to the relatively restricted time frame focused on in these studies, knowledge of the effects of RE during other critical phases of the cancer control
continuum,11 such as prevention, buffering, and palliation, also remains limited and
warrants future inquiry.
58
Resistance Exercise Interventions across the Cancer Control Continuum
Promoting adoption and adherence to exercise interventions and, subsequently,
long-term maintenance of exercise participation are integral to the efficacy of implementing exercise in disease prevention and health promotion efforts.36,41–43 The relatively high adherence rates observed during RE–cancer studies support the feasibility
of implementing this mode of exercise as a supportive care intervention during and
following cancer treatment. Nonetheless, the majority of studies addressed in this
chapter utilized attendance as the primary index of adherence, which, unfortunately,
does not directly address compliance with the actual RE prescription. Expanding
adherence assessments to include measurement of RE prescription characteristics
(sets, repetitions, load, volume, volume–load) would advance knowledge of the benefits of RE in cancer patients and survivors considerably. Moreover, determining the
relationship between adherence to important RE characteristics and improvements
in relevant health, fitness, and QoL outcomes would be integral in guiding the development and refinement of appropriate RE prescription approaches defining for cancer patients and survivors. Finally, using theory-based approaches to determine the
motivational factors that contribute to determining successful adoption and maintenance of regular RE participation during and following cancer treatment would be
particularly informative in tailoring future intervention efforts.
In summary, current findings suggest that RE is a safe, feasible, exercise intervention that results in significant, clinically meaningful improvements in an array of
relevant health, fitness, and QoL outcomes during and following cancer treatment.
Findings of the studies summarized in this chapter support the promise of implementing RE as an adjuvant, supportive care intervention in the treatment of cancer
patients and survivors. If the benefits of RE addressed in this chapter are consistently
replicated, it is our hope that these favorable findings aid progress toward the integration of comprehensive exercise interventions in the routine clinical management
of cancer patients and survivors.
REFERENCES
1.Kraemer WJ, Ratamess NA. Fundamentals of resistance training: progression and exercise prescription. Med Sci Sports Exerc. 2004;36:674–88.
2.Graves JE, Franklin BA. Resistance Training for Health and Rehabilitation. Champaign,
IL: Human Kinetics; 2001.
3.Mosher CE, Sloane R, Morey MC et al. Associations between lifestyle factors and
quality of life among older long-term breast, prostate, and colorectal cancer survivors.
Cancer. 2009;115:4001–9.
4.Courneya KS. Physical activity in cancer survivors: a field in motion. Psychooncology.
2009;18:337–42.
5.Galvao DA, Newton RU, Taaffe DR, Spry N. Can exercise ameliorate the increased
risk of cardiovascular disease and diabetes associated with ADT? Nat Clin Pract Urol.
2008;5:306–7.
6.Schmitz KH, Holtzman J, Courneya KS, Masse LC, Duval S, Kane R. Controlled physical activity trials in cancer survivors: a systematic review and meta-analysis. Cancer
Epidemiol. Biomarkers Prev. 2005;14:1588–95.
7.Speck RM, Courneya KS, Masse LC, Duval S, Schmitz KH. An update of controlled
physical activity trials in cancer survivors: a systematic review and meta-analysis.
J Cancer Surviv. 2010;4:87–100.
Brian C. Focht, Alexander R. Lucas, and Steven K. Clinton
59
8.Schmitz KH, Courneya KS, Matthews C et al. American College of Sports Medicine
roundtable on exercise guidelines for cancer survivors. Med Sci Sports Exerc. 2010;
42:1409–26.
9.Galvao DA, Newton RU. Review of exercise intervention studies in cancer patients.
J Clin Oncol. Feb 1 2005;23(4):899–909.
10.Antonelli J, Freedland SJ, Jones LW. Exercise therapy across the prostate cancer continuum. Prostate Cancer Prostatic Dis. 2009;12:110–15.
11.
Courneya KS, Friedenreich CM. Framework PEACE: an organizational model
for examining physical exercise across the cancer experience. Ann Behav Med.
2001;23:263–72.
12.Cheema B, Gaul CA, Lane K, Fiatarone Singh MA. Progressive resistance training in breast cancer: a systematic review of clinical trials. Breast Cancer Res Treat.
2008;109:9–26.
13.De Backer IC, Schep G, Backx FJ, Vreugdenhil G, Kuipers H. Resistance training in
cancer survivors: a systematic review. Int J Sports Med. 2009;30:703–12.
14.Focht BC, Clinton SK, Devor ST, Garver M, Lucas AR, Thomas-Ahner JM. Resistance
exercise interventions during and following cancer treatment: a systematic review.
J Supp Oncol. 2013;11:45–60.
15.Courneya KS, Segal RJ, Mackey JR et al. Effects of aerobic and resistance exercise
in breast cancer patients receiving adjuvant chemotherapy: a multicenter randomized
­controlled trial. J Clin Oncol. 2007;25:4396–404.
16.Galvao DA, Nosaka K, Taaffe DR et al. Resistance training and reduction of treatment
side effects in prostate cancer patients. Med Sci Sports Exerc. 2006;38:2045.
17.Hansen PA, Dechet CB, Porucznik CA, LaStayo PC. Comparing eccentric resistance
exercise in prostate cancer survivors on and off hormone therapy: a pilot study. PM&R.
2009;1:1019–24.
18.Segal RJ, Reid RD, Courneya KS et al. Resistance exercise in men receiving androgen
deprivation therapy for prostate cancer. J Clin Oncol. 2003;21:1653.
19.Segal RJ, Reid RD, Courneya KS et al. Randomized controlled trial of resistance or
aerobic exercise in men receiving radiation therapy for prostate cancer. J Clin Oncol.
2009;27:344.
20.Rogers LQ, Anton PM, Fogleman A et al. Pilot, randomized trial of resistance exercise during radiation therapy for head and neck cancer. Head Neck. July 30, 2012. doi:
10.1002/hed.23118.
21.Musanti R. A study of exercise modality and physical self-esteem in breast cancer survivors. Med Sci Sports Exerc. 2012;44:352–61.
22.Schmidt T, Weisser B, Jonat W, Baumann FT, Mundhenke C. Gentle strength training
in rehabilitation of breast cancer patients compared to conventional therapy. Anticancer
Res. 2012;32:3229–33.
23.Schmitz KH, Ahmed RL, Hannan PJ, Yee D. Safety and efficacy of weight training in
recent breast cancer survivors to alter body composition, insulin, and insulin-like growth
factor axis proteins. Cancer Epidemiol Biomarkers Prev. 2005;14:1672–80.
24.Schmitz KH, Ahmed RL, Troxel AB et al. Weight lifting for women at risk for breast
cancer-related lymphedema: a randomized trial. JAMA. 2010;304:2699–705.
25.Winters-Stone KM, Dobek J, Bennett JA, Nail LM, Leo MC, Schwartz A. The effect
of resistance training on muscle strength and physical function in older, postmenopausal breast cancer survivors: a randomized controlled trial. J Cancer Surviv.
2012;6:189–99.
26.McNeely ML, Parliament M, Courneya KS et al. A pilot study of a randomized controlled trial to evaluate the effects of progressive resistance exercise training on shoulder
dysfunction caused by spinal accessory neurapraxia/neurectomy in head and neck cancer survivors. Head Neck. 2004;26:518–30.
60
Resistance Exercise Interventions across the Cancer Control Continuum
27.McNeely ML, Parliament MB, Seikaly H et al. Effect of exercise on upper extremity
pain and dysfunction in head and neck cancer survivors: a randomized controlled trial.
Cancer. 2008;113:214–22.
28.Peddle-McIntyre CJ, Bell G, Fenton D, McCargar L, Courneya KS. Feasibility and preliminary efficacy of progressive resistance exercise training in lung cancer survivors.
Lung Cancer. 2012;75:126–32.
29.Katz E, Dugan NL, Cohn JC, Chu C, Smith RG, Schmitz KH. Weight lifting in patients
with lower-extremity lymphedema secondary to cancer: a pilot and feasibility study.
Arch Phys Med Rehabil. 2010;91:1070–76.
30.Cohen J. Statistical power analysis for the behavioral sciences. Mahwah, NJ: Lawrence
Erlbaum; 1988.
31.Ohira T, Schmitz KH, Ahmed RL, Yee D. Effects of weight training on quality of life in
recent breast cancer survivors: the Weight Training for Breast Cancer Survivors (WTBS)
study. Cancer. 2006;106:2076–83.
32.Roach KE, Budiman-Mak E, Songsiridej N, Lertratanakul Y. Development of a shoulder
pain and disability index. Arthritis Care Res. 1991;4:143–49.
33.Ferrer RA, Huedo-Medina TB, Johnson BT, Ryan S, Pescatello LS. Exercise interventions for cancer survivors: a meta-analysis of quality of life outcomes. Ann Behav Med.
2011;41:32–47.
34.Wolin KY, Schwartz AL, Matthews CE, Courneya KS, Schmitz KH. Implementing the
exercise guidelines for cancer survivors. J Support Oncol. 2012;10:171–77.
35.Focht BC, Arent SM. Psychological Responses to Acute Resistance Exercise: Current
Status, Contemporary Considerations, and Future Research Directions. Gottingen:
Cuvilier Verlag; 2008.
36.Rejeski WJ, Focht BC. Aging and physical disability: on integrating group and individual counseling with the promotion of physical activity. Exerc Sport Sci Rev.
2002;30:166–70.
37.Rejeski WJ. Dose-response issues from psychosocial perspective. Physical activity, fitness and health: international proceedings and consensus statement. Champaign, IL:
Human Kinetics Publishers; 1994.
38.Haseen F, Murray LJ, Cardwell CR, O'Sullivan JM, Cantwell MM. The effect of androgen deprivation therapy on body composition in men with prostate cancer: systematic
review and meta-analysis. J Cancer Surviv. 2010;4:128–39.
39.Demark-Wahnefried W, Winer EP, Rimer BK. Why women gain weight with adjuvant
chemotherapy for breast cancer. J Clin Oncol. 1993;11:1418–29.
40.Vance V, Mourtzakis M, McCargar L, Hanning R. Weight gain in breast cancer survivors: prevalence, pattern and health consequences. Obes Rev. 2011;12:282–94.
41.Bandura A. Self-efficacy: the exercise of control. New York, NY: W.H. Freeman; 1997.
42.Rejeski WJ, Brubaker PH, Goff DC, Jr. et al. Translating weight loss and physical activity programs into the community to preserve mobility in older, obese adults in poor
cardiovascular health. Arch Intern Med. 2011;171:880–86.
43.Rejeski WJ, Focht BC, Messier SP, Morgan T, Pahor M, Penninx B. Obese, older adults
with knee osteoarthritis: weight loss, exercise, and quality of life. Health Psychol.
2002;21:419–26.
5
Effects of Resistance
Training on Insulin
Sensitivity and
Glycemic Control
Potential Role in
the Prevention of
Type 2 Diabetes
Christian K. Roberts
CONTENTS
Introduction............................................................................................................... 65
Resistance Training: A Viable Intervention for Reducing Type 2
Diabetes Risk?..........................................................................................................66
Exercise and Insulin Sensitivity................................................................................ 67
Muscle Strength and Insulin Resistance................................................................... 67
Resistance Training, Insulin Sensitivity, and Glucose Tolerance............................. 68
Aerobic versus Resistance Training.......................................................................... 71
Mechanisms.............................................................................................................. 73
Glycemic Control...................................................................................................... 74
Recommendations..................................................................................................... 75
Individualized Programs........................................................................................... 76
Future Directions...................................................................................................... 76
Conclusion................................................................................................................ 76
References................................................................................................................. 76
INTRODUCTION
In recent decades, obesity and one of its primary associated clinical m
­ anifestations
in genetically susceptible individuals, type 2 diabetes (T2D), have progressed into
a major cause of preventable death, increasing from ~1.5 million diagnosed in
1958 to ~21 ­m illion in 2010,1 with an estimated additional 7 million undiagnosed.2
61
62
Effects of Resistance Training on Insulin Sensitivity and Glycemic Control
Furthermore, the increased future prevalence of T2D is a major health care concern, with estimates that ~80 million adults in the United States have prediabetes.3
Thus, ~107 million in the United States have either diabetes or prediabetes, and
it has been estimated that 21%–33% of the U.S. population will be burdened with
diabetes by 2050.4
Aside from the personal burden induced by T2D, there is a significant economic
impact. It has been estimated that diabetes accounts for ~10% of all medical expenditures in the United States at an estimated $245 billion in 2010, a 41% increase
since 2007.5 Moreover, given that traditionally it is well known that obesity is linked
to insulin resistance and T2D, these costs are expected to rise dramatically because
of the rising incidence of metabolic and cardiovascular complications related to
increased obesity over the past 20 years and the aforementioned predicted rise in
T2D over the next 40 years.4 However, it is important to mention that obesity per
se is likely not the underlying cause of T2D-associated clinical manifestations, as
Carnethon et al.6 recently noted that mortality from incident diabetes was not elevated in overweight/obese subjects.
Thus, prevention of future T2D and its primary clinical manifestation of cardiovascular disease, especially in youth, young and middle-aged adults, is a major
public health challenge. Hence, developing optimal therapeutic strategies to combat these growing epidemics is imperative. Along these lines, it is well established
that aerobic exercise prevents T2D (as reviewed by Booth et al.7 and Roberts and
Barnard8). Resistance training (RT) may be an additional viable preventive strategy
for T2D,9 especially in obese subjects precluded from performing aerobic activities
or in instances where aerobic training (AT) is not sustainable. However, to date, no
studies have looked at prevention of T2D per se. Also, RT may play be a potential
therapeutic option in the treatment of T2D. However, the current American Diabetes
Association standards of medical care scarcely mentions the role of RT in T2D.10
This review will discuss the impact of RT on insulin sensitivity and potential therapeutic efficacy for the prevention and treatment of T2D.
RESISTANCE TRAINING: A VIABLE INTERVENTION FOR
REDUCING TYPE 2 DIABETES RISK?
Because of the health risks related to obesity, the development of novel prevention
and treatment programs is a high priority. However, to date, the impact of RT on
prevention of T2D per se has been largely unexplored and is a major gap in the literature. This is evidenced by the following:
• Carnethon11 noted that “now that the science has identified physical activity as a plausible preventive measure [for T2D], additional well-designed
studies are needed to determine…the type…of physical activity required
to prevent T2D; and whether activity independent of weight loss provides
any benefit.”
• The Department of Health and Human Services Physical Activity Guideline
Advisory Committee Report,9 noted that
Christian K. Roberts
63
• “Developing a better understanding of the role of RT in the prevention
and treatment of metabolic syndrome is an area of great interest.”
• “RT has not been explored for its role in prevention of T2D. Future
­studies should further investigate the role of RT in preventing T2D,
given the beneficial effects of such training on the metabolism of
­persons with T2D.”
• The reported effects of RT on abdominal obesity are “less consistent”
and data are “limited.”
Recently, Grøntved et al.12 noted that from >32,000 men followed for 18 years
in the Health Professionals Follow-up Study, performing ≥150 minutes per week
of RT was associated with a 30% reduction in risk of T2D, after adjustment for
aerobic activities and body mass index (BMI). In addition, those with a BMI ≥30
who engaged in RT ≥150 minutes per week exhibited an estimated 60% reduction
in risk. Another interesting observation was the 40% reduction in risk in those
without a family history of T2D; however, no effect was noted in those with family
history.
EXERCISE AND INSULIN SENSITIVITY
Insulin resistance, in concert with defects in the ability for appropriate compensatory insulin secretion, is one of the primary defects contributing to T2D. Skeletal
muscle is a primary site for glucose disposal following a meal13 and shows a major
defect in insulin-resistant T2D patients13 as well as those with prediabetes. Hence,
insulin resistance has been suggested as a major underpinning link between obesity
and T2D.
It is well known that trained subjects and those who perform high levels of physical activity exhibit high levels of insulin sensitivity. This chapter will discuss exercise training per se, rather than acute exercise, and the effects of RT on insulin
sensitivity, glucose tolerance (collectively referred to as insulin action), and glycemic
control. Below is a discussion of selected studies in these areas. The majority of studies discussed will focus on studies using the euglycemic hyperinsulinemic clamp
(EHC), frequently sampled intravenous glucose tolerance test (FSIGT), or oral glucose tolerance test (OGTT). Only training studies will be discussed with the caveat
that the timing of the insulin sensitivity measure after the last bout may impact the
effects noted, as considered below.
MUSCLE STRENGTH AND INSULIN RESISTANCE
Although it has been shown that muscle strength is inversely related to metabolic
syndrome,14–17 to date very few studies have investigated the role of muscle strength
on insulin sensitivity. A previous cross-sectional analysis from National Health and
Nutrition Examination Survey suggested that muscle strength activity is related to
insulin sensitivity.18 In the Health Aging and Body Composition Study, low muscle
strength was associated with increased insulin resistance in older adults, as estimated by the homeostasis model of insulin resistance.19
64
Effects of Resistance Training on Insulin Sensitivity and Glycemic Control
RESISTANCE TRAINING, INSULIN SENSITIVITY,
AND GLUCOSE TOLERANCE
Yki-Jarvinen and Koivisto20 showed cross-sectionally that weight lifters exhibited
similar glucose disposal to long-distance runners. Szczypaczewska et al.21 also noted
that bodybuilders exhibit greater glucose tolerance and insulin action compared to
controls. These findings led to research showing that RT also enhances insulin sensitivity and improves glucose tolerance in a wide range of study groups, including
younger22,23 and older individuals,24 postmenopausal women,25 and those with hypertension26 and T2D.27
Generally, RT does not affect fasting levels of glucose or insulin but does
improve insulin sensitivity, glucose tolerance, and glycemic control. This may be
of clinical value as it is becoming clear that T2D is a postprandial disease.28 As
such, insulin sensitivity has been shown to improve with RT in several studies
using the EHC (Table 5.1). For example, in healthy, middle-aged men, glucose
infusion increased 24% during EHC after RT.31 In subjects with T2D,27 improvements in the glucose infusion rates have been noted, generally attributable to
increases in nonoxidative glucose metabolism. Reynolds et al.26 noted improved
glucose disposal during EHC in older hypertensive subjects. Ryan et al.25 noted an
increase in a small cohort of postmenopausal women. Interestingly, the training
program intensities and durations in these studies were highly variable, suggesting that multiple RT paradigms are capable of improving insulin sensitivity. In
addition, Reynolds et al.37 used EHC and noted no significant changes in fractional glucose extraction or glucose clearance with RT. On the other hand, two
studies33,36 found nonsignificant increases in insulin sensitivity. In the first,33 the
increase was ~10% and did not achieve significance (p < .06). In the latter,36 the
weekly training duration was 60 minutes, suggesting that a potential threshold of
overload may exist.
Several of these studies showed an effect of RT without altering aerobic capacity
or body weight/composition. In older men, Zachwieja et al.24 noted a 33% increase
in insulin sensitivity and an increase in glucose rate of disappearance, using a stable
glucose isotope FSIGT, 7 days after the last bout of training, without a change in
body weight, secondary to reciprocal increases and decreases in lean body mass
(LBM) and fat mass. In obese, middle-aged men, Klimcakova et al.35 noted a 24%
increase in glucose disposal rate, without any change in body weight, fat mass, or
VO2max. Poehlman et al.22 also noted a modest increase, which occurred independent of changes in total body, subcutaneous, or visceral fat. In the study by Ryan
et al.,25 body weight, fat mass, percent body fat, LBM, and VO2max did not change
with RT intervention. The addition of a calorically restricted diet augmented the
response and induced weight loss, suggesting the possibility of additive effects with
multiple lifestyle interventions. Increases in insulin sensitivity during an FSIGT
have also been noted in children, despite no change in weight and an increase in
LBM compared to a control group.23 Van Der Heijden et al.30 noted highly variable responses in youth in peripheral insulin sensitivity but a 24% increase in liver
insulin sensitivity. In addition, improvement in adipose tissue insulin sensitivity has
been noted.38
64–75 year M
66 ± 3 year M, T2D
15 ± 0.5 year M Hispanic
15 ± 0.5 year M/F Hispanic
58 ± 1 year M
58 ± 2 year F
47 ± 9 (SD) year, T2D
28 ± 3 year F
61 ± 2 year, healthy and
T2D
Ibanez et al.29
Shaibi et al.23
Van Der Heijden
et al.30
Miller et al.31
Ryan et al.25
Ishii et al.27
Poehlman et al.22
Holten et al. 32
Subject Population
Zachwieja et al.24
Study
3×/week, 16 week
1 set 90% 1RM for 3 reps
⇩ load up to 15 reps
3×/week, ~16 week
1–2 sets 15 reps
5 ×/week, 4–6 week
2×10–20 reps
40%–50% of 1RM
3×/week, 6 month
80% 1RM
3×/week, 6 week, 1 legged
training, 8–12 reps
4×/week, 16 week
4 × 4−10, 75%–90% one-repetition
maximum (1RM)
2×/week, 16 week
50%–70% 1RM, then 70%–80%
1RM, 10–15 reps
2×/week, 16 week
Progressive increase in workload
2×/week, 12 week
Progressive increase in workload
Design
EHC
EHC
EHC
EHC
EHC
OGTT
FSIGT
(plus tracer)
FSIGT
FSIGT
FSIGT
Testing
~10% ⇧ in leg glucose clearance
9% ⇧ in glucose infusion
48% ⇧ in glucose disposal
⇧ peripheral in 8 of 12 subjects, but ⇩
in 4 of 12; hepatic insulin sensitivity ⇧
24%
24% ⇧ glucose infusion with EHC
⇩ insulin during OGTT, fasting insulin
⇔ glucose during OGTT
16% ⇩ in insulin response
45% ⇧ in insulin sensitivity
25% ⇧ in insulin sensitivity, ⇧ fasting
glucose
33% ⇧ in insulin sensitivity
Major Findings
TABLE 5.1
Studies Incorporating Use of FSIGT or EHC Methodologies to Determine Effect of RT on Insulin Sensitivity
(Continued)
16
96 ± 24
48
24
22–24
72
48–72
24
168
Hour After
Last Bout
Christian K. Roberts
65
3×/week, 3 month
1 + × 12–15 reps
3×/week, 1 set up to 15 reps
(20 min/session)
3×/wk, 6 months 1–2 × 8–12 reps,
80% 1RM
26 ± 1 year M
67 ± 2 year M/F
50 ± 2 M
68 ± 4
63 ± 1 year M
Andersen et al.34
Reynolds et al.26
Klimcakova et al.35
Davidson et al.36
Ferrara et al.53
EHC
EHC
EHC
EHC
EHC
EHC
Testing
Reprinted with permission from Comprehensive Physiology 2013© 2013 American Physiological Society.
3×/week, 6 month
1–2 sets, 8–15 reps
RT cessation for 90 days, RT
was 3×/week, 3 months
periodized workload
3×/week, 16 week
2 × 10–12 reps
Design
69 ± 1 year M/F
Subject Population
Ryan et al.33
Study
~20% increase in glucose disposal
Nonsignificant ⇧ in insulin sensitivity
24% ⇧ glucose disposal
15% ⇧ in glucose disposal,
⇔ insulin response, fasting insulin
11% ⇩ in insulin sensitivity
Nonsignificant ⇧ in insulin sensitivity
Major Findings
TABLE 5.1 (Continued)
Studies Incorporating Use of FSIGT or EHC Methodologies to Determine Effect of RT on Insulin Sensitivity
24–36
36–48
48–72
24
—
24–36
Hour After
Last Bout
66
Effects of Resistance Training on Insulin Sensitivity and Glycemic Control
Christian K. Roberts
67
Similar findings have been noted in subjects with T2D. Ishii et al.27 noted that
RT increased glucose disposal by 48% in lean subjects with T2D, without a change
in VO2max, weight loss, or body composition. In older men with T2D, a 2 days per
week RT program led to a 45% increase in insulin sensitivity and a 10% decrease
in abdominal fat, without a change in body weight29 and an estimated increase in
energy intake of 15%. In addition, Misra et al.39 noted improved insulin sensitivity
by an insulin tolerance test in South Indians with T2D.
Many RT studies have also used OGTT as an index of insulin action, and some,40,41
but not all,31,42–44 have noted improvements in glucose tolerance after RT. Plasma
insulin concentrations have been shown to decrease during OGTT.31,40–43 Using the
OGTT method, RT improves insulin action including subjects with impaired glucose
tolerance (IGT) or T2D.32,41,45,46 Alternatively, glucose and insulin area under the
curves (AUCs) were not altered by 6 weeks of RT in women with T2D.47
Generally, use of the EHC and FSIGT are the gold standard methods for estimation of insulin sensitivity and β-cell function. However, these methods are expensive, not simple to perform and generally not applicable in standard clinical practice.
Thus, many studies mentioned above have used the OGTT that is less expensive, and
its simplicity allows for more widespread use. The OGTT has classically been used
to estimate glucose tolerance via AUCs or the Matsuda index48 of insulin sensitivity. However, given the advantages of the technique, Abdul-Ghani et al.49 validated
a muscle insulin sensitivity index (ISI) and hepatic insulin resistance index (IRI)
with EHC data,50 and an oral disposition index (DI), an estimate of β-cell function,
from FSIGT testing has been validated.51 Roberts et al. (unpublished observations)
recently showed that 12 weeks of RT, in concert with an improvement in glucose
tolerance, improved muscle ISI and oral DI, without a change in hepatic IRI, suggesting that RT affects insulin sensitivity in skeletal muscle but not liver (Figure 5.1).
Overall, a systemic review of 20 studies found that supervised resistance exercise
training improved glycemic control and insulin sensitivity in a wide variety of study
groups.52 However, without supervision, RT compliance and glycemic control are
generally less, suggesting either the need for supervision or alternative incentives to
maximize training-induced benefits.
AEROBIC VERSUS RESISTANCE TRAINING
A handful of studies have directly compared the effects of AT and RT on insulin
action. Smutok et al.40 noted that both modalities led to decreased AUC for both
glucose and insulin and that no significant difference between the interventions were
noted, nor were there any changes in body weight, although body fat percentage
dropped slightly in the AT group. This group also studied the effects of AT or RT
in subjects with T2D or IGT, noting similar results.41 Also, RT and AT were compared in older obese men 3 days per week for 6 months and noted similar 20%–25%
increases with EHC in both groups, despite a decrease in body weight of 2% in the
aerobic group and an increase in body weight of 2% in the RT group.53 In subjects
with T2D, both AT and RT for 4 months results in increases in glucose disposal
rates during EHC.54 In addition, the effects of AT was superior to RT.36 It should
be noted that the total exercise time was 60 minutes per week in the RT group and
68
Effects of Resistance Training on Insulin Sensitivity and Glycemic Control
Pretest
Posttest
Glucose AUC (mg/dL)*min
180
Glucose (mg/dL)
160
140
120
100
80
0
30
60
Time (min)
90
120
Posttest
13,000
12,000
Insulin AUC
(uUI/mL)*min
60
40
20
0
30
60
Time (min)
90
Pretest
Posttest
Pretest
Posttest
1
Hepatic IRI
0.8
4000
3000
0.2
1000
Pretest
(c)
Posttest
0
0.6
0.4
2000
0.5
2000
1.2
5000
1
4000
(b)
6000
1.5
6000
0
7000
2
8000
120
DI
Insulin (uUI/mL)
14,000
10,000
80
2.5
Muscle ISI
15,000
12,000
100
0
16,000
(a)
Pretest
0
17,000
Pretest
(d)
Posttest
0
Pretest
(e)
Posttest
FIGURE 5.1 Effects of 12 weeks of RT on glucose (a) and insulin (b) levels during a 2 hour
oral glucose tolerance test and changes in muscle ISI (c), hepatic IRI (d), and oral DI (e). Data
are presented as median and median absolute deviation. *p < .05.
Christian K. Roberts
69
150 minutes per week in the aerobic group, and suggests when making comparisons
of different training modalities, attempting to match the training overload is critical. However, given differences in energy expenditure that exist with different RT
prescriptions, there is inherent difficulty in trying to match the overload of the different training modalities. Because of this conundrum, from a feasibility standpoint,
one option is to match the duration of the training. Thus, it is important to report the
exercise time and attempt to match the relative intensity when comparing these different training modalities.
MECHANISMS
Although the mechanism for the increase in insulin sensitivity with aerobic exercise
training has been often investigated, the increase with resistance exercise training is
far less studied. Some insight has been provided by cross-sectional and comparison
studies. Takala et al.55 noted no effect of RT on insulin-stimulated glucose uptake
per kilogram of muscle mass, and the positive effect of RT was attributed to the
larger muscle mass. Yki-Jarvinen and Koivisto20 noted that both trained weight lifters and long-distance runners exhibited higher glucose disposal compared to controls during EHC; however, when calculating per LBM, only the runners exhibited
higher values, suggesting that, at least in part, the mechanism for increased glucose
disposal in resistance-trained subjects is due to increased skeletal muscle mass. This
is in agreement with AT versus RT,22 which noted increases in glucose disposal
rate during an EHC with both modalities of training, and when these rates were
express per fat-free mass (FFM), the improved insulin sensitivity persisted in the
AT group but not in the RT group. In other aforementioned studies, the EHC clamp
increases were expressed relative to FFM,27,31,32 suggesting effects independent of
LBM changes. Miller et al.42 noted a significant correlation between insulin AUC
and increase in LBM (r = 0.89).
These data suggest that the mechanism for the improvement with RT, at least in
part, not surprisingly may be due to molecular changes in skeletal muscle. Dela and
Kjaer56 suggested that RT improves insulin action by unknown mechanisms in addition to increased muscle mass. Despite numerous studies investigating the effects
of RT on insulin sensitivity, few studies have attempted to investigate the molecular mechanism(s) responsible for improved insulin sensitivity. Miller et al.31 noted a
40% increase in nonoxidative glucose disposal during insulin infusion, suggesting
increased glycogen synthesis. In addition, in the aforementioned study by Castenada
et al.,57 glycogen stores increased by an estimated 31% with RT, but decreased by
23% in control. Holten et al.32 noted, using the single-leg RT model, increased glucose clearance more than what could be explained by increases in LBM alone. In
addition, these authors reported increased protein content of GLUT4 (T2D subjects
only), insulin receptor, protein kinase B-α/β, glycogen synthase (GS), as well as GS
total activity; however, no training effect was observed for protein content of insulin receptor substrate 1 (IRS-1) or the p85 subunit of phosphatidylinositol-3-kinase
(PI3K). Jorge et al.58 did note increased IRS-1 in response to 12 weeks of RT but not
AT in patients with T2D. RT also did not alter muscle GS total activity, glycogen
70
Effects of Resistance Training on Insulin Sensitivity and Glycemic Control
content, or levels of PI3K in overweight/obese older men.53 Roberts et al. (unpublished data) recently showed that 12 weeks of RT increased GLUT4, HKII, and
AKT2 in obese young men. Alternatively, GLUT4 was not altered in older Hispanic
adults with T2D, although in the latter, sodium-dependent glucose cotransporter
system (hSGLT3) transcript levels in the vastus lateralis muscle was positively correlated with glucose uptake.59 In subjects undergoing bed rest, GLUT4 decreased in
vastus lateralis after bed rest but increased in subjects undergoing RT during bed
rest.60 In addition, regarding the possibility that 5’ AMP-activated protein kinase
(AMPK) might be involved, RT resulted in similar changes to various AMPK
­subunit i­soforms in subjects with T2D and healthy controls.61
Given the dearth of evidence in humans on the molecular mechanism, it is
interesting to note that Krisan et al.62 noted, using a rodent model of RT, increased
GLUT4 content and IRS-1 associated PI3K, AKT, and atypical PKC-ζ/λ activities.
Some further insight has been provided by Andersen et al.,34 who noted that the
decrease in leg glucose uptake, expressed relative to leg muscle mass, was associated
with decreased glycogen content and increased MHC IIx; however, GLUT4 mRNA,
enzymatic changes, or capillary density did not change with detraining.
To try to gain some insight into the potential contribution of adipose tissue to
altered insulin sensitivity in muscle, Klimcakova et al.35 found no effects of RT on
the mRNA levels of adiponectin, leptin, Il-1β, IL-6, and TNFα from subcutaneous adipose tissue. In addition, the effects of RT on adiposity in relation to T2D
is unknown. For example, it is well known that intramyocellular lipid content is
elevated in T2D; however, the mechanistic contribution of this to the pathogenesis of
T2D is unclear. Likewise, the effects of RT on myocellular lipids or lipid metabolites
is unknown. Three studies have investigated biopsy measured intramuscular triglycerides (IMTG) changes with acute RT.63–65 Type I fiber IMTG content decreased
with an acute bout of RT and then returned to pre-exercise levels 2 hours post, indicating that RT may be a training modality associated with dynamic changes in myocellular lipid metabolism.64 In bodybuilders, the drop in IMTG during acute RT was
proportional to the resting level.65
Overall, it is evident that there is a lack of clarity with respect to what are the
molecular mechanisms responsible for the improvement in insulin sensitivity with
RT, and this remains an important area for future research.
GLYCEMIC CONTROL
For T2D, one of the current standards of glycemic control is HbA1c. Along these
lines, in the Action in Diabetes and Vascular Disease: Preterax and Diamicron
Modified Release Controlled Evaluation trial, it was recently estimated that for
­levels >7.0%, every 1% higher HbA1c level was associated with a 38% higher risk of
a macrovascular event or death.66
Several studies have also investigated the effects of RT on HbA1c with mixed results.
In general, when studies use subjects without prediabetes or diabetes, HbA1c does not
change. For example, we (Roberts et al., unpublished data) noted no change in HbA1c
with 12 weeks of RT in overweight and obese young men. This was not surprising since
HbA1c was not elevated and fasting plasma glucose and insulin did not change.
Christian K. Roberts
71
Hence, HbA1c might improve only in those with elevated HbA1c states, such as
diabetes. However, still the data are far from conclusive. For example, several studies noted decreased HbA1c in Latinos57,67 and Whites68 with T2D after 16 weeks of
RT. Cauza et al.69 noted a similar decrease with 4 months of RT in T2D patients.
Following 10 weeks of RT, HbA1c decreased ~1.6% in middle-aged adults with
T2D.70 These decreases appear to be comparable to that noted with monotherapy
and RT elicits many additional benefits. Furthermore, when RT was added to a diet
intervention, HbA1c decreased 1.2% in older adults with T2D; however, there was
no change in the diet only group.46 Other studies, such as the Diabetes Aerobic and
Resistance Exercise trial,71 the Resistance Versus Aerobic Exercise in Type 2 Diabetes
(RAED2),54 a 3-month, nonrandomized trial,39 and earlier studies by Eriksson et al.72
and Honkola et al.,73 noted smaller (0.35%–0.6%) changes in HbA1c after 3–6 months
of RT. Cauza et al.74 noted greater benefits of RT as opposed to endurance training,
on glycemic control (mean blood glucose decreased 15%), in patients with T2D using
continuous glucose monitoring, despite no change in HbA1c. Interestingly, in the
study by Casteneda et al.,57 the decrease in HbA1c occurred in concert with diabetes
medications being reduced in 72% of subjects in the RT group (3% in control) and a
42% increase in medications in control (7% in RT).
On the other hand, HbA1c did not decrease significantly in T2D with RT in several studies.29,74–78 In addition, in the aforementioned study by Ishii et al.,27 HbA1c
decreased 2% with RT, however, did not achieve significance. In the Health Benefits
of Aerobic and Resistance Training in individuals with type 2 diabetes (DART-D)
trial, there was no change in HbA1c after a 9-month RT intervention in middle-aged
subjects with T2D.79 In some instances, this may be due, in part, to the shorter training
period,27,77 nonsupervised training,75,80 and/or in sufficient training overload, as evidenced by a lack of change in body composition.27 Thus, the effects on HbA1c (as with
other phenotypes related to insulin action) may be related to the duration, intensity,
and volume of the training program, as well as the structured or supervised nature
of most trials compared with advice or home-based exercise.81 Ultimately, this is a
critical challenge to consider, given the costs associated with structured, supervised
activities such as gym membership or equipment purchase, instruction costs, and
travel time to exercise facilities. For example, the intensity of training decreased in
the home-based phase of the aforementioned study.80,82 Currently, recommendations
include initial supervision and periodic assessments by qualified exercise specialists.82
RECOMMENDATIONS
As studies to date have incorporated a variety of training programs, there is not a
one-size-fits-all approach to RT for improvements in insulin action and glycemic
control. However, most trials producing a benefit have incorporated training overloads that include ~3 days per week of training, 5–15 repetitions, and a variety of
training intensities. However, some of the aforementioned studies have suggested
that relative intensity may be a critical element to optimize the training adaptations. Given that often trainees will be new to this training modality, it is important
to begin the training with lighter loads in a learning phase. Also, future studies
should look to emphasize periodization models to facilitate optimal progress.
72
Effects of Resistance Training on Insulin Sensitivity and Glycemic Control
INDIVIDUALIZED PROGRAMS
Not all with insulin resistance will respond similarly to any exercise program, and some,
but not others, will likely respond better to RT compared with other forms of exercise.
In the HERITAGE study, Boulé et al.83 noted that although a majority of subjects exhibited an improvement in intravenous glucose tolerance test estimates of insulin sensitivity with AT, the individual response noted was markedly variable in improvements
after 20 weeks of cycle ergometer training, with some subjects being unresponsive.
In addition, they noted the change in insulin secretion was dependent on the baseline
glucose tolerance. We noted (Roberts et al., unpublished data) that glucose AUC (32%
decrease to 16% increase), LBM (<1% to 9% increase), strength (2%–60% increase),
and changes in total fat mass (33% decrease to 13% increase) with RT in young adult
males was highly variable. Therefore, as we learn more about the interaction between
genetic variation and RT, we can identify those who may respond to RT interventions
and better individualize training programs to optimize risk factor modification.
FUTURE DIRECTIONS
Overall, several areas of future research is needed. First, to date, there are no trials
investigating the primary prevention or reversal of T2D. Second, the potential synergistic effects with pharmacotherapies are needed. Third, studies to test the mechanism
by which RT improves insulin action and prevent T2D are needed. This includes investigation of muscle adaptations and adipose tissue, liver, and pancreatic metabolism.
Finally, future studies are needed to provide insight into optimization of individualized
training programs, given differences in motivational factors (psychological), genetic
differences, and known individualized benefits that accrue independent of weight loss.
CONCLUSION
The American College of Sports Medicine/American Diabetes Association joint
statement emphasized that exercise (including RT) plays a major role in the prevention and control of insulin resistance and T2D,84 but large-scale randomized trials
are needed to determine if RT can prevent T2D. It is evident that the next frontier
in RT and T2D research is in the areas of prevention trials and individual effects
that might help determine individual responsiveness to help optimize prevention and
treatment for the growing epidemics of diabetes and prediabetes.
Some portions of this chapter have been used with permission from Comprehensive
Physiology 2013© 2013 American Physiological Society.
REFERENCES
1. Centers for Disease Control and Prevention. 2012. Available from http://www.cdc.gov/
diabetes/statistics. Accessed August 31, 2012.
2. American Diabetes Association. Available from http://www.diabetes.org/diabetesbasics/diabetes-statistics/. Accessed August 31, 2012.
3. American Diabetes Association. National Diabetes Fact Sheet, 2011. www.diabetes.org.
Accessed August 31, 2012.
Christian K. Roberts
73
4. Boyle J, Thompson T, Gregg E, Barker L, Williamson D. Projection of the year 2050
burden of diabetes in the US adult population: dynamic modeling of incidence, mortality, and prediabetes prevalence. Popul Health Metr 2010;8:29.
5. American Diabetes Association. Economic costs of diabetes in the U.S. in 2012.
Diabetes Care. 2013;36:1033–1046.
6. Carnethon MR, De Chavez PJ, Biggs ML et al. Association of weight status with mortality in adults with incident diabetes. JAMA 2012;308:581–90.
7. Booth FW, Roberts CK, Laye MJ. Lack of exercise is a major cause of chronic diseases.
Comprehensive Physiol 2012;2:1143–211.
8. Roberts CK, Barnard RJ. Effects of exercise and diet on chronic disease. J Appl Physiol
2005;98:3–30.
9. Physical Activity Guideline Advisory Committee Report. Washington, DC: U.S.
Department of Health and Human Services; 2008.
10. American Diabetes Association. Standards of medical care in diabetes—2012. Diabetes
Care 2012;35(suppl 1):S11–63.
11. Carnethon M. Can we out-run the diabetes epidemic? Diabetologia 2007;50:1113–5.
12. Grøntved A, Rimm EB, Willett WC, Andersen LB, Hu FB. A prospective study of weight
training and risk of type 2 diabetes mellitus in men. Arch Intern Med 2012;172:1306–12.
13. DeFronzo RA. Lilly lecture 1987. The triumvirate: beta-cell, muscle, liver. A collusion
responsible for NIDDM. Diabetes 1988;37:667–87.
14. Jurca R, Lamonte MJ, Church TS et al. Associations of muscle strength and fitness with
metabolic syndrome in men. Med Sci Sports Exerc 2004;36:1301–7.
15. Jurca R, Lamonte MJ, Barlow CE, Kampert JB, Church TS, Blair SN. Association of
muscular strength with incidence of metabolic syndrome in men. Med Sci Sports Exerc
2005;37:1849–55.
16. Wijndaele K, Duvigneaud N, Matton L et al. Muscular strength, aerobic fitness, and
metabolic syndrome risk in flemish adults. Med Sci Sports Exerc 2007;39:233–40.
17. Atlantis E, Martin SA, Haren MT, Taylor AW, Wittert GA. Inverse associations between
muscle mass, strength, and the metabolic syndrome. Metabolism 2009;58:1013–22.
18. Cheng YJ, Gregg EW, De Rekeneire N et al. Muscle-strengthening activity and its association with insulin sensitivity. Diabetes Care 2007;30:2264–70.
19. Barzilay JI, Cotsonis GA, Walston J et al. Insulin resistance is associated with decreased
quadriceps muscle strength in nondiabetic adults aged > or = 70 years. Diabetes Care
2009;32:736–8.
20. Yki-Jarvinen H, Koivisto VA. Effects of body composition on insulin sensitivity.
Diabetes 1983;32:965–9.
21. Szczypaczewska M, Nazar K, Kaciuba-Uscilko H. Glucose tolerance and insulin
response to glucose load in body builders. Int J Sports Med 1989;10:34–7.
22. Poehlman ET, Dvorak RV, DeNino WF, Brochu M, Ades PA. Effects of resistance training and endurance training on insulin sensitivity in nonobese, young women: a controlled randomized trial. J Clin Endocrinol Metab 2000;85:2463–8.
23. Shaibi GQ, Cruz ML, Ball GD et al. Effects of resistance training on insulin sensitivity
in overweight Latino adolescent males. Med Sci Sports Exerc 2006;38:1208–15.
24. Zachwieja JJ, Toffolo G, Cobelli C, Bier DM, Yarasheski KE. Resistance exercise
and growth hormone administration in older men: effects on insulin sensitivity
and secretion during a stable-label intravenous glucose tolerance test. Metabolism
1996;45:254–60.
25. Ryan AS, Pratley RE, Goldberg AP, Elahi D. Resistive training increases insulin action
in postmenopausal women. J Gerontol A Biol Sci Med Sci 1996;51:M199–205.
26. Reynolds IVTH, Supiano MA, Dengel DR. Resistance training enhances insulin-­
mediated glucose disposal with minimal effect on the tumor necrosis factor-alpha system in older hypertensives. Metabolism 2004;53:397–402.
74
Effects of Resistance Training on Insulin Sensitivity and Glycemic Control
27. Ishii T, Yamakita T, Sato T, Tanaka S, Fujii S. Resistance training improves insulin sensitivity in NIDDM subjects without altering maximal oxygen uptake. Diabetes Care
1998;21:1353–5.
28. Monnier L, Mas E, Ginet C et al. Activation of oxidative stress by acute glucose fluctuations compared with sustained chronic hyperglycemia in patients with type 2 diabetes.
JAMA 2006;295:1681–7.
29. Ibanez J, Izquierdo M, Arguelles I et al. Twice-weekly progressive resistance training
decreases abdominal fat and improves insulin sensitivity in older men with type 2 diabetes. Diabetes Care 2005;28:662–7.
30. Van Der Heijden G-J, Wang ZJ, Chu Z et al. Strength exercise improves muscle mass
and hepatic insulin sensitivity in obese youth. Med Sci Sports Exerc 2010;42:1973–80.
31. Miller JP, Pratley RE, Goldberg AP et al. Strength training increases insulin action in
healthy 50- to 65-yr-old men. J Appl Physiol 1994;77:1122–7.
32. Holten MK, Zacho M, Gaster M, Juel C, Wojtaszewski JFP, Dela F. Strength training
increases insulin-mediated glucose uptake, glut4 content, and insulin signaling in skeletal muscle in patients with type 2 diabetes. Diabetes 2004;53:294–305.
33. Ryan AS, Hurlbut DE, Lott ME et al. Insulin action after resistive training in insulin
resistant older men and women. J Am Geriatr Soc 2001;49:247–53.
34. Andersen JL, Schjerling P, Andersen LL, Dela F. Resistance training and insulin action
in humans: effects of de-training. J Physiol (Lond) 2003;551:1049–58.
35. Klimcakova E, Polak J, Moro C et al. Dynamic strength training improves insulin sensitivity without altering plasma levels and gene expression of adipokines in subcutaneous
adipose tissue in obese men. J Clin Endocrinol Metab 2006;91:5107–12.
36. Davidson LE, Hudson R, Kilpatrick K et al. Effects of exercise modality on insulin
resistance and functional limitation in older adults: a randomized controlled trial. Arch
Intern Med 2009;169:122–31.
37. Reynolds THIV, Supiano MA, Dengel DR. Regional differences in glucose clearance:
effects of insulin and resistance training on arm and leg glucose clearance in older
hypertensive individuals. J Appl Physiol 2007;102:985–91.
38. Polak J, Moro C, Klimcakova E et al. Dynamic strength training improves insulin sensitivity and functional balance between adrenergic alpha 2A and beta pathways in subcutaneous adipose tissue of obese subjects. Diabetologia 2005;48:2631–40.
39. Misra A, Alappan NK, Vikram NK et al. Effect of supervised progressive resistanceexercise training protocol on insulin sensitivity, glycemia, lipids, and body composition
in asian indians with type 2 diabetes. Diabetes Care 2008;31:1282–7.
40. Smutok MA, Kokkinos PF, Farmer C et al. Aerobic versus strength training for risk factor intervension in middle-aged men at high risk for coronary heart disease. Metabolism
1993;42(2):177–84.
41. Smutok MA, Reece C, Kokkinos PF et al. Effects of exercise training modality on glucose
tolerance in men with abnormal glucose regulation. Int J Sports Med 1994;15:283–9.
42. Miller WJ, Sherman WM, Ivy JL. Effect of strength training on glucose tolerance and
post-glucose insulin response. Med Sci Sports Exerc 1984;16:539–43.
43. Craig BW, Everhart J, Brown R. The influence of high-resistance training on glucose
tolerance in young and elderly subjects. Mech Ageing Dev 1989;49:147–57.
44. Hurley BF, Hagberg JM, Goldberg AP et al. Resistive training can reduce coronary risk
factors without altering VO2max or percent body fat. Med Sci Sports Exerc 1988;20:150–4.
45. Cuff DJ, Meneilly GS, Martin A, Ignaszewski A, Tildesley HD, Frohlich JJ. Effective
exercise modality to reduce insulin resistance in women with type 2 diabetes. Diabetes
Care 2003;26:2977–82.
46. Dunstan DW, Daly RM, Owen N et al. High-intensity resistance training improves glycemic control in older patients with type 2 diabetes. Diabetes Care 2002;25:1729–36.
Christian K. Roberts
75
47. Fenicchia LM, Kanaley JA, Azevedo JL, Jr. et al. Influence of resistance exercise training on glucose control in women with type 2 diabetes. Metabolism 2004;53:284–9.
48. Matsuda M, DeFronzo RA. Insulin sensitivity indices obtained from oral glucose tolerance
testing: comparison with the euglycemic insulin clamp. Diabetes Care 1999;22:1462–70.
49. Abdul-Ghani MA, Matsuda M, Balas B, DeFronzo RA. Muscle and liver insulin resistance indexes derived from the oral glucose tolerance test. Diabetes Care 2007;30:89–94.
50. Abdul-Ghani MA, Williams K, DeFronzo RA, Stern M. What is the best predictor of
future type 2 diabetes? Diabetes Care 2007;30:1544–8.
51. Retnakaran R, Shen S, Hanley AJ, Vuksan V, Hamilton JK, Zinman B. Hyperbolic relationship between insulin secretion and sensitivity on oral glucose tolerance test. Obesity
2008;16:1901–7.
52. Gordon BA, Benson AC, Bird SR, Fraser SF. Resistance training improves metabolic
health in type 2 diabetes: a systematic review. Diabetes Res Clin Pract 2009;83:157–75.
53. Ferrara CM, Goldberg AP, Ortmeyer HK, Ryan AS. Effects of aerobic and resistive
exercise training on glucose disposal and skeletal muscle metabolism in older men.
J Gerontol A Biol Sci Med Sci 2006;61:480–7.
54. Bacchi E, Negri C, Zanolin ME et al. Metabolic effects of aerobic training and resistance training in type 2 diabetic subjects. Diabetes Care 2012;35:676–82.
55. Takala TO, Nuutila P, Knuuti J, Luotolahti M, Yki-Jarvinen H. Insulin action on heart
and skeletal muscle glucose uptake in weight lifters and endurance athletes. Am J Physiol
1999;276:E706–11.
56. Dela F, Kjaer M. Resistance training, insulin sensitivity and muscle function in the
elderly. Essays Biochem 2006;42:75–88.
57. Castaneda C, Layne JE, Munoz-Orians L et al. A randomized controlled trial of resistance exercise training to improve glycemic control in older adults with type 2 diabetes.
Diabetes Care 2002;25:2335–41.
58. Jorge MLMP, de Oliveira VN, Resende NM et al. The effects of aerobic, resistance, and
combined exercise on metabolic control, inflammatory markers, adipocytokines, and muscle insulin signaling in patients with type 2 diabetes mellitus. Metabolism 2011;60:1244–52.
59. Castaneda F, Layne JE, Castaneda C. Skeletal muscle sodium glucose co-transporters in
older adults with type 2 diabetes undergoing resistance training. Int J Med Sci 2006;3:84–91.
60. Tabata I, Suzuki Y, Fukunaga T, Yokozeki T, Akima H, Funato K. Resistance training
affects GLUT-4 content in skeletal muscle of humans after 19 days of head-down bed
rest. J Appl Physiol 1999;86:909–14.
61. Wojtaszewski JFP, Birk JB, Frosig C, Holten M, Pilegaard H, Dela F. 5’AMP activated
protein kinase expression in human skeletal muscle: effects of strength training and type
2 diabetes. J Physiol (Lond) 2005;564:563–73.
62. Krisan AD, Collins DE, Crain AM et al. Resistance training enhances components of
the insulin signaling cascade in normal and high-fat-fed rodent skeletal muscle. J Appl
Physiol 2004;96:1691–700.
63. Harber MP, Crane JD, Douglass MD et al. Resistance exercise reduces muscular substrates in women. Int J Sports Med 2008;29:719–25.
64. Koopman R, Manders RJ, Jonkers RA, Hul GB, Kuipers H, van Loon LJ. Intramyocellular
lipid and glycogen content are reduced following resistance exercise in untrained healthy
males. Eur J Appl Physiol 2006;96:525–34.
65. Essén-Gustavsson B, Tesch P. Glycogen and triglyceride utilization in relation to muscle metabolic characteristics in men performing heavy-resistance exercise. Eur J Appl
Physiol Occup Physiol 1990;61:5–10.
66. Zoungas S, Chalmers J, Ninomiya T et al. Association of HbA1c levels with vascular
complications and death in patients with type 2 diabetes: evidence of glycaemic thresholds. Diabetologia 2012;55:636–43.
76
Effects of Resistance Training on Insulin Sensitivity and Glycemic Control
67. Brooks N, Layne JE, Gordon PL, Roubenoff R, Nelson ME, Castaneda-Sceppa C.
Strength training improves muscle quality and insulin sensitivity in Hispanic older
adults with type 2 diabetes. Int J Med Sci 2007;4:19–27.
68. Gordon PL, Vannier E, Hamada K et al. Resistance training alters cytokine gene expression in skeletal muscle of adults with type 2 diabetes. Int J Immunopathol Pharmacol
2006;19:739–49.
69. Cauza E, Strehblow C, Metz-Schimmerl S et al. Effects of progressive strength training
on muscle mass in type 2 diabetes mellitus patients determined by computed tomography. WMW Wien Med Wochenschr 2009;159:141–7.
70. Bweir S, Al-Jarrah M, Almalty A-M et al. Resistance exercise training lowers HbA1c more
than aerobic training in adults with type 2 diabetes. Diabetol Metab Syndr 2009;1:27.
71. Sigal RJ, Kenny GP, Boule NG et al. Effects of aerobic training, resistance training,
or both on glycemic control in type 2 diabetes: a randomized trial. Ann Intern Med
2007;147:357–69.
72. Eriksson J, Taimela S, Eriksson K, Parviainen S, Peltonen J, Kujala U. Resistance
training in the treatment of non-insulin-dependent diabetes mellitus. Int J Sports Med
1997;18:242–6.
73. Honkola A, Forsen T, Eriksson J. Resistance training improves the metabolic profile in
individuals with type 2 diabetes. Acta Diabetol 1997;34:245–8.
74. Cauza E, Hanusch-Enserer U, Strasser B, Kostner K, Dunky A, Haber P. Strength and
endurance training lead to different post exercise glucose profiles in diabetic participants using a continuous subcutaneous glucose monitoring system. Eur J Clin Invest
2005;35:745–51.
75. Cohen ND, Dunstan DW, Robinson C, Vulikh E, Zimmet PZ, Shaw JE. Improved endothelial function following a 14-month resistance exercise training program in adults with
type 2 diabetes. Diabetes Res Clin Pract 2008;79:405–11.
76. Baldi JC, Snowling N. Resistance training improves glycaemic control in obese type 2
diabetic men. Int J Sports Med 2003;24:419–23.
77. Dunstan DW, Puddey IB, Beilin LJ, Burke V, Morton AR, Stanton KG. Effects of a
short-term circuit weight training program on glycaemic control in NIDDM. Diabetes
Res Clin Pract 1998;40:53–61.
78. Plotnikoff RC, Eves N, Jung M, Sigal RJ, Padwal R, Karunamuni N. Multicomponent,
home-based resistance training for obese adults with type 2 diabetes: a randomized controlled trial. Int J Obes 2010;34:1733–41.
79. Church TS, Blair SN, Cocreham S et al. Effects of aerobic and resistance training on
hemoglobin a1c levels in patients with type 2 diabetes: a randomized controlled trial.
JAMA 2010;304:2253–62.
80. Dunstan DW, Daly RM, Owen N et al. Home-based resistance training is not sufficient
to maintain improved glycemic control following supervised training in older individuals with type 2 diabetes. Diabetes Care 2005;28:3–9.
81. Umpierre D, Ribeiro PA, Kramer CK et al. Physical activity advice only or structured
exercise training and association with HbA1c levels in type 2 diabetes: a systematic
review and meta-analysis. JAMA 2011;305:1790–9.
82. Sigal RJ, Kenny GP, Wasserman DH, Castaneda-Sceppa C, White RD. Physical activity/exercise and type 2 diabetes: a consensus statement from the American Diabetes
Association. Diabetes Care 2006;29:1433–8.
83. Boule NG, Weisnagel SJ, Lakka TA et al. Effects of exercise training on glucose homeostasis: the HERITAGE Family Study. Diabetes Care 2005;28:108–14.
84. Colberg SR, Sigal RJ, Fernhall B et al. Exercise and type 2 diabetes: the American
College of Sports Medicine and the American Diabetes Association: joint position statement executive summary. Diabetes Care 2010;33:2692–6.
6
Resistance Training in
Chronic Renal Failure
Birinder S. Cheema and Danwin Chan
CONTENTS
Introduction............................................................................................................... 81
Diagnosis and Classification..................................................................................... 82
Conventional Hemodialysis Treatment..................................................................... 83
Resistance Training for the Primary Prevention of Chronic Kidney Disease...........84
Resistance Training in Chronic Kidney Disease and End-Stage Renal Disease......84
Kidney Function...................................................................................................84
Skeletal Muscle Wasting and Inflammation......................................................... 85
Physical Functioning and Quality of Life............................................................ 91
Forearm Exercise for Arteriovenous Fistula Maturation......................................92
Hemodialysis-Induced Catabolism...................................................................... 93
Efficacy of Intradialytic Resistance Training............................................................94
Exercise Recommendations...................................................................................... 95
References.................................................................................................................96
INTRODUCTION
Chronic kidney disease (CKD), also known as chronic renal failure, is an irreversible disease characterized by the progressive loss of kidney function over
time, usually a period of months to years.1,2 Prevalence data for CKD are difficult to ascertain given that the early stages of the disease process are typically
asymptomatic,3 and given inconsistencies in diagnostic and classification systems.4 However, recent data from the National Health and Nutrition Examination
Survey (NHANES) suggest that 13.1% of adults (aged >20 years) living in the
United States had Stage 1–4 CKD in 2004.5 More recent estimates by the United
States Renal Data System suggest that 15.1% of the adult population in the United
States has CKD.6
The prevalence of CKD has increased gradually over the past several decades
within the United States5 and globally,7 and these trends are expected to continue.7,8 Global estimates suggest that the prevalence of CKD is threatening to
reach epidemic proportions in both developed and developing countries and that
much of the burden can be attributed to the obesity/type 2 diabetes pandemic.7
Certain ethnic populations are severely affected by late-stage CKD. These cohorts
include African-Americans9; Hispanic-Americans10; and the aboriginal people of
77
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Resistance Training in Chronic Renal Failure
Canada,11 the United States,12 New Zealand,13 and Australia,14 among others. The
prevention and treatment of CKD globally will become a major challenge in the
coming decades.7
Diabetes and hypertension are currently the leading causes of CKD accounting for
almost 70% of cases.15 Other causes include glomerulonephritis, IgA ­nephropathy,
polycystic kidney disease, analgesic (aspirin, ibuprofen, and paracetamol) use, systemic lupus erythematosus, benign prostate hyperplasia, HIV infection, amyloidosis, kidney infections, kidney stones, sickle cell disease, heroine use, and certain
cancers.16 The etiology of CKD is influenced by infectious diseases and genetic
predisposition only in a minority of cases (e.g., polycystic kidney disease and HIV
infection), while the majority of cases are heavily influenced by lifestyle factors.
Physical inactivity, cigarette smoking, and associated diseases (e.g., obesity, hypertension, dyslipidemia, and diabetes) are consistently recognized as major modifiable
risk factors for CKD.17,18
Individuals with a diagnosis of CKD are at significantly elevated risk of cardiovascular disease and all cause mortality versus healthy peers.19 Cardiovascular
disease remains the leading cause of death in this population and the risk of cardiovascular mortality increases as kidney function declines.20 Notably, mortality
rates due to cardiovascular disease have been reported to be 10–30 times higher in
dialysis-dependent CKD patients than in the general population.20
DIAGNOSIS AND CLASSIFICATION
Healthy kidneys filter approximately 170 L of blood and process 1.5 L of urine each
day.21 Similar to the lungs, the kidneys can be considered “overbuilt” in that the kidneys can incur tremendous damage and still sustain life without any adverse effects.
For example, human beings can live normal, healthy lives with just a single kidney
and have a life expectancy no different to that of the general population.22
CKD is defined according to the presence or absence of kidney damage and the
level of kidney function, regardless of disease etiology.16 CKD presents with no or
few symptoms until the advanced stages.3,16 Therefore, diagnosis can only be undertaken via laboratory tests, including urinalysis, blood tests, imaging tests, and kidney
biopsy.16 Each diagnostic method has limitations and, therefore, multiple methods
are typically used.16 However, definitive diagnosis is based on biopsy or imaging
studies.16 The pathophysiology of CKD depends on the causative factors. Vascular
changes that occur with disease progression include ischemia and stenosis of the
small and large vessels of the kidney. Damage to the glomeruli and renal tubules
within the kidney may also underlie CKD progression.
Urinalysis can be used to detect the presence of urine casts and crystals.16 In addition, the urine is analyzed for total protein, albumin, urea nitrogen, and creatinine
concentrations, measures that are all elevated in CKD. The amount of creatinine and
urea in the urine serves as marker of renal function and can be used to compute the
glomerular filtration rate (GFR). The Kidney Disease Outcomes Quality Initiative
(K/DOQI) has classified the severity (progression) of kidney disease by the decline
in the GFR (Table 6.1).16 The GFR is widely accepted as the best overall measure of
kidney function.16
79
Birinder S. Cheema and Danwin Chan
TABLE 6.1
Stages of CKD as Defined by the K/DOQI
Stage
Description
GFR (mL/min/1.73 m2)
≥90
1
Kidney damage with
normal or elevated GFR
2
60–89
3
Kidney damage with mild
decrease in GFR
Moderate decrease in GFR
4
Severe decrease in GFR
15–29
5
Kidney failure
30–59
<15 or dialysis dependent
Action
Diagnosis and treatment,
treatment of comorbid
conditions, slowing
progression, and
cardiovascular disease risk
reduction
Estimating rate of
progression
Evaluating and treating
complications
Preparation for kidney
replacement therapy
Kidney transplanted or
receiving dialysis
Source: National Kidney Foundation, Am J Kidney Dis, 39, S1–266, 2002.
However, it should be noted that glomerular injury in the early stages of CKD may
induce compensatory glomerular hypertrophy, hypertension, and hyperfiltration,
reflected by an increase of GFR.16 However, this rise of GFR is typically followed
by the progressive decline of GFR, if preventative measures are not undertaken.
Hyperfiltration has often been noted in individuals with diabetes mellitus, polycystic
kidney disease, hypertension, and obesity.23–25
In Stage 4 CKD (GFR = 15–29 mL/min/1.73 m2), the patient is required to prepare for kidney replacement therapy, including hemodialysis, peritoneal dialysis, or
kidney transplant. Stage 5 CKD (GFR < 15-mL/min/1.73 m2) is also known as endstage renal disease (ESRD) or end-stage kidney disease. In Stage 5, the kidneys
can no longer function at a level to sustain life.16 Hence, individuals with ESRD are
dialysis-dependent for the remainder of their lifetime, or until a successful kidney
transplant.16
CONVENTIONAL HEMODIALYSIS TREATMENT
Of the patients diagnosed with ESRD, more than 91% undertake h­ emodialysis treatment, 6% undertake peritoneal dialysis, and only 2% receive a transplant.6 Failure
to undertake dialysis therapy in patients with Stage 5 CKD will result in imminent
death.26 Conventional hemodialysis treatment is typically received three times per
week for approximately 3–5 hours per treatment at an outpatient clinic. Specialist
nursing staff is involved in administering the dialysis sessions. Alternatives to conventional hemodialysis include daily hemodialysis treatment or nocturnal ­hemodialysis,
which are both typically administered by the patient and/or a trained care provider
at home. During conventional hemodialysis, blood is continually drawn out of the
80
Resistance Training in Chronic Renal Failure
body at a rate of 200–400 mL/min to the dialysis machine where it is filtered and
then returned. The entire blood volume of the patient (approximately 5L) circulates
through the machine every 15 minutes. Sodium bicarbonate is often administered
during hemodialysis to correct blood acidity. Recombinant human erythropoietin
may be administered to correct anemia. Common side effects of hemodialysis
treatment include hypotension, fatigue, chest pains, leg cramps, nausea, and headaches. Such symptoms may occur during treatment and may persist after treatment.
Hemodialysis patients are typically older and suffer from many comorbid conditions
and, therefore, medication use is often high. Depression is a common comorbidity in
this patient population.
RESISTANCE TRAINING FOR THE PRIMARY PREVENTION
OF CHRONIC KIDNEY DISEASE
Interventions for the primary prevention of CKD must target such risk factors as inactivity, overweight-obesity, insulin resistance, diabetes, hypertension, dyslipidemia,
cigarette smoking, and low-quality westernized diet. Scientific investigations have
shown that resistance training (RT) prescribed in isolation can reverse overweightobesity,27 type 2 diabetes27–30 and hypertension.31–33 Hence, interventions such as RT
have the potential to prevent CKD and hence drastically mitigate the rising incidence
of CRF globally.7
RESISTANCE TRAINING IN CHRONIC KIDNEY DISEASE
AND END-STAGE RENAL DISEASE
Exercise training has been investigated in CKD since the late 1970s. Most of these
investigations have involved hemodialysis patients, and have prescribed ­aerobic
training in isolation or in combination with light to moderate strength training.34–36
Investigations that have prescribed RT in isolation have all been published after
the year 2000.37–50 Likewise, the majority of these studies have enrolled hemodialysis patients,39–42,46,47,49–54 while only a few trials have enrolled predialysis
patients.37,38,43–45,48 We are unaware of any study that has prescribed RT in patients
receiving peritoneal dialysis or kidney transplants.
Research of the therapeutic potential of RT in patients with CKD is in its early
stages, and many research questions remain to be answered. Nevertheless, the studies
published to date, which have prescribed RT in conventional fitness or rehabilitation
settings, as well as during hemodialysis treatment, have largely been of good quality39–45,51,52 and have provided convincing evidence that RT is safe and can induce a
broad spectrum of physiological, functional, and psychological adaptations that are
particularly important for patients with CKD and ESRD.
Kidney Function
RT has been proven effective in targeting the main metabolic risk factors contributing
to kidney damage (e.g., hypertension, type 2 diabetes, dyslipidemia, and obesity).27–33,55
Therefore, it is highly likely that RT can also play a significant role in slowing disease
Birinder S. Cheema and Danwin Chan
81
progression in those already diagnosed with the disease. Interventions that induce
fat loss may be particularly important for this purpose. Many trials in patients with
CKD have shown that weight loss induced via hypocaloric diet, bariatric surgery,
drugs, exercise, or lifestyle modification can reduce proteinuria and albuminuria,
which indicate improved renal function.56,57 Weight loss can also normalize the GFR
in overweight and obese individuals with glomerular hyperfiltration.57–59 There is substantial evidence that regular RT can increase total fat-free mass and resting metabolic rate contributing to the mobilization/utilization of visceral and subcutaneous
adipose tissue, thereby reducing whole body adiposity.27 Hence, RT may potentially
reduce proteinuria and albuminuria in individuals with CKD by inducing favorable
shifts in body composition. Trials are presently required to test this hypothesis.
There is currently no consensus regarding the effect of preventative therapies on
the GFR. The data suggest that reducing hypertension is particularly important for
slowing CKD progression.27,60 Some studies have actually shown that the GFR in
patients with CKD can be increased with aerobic training interventions involving
cycling or swimming.61–63 However, the findings are not always consistent.64
To our knowledge, only one trial has reported on the effect of RT on renal function
to date. Castaneda et al.45 conducted a randomized controlled trial that enrolled 26
patients with predialysis CKD (i.e., Stages 3–4). All 26 participants (aged >50 years)
adhered to a protein-restricted diet (0.6 g/kg/day) during the trial. Protein restriction
is typically prescribed for slowing disease progression.65 Fourteen of the participants
were assigned to a 12-week RT program, while 12 participants received sham training (unloaded exercises). RT was prescribed three sessions per week and involved
five exercises (chest press, leg press, lat pull-down, knee extension, and knee flexion)
performed for three sets at 80% of one repetition maximum (1RM). The training
loads were adjusted with strength adaptation. At the end of the 12-week intervention,
the RT group experienced a statistically significant increase in the GFR from baseline (+1.18 mL/min/1.73 m2) versus the sham exercise group (−1.62 mL/min/1.73 m2;
p = .046). The improvement of GFR was also reflected by a trend toward reduced
urinary creatinine concentration (p = .074).
At present, the mechanisms underlying the RT or aerobic exercise-induced
improvement of GFR45,61–63 are not known; however, the reduction of sympathetic
vasoconstrictor activity and metabolic risk factors (e.g., obesity, hypertension, and
insulin resistance) and improved endothelial function may be implicated.61,66 Largescale randomized controlled trials (RCTs) are required to confirm or refute the findings of Castaneda et al.,45 and elucidate the physiological mechanisms contributing
to the improvement of GFR with RT. Trials are also needed to determine the clinical
significance of improved GFR in Stage 4 CKD. It is generally accepted that Stages
3–4 CKD progresses to ESRD,67 however, it is possible that this deterioration can
be delayed or even prevented with RT and other robust forms of exercise training.
Skeletal Muscle Wasting and Inflammation
Skeletal muscle wasting, also called protein-energy malnutrition, is common in the
later stages of CKD (i.e., Stages 3–5).68–70 Factors such as acidosis,71 comorbid illnesses, corticosteroid usage, aging, oxidative stress, dialysis treatment,72 and very
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Resistance Training in Chronic Renal Failure
low levels of physical activity can all contribute to the loss and atrophy of muscle
fibers in this cohort.73,74 Low anabolic gene expression has been noted to underlie
the muscle wasting observed in ESRD.42 Muscle wasting can occur despite adequate
nutritional intake75 and is associated with an array of physiological consequences
including insulin resistance and chronic inflammation.75,76 Patients with CKD and
ESRD often suffer from low-grade inflammation reflected by chronic, two- to fourfold elevations of circulating proinflammatory cytokines including C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), among
others.77–81 Numerous investigations have shown that muscle wasting and inflammation, also termed the “malnutrition-inflammation complex,” are significant predictors of mortality in this cohort.79,82–84
Recent evidence suggests that RT can counteract muscle wasting and inflammation in CKD and ESRD. Castaneda et al.45 documented a significant increase in total
body potassium (p = .014), type I and type II muscle fiber cross-sectional area (CSA)
(p = .031 and p = .045, respectively), serum prealbumin (p = .050), leucine oxidation (p = .046) and trend toward increased mid-thigh CSA (p = .113) in participants
prescribed 12 weeks of RT versus sham exercise. The RT group also maintained
body weight while the sham exercise group reduced body weight (p = .049). These
adaptations are clinically relevant as they collectively indicate a reversal of skeletal muscle wasting despite a low protein diet. A subsequent report by Castaneda
et al.44 revealed that the anabolic effect was accompanied by reduced inflammation, reflected by reduction in CRP and IL-6. Moreover, the RT program elicited
an increase in skeletal muscle mitochondrial DNA.43 This is an important adaptation given that mitochondrial dysfunction is common in CKD85 and that associated
deficits in energy metabolism contribute to mortality.86 In contrast to these findings,
a study by Heiwe et al.37 found no significant change in type I, type IIa, or type IIb
CSA, despite improvements in 1RM, in 12 elderly predialysis (GFR ≤ 25 mL/min)
patients prescribed 12 weeks of RT. Notably, the RT regimen in this study involved
only knee extensor exercises at a low intensity (60% of 1RM) (Table 6.2).
Three recent RCTs have shown that RT can reduce or reverse muscle wasting and
inflammatory markers in patients with ESRD receiving hemodialysis treatment.51
Cheema et al.39–41 evaluated the effect of a supervised RT program that prescribed
three sessions per week during routine hemodialysis treatment in 49 patients with
ESRD. The regimen has been fully detailed in a recent article.87 The limb containing the vascular access was exercised just prior to the dialysis session while all
other exercises were performed while the patient was in a seated or supine position receiving dialysis. During each RT session, two sets of eight repetitions of 10
exercises targeting the major muscle groups of the upper and lower extremities were
performed at a rating of perceived exertion (RPE) of 15-17/20 (“hard” to “very
hard”). Upper body exercises performed using free-weight dumbbells included the
shoulder press, side shoulder raise, triceps extension, biceps curl, and external shoulder rotation. Lower-body exercises, performed using weighted ankle cuffs included
seated knee extension, supine hip flexion, supine hip abduction, and supine straightlegged raise. Seated hamstring curls were performed using Thera-Band tubing (The
Hygenic Corporation, Akron, OH) attached to a fixed position on the weight trolley.
Abdominal musculature was targeted with bilateral leg raises in a supine position
43, 44, 45 Stage 3–4 CKD
14 TRN; 12 P
ESRD 10 TRN
ESRD 24 TRN
19 WLC
46, 47
39–41
37, 38
Resistance Type
During nondialysis time;
machine weights: leg press,
knee extension, and flexion;
chest press; compound row;
lateral raises; biceps curls;
triceps extensions; and
abdominal curls
Intradialytic RT; free weights:
shoulder press, side shoulder
raise, triceps extension, bicep
curls, external shoulder
rotation and bilateral leg raise/
leg lift; ankle weights: knee
extension, hip flexion and hip
abduction; elastic tubing:
hamstring curl
TRN = knee flexion and
extension, lat pull-down,
chest and leg press;
P = sham movements
Predialysis CKD, TRN = knee extensions,
16 TRN, 9
CNTL = no training
CNTL
Subject
Reference Characteristics
Training Prescription
Two sets of 8 repetitions at RPE
15–17, 3 times per week for
24 weeks. WLC group ­­crossedover to intervention at week 13
Three sets of eight repetitions at
80% 1RM, 3 times per week for
12 weeks 1RM tested each month
to adjust loading
Three sets of 20 repetitions of knee
extension at 60% 1RM, 3 times
per week for 12 weeks. 1RM tested
every 2 weeks to adjust loading
One set of 10–15 repetitions,
2 times weekly at initiation,
gradual increase of set/repetitions
every 2–3 weeks. Loads increased
with adaptation
TABLE 6.2
Resistance Training Interventions in CKD and ESRD
Key Findings in Isolated RT Group
(Continued)
Thigh muscle CSA and
Significant improved muscle
attenuation, CRP and other attenuation, CRP, anthropometrics,
cytokines, anthropometrics, total body strength, physical function
functional measures, QoL
and vitality QoL No Δ in IL-1b, IL-6,
IL-8, IL-10, IL-12, and TNF-α
GFR, muscle CSA,
Significant ↑ in type I, type II CSA,
proinflammatory cytokines, GFR, total body potassium, leucine
mtDNA
oxidation, prealbumin, mtDNA,
significant ↓ in CRP and IL-6
Muscle fiber CSA,
No Δ in muscle fiber CSA or QoL,
hematological data,
significant ↑ in 1RM, muscle
functional measures, QoL
endurance, 6-min walk, significant ↓
in “timed up and go”
Isometric strength,
Significant ↑ in quad isometic
functional measures, CRP
strength, 6-minute walk, maximal
walking speed, significant ↓ in CRP,
sit-to-stand time
Dependent Variables of
Interest
Birinder S. Cheema and Danwin Chan
83
ESRD 19
TRN+ND, 16
TRN+P, 17 P
ESRD 22 TRN,
22 P
ESRD 15 TRN,
15 P
ESRD 11 TRN
51
52
42
100
Subject
Reference Characteristics
Training Prescription
Intradialytic RT; elastic bands
with seven graded resistance:
flexion and extension at foot,
knee and hip; hip abduction
and adduction
Functional measures, body
composition, QoL and
perceived ADL disability
Lean body mass, thigh
muscle CSA, strength
measures, functional
measures, QoL
Dependent Variables of
Interest
Key Findings in Isolated RT Group
No Δ in lean body mass, significant ↑
in quadriceps CSA, strength
measures and physical function QoL.
No Δ in gait speed, sit-to-stand or
stair climbing
Significant ↓ in sit-to-stand, body fat
and ADL disability, significant ↑ in
knee extension strength, lean body
mass, physical functioning QoL
Anabolic and catabolic gene Significant ↑ in muscle mRNA
expression, body
IGF-IEa; nonsignificant ↑ in other
composition, CRP, TNF-α,
muscle mRNA levels except;
IL-6
nonsignificant ↓ in mRNA myostatin,
significant ↑ in IGF-I protein, no Δ in
CRP, TNF- α, IL-6, lean body mass
or body fat
Initial 2–4 week learning phase,
Functional measures
Significant ↑ in Tinetti score (gait and
then three sets of 20 repetitions at
balance); significant ↓ in “timed up
moderate RPE, resistance increased
and go”; no Δ in one leg balance or
as tolerated, 2 times per week for
6-minute walk
4.5–6 months
Intradialytic RT; ankle weight: Two sets of eight repetitions at
knee extension and flexion,
moderate RPE (6/10) 2 times per
hip adductor and straight leg
week for 48 sessions
dorsi/plantar flexion. Seated
pelvic tilt without free weight
Just prior to dialysis sessions; Week 1–4: 1 set of 12–15
machine weights: knee
repetitions at 70% 5RM; Week 5–8:
extension and flexion, leg
2 sets of 12–15 repetitions to
press, and calf extension
tolerance; After wk 8: 3 sets of 6–8
repetitions at 80% 5RM; 3 times
per week for 21 weeks
Intradialytic RT; ankle weights: Two to three sets of 10 repetitions
knee extension, hip abduction 60% 3RM, 3 times per week for
and flexion, ankle dorsiflexion 12 weeks
and plantar flexion
Resistance Type
TABLE 6.2 (Continued)
Resistance Training Interventions in CKD and ESRD
84
Resistance Training in Chronic Renal Failure
ESRD 10 TRN + Just prior to dialysis sessions; Three sets of 12 repetitions at
pneumatic resistance leg press 70% 1RM. 1RM reassessed at 3
oral nutrition,
and 6 months, 3 times per week,
12 oral nutrition
6 months
Six-minute walk
Significant ↑ in radial artery and
average vein diameter, and brachial
artery endothelial function
Positive total amino acid balance
postdialysis (nonsignificant ↑);
significant ↑ in forearm muscle
protein balance; no Δ in whole body
protein balance
No Δ in 1RM, percent body fat or lean
body mass
Significant ↑ in vein CSA with/without
tourniquet
Acute significant ↑ fistula diameter
No Δ in 6-minute walk
TRN, training; P, placebo; CNTL, control; CSA, cross-sectional area; 1RM, one repetition maximum; RPE, rating of perceived exertion; ND, nandrolone decanoate; IGF,
insulin-like growth factor; IL, interleukin; MVC, maximum voluntary contraction; QoL, quality of life; RT, resistance training; AT, aerobic training; GFR, glomerular
filtration rate; WLC, Wait-list control; ADL, activities of daily living.
Leg press 1RM, body
composition
Single session, 5-minute ball
Fistula diameter
squeezing
Handgrip dynamometer: 30%–40% Cephalic vein size CSA
of MVC for 80–360 seconds, plus
repetitive ball squeezing, 4 times
per week for 6 months
20 compression/min for 30 minute, Radial and brachial arteries
every day for 8 weeks
blood flow, and vein
diameter
Single session. three sets of 12
Total amino acid balance,
repetitions at 75% 1RM
forearm muscle protein
balance, whole body protein
balance
108
54
49
48
50
3–4 sets of 10–15 reps, 3 times per
week for 10 week, progression as
tolerated
Elastic bands, dumbbells, and
ankle weights of 1–2 lbs.
Elbow flexor, shoulder flexors,
hip flexors with knees flexed/
extended, hip abductor.
Hamstring curl against a
therapeutic ball
ESRD 23 TRN Rubber ball for repetitive
squeezing handgrip
Stage 3–4 CKD Handgrip dynamometer for
5 TRN
isometric handgrip squash ball
and racquet ball for repetitive
handgrip
ESRD 14 TRN Rubber ring (maximum
compression force = 50 N) for
repetitive handgrip exercise
ESRD 8 TRN + Intradialytic RT; patients
ambulated to resistance
oral nutrition
machine for leg press
ESRD 13 TRN
(RT) 13 TRN
(RT + AT)
101
Birinder S. Cheema and Danwin Chan
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Resistance Training in Chronic Renal Failure
or bilateral leg lifts in a seated position, depending on subject p­ reference and level
of ability. The loading of exercises was progressed appropriately with strength
­adaptation. After 12 weeks, participants randomized to the intradialytic RT program (n = 24) ­experienced statistically significantly improvements in mid-thigh
muscle ­attenuation and clinically significant improvements in mid-thigh muscle
CSA, evaluated via computed ­tomography, as compared to those randomized to the
wait-list control group (n = 25).39 This improvement of muscle quality and quantity was accompanied by the significant improvement of anthropometric measures
(e.g., increases in BMI and mid-thigh and mid-arm circumferences) and the reduction of the inflammatory marker CRP.39 Notably, the intradialytic RT regimen did
not change other circulating cytokine concentrations including TNF-α, IL-1b, IL-6,
IL-8, IL-10, and IL-12.41 The reduction of CRP has been noted in other additional
trials prescribing 8 weeks of intradialytic RT88 and 12 weeks of RT during nondialysis time.47 This is an important finding given the morbidity and mortality associated
with elevations of CRP in ESRD.83 Cheema et al.40 have also noted that a longer
duration of intradialytic RT can induce greater gains in muscle CSA.
Only a few additional RCT has investigated the myogenic potential of RT prescribed during hemodialysis treatment51,52; Johansen et al.51 conducted a 2 × 2
­factorial RCT of intradialytic RT and double-blind weekly anabolic steroid (nandrolone decanoate) or placebo injections in 79 patients with ESRD. Patients randomized to the RT intervention performed five lower-body exercises using ankle weights
(knee extension, hip flexion, hip abduction, plantarflexion, and dorsiflexion) during
thrice-weekly dialysis. Two to three sets of 10 repetitions of each exercise were performed progressing from 60% of 3RM. Training loads were increased with strength
adaptation. After 12 weeks, quadriceps muscle CSA evaluated via MRI showed an
increase in the patients assigned to both RT + placebo (p = .02) and RT + nandrolone (p < .0001) versus control. The RT intervention did not improve total lean body
mass, evaluated via dual-energy x-ray absorptiometry (DEXA), perhaps because
of RT targeted only the lower extremities. However, using a similar intervention,
Chen et al.52 did note significant increases in leg and whole body fat-free mass and
significant reductions in whole body fat mass after approximately 6 months of lowintensity, lower-body intradialytic RT.
To date, there has been limited exploration of the subcellular mechanisms that
contribute to muscular hypertrophy in patients with ESRD. Kopple et al.42 investigated changes in anabolic and catabolic gene expression in 80 patients with ESRD
randomized to four groups: (1) aerobic training, (2) RT, (3) aerobic + RT, and (4) control. All training sessions were administered three times per week for 21 weeks. The
isolated RT group performed four lower-body exercises (leg extension, leg curl, leg
press, and calf extension) three times per week immediately preceding each dialysis
session. One set of 12–15 repetitions at 70% of 5RM was performed during the first
four weeks of intervention. The intervention was then systematically progressed,
as tolerated, up to three sets of six to eight repetitions of 80% of reassessed 5RM.
Investigation of vastus lateralis biopsy specimens obtained from 15 patients in the
RT group revealed significant increases in IGF-IEa mRNA and IGF-I protein from
pre- to posttraining. Additional anabolic genes, including IGF-IEc, IGF-IR, IGF-II
and IGFBP-2, and IGFBP-3 also increased in expression, while anti-growth factor
Birinder S. Cheema and Danwin Chan
87
myostatin mRNA decreased in expression; however, these changes did not achieve
statistical significance in the RT group. No changes were noted in measures of body
composition (i.e., lean mass or fat mass) or circulating CRP, TNF-α, or IL-6 following the intervention. Overall, these findings suggest that RT can induce changes in
gene expression that may promote protein synthesis and reduce protein degradation
in patients with ESRD. Greater adaptation may have been achieved with a larger
sample size and/or more potent anabolic intervention.
Physical Functioning and Quality of Life
Physical functioning, including the ability to engage in activities of daily living,89
is lower in patients with CKD as compared to age-matched individuals with normal renal function.89 Deficits in physical functioning have also been documented
via self-report surveys,89,90 performance-based tests (e.g., 6-minute walk, gait
speed, strength, and sit-to-stand)91–93 and maximal exercise tests.45,64,94,95 Physical
inactivity96,97 and low physical functioning90,98 contribute to reduced quality of life,
increased hospitalization, and increased mortality in patients with CKD. Notably,
a recent international survey has revealed that physical activity levels are directly
proportional to survival in patients with ESRD.99
Only one study to date has investigated the effect of RT on physical functioning
and/or quality of life in predialysis CKD patients. Heiwe et al.38 prescribed relatively low-intensity (20 repetitions per set) quadriceps muscle training three times
per week for 12 weeks in elderly patients with a GFR ≤ 25 mL/min and noted significant improvements in isometric quadriceps muscle strength, quadriceps endurance, 6-minute walk distance, and speed on the “timed up and go test” from pre- to
postintervention. However, these functional adaptations were not accompanied by
improvements in quality of life.
Several studies have noted improvements in physical functioning and quality
of life in patients with ESRD. Cheema et al.39 noted significant improvements in
total body strength (p < .001), and a trend toward improved 6-minute walk distance
(p = .16) secondary to 12 weeks of high-intensity intradialytic RT versus usual
care. These improvements in functioning were concomitant with the enhancement
of quality-of-life domains including vitality and physical function.39 Cheema et al.40
have also reported that greater strength adaptation can be achieved with longer
durations of intradialytic RT.
Several studies have noted functional adaptations secondary to low-intensity
intradialytic RT. Chen et al.52 found that patients who engaged in approximately
6 months of lower-body RT experienced significant improvements in knee extensor strength, sit-to-stand movement time, leisure time physical activity, and selfperceived ­physical functioning and activities of daily living versus a sham exercise
group. Similar functional and/or quality-of-life adaptations have also been reported
in smaller trials prescribing intradialytic RT.53,100 By contrast, Orcy et al.101 did
not observe a significant improvement in 6-minute walk distance with 10 weeks
of isolated, full body RT. However, the RT intervention may have been prescribed
at too low an intensity. For example, leg exercises were performed with very light
(1–2 lb) ankle cuffs. The exercises prescribed by Chen et al.52 involved the use of
88
Resistance Training in Chronic Renal Failure
weighted ankle cuffs that could be loaded only up to 20 lbs (9 kg). Johansen et al.51
also prescribed relatively low-intensity, lower-body exercises and noted significant
improvements in the physical function domain of quality of life after 12 weeks of
intervention; however, stair climbing, gait speed, or rising from a chair did not significantly improve over time versus the placebo-controlled condition.
Headley et al.46 conducted an uncontrolled trial that evaluated the effect of an
RT program prescribed during nondialysis time in 10 patients with ESRD. RT
sessions were prescribed twice per week for 12 weeks. During each session, the
patients completed 1–2 sets of 10–15 repetitions of nine machine weight exercises (leg press, leg extension, leg curl, chest press, compound row, lateral raise,
biceps curl, triceps extension, and abdominal curl). Loads were adjusted accordingly with strength adaptation. In addition, the patients were also prescribed an
unsupervised home-based RT program that involved the performance of nine
exercises (squat, elbow extension, knee flexion, elbow flexion, calf raise, shoulder shrug, hip abduction, scapula retraction, and ankle dorsiflexion) using TheraBand tubing (The Hygenic Corporation). The home-based exercises were also
prescribed at 1–2 sets of 10–15 repetitions, and heavier resistance bands were
used in the latter weeks of training. The home-based component of the intervention was delivered via a prerecorded video. At the end of the intervention period,
the patients significantly improved peak knee extension isometric strength at
90° of flexion, 6-minute walk distance, maximal walking speed, and sit-to-stand
movement time.
Forearm Exercise for Arteriovenous Fistula Maturation
One of three vascular accesses is typically used to access the blood supply for hemodialysis treatment in patients with ESRD: an arteriovenous (AV) fistula, a synthetic
graft, or an intravenous catheter. All vascular accesses must be surgically created.
The AV fistula is the preferred vascular access for chronic hemodialysis treatment
as it is associated with fewer complications (e.g., thrombosis, stenosis, and infection)
and a longer functional lifespan versus the synthetic graft.102–104 The preferred site
for the creation of an AV fistula or synthetic graft is the forearm,105 and the choice of
access is influenced by the condition of the vasculature. The AV fistula and synthetic
graft must be given time to heal and mature. In the interim, the patient will receive
dialysis via an intravenous catheter, the least preferable vascular access for long-term
dialysis given that it is most prone to complications.
It is a routine practice to instruct patients to perform arm exercises, especially ball
squeezing prior to, and sometimes after, AV fistula surgery, and empirical data support
this practice. Robbin et al.106 determined that patients with an AV fistula adequate for
dialysis had a venous diameter >0.4 cm and flow volume >500 mL/min within four
months of fistula creation. Recent trials involving forearm resistance exercises have
been shown to acutely and chronically increase vessel diameter, CSA, and dilation.48–50
Oder et al.50 in a trial enrolling 23 hemodialysis patients revealed that 5 minutes
of ball squeezing exercise with the AV fistula-containing arm could acutely dilate
the fistula diameter by about 9.3%. This acute effect may contribute to chronic adaptation of the blood vessels with prolonged training.48,49
Birinder S. Cheema and Danwin Chan
89
Leaf et al.48 investigated a 6-week intervention that combined 10 minutes of
­preexercise forearm heating and RT in five patients with predialysis renal failure.
The sessions were prescribed four times per week and exercises involved isometric
handgrip contractions at 30%–40% of maximal voluntary contractions for 80–360
seconds. In addition, the patients repetitively squeezed a squash ball and/or racquet
ball. The volume and intensity of isometric exercise was adjusted weekly, based on
the assessment of grip strength using a handgrip dynamometer and according to
patient tolerance. At the end of the training program, the cephalic vein, commonly
used to create an AV fistula, significantly increased in CSA by approximately twofold. The authors concluded that this increase in vessel size and related increase in
blood flow might accelerate the maturation of the AV fistula and reduce vascular
access-related morbidities.
Rus et al.49 investigated the effect of handgrip exercises prescribed daily for
8 weeks in 14 hemodialysis patients. The exercises involved the use of a rubber ring
(maximum compression force = 50 N) and were performed using the nonfistulacontaining arm. Twenty compressions per minute were performed for a total of
30 ­minutes. No information regarding training progression was provided. At the end
of the intervention period, the participants significantly increased measures of radial
artery and average vein diameter. Improvements in brachial artery endotheliumdependent vasodilation were also noted. These effects highlight the importance of
handgrip training prior to the construction of the AV fistula as a means to potentially
improve fistula maturation.
Hemodialysis-Induced Catabolism
Hemodialysis treatment, although essential for preserving life in patients with
ESRD, also has negative consequences. Recent investigations have shown that
hemodialysis treatment itself can induce skeletal muscle protein catabolism72
marked by increases in proinflammatory cytokines (IL-6) and catabolic markers
including caspase-3, annexin-V, ubiquitin, and BCKAD-E2.107 Majchrzak et al.54
recently evaluated the effect of a single session of resistance exercise performed
during hemodialysis treatment on protein kinetics in patients with ESRD both during and for 2 hours after dialysis treatment. The study used a randomized crossover
design. Eight patients were allocated, in random order, to oral nutritional supplementation (NEPRO®) and oral nutritional supplementation (NEPRO) + resistance
exercise, during dialysis. The investigators hypothesized that the addition of resistance exercise would augment skeletal muscle protein accretion as compared to
nutritional supplementation alone. Three sets of leg press exercise at 75% 1RM
were prescribed during the combined (nutrition + resistance) condition. There
were no statistically significant differences in protein homeostasis between conditions during dialysis treatment; however, in the posttreatment phase, the condition involving resistance exercises resulted in a positive total amino acid balance
and a significantly higher forearm muscle net protein balance when compared to
nutritional supplementation alone. No differences were noted in whole-body protein balance. The researchers concluded that RT during dialysis might counteract
dialysis-induced protein catabolism.
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Resistance Training in Chronic Renal Failure
Notably, however, a follow-up study by the same research group using a nearly
identical intervention over a 6-month period failed to elicit significant increases in
lean body mass in patients randomized to oral nutritional supplementation + RT
versus those randomized to oral nutritional supplementation only.108 The null effect
could have been attributed to the fact that only one RT exercise (i.e., leg press) was
performed over the entire 6-month intervention. The authors acknowledged the need
to test more rigorous RT prescriptions.
EFFICACY OF INTRADIALYTIC RESISTANCE TRAINING
Painter et al.109 published the first study to investigate the efficacy of aerobic training
(e.g., exercise cycling) prescribed during hemodialysis treatment. This study, and
approximately 60 additional reports to date, has clearly showed that exercise training during maintenance hemodialysis treatment is safe, can induce many clinically
meaningful and statistically significant health-related adaptations, and can result in
better compliance than training during nondialysis time.110,111 The findings of studies
prescribing intradialytic exercise have been summarized in several recent review
articles that provide support for the integration of intradialytic exercise as best practice in ESRD.112,113
Investigations that have prescribed isolated high-intensity and low-intensity
intradialytic RT have reported no life-threatening events, and few adverse events
or symptoms.40–42,51 Cheema et al.39,40 noted that high-intensity intradialytic RT did
not exacerbate common dialysis-related complaints including headaches, hypotension, fistula/cannulation difficulties, and cramping during a 24-week trial that
prescribed intradialytic RT to 49 patients. These findings have been supported by
an additional randomized controlled trial.52 Adverse events have generally been
musculoskeletal.100,114 For example, Cheema et al.39,40 documented only one adverse
event induced by the intradialytic RT program, a full-thickness tear of a right supraspinatus muscle in an elderly woman. Investigation suggested that the woman may
have been predisposed to this injury.114
Recruitment data presented in recent RCTs suggest that the majority of patients in
the conventional dialysis setting are medically eligible to engage in RT. For example,
of 278 patients reviewed by Johansen et al.,51 only 60 (22%) were excluded for reasons of illness, medical instability, cognitive impairment, and cancer. Others were
excluded because of lower-extremity amputation and active drug abuse; however,
these are not absolute contraindications to exercise, and modifications could be
applied to the regimen to accommodate such individuals. Cheema et al.39 excluded
only 26 of 142 patients (18%) due to a medical contraindication to intradialytic progressive resistance training, while Chen et al.52 indicated that 66 of 250 patients
(26%) did not meet their study eligibility criteria, which were mostly related to unstable chronic disease.
Exercising during hemodialysis is often recommended as a more feasible, convenient, and time-effective solution to promote exercise adherence in ESRD.112 For
example, delivering RT during dialysis may enhance compliance by removing the
common cited barriers to exercise participation in this cohort, including “lack of
motivation,” “lack of time,” and “transportation difficulties.”112 Further, patients
Birinder S. Cheema and Danwin Chan
91
are more likely to participate if it is considered normal, “part of the woodwork”
and reinforced as beneficial to do so by other patients and the attending healthcare professionals. While clinically trained exercise physiologists should ideally
deliver the program, the endorsement of nephrologists, dialysis nursing staff, and
renal dietitians is critically important for continued success.115 Unfortunately, many
nephrologists and health-care professionals appear unaware of the benefits and/or
are indifferent to the idea.116
Training packages are now available to establish a cost-effective RT program
within any dialysis unit.117 As programs become more widely practiced, the demand
for novel equipment will be increased and, accordingly, the effectiveness of the
interventions will be improved. For example, a novel lower-body RT device customized for the hemodialysis setting has been recently developed by an Australian
group.118 Established training programs also provide a perfect venue for continued
research.
EXERCISE RECOMMENDATIONS
The research to date suggests that participation in RT is important for patients at high
risk of developing CKD and for those diagnosed with CKD and ESRD. RT can play
an important role in targeting risk factors including type 2 diabetes, hypertension,
and obesity and hence can play a key role in reducing the CKD burden that has been
forecast for the decades ahead.7 Preliminary data suggest that RT can reduce the
decline, or potentially improve renal function (GFR) in patients diagnosed with the
CKD, which could potentially contribute to reduced growth of the dialysis population
and the reduction of health-care expenditures attributed to dialysis care. Moreover,
RT has been shown to improve many important outcomes in patients with CKD and
ESRD, including skeletal muscle wasting, inflammation, physical functioning, and
quality of life. Such adaptations may potentially contribute to greater life expectancy in this vulnerable patient population. At present, more robust investigations are
required to evaluate the efficacy of RT delivered across the CKD continuum, from
at-risk individuals to individuals who have received successful kidney transplants.
A broad range of clinically relevant outcome measures should be investigated and
greater efforts must be directed toward elucidating the relationship between these
adaptations and survival advantage.
There are currently no standardized RT guidelines for individuals with CKD.
However, Johansen and Painter34 have provided general exercise recommendations
that align with the American College of Cardiology and American Heart Association
guidelines for exercise testing.119 We have adapted and added to these recommendations in light of the latest research on RT in patients with CKD and ESRD presented
in this chapter:
• Patients with CKD and ESRD are typically older, extremely deconditioned,
and suffer from a high burden of comorbidities. All patients should undergo
appropriate medical screening prior to participating in any structured RT
program. It is appropriate to refer patients with known cardiac disease to
cardiac rehabilitation programs.
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Resistance Training in Chronic Renal Failure
• Exercise programs for patients with CKD should be individually tailored
to meet the expectations, goals, needs, and preferences of the individual
patient. Prescriptions should be holistic and involve aerobic training, RT,
balance training, and flexibility training elements.
• Evidence suggests that the majority of patients with CKD and ESRD are
capable of engaging in and benefitting from low- to high-intensity RT.
Training programs can be initiated at low dosages and progressed according to patient tolerance.
• Trainers should be aware of drug–exercise interactions and pay vigilant
attention to any untoward symptoms during training. RT sessions should
not be undertaken during acute illnesses.
• Intradialytic RT can be safely undertaken by most hemodialysis patients
and such programs can be successfully implemented at low cost with the
involvement of exercise physiologists and the support of the dialysis nursing
staff and nephrologists.
• Intradialytic RT sessions should be initiated within the first two hours of
treatment in individuals who commonly experience dialysis-induced symptoms (e.g., hypotension, cramping, headache, and nausea).
• Clinical, health and fitness-related outcomes should be assessed at ­regular
intervals. The findings of such assessments should be shared with the patient
and health-care providers, including the nephrologist and nursing staff.
• Patients should always be referred to the appropriate allied health-care professional in cases where the RT prescriber is not qualified to deal with the
presenting illness or adverse event.
• All patients with CKD should be encouraged to be as physically active
as possible. RT should be implemented to complement an active lifestyle.
Other forms of exercise should be encouraged (e.g., walking, cycling, yoga,
pilates, and group exercise classes).
REFERENCES
1. Eckardt KU, Berns JS, Rocco MV, Kasiske BL. Definition and classification of CKD:
the debate should be about patient prognosis—a position statement from KDOQI and
KDIGO. Am J Kidney Dis 2009;53:915–20.
2. Levey AS, Eckardt KU, Tsukamoto Y et al. Definition and classification of chronic kidney disease: a position statement from Kidney Disease: Improving Global Outcomes
(KDIGO). Kidney Int 2005;67:2089–100.
3. Dasmahapatra P, Srinivasan SR, Mokha J et al. Subclinical atherosclerotic changes
related to chronic kidney disease in asymptomatic black and white young adults: the
Bogalusa heart study. Ann Epidemiol 2011;21:311–7.
4. Glassock RJ, Winearls C. The global burden of chronic kidney disease: how valid are the
estimates? Nephron Clin Pract 2008;110:c39–46; discussion c7.
5. Coresh J, Selvin E, Stevens LA et al. Prevalence of chronic kidney disease in the United
States. JAMA 2007;298:2038–47.
6. USRDS. U.S. Renal Data System 2009 Annual Data Report: Atlas of End-Stage Renal
Disease in the United States. National Institutes of Health, National Institute of Diabetes
and Digestive and Kidney Diseases. Bethesda, MD, 2011.
Birinder S. Cheema and Danwin Chan
93
7. El Nahas AM, Bello AK. Chronic kidney disease: the global challenge. The Lancet
2005;365:331–40.
8. Lysaght MJ. Maintenance dialysis population dynamics: current trends and long-term
implications. J Am Soc Nephrol 2002;13 Suppl 1:S37–40.
9. Klag M, Whelton PK, Randall BL, Neaton JD, Brancati FL, Stamler J. End-stage
renal disease in African-American and white men: 16-year MRFIT findings. JAMA
1997;277:1293–8.
10. Lora CM, Daviglus ML, Kusek JW et al. Chronic kidney disease in United States
­hispanics: a growing public health problem. Ethn Dis 2009;19:466–72.
11. Yeates K, Tonelli M. Chronic kidney disease among aboriginal people living in Canada.
Clin Nephrol 2010;74 Suppl 1:S57–60.
12. Narva AS. Reducing the burden of chronic kidney disease among American Indians.
Adv Chronic Kidney Dis 2008;15:168–73.
13. Collins JF. Kidney disease in Maori and Pacific people in New Zealand. Clin Nephrol
2010;74 Suppl 1:S61–5.
14. Australia and New Zealand Dialysis and Transplant Registry. ANZDATA Registry, 2012.
Available at: http://www.anzdata.org.au/ANZDATA/anzdatawelcome.htm. Accessed
October 9, 2012.
15. Bakris GL, Ritz E, World Kidney Day Steering Committee. The message for World
Kidney Day 2009: hypertension and kidney disease: a marriage that should be prevented. J Clin Hypertens 2009;11:144–7.
16. National Kidney Foundation. K/DOQI clinical practice guidelines for chronic kidney
disease: evaluation, classification, and stratification. Am J Kidney Dis 2002;39:S1–266.
17. Hallan S, de Mutsert R, Carlsen S, Dekker FW, Aasarod K, Holmen J. Obesity, smoking,
and physical inactivity as risk factors for CKD: are men more vulnerable? Am J Kidney
Dis 2006;47:396–405.
18. White SL, Dunstan DW, Polkinghorne KR, Atkins RC, Cass A, Chadban SJ. Physical
inactivity and chronic kidney disease in Australian adults: the AusDiab study. Nutr
Metab Cardiovasc Dis 2011;21:104–12.
19. Tonelli M, Wiebe N, Culleton B et al. Chronic kidney disease and mortality risk: a systematic review. J Am Soc Nephrol 2006;17:2034–47.
20. Sarnak MJ, Levey AS, Schoolwerth AC et al. Kidney disease as a risk factor for development of cardiovascular disease: a statement from the American Heart Association
Councils on Kidney in Cardiovascular Disease, High Blood Pressure Research, Clinical
Cardiology, and Epidemiology and Prevention. Circulation 2003;108:2154–69.
21. The National Kidney Foundation. How Your Kidneys Work, 2012. Available at: http://
www.kidney.org/kidneydisease/howkidneyswrk.cfm. Accessed October 9, 2012.
22. Ibrahim HN, Foley R, Tan L et al. Long-term consequences of kidney donation. N Engl
J Med 2009;360:459–69.
23. Helal I, Fick-Brosnahan GM, Reed-Gitomer B, Schrier RW. Glomerular hyperfiltration:
definitions, mechanisms and clinical implications. Nat Rev Nephrol 2012;8:293–300.
24. Palatini P. Glomerular hyperfiltration: a marker of early renal damage in pre-diabetes
and pre-hypertension. Nephrol Dial Transplant 2012;27:1708–14.
25. Brenner BM, Lawler EV, Mackenzie HS. The hyperfiltration theory: a paradigm shift in
nephrology. Kidney Int 1996;49:1774–7.
26. Galla JH. Clinical practice guideline on shared decision-making in the appropriate
initiation of and withdrawal from dialysis. The Renal Physicians Association and the
American Society of Nephrology. J Am Soc Nephrol 2000;11:1340–2.
27. Tresierras M, Balady G. Resistance training in the treatment of diabetes and obesity:
mechanisms and outcomes. J Cardiopulm Rehabil Prev 2009;29:67–75.
28. Willey K, Fiatarone-Singh MA. Battling insulin resistance in elderly obese people with
type 2 diabetes. Diabetes Care 2003;26:1580–8.
94
Resistance Training in Chronic Renal Failure
29. Sukala W, Page R, Cheema B. Exercise training in high-risk ethnic populations
with type 2 diabetes: a systematic review of clinical trials. Diabetes Res Clin Pract
2012;97:206–16.
30. Sigal R, Kenny G, Boulé N et al. Effects of aerobic training, resistance training, or both
on glycemic control in type 2 diabetes. Ann Int Med 2007;147:357–69.
31. Fagard RH. Exercise is good for your blood pressure: effects of endurance training and
resistance training. Clin Exp Pharmacol Physiol 2006;33:853–6.
32. Cornelissen VA, Fagard RH, Coeckelberghs E, Vanhees L. Impact of resistance training
on blood pressure and other cardiovascular risk factors: a meta-analysis of randomized,
controlled trials. Hypertension 2011;58:950–8.
33. Moraes MR, Bacurau RF, Casarini DE et al. Chronic conventional resistance exercise reduces blood pressure in stage 1 hypertensive men. J Strength Cond Res
2012;26:1122–9.
34. Johansen KL, Painter P. Exercise in individuals with CKD. Am J Kidney Dis
2012;59:126–34.
35. Johansen K. Exercise in the end-stage renal disease population. J Am Soc Nephrol
2007;18:1845–54.
36. Cheema B, Fiatarone Singh M. Exercise training in patients receiving maintenance
hemodialysis: a systematic review of clinical trials. Am J Nephrol 2005;25:352–64.
37. Heiwe S, Clyne N, Tollback A, Borg K. Effects of regular resistance training on muscle
histopathology and morphometry in elderly patients with chronic kidney disease. Am J
Phys Med Rehabil 2005;84:865–74.
38. Heiwe S, Tollback A, Clyne N. Twelve weeks of exercise training increases muscle function and walking capacity in elderly predialysis patients and healthy subjects. Nephron
2001;88:48–56.
39. Cheema B, Abas H, Smith B et al. Progressive exercise for anabolism in kidney disease
(PEAK): a randomized controlled trial of resistance training during hemodialysis. J Am
Soc Nephrol 2007;18:1594–601.
40. Cheema B, Abas H, Smith B et al. Randomized controlled trial of intradialytic resistance
training to target muscle wasting in ESRD: the progressive exercise for anabolism in
kidney disease (PEAK) study. Am J Kidney Dis 2007;50:574–84.
41. Cheema B, Abas H, Smith B et al. Effect of resistance training during hemodialysis on circulating cytokines: a randomized controlled trial. Eur J Appl Physiol
2011;111:1437–45.
42. Kopple J, Wang H, Casaburi R et al. Exercise in maintenance hemodialysis patients
induces transcriptional changes in genes favoring anabolic muscle. J Am Soc Nephrol
2007;18: 2975–86.
43. Balakrishnan VS, Rao M, Menon V et al. Resistance training increases muscle mitochondrial biogenesis in patients with chronic kidney disease. Clin J Am Soc Nephrol
2010;5:996–1002.
44. Castaneda C, Gordon P, Parker R, Uhlin K, Roubenoff R, Levey A. Resistance training
to reduce the malnutrition-inflammation complex syndrome of chronic kidney disease.
Am J Kidney Dis 2004;43:607–16.
45. Castaneda C, Gordon P, Uhlin K et al. Resistance training to counteract the catabolism
of a low-protein diet in patients with chronic renal insufficiency. A randomized, controlled trial. Ann Intern Med 2001;135:965–76.
46. Headley S, Germain M, Mailloux P et al. Resistance training improves strength
and functional measures in patients with end-stage renal disease. Am J Kidney Dis
2002;40:355–64.
47. Nindl BC, Headley SA, Tuckow AP et al. IGF-I system responses during 12 weeks
of resistance training in end-stage renal disease patients. Growth Horm IGF Res
2004;14:245–50.
Birinder S. Cheema and Danwin Chan
95
48. Leaf DA, Macrae HSH, Grant E, Kraut J. Isometric exercise increases the size of forearm
veins in patients with chronic renal failure. Am J Med Sci 2003;325:115–9.
49. Rus RR, Ponikvar R, Kenda RB, Buturovic-Ponikvar J. Effect of local physical training
on the forearm arteries and veins in patients with end-stage renal disease. Blood Purif
2003;21:389–94.
50. Oder TF, Teodorescu V, Uribarri J. Effect of exercise on the diameter of arteriovenous
fistulae in hemodialysis patients. ASAIO J 2003;49:554–5.
51. Johansen K, Painter P, Sakkas G et al. Effects of resistance exercise training and nandrolone decanoate on body composition and muscle function among patients who receive
hemodialysis: a randomized controlled trial. J Am Soc Nephrol 2006;17:2307–14.
52. Chen JL, Godfrey S, Ng TT et al. Effect of intra-dialytic, low-intensity strength training
on functional capacity in adult haemodialysis patients: a randomized pilot trial. Nephrol
Dial Transplant 2010;25:1936–43.
53. Segura-Orti E, Rodilla-Alama V, Lison JF. [Physiotherapy during hemodialysis: results
of a progressive resistance-training programme]. [Article in Spanish]. Nefrologia
2008;28:67–72.
54. Majchrzak K, Pupim L, Flakoll, PJ, Ikizler T. Resistance exercise augments the acute anabolic effects of intradialytic oral nutritional supplementation. Nephrol Dial Transplant
2008;23:1362–9.
55. Thomas D, Elliott E, Naughton G. Exercise for type 2 diabetes mellitus. Cochrane
Database Syst Rev 2006; CD002968. doi:10.1002/14651858.CD002968.pub2.
56. Afshinnia F, Wilt TJ, Duval S, Esmaeili A, Ibrahim HN. Weight loss and proteinuria:
systematic review of clinical trials and comparative cohorts. Nephrol Dial Transplant
2010;25:1173–83.
57. Navaneethan SD, Yehnert H, Moustarah F, Schreiber MJ, Schauer PR, Beddhu S. Weight
loss interventions in chronic kidney disease: a systematic review and meta-analysis. Clin
J Am Soc Nephrol 2009;4:1565–74.
58. Chagnac A, Weinstein T, Herman M, Hirsh J, Gafter U, Ori Y. The effects of weight loss
on renal function in patients with severe obesity. J Am Soc Nephrol 2003;14:1480–6.
59. Navarro-Diaz M, Serra A, Romero R et al. Effect of drastic weight loss after bariatric
surgery on renal parameters in extremely obese patients: long-term follow-up. J Am Soc
Nephrol 2006;17:S213–7.
60. Ruggenenti P, Perticucci E, Cravedi P et al. Role of remission clinics in the longitudinal
treatment of CKD. J Am Soc Nephrol 2008;19:1213–24.
61. Straznicky NE, Grima MT, Lambert EA et al. Exercise augments weight loss induced
improvement in renal function in obese metabolic syndrome individuals. J Hypertens
2011;29:553–64.
62. Toyama K, Sugiyama S, Oka H, Sumida H, Ogawa H. Exercise therapy correlates
with improving renal function through modifying lipid metabolism in patients with
cardiovascular disease and chronic kidney disease. J Cardiol 2010;56:142–6.
63. Pechter U, Ots M, Mesikepp S et al. Beneficial effects of water-based exercise in patients
with chronic kidney disease. Int J Rehabil Res 2003;26:153–6.
64. Boyce M, Robergs R, Avasthi P et al. Exercise training by individuals with predialysis
renal failure: cardiorespiratory endurance, hypertension, and renal function. Am J Kidney
Dis 1997;30:180–92.
65. Bellizzi V, Di Iorio BR, De Nicola L et al. Very low protein diet supplemented with
ketoanalogs improves blood pressure control in chronic kidney disease. Kidney Int
2007;71:245–51.
66. Perticone F, Maio R, Perticone M et al. Endothelial dysfunction and subsequent decline
in glomerular filtration rate in hypertensive patients. Circulation 2010;122:379–84.
67. Remission Clinic Task Force. The Remission Clinic approach to halt the progression of
kidney disease. J Nephrol 2011;24:274–81.
96
Resistance Training in Chronic Renal Failure
68. Fouque D, Kalantar-Zadeh K, Kopple J et al. A proposed nomenclature and diagnostic criteria for protein-energy wasting in acute and chronic kidney disease. Kidney Int
2008;73:391–8.
69. Kopple J. Pathophysiology of protein-energy wasting in chronic renal failure. J Nut
1999;129:247S–51S.
70. Workeneh BT, Mitch WE. Review of muscle wasting associated with chronic kidney
disease. Am J Clin Nutr 2010;91:1128S–32S.
71. Caso G, Garlick P. Control of muscle protein kinetics by acid-base balance. Curr Opin
Clin Nutr Metab Care 2005;8:73–6.
72. Raj DS, Zager P, Shah VO et al. Protein turnover and amino acid transport kinetics in
end-stage renal disease. Am J Physiol Endocrinol Metab 2004;286:E136–43.
73. Kouidi E, Albani M, Natsis K et al. The effects of exercise training on muscle atrophy in
hemodialysis patients. Nephrol Dial Transplant 1998;13:685–99.
74. Diesel W, Emms M, Knight B et al. Morphologic features of the myopathy associated
with chronic renal failure. Am J Kidney Dis 1993;22:677–84.
75. Rajan VR, Mitch WE. Muscle wasting in chronic kidney disease: the role of the ubiquitin proteasome system and its clinical impact. Pediatr Nephrol 2008;23:527–35.
76. Price SR, Gooch JL, Donaldson SK, Roberts-Wilson TK. Muscle atrophy in chronic kidney
disease results from abnormalities in insulin signaling. J Ren Nutr 2010;20:S24–8.
77. Carrero JJ, Yilmaz MI, Lindholm B, Stenvinkel P. Cytokine dysregulation in chronic
kidney disease: how can we treat it? Blood Purif 2008;26:291–9.
78. Avesani CM, Carrero JJ, Axelsson J, Qureshi AR, Lindholm B, Stenvinkel P. Inflammation
and wasting in chronic kidney disease: partners in crime. Kidney Int 2006;70:S8–13.
79. Kalantar-Zadeh K. The latest addition to the inflammatory homeboys in chronic kidney
disease: interleukin-8. Nephron Clin Pract 2006;102:c59–60.
80. Kalantar-Zadeh K. Inflammatory marker mania in chronic kidney disease: pentraxins at
the crossroad of universal soldiers of inflammation. Clin J Am Soc Nephrol 2007;2:872–5.
81. Kalantar-Zadeh K, Ikizler TA, Block G, Avram MM, Kopple JD. Malnutrition-inflammation
complex in dialysis patients: causes and consequences. Am J Kidney Dis 2003;42:864–81.
82. Wanner C, Metzger T. C-reactive protein a marker for all-cause and cardiovascular mortality in haemodialysis patients. Nephrol Dial Transplant 2002;17:29–32.
83. Shlipak M, Fried L, Cushman M et al. Cardiovascular mortality risk in chronic kidney
disease. JAMA 2005;293:1737–45.
84. Desmeules S, Levesque R, Jaussent I, Leray-Moragues H, Chalabi L, Canaud B. Creatine
index and lean body mass are excellent predictors of long-term survival in haemodiafiltration patients. Nephrol Dial Transplant 2004;19:1182–9.
85. Granata S, Zaza G, Simone S et al. Mitochondrial dysregulation and oxidative stress in
patients with chronic kidney disease. BMC Genomics 2009;10:388.
86. Sietsema KE, Amato A, Adler SG, Brass EP. Exercise capacity as a predictor of survival
among ambulatory patients with end-stage renal disease. Kidney Int 2004;65:719–24.
87. Cheema B, O'Sullivan A, Chan M et al. Progressive resistance training during hemodialysis: rationale and method of a randomized controlled trial. Hemodial Int 2006;10:303–10.
88. Afshar R, Shegarfy L, Shavandi N, Sanavi S. Effects of aerobic exercise and resistance
training on lipid profiles and inflammation status in patients on maintenance hemodialysis. Indian J Nephrol 2010;20:185–9.
89. Painter P. Physical functioning in end-stage renal disease patients: update 2005.
Hemodial Int 2005;9:218–35.
90. DeOreo P. Hemodialysis patient-assessed functional health status predicts c­ ontinued
survival, hospitalization, and dialysis-attendance compliance. Am J Kidney Dis
1997;30:204–12.
91. Painter P, Carlson L, Carey S, Paul S, Myll J. Low-functioning hemodialysis patients
improve with exercise training. Am J Kidney Dis 2000;36:600–8.
Birinder S. Cheema and Danwin Chan
97
92. Painter P, Carlson L, Carey S, Paul SM, Myll J. Physical functioning and health-related
quality-of-life changes with exercise training in hemodialysis patients. Am J Kidney Dis
2000;35:482–92.
93. Johansen KL, Kaysen GA, Young BS, Hung AM, da Silva M, Chertow GM. Longitudinal
study of nutritional status, body composition, and physical function in hemodialysis
patients. Am J Clin Nutr 2003;77:842–6.
94. Johansen KL. Physical functioning and exercise capacity in patients on dialysis. Adv
Ren Replace Ther 1999;6:141–8.
95. Painter P, Messer-Rehak D, Hanson P, Zimmerman SW, Glass NR. Exercise capacity in
hemodialysis, CAPD, and renal transplant patients. Nephron 1986;42:47–51.
96. Johansen KL, Chertow GM, Ng AV et al. Physical activity levels in patients on hemodialysis and healthy sedentary controls. Kidney Int 2000;57:2564–70.
97. O'Hare AM, Tawney K, Bacchetti P, Johansen KL. Decreased survival among sedentary
patients undergoing dialysis: results from the dialysis morbidity and mortality study
wave 2. Am J Kidney Dis 2003;41:447–54.
98. Molsted S, Eidemak I, Sorensen HT, Kristensen JH, Harrison A, Andersen JL. Myosin
heavy-chain isoform distribution, fibre-type composition and fibre size in skeletal muscle of patients on haemodialysis. Scand J Urol Nephrol 2007;41:539–45.
99. Tentori F, Elder SJ, Thumma J et al. Physical exercise among participants in the Dialysis
Outcomes and Practice Patterns Study (DOPPS): correlates and associated outcomes.
Nephrol Dial Transplant 2010;25:3050–62.
100. Bullani R, El-Housseini Y, Giordano F et al. Effect of intradialytic resistance band exercise on physical function in patients on maintenance hemodialysis: a pilot study. J Ren
Nutr 2011;21:61–5.
101. Orcy RB, Dias PP, Seus TL, Barcellos FC, Bohlke M. Combined resistance and aerobic exercise is better than resistance training alone to improve functional performance
of haemodialysis patients—results of a randomized controlled trial. Physiother Res Int
2012;17(4):235–43.
102. Churchill DN, Taylor DW, Cook RJ et al. Canadian hemodialysis morbidity study. Am J
Kidney Dis 1992;19:214–34.
103. Woods JD, Turenne MN, Strawderman RL et al. Vascular access survival among incident hemodialysis patients in the United States. Am J Kidney Dis 1997;30:50–7.
104. Allon M, Robbin ML. Increasing arteriovenous fistulas in hemodialysis patients: problems and solutions. Kidney Int 2002;62:1109–24.
105. Foundation NK. KDOQI Clinical practice guidelines and clinical practice recommendations for 2006 updates: hemodialysis adequacy, peritoneal dialysis adequacy and vascular
access. Am J Kidney Dis 2006;48:S1–322.
106. Robbin ML, Chamberlain NE, Lockhart ME et al. Hemodialysis arteriovenous fistula
maturity: US evaluation. Radiology 2002;225:59–64.
107. Raj D, Shah H, Shah V et al. Markers of inflammation, proteolysis, and apoptosis in
ESRD. Am J Kidney Dis 2003;42:1212–20.
108. Dong J, Sundell MB, Pupim LB, Wu P, Shintani A, Ikizler TA. The effect of resistance
exercise to augment long-term benefits of intradialytic oral nutritional supplementation
in chronic hemodialysis patients. J Ren Nutr 2011;21:149–59.
109. Painter PL, Nelson-Worel JN, Hill MM et al. Effects of exercise training during hemodialysis. Nephron 1986;43:87–92.
110. Kouidi E, Grekas D, Deligiannis A, Tourkantonis A. Outcomes of long-term ­exercise
training in dialysis patients: comparison of two training methods. Clin Nephrol
2004;61:S31–8.
111. Konstantinidou E, Koukouvou G, Kouidi E, Deligiannis A, Tourkantonis A. Exercise
training in patients with end-stage renal disease on hemodialysis: comparison of three
rehabilitation programs. J Rehabil Med 2002;34:40–5.
98
Resistance Training in Chronic Renal Failure
112. Cheema B. Review article: Tackling the survival issue in end-stage renal disease: time
to get physical on haemodialysis. Nephrol (Carlton) 2008;3:560–9.
113. Cheema B, Smith B, Fiatarone Singh M. A rationale for intradialytic exercise training as
standard clinical practice in end stage renal disease. Am J Kidney Dis 2005;45:912–6.
114. Cheema B, Lassere M, Shnier R, Fiatarone Singh M. Rotator cuff tear in an elderly
woman performing progressive resistance training: case report from a randomized controlled trial. J Phys Act Health 2007;4:1–8.
115. Bennett PN, Breugelmans L, Barnard R et al. Sustaining a hemodialysis exercise program: a review. Semin Dial 2010;23:62–73.
116. Johansen KL, Sakkas GK, Doyle J, Shubert T, Dudley RA. Exercise counselling practices
among nephrologists caring for patients on dialysis. Am J Kidney Dis 2003;41:171–8.
117. American College of Physicians Online. Weight Training Lightens Physical,
Psychological Loads, 2007. Available at: http://www.acponline.org/clinical_information/journals_publications/acp_internist/sep07/weight.htm (accessed July 9, 2008).
118. Bennett P, Breugelmans L, Agius M, Simpson-Gore K, Barnard B. A haemodialysis
exercise programme using novel exercise equipment: a pilot study. J Ren Care
2007;33:153–8.
119. Gibbons RJ, Balady GJ, Bricker JT et al. ACC/AHA 2002 guideline update for exercise
testing: summary article: a report of the American college of cardiology/American heart
association task force on practice guidelines (committee to update the 1997 exercise
testing guidelines). Circulation 2002;106:1883–92.
7
Beneficial Effects
of Progressive
Resistance Training in
Multiple Sclerosis
Lara A. Pilutti and Robert W. Motl
CONTENTS
Introduction............................................................................................................. 103
Muscle Weakness in Multiple Sclerosis.................................................................. 104
Mechanisms of Muscle Weakness in Multiple Sclerosis................................... 105
Resistance Training in Multiple Sclerosis.............................................................. 107
Progressive Resistance Training for Muscular Strength and the Skeletal
Muscle Profile.................................................................................................... 107
Progressive Resistance Training for Mobility, Fatigue, and Quality
of Life................................................................................................................. 110
Prescription of Resistance Training in Persons with Multiple Sclerosis................ 112
Limitations of the Literature................................................................................... 113
Conclusions............................................................................................................. 113
References............................................................................................................... 114
INTRODUCTION
Multiple sclerosis (MS) is an immune-mediated, neurodegenerative disease of white
and gray matter in the central nervous system (CNS). There are many consequences
of MS such as worsening disability, ambulation, symptomology, and quality of life
(QoL). These consequences may be the direct result of damage and atrophy of CNS
tissue, or may be brought about by other changes such as muscle weakness and associated changes in the skeletal muscle profile. Indeed, muscle weakness and altered
skeletal muscle characteristics are common in MS1–6 and may be a consequence of
the disease process itself,7 or a secondary effect of deconditioning caused by physical
inactivity.8,9 We further note that markers of muscle weakness have been associated
with ambulatory impairment, postural instability, fatigue, and poor cognitive performance in MS.2,10–12
99
100
Beneficial Effects of Progressive Resistance Training in Multiple Sclerosis
Resistance training represents a strategy for preserving, maintaining, or i­ mproving
skeletal muscle strength and morphological characteristics in persons with MS and
may, in turn, have meaningful functional and symptomatic consequences. This
chapter describes changes in skeletal muscle characteristics in persons with MS and
provides a review of the potential benefits of progressive resistance training (PRT)
primarily with respect to adaptations in strength and the skeletal muscle profile, but
secondarily with respect to mobility, fatigue, and QoL.
MUSCLE WEAKNESS IN MULTIPLE SCLEROSIS
There is consistent evidence that muscular strength is impaired in persons with MS.
This impairment has been observed in both static2,6,13,14 and dynamic1,5,15,16 muscle
strength assessments. For example, maximal voluntary contraction (MVC) of ankle
dorsiflexors was 27% weaker in a sample of 16 persons with MS who had a mean
Expanded Disability Status Scale (EDSS) score of 3.2 compared to 18 healthy
controls.6 Asymmetries in muscular strength (i.e., relative difference in strength
between muscles on opposite sides of the body) have been observed in persons with
MS compared to healthy controls.2,10 For example, asymmetry in knee extensor
power was observed in 12 women with moderate MS (mean EDSS = 4.0) compared
to age-matched non-MS controls.2 Such strength deficits seemingly affect the lower
extremities to a greater extent than the upper extremities,14,17 and this is not surprising as MS often compromises the long motor tracts in the CNS.18,19 For instance, one
study reported that strength was compromised in the lower extremity muscles (i.e.,
hip flexors, knee flexors and extensors, and ankle dorsiflexors), whereas strength
was generally preserved in the upper extremities (i.e., elbow flexors and extensors,
and handgrip strength) in a sample of 20 ambulatory persons with MS (mean EDSS
= 5.5) compared to non-MS controls.14 Significant impairments in muscular strength
even have been documented in patients with clinically isolated syndrome (CIS), the
first neurological presentation of MS.10 This suggests that strength deficits may begin
early on in the disease process.
Importantly, strength impairments often are associated with meaningful functional and symptomatic consequences. The strength of hamstring and quadriceps
muscles was significantly correlated with walking velocity in a sample of 100 ambulatory persons with MS (EDSS ≤ 6.5).11 Knee extensor power asymmetry correlated
significantly with walking performance, postural stability, and symptomatic fatigue
in 12 women with moderate MS (mean EDSS = 4.0);2 other studies, however, have
not confirmed the association between strength deficits and fatigue.6,14 Ankle and
knee-muscle torque asymmetries have been associated with the percentage of the
gait cycle spent in double support (i.e., time spent with both feet on the ground)
in 52 participants with CIS; individuals with greater strength asymmetries spent
more time in double support.10 Such an effect extends beyond ambulation and gait,
as knee-muscle extensor asymmetry has been associated with cognitive processing
speed in persons with MS but not controls.12 Taken together, strength deficits and
asymmetries are prevalent in persons with MS and may have important mobility
and symptomatic consequences. This underscores that such deficits are likely to be
important targets for rehabilitation interventions in MS.
Lara A. Pilutti and Robert W. Motl
101
Mechanisms of Muscle Weakness in Multiple Sclerosis
Strength impairment in MS might arise from deficits in both central (i.e., neural) and
peripheral (i.e., skeletal muscle characteristics) mechanisms. CNS damage associated
with MS can alter neural drive to the muscles and results in incomplete activation of
skeletal muscles.6,13,20 For instance, maximal force of the quadriceps with the addition of electrical stimulation exceeded the force produced during voluntary contraction alone in 12 persons with MS who had EDSS scores between 2.0 and 6.0 (mean
EDSS = 3.8).13 This indicates that persons with MS are unable to fully activate muscles under voluntary control, which, in turn, reduces force production. Impairments
in several measures of central motor function (i.e., rate of force development, foottap speed, and central activation ratio) have significantly correlated with muscle
weakness (assessed as MVC) based on Pearson (r) correlations; (r = 0.56–0.66) in 16
persons with mild-to-moderate MS (EDSS = 1.0–6.5).6 Impaired neural drive can
alter the frequency of muscle activation, and this might contribute to reduced force
production.20 Low motoneuron firing rates have been observed in four patients with
MS (EDSS = 3.5–6.0) compared to healthy controls.20 Few studies have examined
the relationship between impaired neural activation and functional outcomes in persons with MS. One study reported that measures of central motor function (i.e., rate
of force development and foot-tap speed) correlated significantly with timed 25-foot
walk (T25FW) performance (r = −0.58 to −0.78), but not symptomatic fatigue, in
persons with MS.6 This provides some evidence for the role of impaired neural drive
in strength and ambulatory deficits in persons with MS.
Peripheral mechanisms that account for strength loss in MS may include changes
in metabolic, functional, and structural skeletal muscle profile. Based on biopsies
of the tibialis anterior (TA) muscle, there were reductions in oxidative, but not glycolytic, enzyme activities, as well as the ratio of oxidative to glycolytic enzyme
activities, in a sample of nine persons with MS (median EDSS = 4.0) compared
to healthy controls.4 Oxidative enzyme activities further correlated with levels of
physical activity (r = 0.78, p = .008), assessed through accelerometry, and there
was a trend for an association between oxidative enzyme activities and symptomatic fatigue (r = 0.57, p = .07).4 This suggests that there may be more reliance on
anaerobic than aerobic pathways for generating energy supplies and these metabolic
changes may be related to physical and symptomatic outcomes in persons with MS.
There have been contradictory findings regarding skeletal muscle fiber composition in persons with MS compared to healthy controls.1,3,4 One study reported a
significantly higher percentage of fast-twitch (i.e., type IIa) fibers and a significantly
lower percentage of slow-twitch (i.e., type I) fibers in the TA of nine persons with
MS (median EDSS = 4.0) compared to healthy controls.4 Similar changes in fibertype composition have been observed following spinal cord injury.21 Conversely,
muscle biopsies of the vastus lateralis (VL) revealed a decrease in fibers expressing the type IIa myosin heavy chain (MHC) isoform, without changes in the
expression of any other fiber groups, in six persons with moderate MS (mean
EDSS = 4.8) compared to age- and sex-matched controls.3 Based on squaredmultiple correlation (R 2), this study further reported that fiber type was associated
with EDSS scores (r 2 = 0.79) such that a higher percentage of fibers coexpressing
102
Beneficial Effects of Progressive Resistance Training in Multiple Sclerosis
type IIa and IIx MHC isoforms (i.e., hybrid fibers) was associated with a higher
level of disability.3 Hybrid fibers may represent a transition from one fiber type to
another and, therefore, may indicate a shift in the fast-twitch fiber pool.3 Another
study demonstrated an increase in only the expression of type I/IIa/IIx hybrid
fibers (i.e., those expressing all three MHC isoforms) in seven persons with relapsing–remitting MS compared to healthy controls1; again, this may be indicative of
fiber-type shifts. The limited and conflicting evidence from small samples with a
range of disability levels prevents a firm conclusion regarding fiber-type distribution in persons with MS, but further research in this area is warranted considering
the nature of existing data and the importance for understanding mechanisms of
strength changes and perhaps disability in MS.
The evidence for muscle atrophy from the level of a single fiber to the whole
body is further limited and inconsistent in persons with MS. Muscle biopsy of
the TA revealed a 26% reduction in overall fiber cross-sectional area (CSA) in
nine persons with MS compared to eight healthy controls.4 Similar reductions in
CSA of fibers from the VL were observed in a sample of 6 persons with MS versus 6 ­­age- and sex-matched non-MS controls,3 although no difference in singlefiber CSA in the VL was reported in a study of 14 persons with mild-to-moderate
relapsing–remitting MS (EDSS range = 2.5–6.5) compared to healthy controls.1
An approximate 30% reduction in fat-free CSA of the anterior leg compartment,
as assessed by magnetic resonance imaging (MRI), was reported in persons with
MS compared to healthy controls,4 and fat-free CSA and average fiber CSA were
significantly correlated with dorsiflexor strength (r = 0.71–0.80).4 Another study,
however, did not identify any difference in fat-free CSA in the anterior leg compartment between persons with MS and controls using the same methodologies.6
Total-body fat-free mass (FFM) has been evaluated in persons with MS, most
commonly using dual-energy x-ray absorptiometry. One study reported a significant reduction in FFM in a sample of 71 females with MS ranging from mild-tosevere disability compared to age-matched controls.22 FFM was significantly and
negatively associated with EDSS scores (r = 0.41) (i.e., disability status), which
suggests the preservation of lean tissue may be important in maintaining function in persons with MS. Another examination, however, revealed no difference
in FFM between 17 women with MS compared to 12 non-MS controls, and there
was no relationship between lean mass and EDSS scores23; this discrepancy may
be related to the small sample size of this investigation. Lean mass was further
associated with femoral bone mineral content in a sample of 29 ambulatory women
with MS.24 Glucocorticoid therapy may lead to the loss of bone and lean mass25 and
is commonly prescribed for persons with MS during periods of disease activity
(i.e., relapse). This makes it particularly important to find solutions for preserving
lean mass in patients with MS.
Overall, strength deficits are a common feature of MS and may translate into
meaningful functional and symptomatic consequences. The mechanisms of muscular weakness are complex and may involve both central and peripheral contributions.
One potential solution for maintaining and improving muscle strength in persons
with MS is resistance training.
Lara A. Pilutti and Robert W. Motl
103
RESISTANCE TRAINING IN MULTIPLE SCLEROSIS
The study of exercise in persons with MS has primarily focused on the consequences
of aerobic or combined aerobic and resistance modes of training. There are fewer studies that have exclusively examined the effects of resistance training for persons with
MS. This chapter focuses only on the effects of PRT interventions among adults with
MS. We searched PubMed, Google Scholar, and Web of Science electronic d­ atabases
using the terms “resistance,” OR “strength,” OR “weight,” AND “training,” OR “exercise,” WITH “multiple sclerosis.” The search was supplemented with a­ rticles from our
personal libraries. We reviewed 17 published articles that were based on 11 PRT interventions.26–42 Of the 11 interventions, four26,27,30,32 were randomized ­controlled trials
(RCTs) and seven were pre-post or crossover designs. The studies generally included
participants with various MS courses (i.e., relapsing–remitting, primary progressive,
and secondary progressive) with mild-to-moderate disability (range of EDSS = 1.0–
6.5); only one study included participants with EDSS score > 6.5.34 Mean disease
duration ranged between 6.0 and 14.1 years in the five studies27,30,35–37 reporting this
clinical characteristic. Participants were reported taking disease-modifying therapies
(e.g., interferons and glatiramer acetate) in only two of the studies.34,39
We provide a summary of the 11 PRT regimes in Table 7.1. The duration of training ranged between 3 and 24 weeks, and the frequency ranged between two and five
times per week, although two training sessions per week was most common. The
number of sets performed ranged between one and four, and strength improvements
were typically observed with only one to two sets of exercise. The number of repetitions per exercise ranged between 4 and 15, and training intensity ranged between
8 and 15RM (RM stands for repetition maximum) or approximately 60%–90%
1RM. The majority of PRT interventions involved resistance training of the lower
extremity muscles, although some included upper extremity and core strengthening exercises. Conventional weight machines were used in most training regimes,
although some studies included plyometric exercises using body weight, a weighted
vest, free weights, or ankle weights to provide resistance. Only one study30 conducted a primarily home-based intervention, whereas the training sessions in the
other studies were undertaken in a supervised facility.
The studies detailed a number of potential benefits of PRT for persons with MS,
which are summarized in Figure 7.1. PRT may result in peripheral (i.e., strength and
skeletal muscle profile changes) as well as central (i.e., neural adaptations) adaptations. Neural adaptations from PRT may further contribute to peripheral changes. Such
adaptations may result in improvements in muscle strength primarily, which, in turn,
may contribute to secondary benefits such as improved mobility, fatigue, and QoL.
Progressive Resistance Training for Muscular
Strength and the Skeletal Muscle Profile
There is consistent evidence for the beneficial effects of PRT on muscle strength, both
static and dynamic, in persons with MS.26,27,30–32,35–37,39 An 8 week lower body resistance training regime (one set of 8–15 repetitions at 50%–70% MVC 2 days/week)
2
2
2
2
5
2
2
2
De Souza et al.31
Dodd32
Filipi et al.33
Filipi et al.34
Fimland et al.35
Sabapathy et al.36
Taylor et al.37; Dodd et al.38
White et al.39,40,41
8
14
3
8
24
24
8
10
8
20
12
Weeks
Note: BW, body weight; RPE, rate of perceived exertion.
3
5×/2 weeks
2
Broekmans et al.26
Dalgas et al.27,28,29
DeBolt et al.30
Days/Week
Reference
TABLE 7.1
Summary of PRT in Persons with MS
1
2
4
2–3
2–3
2–3
3
2
2, 3
1, 2
3, 4
Sets
8–15
10–12
4
6–10
10
10
10–15
10–12
8–12
10–15
8–12
Repetitions
Intensity
50%–70% MVC
60–80% 1RM
85%–90% 1RM
3–5 RPE
10RM
10RM
Weighted vest—
initial 0.5% BW
40%–70% MVC
10–12RM
50%–60% 1RM
8–15 RM
Training Program
Exercises
Leg press, leg extension, leg curl
Leg press, knee extension, hip
flexion, hamstring curl, hip
extension
Chair raises, forward lunges,
step-ups, heel–toe raises, leg curls
Leg extension
Leg press, knee extension, calf
raise, leg curl, reverse leg press
Upper body, lower body, and core
exercises
Upper body, lower body, and core
exercises
Leg press, calf raise
Upper body, lower body, and core
exercises
Leg press, knee extension, calf raise,
lat pull down, arm press, seated row
Knee flexion/extension, plantar
flexion/extension, spinal flexion/
extension
104
Beneficial Effects of Progressive Resistance Training in Multiple Sclerosis
105
Lara A. Pilutti and Robert W. Motl
Central adaptations
(i.e., neural)
Strength
PRT
Mobility
Fatigue
Physical QOL
Peripheral adaptations
(i.e., skeletal muscle)
FIGURE 7.1 Potential model for the benefits of progressive resistance training in persons
with multiple sclerosis.
resulted in improvements in isometric strength of the knee extensors and plantar flexors in eight persons with MS who had a mean EDSS score of 3.7 (i.e., moderate disability).39 Dynamic strength, assessed as 1RM, for leg press and reverse leg press
exercises improved following 10 weeks of lower extremity PRT (two sets of 10–12
repetitions at 10–12RM 2 days/week) in 36 participants with MS who had an ambulation index score of 2–4 (i.e., mild-to-moderate disability).32 A 12-week RCT of lower
extremity PRT (three to four sets of 8–12 repetitions at 8–15RM 2 days/week) resulted
in significant improvements in MVC of knee flexors and extensors, as well as leg press
1RM in 19 persons with MS compared to 19 persons with MS who were controls; all
participants had a moderate level of impairment (EDSS score between 3.0 and 5.5).27
Beyond strength, muscular endurance, commonly assessed as the maximum
number of repetitions performed within a single set at a submaximal intensity, has
improved following PRT in persons with MS.26,31,32,37 One study that included 8
weeks of leg extension training (three sets of 10–15 repetitions at 40%–70% MVC
2 days/week) reported an improvement in endurance of leg muscle extensors among
13 persons with MS who had a mean EDSS score of 3.4 (range of 1 through 6).31
Another 10 week lower body PRT intervention (two sets of 10–12 repetitions at
10–12RM 2 days/week) resulted in a significant improvement in reverse leg press
endurance and a nonsignificant (p = .07) increase in leg press endurance.32
The majority of PRT studies have examined lower extremity strength after lower
body–specific training regimes, but some researchers have investigated improvements in upper body strength after training regimes that have included an upper
body strengthening component in persons with MS.33,34,36,37 One PRT program
included leg press, knee extension, calf raises, arm press, and seated row exercises
and resulted in greater 1RM and muscular endurance of arm and leg press exercises
among nine persons with MS who had mild-to-moderate disability.37 Another study
reported no changes in grip strength after upper extremity, lower extremity, and core
strength training in persons with relapsing–remitting and progressive types of MS
and mild-to-moderate disability.36 Such null results may be because the upper body
resistance exercises primarily targeted chest and shoulder muscles rather than forearm flexors; upper body strength gains may have been captured with strength assessments targeting the appropriate muscle groups.
Very few studies have examined changes in the skeletal muscle profile itself following PRT in persons with MS. We located two studies that ­examined ­neural adaptations
after PRT.35,39 One study observed an increase in neural drive (i.e., electromyogram
106
Beneficial Effects of Progressive Resistance Training in Multiple Sclerosis
activity) and voluntary motor output (i.e., augmented ­normalized V-wave response)
of the soleus by 40% and 55%, respectively, f­ollowing 15 sessions of leg press and
calf raise exercises (four sets of four repetitions at 85%–90% 1RM 5 days/week) in
14 patients with MS who had moderate disability.35 This might reflect an increase in
efferent motor outflow from spinal motoneurons.35 Another study reported that an
8 week PRT intervention (one set of 8–15 repetitions at 5­ 0%–70% MVC 2 days/week)
resulted in no changes in voluntary activation (i.e., central a­ ctivation ratio) of the
quadriceps in eight persons with MS who had a mean EDSS score of 3.7 (i.e., moderate disability).39
Some studies have reported changes in muscle morphology after PRT in persons with MS based on MRI31,39 or muscle biopsy techniques.28 One study reported
a ­significant increase in CSA of the quadriceps by 3.6% based on MRI following
8 weeks of leg extension training (three sets of 10–15 repetitions at 40%–70% MVC
2 days/week) in 13 persons with MS.31 There were nonsignificant increases of 0.7%
and 1.0% in quadriceps CSA and volume, respectively, following 8 weeks of PRT
(one set of 8–15 repetitions at 50%–70% MVC 2 days/week) in a small (n = 8) s­ ample
of participants with moderate MS (mean self-reported EDSS = 3.7).39 The same study
reported that hamstring CSA and volume increased nonsignificantly by 9.5% and
9.2%, respectively.39 PRT consisting of five lower extremity exercises (three to four
sets of 8–12 repetitions at an intensity of 8–15RM 2 days/week) resulted in muscle
fiber hypertrophy based on muscle biopsies from the VL in 38 participants with MS
with moderate disability (EDSS range = 3.0–5.5).28 This study further reported an
increase in CSA of 7.9% in all fiber types and 14.0% in type II fibers following the
12 week training intervention.28
Overall, there is evidence for improvements in muscle strength and to some
extent muscle endurance following PRT in persons with MS. Although most strength
improvements have been observed in the lower extremities, results suggest upper
body strength improvements may also occur with targeted PRT. The limited e­ vidence
regarding the benefits of PRT for neural and muscle profile adaptations makes it
­difficult to provide conclusions regarding the mechanisms of strength gains. This is
because many of the studies have been uncontrolled with small participant samples,
and such limitations should be addressed in future investigations. Regardless, such
strength gains may have important functional and symptomatic consequences for
persons with MS.
Progressive Resistance Training for Mobility,
Fatigue, and Quality of Life
Beyond muscle strength and skeletal muscle profile, researchers have examined
changes in mobility, fatigue, and QoL as outcomes of PRT in MS. Of the 11 studies
of PRT, 7 have included mobility outcomes such as the 6 minute walk test (6MW)
or 2 minute walk (2MW), timed up-and go (TUG), and T25FW or gait analysis.
For example, one RCT of supervised PRT (three to four sets of 8–12 repetitions at
8–15RM 2 days/week for 12 weeks) that focused on the lower extremities compared
with control reported a statistically significant 15.3% improvement in 6MW test
Lara A. Pilutti and Robert W. Motl
107
performance in 38 moderately impaired patients with MS (EDSS range = ­3.0–5.5)27;
this change was accompanied by improvements in 10 m walk (12.3%), stair climb
(12.3%), and chair stand (27.5%) performance. Another study adopted a non-RCT
design and reported that supervised PRT (two to three sets of 6–10 repetitions 2 days/
week for 8 weeks) that focused on upper and lower extremities resulted in statistically
significant improvements in performance on 6MW (8.5%), TUG (9.3%), and fourstep square test (12.6%) in 16 persons with MS36; the effects of PRT were not different from those of aerobic exercise training. Importantly, one RCT of home-based
PRT (2 weeks of instruction followed by 8 weeks of home-based training of two to
three sets of 8–12 repetitions 3 days/week) versus control reported a nonsignificant
improvement in TUG performance among 36 persons with mild-to-moderate MS
(EDSS range = 1.0–6.5),30 although the percentage change (12.7%) was consistent
with previous research. Collectively, there appears to be consistent evidence that
mobility outcomes can be improved with PRT in persons with MS.
PRT might have additional benefits for managing fatigue in persons with MS.
Indeed, fatigue has been an outcome in 5 of the 11 studies on PRT in MS.29,32,33,36,39
For example, one RCT of supervised PRT (three to four sets of 8–12 repetitions at
8–15RM 2 days/week for 12 weeks) that focused on the lower extremities compared
with control reported statistically significant improvements in scores on the Fatigue
Severity Scale and Multidimensional Fatigue Inventory (MFI-20) in 38 moderately
impaired patients with MS (EDSS range = 3.0–5.5); the beneficial change in fatigue
was further observed for MFI-20 in a delayed delivery of the PRT intervention in the
control group.29 One nonrandomized, nonblinded prospective study of whole-body
PRT (two to three sets of 10 repetitions at 10RM 2 days/week for 24 weeks) reported
improvements in Modified Fatigue Impact Scale (MFIS) scores after 3 and 6 months
in 33 persons with MS who were independently ambulatory or ambulatory with a
cane.33 This beneficial effect of PRT on MFIS scores has been reported in two other
non-RCTs involving persons with MS.36,39 Overall, there appears to be consistent
evidence that perceptions of fatigue can be improved with PRT in persons with MS.
The improvements in mobility and symptomatic fatigue with PRT might translate
into beneficial changes for QoL in persons with MS. To that end, we are aware of four
studies that have assessed QoL as an outcome of PRT in persons with MS.29,32,36,37
Notably, one RCT of supervised PRT (three to four sets of 8–12 repetitions at 8–15RM
2 days/week for 12 weeks) that focused on the lower extremities compared with control
reported a statistically significant improvement in the physical, but not mental, component of Short-Form Health Survey-36 (SF-36) in 38 moderately impaired patients
with MS (EDSS range = 3.0–5.5)29; the opposite changes in SF-36 components were
observed in a delayed delivery of the PRT intervention in the control group. Another
RCT of supervised PRT (two sets of 10–12 repetitions at 10–12RM 2 days/week for 12
weeks) that focused on the lower extremities compared with control (usual care plus
social program) reported a statistically significant improvement in the physical component of World Health Organization Quality of Life-Bref scale in 35 patients with
MS who had mild-to-moderate walking disabilities (ambulation index = 2.0–4.0).32
Interestingly, two nonrandomized trials reported improvements in the physical, but
not mental, component of the Multiple Sclerosis Impact Scale-29 after PRT in persons
108
Beneficial Effects of Progressive Resistance Training in Multiple Sclerosis
with MS36,37; there were no further changes in the components on SF-36 after PRT in
one of the trials.36 Overall, there appears to be some evidence for improvements in
QoL, particularly physical QoL, following PRT in persons with MS.
PRESCRIPTION OF RESISTANCE TRAINING IN
PERSONS WITH MULTIPLE SCLEROSIS
There are two existing recommendations by two research groups43,44 on the prescription of resistant training for persons with MS. The first group recommended three
sets of 10–12 repetitions through a full range of motion, reaching a moderate level of
fatigue by the end of the third exercise set.44 The exercises should be conducted using
all major muscle groups. This prescription was deemed appropriate for individuals
with MS with little or no motor deficit; adapted resistance exercises were suggested
for those with higher disability levels, although no recommendation as to the training
prescription was provided. The other group recommended two to three sessions per
week of 4–8 full-body exercises with a focus on lower extremity resistance training.43
The number of recommended sets was 1–3, progressing to three to four over time, at
an intensity of 8–15RM, progressing from 15RM to 8–10RM over several months.
Early on, supervised resistance training using weight machines was recommended,
although home-based training using body weight or elastic bands was a suggested
alternative. These recommendations provide a starting point for the prescription of
resistance training in persons with MS; however, it is important to further examine
the training regimes of the PRT trials reviewed herein to provide the most appropriate and effective recommendations for resistance training in persons with MS.
Based on the literature reviewed, we provide the following exercise recommendations for PRT in persons with MS, which are summarized in Table 7.2. We recommend that adults with MS participate in two weekly sessions of resistance training.
This should include 1–3 sets at an intensity of 10–15RM, focusing primarily on lower
extremity exercises. Progression should proceed gradually over several months and
may include increasing the weight lifted or including an additional training set.
Traditional weight machines are advisable, particularly when beginning a training program, although other resistance training might include body weight or freeweight exercises. We recommend supervised resistance training due to the limited
evidence for benefits of home-based PRT. These recommendations are appropriate
TABLE 7.2
Recommendations for PRT in Persons with MS
Training Parameter
Frequency
Intensity
Modality
Other recommendations
Exercise Prescription
2 sessions/week
1–3 sets, 10–15RM
Weight machines, body weight or free-weight exercises
Lower extremity training focus is recommended
Supervised training is advisable
Adaptations may be necessary for those with severe MS
Lara A. Pilutti and Robert W. Motl
109
for persons with MS with mild-to-moderate disability. For those with advanced MS,
adaptations to traditional PRT may be necessary. Accessible weight machines, free
weights, or pulley systems may be alternative strategies for this population, although
the effects of these modalities have not yet been established.
LIMITATIONS OF THE LITERATURE
There are a number of limitations for the literature on PRT in persons with MS. One
limitation is that most studies included small samples with primarily a relapsing–
remitting disease course and a mild-to-moderate level of disability. This seemingly
limits the generalizability of findings regarding the benefits of PRT among those with
MS, particularly those with progressive MS and severe disability. We do note, however, that there is some evidence of similar strength gains after PRT regardless of the
disability level.34 The effects of PRT on muscle morphology and neural adaptations
have received very limited attention and may provide important mechanisms by which
this training modality exerts beneficial effects for persons with MS. The development
of advanced imaging techniques may provide a useful, noninvasive tool for examining structural adaptations in skeletal muscle with PRT, and structural and functional
adaptations within the CNS. The majority of research examining secondary effects
of PRT in MS has focused on mobility, fatigue, and QoL outcomes, but there are a
limited number of studies that have considered cognition,33 balance,30,33 spasticity,30,32
upper body function,33 and mood29 outcomes. Accordingly, the current knowledge is
limited regarding the range and extent of beneficial effects of PRT in MS.
There may be additional benefits of resistance training for the health and wellbeing of persons with MS. For example, resistance training may be an additional
therapy for smoking cessation in persons with MS,45 which has been associated with
an increased rate of disease progression.46–48 Resistance training has been beneficial
for smoking cessation in the general population49; however, future research is needed
to establish the potential of resistance training as an alternative treatment for smoking
cessation, as well as other health behaviors, in persons with MS.
CONCLUSIONS
Muscle weakness is a prevalent and debilitating feature of MS. Such weakness may
arise from impairments in central and peripheral mechanisms, which may be a consequence of the disease process itself, as well as deconditioning due to inactivity.
Muscle weakness may, in turn, have important functional and symptomatic consequences. The study of PRT in persons with MS has been limited, but it shows
promise for beneficial effects on muscle strength, mobility, symptomatic fatigue,
and physical QoL. The effects of PRT on mechanisms of strength gains (i.e., central
and peripheral factors) are less conclusive, although initial data are promising. The
effects of PRT on many secondary outcomes (i.e., cognition, balance, and spasticity)
also require further investigation, as there may be a number of important benefits of
PRT beyond strength gains. Overall, PRT is a potentially important, but understudied, strategy for improving and maintaining function, independence, and health of
persons with MS.
110
Beneficial Effects of Progressive Resistance Training in Multiple Sclerosis
REFERENCES
1. Carroll CC, Gallagher PM, Seidle ME, Trappe SW. Skeletal muscle characteristics of
people with multiple sclerosis. Arch Phys Med Rehabil. 2005;86(2):224–229.
2. Chung LH, Remelius JG, Van Emmerik REA, Kent-Braun JA. Leg power asymmetry and postural control in women with multiple sclerosis. Med Sci Sports Exerc.
2008;40(10):1717–1724.
3. Garner DJ, Widrick JJ. Cross-bridge mechanisms of muscle weakness in multiple sclerosis. Muscle Nerve. 2003;27(4):456–464.
4. Kent-Braun JA, Ng AV, Castro M et al. Strength, skeletal muscle composition, and
enzyme activity in multiple sclerosis. J App Physiol. 1997;83(6):1998–2004.
5. Lambert CP, Archer RL, Evans WJ. Muscle strength and fatigue during isokinetic exercise
in individuals with multiple sclerosis. Med Sci Sports Exerc. 2001;33(10):1613–1619.
6. Ng AV, Miller RG, Gelinas D, Kent-Braun JA. Functional relationships of central and
peripheral muscle alterations in multiple sclerosis. Muscle Nerve. 2004;29(6):843–852.
7. Frohman EM, Racke MK, Raine CS. Multiple sclerosis—the plaque and its pathogenesis. N Engl J Med. 2006;354(9):942–955.
8. Motl RW, McAuley E, Snook EM. Physical activity and multiple sclerosis: a metaanalysis. Mult Scler. 2005;11(4):459–463.
9. Sandroff BM, Dlugonski D, Weikert M, Suh Y, Balantrapu S, Motl RW. Physical
activity and multiple sclerosis: new insights regarding inactivity. Acta Neurol Scand.
2012;126(4):256–262.
10. Kalron A, Achiron A, Dvir Z. Muscular and gait abnormalities in persons with early
onset multiple sclerosis. J Neurol Phys Ther. 2011;35(4):164–169.
11. Thoumie P, Lamotte D, Cantalloube S, Faucher M, Amarenco G. Motor determinants of
gait in 100 ambulatory patients with multiple sclerosis. Mult Scler. 2005;11(4):485–491.
12. Sandroff BM, Motl RW. Fitness and cognitive processing speed in persons with
multiple sclerosis: a cross-sectional investigation. J Clin Exp Neuropsychol. 2012;
34(10):1041–1052.
13. De Haan A, De Ruiter CJ, Van Der Woude LH, Jongen PJ. Contractile properties and fatigue
of quadriceps muscles in multiple sclerosis. Muscle Nerve. 2000;23(10):1534–1541.
14. Schwid SR, Thornton CA, Pandya S et al. Quantitative assessment of motor fatigue and
strength in MS. Neurology. 1999;53(4):743–750.
15. Armstrong LE, Winant DM, Swasey PR, Seidle ME, Carter AL, Gehlsen G. Using isokinetic dynamometry to test ambulatory patients with multiple sclerosis. Phys Ther.
1983;63(8):1274–1279.
16. Ponichtera JA, Rodgers MM, Glaser RM, Mathews TA, Camaione DN. Concentric
and eccentric isokinetic lower extremity strength in persons with multiple sclerosis.
J Orthop Sports Phys Ther. 1992;16(3):114–122.
17. De Ruiter CJ, Jongen PJ, Van der Woude LH, De Haan A. Contractile speed and fatigue
of adductor pollicis muscle in multiple sclerosis. Muscle Nerve. 2001;24(9):1173–1180.
18. Bjartmar C, Trapp BD. Axonal and neuronal degeneration in multiple sclerosis: mechanisms and functional consequences. Curr Opin Neurol. 2001;14(3):271–278.
19. Compston A, Coles A. Multiple sclerosis. Lancet. 2008;372(9648):1502–1517.
20. Rice CL, Vollmer TL, Bigland-Ritchie B. Neuromuscular responses of patients with
multiple sclerosis. Muscle Nerve. 1992;15(10):1123–1132.
21. Burnham R, Martin T, Stein R, Bell G, MacLean I, Steadward R. Skeletal muscle fibre
type transformation following spinal cord injury. Spinal Cord. 1997;35(2):86–91.
22. Formica CA, Cosman F, Nieves J, Herbert J, Lindsay R. Reduced bone mass and fat-free
mass in women with multiple sclerosis: effects of ambulatory status and glucocorticoid
use. Calcif Tissue Int. 1997;61(2):129–133.
Lara A. Pilutti and Robert W. Motl
111
23. Lambert CP, Lee Archer R, Evans WJ. Body composition in ambulatory women with
multiple sclerosis. Arch Phys Med Rehabil. 2002;83(11):1559–1561.
24. Mojtahedi MC, Snook EM, Motl RW, Evans EM. Bone health in ambulatory individuals
with multiple sclerosis: impact of physical activity, glucocorticoid use, and body composition. J Rehabil Res Dev. 2008;45(6):851–861.
25. Czerwinski SM, Kurowski TG, O’Neill TM, Hickson RC. Initiating regular exercise protects against muscle atrophy from glucocorticoids. J Appl Physiol. 1987;
63(4):1504–1510.
26. Broekmans T, Roelants M, Alders G, Feys P, Thijs H, Eijnde BO. Exploring the effects
of a 20-week whole-body vibration training programme on leg muscle performance and
function in persons with multiple sclerosis. J Rehabil Med. 2010;42(9):866–872.
27. Dalgas U, Stenager E, Jakobsen J et al. Resistance training improves muscle strength
and functional capacity in multiple sclerosis. Neurology. 2009;73(18):1478–1484.
28. Dalgas U, Stenager E, Jakobsen J, Petersen T, Overgaard K, Ingemann-Hansen T.
Muscle fiber size increases following resistance training in multiple sclerosis. Mult
Scler. 2010;16(11):1367–1376.
29. Dalgas U, Stenager E, Jakobsen J et al. Fatigue, mood and quality of life improve in MS
patients after progressive resistance training. Mult Scler. 2010;16(4):480–490.
30. DeBolt LS, McCubbin JA. The effects of home-based resistance exercise on balance, power, and mobility in adults with multiple sclerosis. Arch Phys Med Rehabil.
2004;85(2):290–297.
31. De Souza-Teixeira F, Costilla S, Ayan C, Garcia-Lopez D, Gonzalez-Gallego J,
De Paz JA. Effects of resistance training in multiple sclerosis. Int J Sports Med.
2009;30(4):245–250.
32. Dodd KJ, Taylor NF, Shields N, Prasad D, McDonald E, Gillon A. Progressive resistance training did not improve walking but can improve muscle performance, quality
of life and fatigue in adults with multiple sclerosis: a randomized controlled trial. Mult
Scler. 2011;17(11):1362–1374.
33. Filipi ML, Leuschen MP, Huisinga J et al. Impact of resistance training on balance and
gait in multiple sclerosis. IJMSC. 2010;12(1):6–11.
34. Filipi ML, Kucera DL, Filipi EO, Ridpath AC, Leuschen MP. Improvement in
strength following resistance training in MS patients despite varied disability levels.
NeuroRehabilitation. 2011;28(4):373–382.
35. Fimland MS, Helgerud J, Gruber M, Leivseth G, Hoff J. Enhanced neural drive
after maximal strength training in multiple sclerosis patients. Eur J Appl Physiol.
2010;110(2):435–443.
36. Sabapathy NM, Minahan CL, Turner GT, Broadley SA. Comparing endurance- and
resistance-exercise training in people with multiple sclerosis: a randomized pilot study.
Clin Rehabil. 2011;25(1):14–24.
37. Taylor NF, Dodd KJ, Prasad D, Denisenko S. Progressive resistance exercise for people
with multiple sclerosis. Disabil Rehabil. 2006;28(18):1119–1126.
38. Dodd KJ, Taylor NF, Denisenko S, Prasad D. A qualitative analysis of a progressive
resistance exercise programme for people with multiple sclerosis. Disabil Rehabil.
2006;28(18):1127–1134.
39. White LJ, McCoy SC, Castellano V et al. Resistance training improves strength and
functional capacity in persons with multiple sclerosis. Mult Scler. 2004;10(6):668–674.
40. White LJ, Castellano V, McCoy SC. Cytokine responses to resistance training in people
with multiple sclerosis. J Sports Sci. 2006;24(8):911–914.
41. White LJ, McCoy SC, Castellano V, Ferguson MA, Hou W, Dressendorfer RH. Effect of
resistance training on risk of coronary artery disease in women with multiple sclerosis.
Scand J Clin Lab Invest. 2006;66(4):351–355.
112
Beneficial Effects of Progressive Resistance Training in Multiple Sclerosis
42. Gutierrez GM, Chow JW, Tillman MD, McCoy SC, Castellano V, White LJ. Resistance
training improves gait kinematics in persons with multiple sclerosis. Arch Phys Med
Rehabil. 2005;86(9):1824–1829.
43. Dalgas U, Ingemann-Hansen T, Stenager E. Physical exercise and MS recommendations. Int MS J. 2009;16(1):5–11.
44. Petajan JH, White AT. Recommendations for physical activity in patients with multiple
sclerosis. Sports Med. 1999;27(3):179–191.
45. Ciccolo JT, Lo AC, Jennings EG, Motl RW. Rationale and design of a clinical trial
investigating resistance training as an aid to smoking cessation in persons with multiple
sclerosis. Contemp Clin Trials. 2012;33(4):848–852.
46. Healy BC, Ali EN, Guttmann CRG et al. Smoking and disease progression in multiple
sclerosis. Arch Neurol. 2009;66(7):858–864.
47. Hernán MA, Jick SS, Logroscino G, Olek MJ, Ascherio A, Jick H. Cigarette smoking
and the progression of multiple sclerosis. Brain. 2005;128(Pt 6):1461–1465.
48. Zivadinov R, Weinstock-Guttman B, Hashmi K et al. Smoking is associated with increased
lesion volumes and brain atrophy in multiple sclerosis. Neurology. 2009;73(7):504–510.
49. Ciccolo JT, Dunsiger SI, Williams DM et al. Resistance training as an aid to standard
smoking cessation treatment: a pilot study. Nicotine Tob Res. 2011;13(8):756–760.
8
Resistance Training for
Parkinson’s Disease
Brian K. Schilling and Kelley G. Hammond
CONTENTS
Introduction............................................................................................................. 117
Nervous System and Potential Mechanisms for Adaptation................................... 118
Rate of Force Development................................................................................ 119
Bone Health and Body Composition................................................................. 119
Strength Training Studies........................................................................................ 120
Resistance Exercise and Nutritional Intervention.............................................. 124
Exercise Recommendations.................................................................................... 125
Conclusion.............................................................................................................. 126
References............................................................................................................... 126
INTRODUCTION
Idiopathic Parkinson’s disease (PD) is a chronic, progressive disorder of the central
nervous system.1 It occurs when dopaminergic cells in the substantia nigra die. The
cardinal symptoms include tremor, rigidity, bradykinesia, and postural instability;
however, emotional, cognitive, motor, and fatigue symptoms are also common. At
the time of presentation, as many as 60%–80% of the dopaminergic neurons are
lost, and there may also be a loss of norepinephrine-generating nerve endings.1 There
appears to be a combination of genetic susceptibility and exposure to the environment that leads to the development of the disease, and the progression is nonlinear.
At least 500,000 people in the United States currently have PD, and annual costs
may exceed $6 billion per year. Worldwide, it is estimated that 7–10 million people have PD.1 Although most cases appear around the age of 60, 5%–10% of cases
are denoted “early onset” and are diagnosed before the age of 50. Current common
treatment options include drugs such as levodopa and dopamine agonists and other
medications and also surgery in the form of deep brain stimulator implantation.1
Both of these treatments have limitations,2 so alternative treatments are still being
sought. Clinical status is measured by Hoehn and Yahr staging (I–V) and the Unified
Parkinson’s Disease Rating Scale (UPDRS), which includes Hoehn and Yahr staging
with additional measures.
Exercise has been proposed as a treatment for PD, but there are many unanswered
questions as to the proper exercise regimen. Often, exercise is an all-­encompassing
term used to describe physical movement that is carried out with the intent of
113
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Resistance Training for Parkinson’s Disease
stimulating progressive changes in body composition, neuromuscular function, or
cardiorespiratory fitness. PD has been suggested to elicit negative effects on these
physical attributes, especially neuromuscular strength,3–10 and can adversely impact
an individual’s quality of life and activities of daily living (ADLs). Although physical therapy/exercise modalities of treatment have been explored in PD as far back as
the late 1950s and early 1960s, much remains to be understood regarding the disease
itself and the potential benefits of exercise due, in part, to the diverse approach to
training protocols in the literature.
Throughout this chapter, the phrase “resistance training” (RT) is used specifically
to describe physical efforts that are well defined and measurable, having a specified volume and suggested voluntary intensity, which is typically determined relative
to maximum (in percentage; one-repetition maximum weight lifted). Programming
of resistance exercise should be variable and progressive and can be recommended
based on the aforementioned and other acute training variables. Resistance exercise
regimens following these guidelines are fairly generalizable but should be individualized for each patient, keeping in mind his or her specific strengths and weaknesses.
“Despite the overlapping verbiage describing exercise and physical therapy in the
PD literature to date,11 it is critical to decipher the two types of treatment, as the outcomes of such activities are rather distinct and can both elicit positive results for persons with PD.” Methods of therapy where muscular strength, power, and endurance
are not the foremost interest, such as occupational therapy, gait cueing, treadmill
training for gait, and other types of physiotherapy (which focus exclusively on skill
acquisition/reacquisition), or those where the training regimen is not well defined
and measureable will not be included. In addition, this chapter will not emphasize
cardiorespiratory training, as aerobic exercise brings about unique adaptations that
are somewhat different and should be addressed separately. All the characteristics
of physical conditioning clearly affect ADLs that also include a skill component,
such as locomotion. However, RT appears to elicit additional comprehensive effects
on other systems of the body that are affected by PD, thus improving quality of
life.12,13 A meta-analysis of randomized clinical trials of exercise/physical therapy by
Goodwin et al.11 supports exercise as an effective method to treat many of the symptoms of PD. Still, there remains extensive promise for future research in justifying all
modes of exercise, specifically RT, as valuable therapeutic strategies for treating PD.
NERVOUS SYSTEM AND POTENTIAL MECHANISMS
FOR ADAPTATION
Numerous studies have demonstrated reduced neuromuscular performance in persons
with PD compared with neurologically healthy participants.3–10,14–19 Furthermore,
several studies reporting auxiliary reductions in strength following the withdrawal
of antiparkinson medication4,20,21 and laterality of strength deficits22 imply the central nervous system effects of PD on muscle activation. Clinical stage of PD has
also been shown to correlate with neuromuscular performance.9,20,21,23–25 Reduced
strength and power in PD may also be associated with balance,4,26 gait,4,16,27 and
function.8,14,19,21,26
Brian K. Schilling and Kelley G. Hammond
115
A recent review of the literature has highlighted potential central and peripheral
mechanisms for RT adaptation in PD.2 Studies have evaluated the therapeutic potential of exercise on several physical and cognitive/psychological performance variables
in PD, but few have focused on the effects of exercise on PD-induced physiological
changes to the central and peripheral nervous system. Among healthy persons, surface electromyography (EMG) has been used to display numerous neural adaptations
to RT, although analogous measures have not been explored in conjunction with
PD.2 Still, peripheral EMG activity in PD including bilateral differences in activation28 and co-contraction29 and differences in flexion versus extension18 have been
assessed in cross-sectional investigations. Therefore, much remains to be examined
using EMG to detect adaptations to RT in PD.30 Several mechanisms, including neurogenesis due to neurotrophins, synaptogenesis, increased capillarization, decreased
oxidative stress,31 and increased proteolytic degradation via proteasome and neprilysin, have been identified32 as possible targets of exercise in the PD-affected brain.
Specifically, brain-derived neurotrophin, glia-derived neurotrophin, nerve growth
factor, and galanin are among the neurotrophins of interest.33 Most obviously of relevance to the PD community, animal models have exhibited increases in calcium levels with exercise, resulting in increased dopamine.34 In addition to potential chronic
effects, acute effects of exercise may include increased sensitivity to levodopa in the
brain, leading to improved motor scores35; the central effect is probably accountable
for this improvement, as no change in plasma levodopa was observed. How these
adaptations might manifest themselves via RT is currently unknown and has great
potential for research.
Rate of Force Development
Persons with PD present a decreased rate of force development (RFD) independently36,37 and in conjunction with reduced maximal strength5,6,19,20,38 compared with
their similarly aged, neurologically healthy counterparts. Arguably, the deficit of
RFD may be of greater concern than the reduction in maximal strength. If RFD is
not sufficient to reach the minimum levels of force needed to recover from a loss of
balance, falls may result.39 Although RFD has not been used as a performance measure in PD training studies, evidence exists that it is trainable40 and correlated with
maximum strength41 in neurologically normal elderly persons. To achieve optimal
gains in RFD, participants should be instructed to move the weight or contract the
muscle as quickly as possible42 while maintaining proper exercise technique; exercises executed at slower tempos may likely yield inferior results.
Bone Health and Body Composition
Bone health, as evaluated using bone mineral density (BMD) and associated measures, is adversely altered in PD.43–45 Decrements in BMD in addition to a higher incidence of falling in PD46 clarify, to a great extent, the amplified rate of bone fracture
in PD.43,45,47 Probable improvements in balance4 and favorable skeletal adaptations48
via RT interventions hold promise for reducing fracture risk in persons with PD, as
sedentary lifestyle is a risk factor for bone loss in PD.44 As PD progresses physical
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Resistance Training for Parkinson’s Disease
activity typically diminishes, which can exacerbate BMD loss. This is likely associated with the decrease in body mass associated with the disease.49 Furthermore,
persons with PD often experience muscle atrophy, which is replaced with excess
adiposity, termed “sarcopenic obesity.”50 Because RT interventions have demonstrated maintenance of or increases in BMD in neurologically healthy adults,48 and
lean body mass in PD,51,52 stressing the musculoskeletal system via RT is likely an
effective therapy for preventing or treating sarcopenic obesity. Exercises such as
squats and leg presses, which load the lumbar spine and pelvis, may be particularly
beneficial for persons with PD.48 As evidenced by Pang et al.,54 this hypothesis is
encouraging for future studies because trunk muscle strength is positively associated with lumbar spine BMD53 and leg muscle strength is positively associated with
greater hip BMD in PD.
STRENGTH TRAINING STUDIES
Glendinning et al.30 proposed RT interventions for persons with PD nearly a decade
ago and, since then, several investigations have effectively demonstrated improvements in strength indices in this population using RT programs12,31,51,55–59; however,
considerable differences in mode, intensity, volume, rest periods, and frequency of
training are common among the studies (Table 8.1).
Single-set programs are common programming in the PD literature to date,51,55,56
yet optimal training volume for RT remains fairly controversial in the exercise
research across populations. For example, higher volume training has stimulated
greater improvements in strength in older individuals than single-set protocols.60
Still, because fatigue can be overwhelming for persons with PD, caution should be
used when prescribing higher exercise volumes.61
Single-joint exercises have been emphasized in several RT intervention studies to
date.13,51,55,62 Such single-joint measures of strength have been correlated with performance in gait initiation26 and fall frequency.9 Because ADLs such as rising from
a chair require coordinated activation of multiple muscle groups across several joints
concurrently, RT programs targeting single joints and individual muscle groups may
have less carryover than programs that use a multijoint approach. One of the benefits
of strength training is increased motor recruitment of the targeted muscles, which
can translate into improved efficiency in ADLs; a loaded leg press exercise requires
activation of the same knee and hip extensor muscles that are recruited to rise from a
chair.6,8 The likelihood of neurologically healthy elderly persons falling can be predicted by multijoint strength measures,63 and such strength measures have also been
correlated with timed-up-and-go performance in persons with PD.8
Other modes of training have been used for interventions in PD, such as multijoint
eccentric ergometers.12,52,58 Eccentric muscle actions occur when a muscle lengthens
while activated. Typical weight training movements, which have both concentric
(muscle shortening while activated) and eccentric muscle actions, require a higher
metabolic expense; however, when the eccentric portion is isolated and stressed the
energy cost is quite reduced,64 despite the targeted muscles’ reasonably high force
production. Because fatigue is a considerable burden for many persons with PD,
eccentric-only RT may be valuable for stimulating increases in muscle strength and
6 PD TRN; 7 PD
CNTL, H&Y 2.0
10 ECC; 9 PD
standard
exercise,
H&Y 2.5
10 ECC; 9 PD
CNTL, H&Y 2.5
10 PD, H&Y 1–3,
no CNTL
Dibble et al.12
Dibble et al.52
Dibble et al.58
Subject
Characteristics
Bloomer et al.31
Reference
ECC, ergometer for leg
extensors
ECC, ergometer for leg
extensors, CNTL,
treadmill walking,
cycling, upper-body
resistance exercise
ECC, ergometer for leg
extensors, CNTL,
treadmill walking,
cycling, upper-body
weight training
PD, knee flexion,
plantar flexion, and
leg press; CNTL,
standard care
Resistance Type
TABLE 8.1
Resistance Exercise Interventions in PD
Training Prescription
Increasing RPE (7–13) over
12 weeks. Time increased
from 3–5 minutes (week 1)
to 15–30 minutes
(week 12). 36 sessions, 3×
weekly for 12 weeks.
Increasing RPE (9–15) over
12 weeks.
Increasing RPE (7–13) over
12 weeks.
3 Sets of up to 8 repetitions,
2× weekly for 8 weeks.
Load ↑ when 8 repetitions
accomplished.
Dependent Variables
Serum CK, muscle pain
scores, isometric knee
extensor force at 60° knee
angle
Isometric knee extensor
torque at 60° knee angle,
MRI for knee extensor
volume, 6MW, stair ascent/
descent time
UPDRS motor, isometric
knee extensor maximum
force, 10MW, TUG,
PDQ-39
Antioxidative/oxidative
stress variables, 1RM leg
press
Findings
(Continued)
18% ↑ in leg press 1RM,
significant ↓ for H2O2 in TRN
group. Moderate-to-large effect
sizes for several variables
indicate positive changes in
oxidative status.
Significant interaction for
10MW, TUG, and PDQ-39
with ECC group better than
CNTL postintervention.
Moderate-to-large effect size
seen for UPDRS and muscle
force in ECC.
All measures not including knee
extensor torque and stair ascent
time that had significant
interaction were significantly
better in ECC group post
intervention.
Significant ↑ in knee extensor
force and transient significant
increase in muscle pain scores.
Brian K. Schilling and Kelley G. Hammond
117
10 PD CM; 10 PD
placebo CNTL,
H&Y ~2.2
9 PD training;
9 PD CNTL,
gender-matched,
H&Y 2.3
9 PD balance
only, 1.9 H&Y;
6 PD balance +
weight training,
1.8 H&Y
Hass et al.59
Hirsch et al.55
Subject
Characteristics
Hass et al.51
Reference
Knee extensor and
flexion, leg press,
abdominal curl, back
extensor, seated calf
raise, and
multidirectional ankle
protocol in circuit
fashion
Both groups did
balance exercises, and
one group added knee
flexion and extensor,
plantar flexion
Machine-based knee
extensor and flexion,
seated calf raise, chest
press, pull down,
shoulder press, back
extensor, biceps curl,
and triceps extensor
Resistance Type
TABLE 8.1 (Continued)
Resistance Exercise Interventions in PD
Training Prescription
1 set of 12 repetitions at
60% 4RM; 6 second
contraction Load ↑ to 80%
in week 2 and readjusted.
30 sessions, 3× weekly for
10 weeks.
1 set of 8–12 repetitions at
70% 1RM; 1 set of 8–12
fast repetitions at 50%
1RM for leg extensor and
flexion. Load ↑ when target
repetitions achieved.
24 sessions, 2× weekly for
12 weeks.
2 sets of 12–20 repetitions at
70% 1RM to volitional
fatigue. 5 minute rest
between circuits.
Dependent Variables
4-repetition maximum
postintervention and after
4-week nontraining period
Length and velocity of initial
stride. Disp. of COP during
APA phase, weight
transition phase, and
locomotor phase
1RM for each exercise, and
muscle endurance via
maximum number of
repetitions at 60% 1RM,
3 repetition sit-to-stand
time
Findings
Balance + weight training had
greater ↑ strength (52%) over
balance alone (9%), and both
improved balance. Values still
greater than baseline after
4-week nontraining period.
Training significance. ↑ knee
extensor. and flexion strength.
COP posterior disp. in the APA
phase was also significant.
Improved initial stride velocity.
All subjects lean body mass ↑,
1RM strength ↑, muscle
endurance ↑, sit-to-stand time
↓. CM group ↑ sit-to-stand
performance, ↑ chest press,
biceps curl and sit-to-stand to a
greater degree than CNTL.
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Resistance Training for Parkinson’s Disease
20 PD; H&Y 1–3,
no CNTL
14 PD, 2.5 H&Y;
6 non-PD
training CNTL
(62.5 years)
8 PD RT; 7 PD
standard care
CNTL,
H&Y 2.0
4 PD RT, 3PD
CNTL; 2.3
H&Y
Rodrigues de
Paula et al.13
Scandalis et al.56
Schilling et al.80
Toole et al.62
Machine knee flexion
and extensor along
with ankle inversion
Leg press, seated leg
curl, calf press
Leg press, knee flexion
and extensor, calf
raise, abdominal
crunch
Trunk, hip, knee and
ankle flexion and
extensor combined
with aerobic training
6 lower-limb and
3 upper-limb
exercises
Stride length and velocity,
total exercise volume,
abdominal muscle
endurance (tested off
medication)
6MW, TUG, 1RM leg press,
ABC
Isokinetic knee flexion and
extensor torque at 90° and
180°/s, Isokinetic ankle
inversion toque at 120°/s
3 × 10 repetitions at 60%
4RM; 6 second
contraction, load adjusted
each week. 30 sessions, 3×
weekly for 10 weeks.
Nottingham health profile
completed in interview
format
Qualitative analysis of
participation and outcomes
1 × 12 repetitions at 60%
1RM, Load increased by
5 lbs when 12 repetitions
reached. 16 sessions, twice
weekly for 8 weeks.
5–8 repetitions per set × 3
sets per exercise, 2× per
week for 8 weeks.
2 sets of 10–12 repetitions
with Thera-Band®.
Resistance increased when
12 repetitions was reached.
2× per week for 10 weeks.
2 sets of 10 repetitions
adjusted in 0.5 kg
increments with strength
gain.
Participation was attributed to
reasons over and above
physical outcomes. Subjects
viewed the exercise as
worthwhile for varied reasons.
Significant ↑ in total score and
subscales of emotional
reaction, social interaction, and
physical ability. Nonsignificant
improvement in energy level,
pain, and sleep scores.
Individuals with PD showed
similar strength gains to
healthy controls. PD had
significant increased stride
length and gait velocity.
Significant ↑ in 1RM for RT
group, no change in CNTL. No
interaction for TUG, 6MW, or
ABC. Significant time effect ↑
for 6MW.
Significant interaction for
strength, with CNTL subjects’
strength decreasing through
training period.
Note: TRN, training; CNTL, control; H&Y, Hoehn and Yahr stage; H2O2, hydrogen peroxide; ECC, eccentric-only exercise; RPE, rating of perceived exertion; TUG, timed
up and go; PDQ-39, Parkinson’s Disease Questionnaire; 10MW, 10 minute walk; MRI, magnetic resonance imaging; 6MW, 6 minute walk; CK, creatine kinase; CM,
creatine monohydrate; COP, center of pressure; APA, anticipatory postural adjustment; ABC, Activities-Specific Balance Confidence scale.
12 PD; H&Y 1–4
O’Brien et al.66
Brian K. Schilling and Kelley G. Hammond
119
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Resistance Training for Parkinson’s Disease
bone density while curtailing fatigue. Still, most functional movements, such as rising from a chair, are driven by primarily concentric muscle actions. Additionally,
eccentric strength appears to be better preserved compared to concentric strength
in PD.16,21 Therefore, it remains to be seen whether eccentric-only training provides
sufficient carryover to ADLs compared to concentric/eccentric training. Although
it has yet to be investigated, one could speculate that some amalgamation of conventional RT with an augmented emphasis on the eccentric portion of each exercise
may be of the greatest benefit for PD. Even so, eccentric loading interventions in PD,
when evaluated versus standard care, affirm a case for the restorative potential of
such training. Studies have shown increased performance in 10 minute walk, timed
up and go, Parkinson’s Disease Questionnaire-39,12 muscle volume, 6 minute walk,
and stair descent time,52 as well as an increase in knee extensor force.58 A direct
comparison of eccentric-only and traditional training is thus warranted.
Despite the aforementioned benefits of isolated eccentric training, notable variation in the evaluation of strength can be problematic when the mode of testing lacks
specificity to the method of training. In such cases, there can be a masking of the
potential training effect.65 Some of the modes used to assess strength change in PD
include isokinetic (constant velocity),62 isoinertial (constant load), 8,31,56,59 and isometric12,52 modes, and forms of accommodating or variable resistance have been
reported by declaration of the brand of machine or nature of the applied resistance
in some studies.51,55,66 Some studies to date have not explicitly stated the type of
strength training machines used and whether or not they provided accommodating
resistance62; however, isoinertial training is widespread in the current literature and
is probably the most available mode of RT. Isoinertial resistance is almost certainly
more valid than the other loading methods because of its similarity to the constant
loading (body mass) during ADLs.
The effectiveness of RT interventions endures in several areas regardless of the
inconsistency in strength testing methods, including mobility.67 RT has also elicited improvements in gait velocity,56 gait initiation,59 and functional mobility.12,51,52
Interestingly, persons with PD who perform similar training to neurologically healthy
adults appear to acquire the same relative strength gains.56 One study31 examined
plasma markers of oxidative stress, which are increased in PD68 and are related to
both fatigue69 and inhibition of the excitation–contraction coupling in muscle activation.70 The study31 reported a decrease in H2O2 following 8 weeks of RT in PD, which
was accompanied by increases in leg press strength. In addition, outcomes from a
qualitative study demonstrated supplementary justifications for participation in RT
programs such as adding to the body of knowledge about the effects of training in
PD and slowing the progression of the disease, as well as increased social interaction, decreased fatigue, and increased function.66
Resistance Exercise and Nutritional Intervention
Presently, there is minimal research exploring pairing nutritional intervention along
with RT in PD. Creatine has gained attention over the last several years in PD for its
potential for neuroprotection71,72; yet, most extant data on creatine are focused on the
effects of supplementation on strength outcomes and body composition in healthy
Brian K. Schilling and Kelley G. Hammond
121
men and women.73 Other physiological and psychological variables affected by PD
may be positively impacted by creatine supplementation, including changes in bone
mass74 and cognition.75 Corresponding gains in performance measures such as sitto-stand time and strength have been reported for individuals participating in RT
interventions supplemented with creatine, in both healthy older adults76 and persons
with PD.51
EXERCISE RECOMMENDATIONS
Overall, current research suggests that RT may be advantageous in minimizing a
myriad of PD symptoms related to the musculoskeletal system and might also benefit
central nervous system function as well. Any RT program should be supervised by
a qualified fitness professional in concert with appropriate medical personnel and
employ systematic variation to maximize training effects and minimize potential
boredom. Fitness personnel should possess a certification from a professional organization such as the National Strength and Conditioning Association and have some
knowledge of PD.
Falvo et al.67 prepared guidelines for RT in PD based on recommendations for
healthy adults77 and older adults,78 and the subsequent suggestions also apply to bone
health57:
• Commencing exercise immediately after or during the process of PD diagnosis is essential for maintaining physical attributes and slowing their deterioration as much as possible.
• Because balance may be the most likely trigger of injury during exercise, patients should have adequate screening and monitoring for balance
impairment.4
• Variation in exercises is advised, and both concentric and eccentric muscle
actions should be executed. Still, substantiation of the benefits of eccentriconly loading has been confirmed in PD,12,52,58 and can be utilized.
• Loading should be 60%–70% for beginning and intermediate trainees and
may progress to 80%–100% of one-repetition maximum.
• A volume of one to three sets per exercise, including all the major muscle
groups of the body, is recommended. A reduced volume early in the exercise program may be necessary, particularly if fatigue is limiting performance or overall quality of life.
• Training regimen should emphasize multijoint exercises and contain purposeful inclusion of both unilateral and bilateral single and multijoint
exercises. Unilateral exercise may be emphasized in cases where marked
laterality in PD symptoms exists.
• Both machines and free weights should be utilized, with an emphasis on
free weights. Postural instability issues in PD may require more machinebased exercise for safety.
• Exercise order should move from larger, multijoint exercises to smaller,
single-joint or unilateral exercises.
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• Interset rest periods of 2–3 minutes for large muscle mass exercises and
1–2 minutes for smaller muscle mass exercises are recommended. Again,
managing fatigue in PD may require the use of longer rest periods.
• Slow velocities should be used in beginners, with moderate velocities and
fast velocities for intermediate and advanced trainees, respectively. Evidence
suggests that weight should be lifted as fast as possible while maintaining
proper technique to maximize RFD42 and power, both of which may be
critical to PD.3,5,6,19,20,27,38
• All of the major muscle groups in the body can be worked with a frequency
of 2–3 days per week.
CONCLUSION
The substantiation of the unique benefits of RT as a therapy in PD is growing, and
these benefits are divergent from those of physical therapy and occupational therapy regarding muscular strength, power, and endurance, as well as body composition. Several investigations have resulted in encouraging adaptations to RT, and
other modes of exercise, such as cardiorespiratory training, may have supplementary
effects on other body systems, including positive adaptations in the PD brain. Future
research on RT in PD should focus on systematically manipulating individual acute
training variables over extended periods (~1 year) to determine optimal exercise prescription in PD and explore the specific mechanisms of adaptation. Also, sophisticated outcomes should be utilized2 to better elucidate the cause–effect relationship
with RT and PD symptomology. Regardless of future research, there is ample evidence for RT as a therapeutic tool in PD.
REFERENCES
1. NINDS. Parkinson’s Disease: Hope Through Research. 2012. http://www.ninds.nih.gov/
disorders/parkinsons_disease/detail_parkinsons_disease.htm. Accessed May 19, 2013.
2. David FJ, Rafferty MR, Robichaud JA et al. Progressive resistance exercise
and Parkinson’s disease: a review of potential mechanisms. Parkinson’s Dis.
2012;2012:124527. http://dx.doi.org/10.1155/2012/124527.
3. Allen NE, Canning CG, Sherrington C, Fung VSC. Bradykinesia, muscle weakness and
reduced muscle power in Parkinson’s disease. Mov Disord. 2009;24(9):1344–1351.
4. Nallegowda M, Singh U, Handa G et al. Role of sensory input and muscle strength
in maintenance of balance, gait, and posture in Parkinson’s disease: a pilot study. Am
J Phys Med Rehabil. 2004;83(12):898–908.
5. Paasuke M, Mottus K, Ereline J, Gapeyeva H, Taba P. Lower limb performance in older
female patients with Parkinson’s disease. Aging Clin Exp Res. 2002;14(3):185–191.
6. Paasuke M, Ereline J, Gapeyeva H, Joost K, Mottus K, Taba P. Leg-extension strength
and chair-rise performance in elderly women with Parkinson’s disease. J Aging Phys
Act. 2004;12(4):511–524.
7. Pedersen SW, Oberg B. Stretch-shortening contraction in Parkinson patients: evidence
of normal muscle contraction execution with low efficiency. Scand J Rehabil Med.
1997;29(4):251–255.
Brian K. Schilling and Kelley G. Hammond
123
8. Schilling BK, Karlage RE, LeDoux MS, Pfeiffer RF, Weiss LW, Falvo MJ. Impaired
leg extensor strength in individuals with Parkinson disease and relatedness to functional
mobility. Parkinsonism Relat Disord. 2009;15(10):776–780.
9. Durmus B, Baysal O, Altinayar S, Altay Z, Ersoy Y, Ozcan C. Lower e­ xtremity isokinetic muscle strength in patients with Parkinson’s disease. J Clin Neurosci.
2010;17(7):893–896. doi: 10.1016/j.jocn.2009.11.014.
10. Cano-de-la-Cuerda R, Perez-de-Heredia M, Miangolarra-Page JC, Munoz-Hellin E,
Fernandez-de-Las-Penas C. Is there muscular weakness in Parkinson’s disease? Am
J Phys Med Rehabil. 2010;89(1):70–76. doi: 10.1097/PHM.0b013e3181a9ed9b.
11. Goodwin VA, Richards SH, Taylor RS, Taylor AH, Campbell JL. The effectiveness of
exercise interventions for people with Parkinson’s disease: a systematic review and
meta-analysis. Mov Disord. 2008;23(5):631–640.
12. Dibble LE, Hale TF, Marcus RL, Gerber JP, LaStayo PC. High intensity ­eccentric
resis­tance training decreases bradykinesia and improves quality of life in p­ ersons with
Parkinson’s ­disease: a preliminary study. Parkinsonism Relat Disord. 2009;15(10):752–757.
13. Rodrigues de Paula F, Teixeira-Salmela LF, Coelho de Morais Faria CD, Rocha
de Brito P, Cardoso F. Impact of an exercise program on physical, emotional, and
social aspects of quality of life of individuals with Parkinson’s disease. Mov Disord.
2006;21(8):1073–1077.
14. Inkster LM, Eng JJ, MacIntyre DL, Stoessl AJ. Leg muscle strength is reduced
in Parkinson’s disease and relates to the ability to rise from a chair. Mov Disord.
2003;18(2):157–162.
15. Koller W, Kase S. Muscle strength testing in Parkinson’s disease. Eur Neurol.
1986;25(2):130–133.
16. Pedersen SW, Oberg B, Larsson LE, Lindval B. Gait analysis, isokinetic muscle
strength measurement in patients with Parkinson’s disease. Scand J Rehabil Med.
1997;29(2):67–74.
17. Malicka I, Charmela-Bilinska D, Koszewicz M, Dabrowska G, Wozniewski M.
Parameters characterising isokinetic muscular activity in patients with Parkinson’s
­disease—a pilot study. Med Rehabil. 2006;10(3):29–37.
18. Robichaud JA, Pfann KD, Comella CL, Brandabur M, Corcos DM. Greater impairment
of extension movements as compared to flexion movements in Parkinson’s disease.
Exp Brain Res. 2004;156(2):240–254.
19. Mak MK, Levin O, Mizrahi J, Hui-Chan CW. Joint torques during sit-to-stand in
healthy subjects and people with Parkinson’s disease. Clin Biomech (Bristol, Avon).
2003;18(3):197–206.
20. Corcos DM, Chen CM, Quinn NP, McAuley J, Rothwell JC. Strength in Parkinson’s
disease: relationship to rate of force generation and clinical status. Ann Neurol.
1996;39(1):79–88.
21. Pedersen SW, Oberg B. Dynamic strength in Parkinson’s disease: quantitative measurements following withdrawal of medication. Eur Neurol. 1993;33(2):97–102.
22. Kakinuma S, Nogaki H, Pramanik B, Morimatsu M. Muscle weakness in Parkinson’s
disease: isokinetic study of the lower limbs. Eur Neurol. 1998;39(4):218–222.
23. Stevens-Lapsley J, Kluger BM, Schenkman M. Quadriceps muscle weakness, activation deficits, and fatigue with Parkinson disease. Neurorehabil Neural Repair.
2012;26(5):533–541. doi: 10.1177/1545968311425925.
24. Nogaki H, Kakinuma S, Morimatsu M. Muscle weakness in Parkinson’s disease:
a ­follow-up study. Parkinsonism Relat Disord. 2001;8(1):57–62.
25. Nogaki H, Kakinuma S, Morimatsu M. Movement velocity dependent muscle strength
in Parkinson’s disease. Acta Neurol Scand. 1999;99(3):152–157.
124
Resistance Training for Parkinson’s Disease
26. Nocera JR, Buckley T, Waddell D, Okun MS, Hass CJ. Knee extensor strength, dynamic
stability, and functional ambulation: are they related in Parkinson’s disease? Arch Phys
Med Rehabil. 2010;91(4):589–595. doi: 10.1016/j.apmr.2009.11.026.
27. Allen NE, Sherrington C, Canning CG, Fung VSC. Reduced muscle power is associated
with slower walking velocity and falls in people with Parkinson’s disease. Parkinsonism
Relat Disord. 2010;16(4):261–264.
28. Ramsey VK, Miszko TA, Horvat M. Muscle activation and force production in
Parkinson’s patients during sit to stand transfers. Bristol Avon. 2004;19(4):377–384.
29. Dietz V, Zijlstra W, Prokop T, Berger W. Leg muscle activation during gait in Parkinson’s
disease: adaptation and interlimb coordination. Electroencephalogr Clin Neurophysiol.
1995;97(6):408–415.
30. Glendinning DS, Enoka RM. Motor unit behavior in Parkinson’s disease. Phys Ther.
1994;74(1):61–70.
31. Bloomer RJ, Schilling BK, Karlage RE, Ledoux MS, Pfeiffer RF, Callegari J. Effect of
resistance training on blood oxidative stress in Parkinson disease. Med Sci Sports Exerc.
2008;40(8):1385–1389.
32. Radak Z, Kumagai S, Taylor AW, Naito H, Goto S. Effects of exercise on brain function:
role of free radicals. Appl Physiol Nutr Metab. 2007;32(5):942–946.
33. Hirsch MA, Farley BG. Exercise and neuroplasticity in persons living with Parkinson’s
disease. Eur J Phys Rehabil Med. 2009;45(2):215–229.
34. Sutoo D, Akiyama K. Regulation of brain function by exercise. Neurobiol Dis.
2003;13(1):1–14.
35. Muhlack S, Welnic J, Woitalla D, Müller T. Exercise improves efficacy of levodopa in
patients with Parkinson’s disease. Mov Disord. 2007;22(3):427–430.
36. Hammond KG, Schilling BK, Pfeiffer RF, LeDoux MS. Voluntary and involuntary neuromuscular force in Parkinson’s disease: a pilot study. Mov Dis. In Review.
37. Park JH, Stelmach GE. Force development during target-directed isometric force production in Parkinson’s disease. Neurosci Lett. 2007;412(2):173–178.
38. Jordan N, Sagar HJ, Cooper JA. A component analysis of the generation and release of isometric force in Parkinson’s disease. J Neurol Neurosurg Psychiatr. 1992;55(7):572–576.
39. Pijnappels M, Bobbert MF, van Dieën JH. Control of support limb muscles in recovery
after tripping in young and older subjects. Exp Brain Res. 2005;160(3):326–333.
40. Maganaris CN, Narici MV, Reeves ND. In vivo human tendon mechanical properties: effect of resistance training in old age. J Musculoskelet Neuron Interact.
2004;4(2):204–208.
41. Izquierdo M, Aguado X, Gonzalez R, López JL, Häkkinen K. Maximal and explosive
force production capacity and balance performance in men of different ages. Eur J Appl
Physiol Occup Physiol. 1999;79(3):260–267.
42. Sahaly R, Vandewalle H, Driss T, Monod H. Maximal voluntary force and rate
of force development in humans—importance of instruction. Eur J Appl Physiol.
2001;85(3–4):345–350.
43. Fink HA, Kuskowski MA, Taylor BC et al. Association of Parkinson’s disease with
accelerated bone loss, fractures and mortality in older men: the osteoporotic fractures in
men (MrOS) study. Osteoporos Int. 2008;19(9):1277–1282.
44. Lorefält B, Toss G, Granérus AK. Bone mass in elderly patients with Parkinson’s disease. Acta Neurol Scand. 2007;116(4):248–254.
45. Schneider JL, Fink HA, Ewing SK, Ensrud KE, Cummings SR, Study of Osteoporotic
Fractures (SOF) Research Group. The association of Parkinson’s disease with bone mineral density and fracture in older women. Osteoporos Int. 2008;19(7):1093–1097.
46. Grimbergen YA, Munneke M, Bloem BR. Falls in Parkinson’s disease. Curr Opin
Neurol. 2004;17(4):405–415.
Brian K. Schilling and Kelley G. Hammond
125
47. Sato Y, Kaji M, Tsuru T, Oizumi K. Risk factors for hip fracture among elderly patients
with Parkinson’s disease. J Neurol Sci. 2001;182(2):89–93.
48. Guadalupe-Grau A, Fuentes T, Guerra B, Calbet JA. Exercise and bone mass in adults.
Sports Med. 2009;39(6):439–468.
49. Uc EY, Struck LK, Rodnitzky RL, Zimmerman B, Dobson J, Evans WJ. Predictors of
weight loss in Parkinson’s disease. Mov Disord. 2006;21(7):930–936.
50. Petroni ML, Albani G, Bicchiega V et al. Body composition in advanced-stage
Parkinson’s disease. Acta Diabetol. 2003;40(Suppl 1):S187–S190.
51. Hass CJ, Collins MA, Juncos JL. Resistance training with creatine monohydrate
improves upper-body strength in patients with Parkinson disease: a randomized trial.
Neurorehabil Neural Repair. 2007;21(2):107–115.
52. Dibble LE, Hale TF, Marcus RL, Droge J, Gerber JP, LaStayo PC. High-intensity
resistance training amplifies muscle hypertrophy and functional gains in persons with
Parkinson’s disease. Mov Disord. 2006;21(9):1444–1452.
53. Pang MY, Mak MK. Trunk muscle strength, but not trunk rigidity, is independently
associated with bone mineral density of the lumbar spine in patients with Parkinson’s
disease. Mov Disord. 2009;24(8):1176–1182.
54. Pang MY, Mak MK. Muscle strength is significantly associated with hip bone mineral
density in women with Parkinson’s disease: a cross-sectional study. J Rehabil Med.
2009;41(4):223–230.
55. Hirsch MA, Toole T, Maitland CG, Rider RA. The effects of balance training and highintensity resistance training on persons with idiopathic Parkinson’s disease. Arch Phys
Med Rehabil. 2003;84(8):1109–1117.
56. Scandalis TA, Bosak A, Berliner JC, Helman LL, Wells MR. Resistance training and gait function in patients with Parkinson’s disease. Am J Phys Med Rehabil.
2001;80(1):38–43; quiz 44–6.
57. Schilling BK, Pfeiffer RF, Ledoux MS, Karlage RE, Bloomer RJ, Falvo MJ. Effects of
moderate-volume, high-load lower-body resistance training on strength and function in
persons with Parkinson’s disease: a pilot study. Parkinson’s Dis. 2010;2010:824734.
doi: 10.4061/2010/824734.
58. Dibble LE, Hale T, Marcus RL, Gerber JP, Lastayo PC. The safety and feasibility of
high-force eccentric resistance exercise in persons with Parkinson’s disease. Arch Phys
Med Rehabil. 2006;87(9):1280–1282.
59. Hass CJ, Buckley TA, Pitsikoulis C, Barthelemy EJ. Progressive resistance training improves gait initiation in individuals with Parkinson’s disease. Gait Posture.
2012;35(4):669–673. doi: 10.1016/j.gaitpost.2011.12.022.
60. Galvão DA, Taaffe DR. Resistance exercise dosage in older adults: single- versus
multiset effects on physical performance and body composition. J Am Geriatr Soc.
2005;53(12):2090–2097.
61. Garber CE, Friedman JH. Effects of fatigue on physical activity and function in patients
with Parkinson’s disease. Neurology. 2003;60(7):1119–1124.
62. Toole T, Hirsch MA, Forkink A, Lehman DA, Maitland CG. The effects of a balance
and strength training program on equilibrium in parkinsonism: a preliminary study.
NeuroRehabilitation. 2000;14(3):165–174.
63. Pijnappels M, van der Burg PJ, Reeves ND, van Dieën JH. Identification of elderly fallers by muscle strength measures. Eur J Appl Physiol. 2008;102(5):585–592.
64. Bigland-Ritchie B, Woods JJ. Integrated electromyogram and oxygen uptake during
positive and negative work. J Physiol. 1976;260(2):267–277.
65. Morrissey MC, Harman EA, Johnson MJ. Resistance training modes: specificity and
effectiveness. Med Sci Sports Exerc. 1995;27(5):648–660.
126
Resistance Training for Parkinson’s Disease
66. O’Brien M, Dodd KJ, Bilney B. A qualitative analysis of a progressive resistance exercise programme for people with Parkinson’s disease. Disabil Rehabil.
2008;30(18):1350–1357.
67. Falvo MJ, Schilling BK, Earhart GM. Parkinson’s disease and resistive exercise: rationale, review, and recommendations. Mov Disord. 2008;23(1):1–11.
68. Buhmann C, Arlt S, Kontush A et al. Plasma and CSF markers of oxidative stress
are increased in Parkinson’s disease and influenced by antiparkinsonian medication.
Neurobiol Dis. 2004;15(1):160–170.
69. Juel C. Muscle fatigue and reactive oxygen species. J Physiol. 2006;576(Pt 1).
70. Goldhaber JI, Qayyum MS. Oxygen free radicals and excitation-contraction coupling.
Antioxid Redox Signal. 2000;2(1):55–64.
71. Bender A, Koch W, Elstner M et al. Creatine supplementation in Parkinson disease:
a placebo-controlled randomized pilot trial. Neurology. 2006;67(7):1262–1264.
72. Yang L, Calingasan NY, Wille EJ et al. Combination therapy with coenzyme Q10
and creatine produces additive neuroprotective effects in models of Parkinson’s and
Huntington’s diseases. J Neurochem. 2009;109(5):1427–1439.
73. Candow DG, Chilibeck PD. Effect of creatine supplementation during resistance training on muscle accretion in the elderly. J Nutr Health Aging. 2007;11(2):185–188.
74. Chilibeck PD, Chrusch MJ, Chad KE, Shawn Davison K, Burke DG. Creatine monohydrate and resistance training increase bone mineral content and density in older men. J
Nutr Health Aging. 2005;9(5):352–353.
75. McMorris T, Mielcarz G, Harris RC, Swain JP, Howard A. Creatine supplementation
and cognitive performance in elderly individuals. Neuropsychol Dev Cogn B Aging
Neuropsychol Cogn. 2007;14(5):517–528.
76. Stout JR, Sue Graves B, Cramer JT et al. Effects of creatine supplementation on the
onset of neuromuscular fatigue threshold and muscle strength in elderly men and women
(64–86 years). J Nutr Health Aging. 2007;11(6):459–464.
77. American College of Sports Medicine. American College of Sports Medicine position stand: progression models in resistance training for healthy adults. Med Sci Sports
Exerc. 2009;41(3):687–708.
78. Chodzko-Zajko WJ, Proctor DN, Fiatarone Singh MA et al. American College of Sports
Medicine position stand: exercise and physical activity for older adults. Med Sci Sports
Exerc. 2009;41(7):1510–1530.
79. Kohrt WM, Bloomfield SA, Little KD, Nelson ME, Yingling VR. American College of
Sports Medicine position stand: physical activity and bone health. Med Sci Sports Exerc.
2004;36(11):1985–1996.
9
Resistance Training
for Fibromyalgia
J. Derek Kingsley
CONTENTS
Introduction............................................................................................................. 131
Etiology of Fibromyalgia................................................................................... 132
Pain Processing.................................................................................................. 132
Hypothalamic-Pituitary Dysfunction................................................................. 133
Diagnosis............................................................................................................ 134
Benefits of Resistance Training for Fibromyalgia............................................. 135
Designing Resistance Training Programs for Fibromyalgia.............................. 141
Decreasing Peripheral Pain Generators......................................................... 141
Minimize Eccentric Work.............................................................................. 142
Nonrestorative Sleep and Morning Stiffness................................................. 142
Medications................................................................................................... 142
Depression, Anxiety, and Fear Prevalence.................................................... 142
Autonomic Dysfunction................................................................................ 142
Avoid Overhead Lifts.................................................................................... 143
Energy Conservation..................................................................................... 143
Flare-Ups....................................................................................................... 143
Cognitive Dysfunction....................................................................................... 143
Positive Feedback Is Critical......................................................................... 144
References............................................................................................................... 144
INTRODUCTION
Fibromyalgia (FM) is an idiopathic disease characterized by widespread pain and
variety of symptoms. Symptoms are very diverse and include anxiety, depression,
lack of sleep, morning stiffness, reduced muscle strength and endurance, and an
inability to stand for prolonged periods of time. It has been suggested that FM affects
1%–11% of the U.S. population,1,2 with a worldwide prevalence ranging between
0.5% and 5.0%.3 In addition, FM mainly affects women, with a 9:1 ratio of women
to men who are diagnosed.4 The condition also appears to predominantly affect individuals between the ages of 20 and 60 years.1 Clearly, FM may have significant
detrimental effects on quality of life, the ability to perform activities of daily living
127
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(ADLs), as well as social interactions with friends and family. At this point in time,
there is no known cause, or cure, for this condition.
Etiology of Fibromyalgia
Although the pathophysiology of FM is currently unknown, numerous theories have
been suggested to explain the pain and the symptoms. One theory is that the widespread pain of FM is neurogenic.5–11 Another theory is that there are alterations in
the hypothalamic–pituitary axis resulting in dysfunction of the autonomic nervous
system (ANS) and hormones.12–16 The most likely explanation is a combination of
both. However, what makes this condition so difficult is the multifaceted nature of
it, as many individuals with FM present with multiple conditions such as chronic
fatigue syndrome, Raynaud’s condition, and irritable bowel syndrome.12
Pain Processing
Normal pain processing involves both descending and ascending pathways. Afferent
signals are transmitted to the spinal cord to be sent to the brain for processing through
ascending nociceptive (pain-inducing) pathways. These nociceptive signals are activated by sensory receptors in the peripheral nerve, which are termed “nociceptors”
and are triggered by temperature, pressure, or impact. The descending pathway of
pain is modulated by both inhibitory and facilitatory signals that are regulated by
neurochemicals such as norepinephrine, dopamine, and serotonin. These neurochemicals act to either amplify or inhibit the nociceptive signals.
In individuals with FM, the nociceptive signaling pathway may be altered.7–11
This alteration in nociceptive signaling results in central amplification of pain signals, also referred to as central sensitization.8,17 Although the origin of this central
amplification is not well understood in individuals with FM, it does appear to stem
from multiple areas within the central nervous system.18 Although the peripheral
nociceptive signaling may also contribute to central amplification, the majority of
research suggests that the central nervous system is the predominant source. Central
amplification has been suggested to result in both increased excitability and reduced
pain inhibition of the central neurons.9 Individuals with FM have shown higher levels
of substance P, brain-derived nerve growth factor, and glutamate in the cerebrospinal
fluid (CSF), which act to excite the ascending nociceptive pathway.19 Glutamate has
been shown to bind with N-methyl-d-aspartate receptors to produce what is known
as pain “windup.”8 “Windup” is greater levels of central pain amplification after
exposure to repeated noxious stimuli.9 Windup may result in a normally nonpainful stimulus being perceived as painful (allodynia) and an exaggerated response to
pain (hyperalgesia).8,20 In addition, the data also suggest that inhibiting signals of the
descending pathway are also reduced, which would include lower levels of norepinephrine, dopamine, and serotonin in the CSF.9 Interestingly, the levels of opioids
in the CSF may be increased in individuals with FM.21 The high levels of opioids
in turn result in downregulation of opioid receptors, and thus a reduction in pain
control.22
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J. Derek Kingsley
Hypothalamic-Pituitary Dysfunction
The hypothalamic-pituitary system is an important link between the endocrine system and ANS. Alterations in this system may play a strong role in the pathogenesis
of FM. It has been suggested that individuals with FM suffer from hypothalamicpituitary-adrenal (HPA) dysfunction,23–26 hypothalamic-pituitary-growth hormone
dysfunction,27,28 and alterations in the ANS.12,29–31 Alterations in the HPA axis in
individuals with FM may result in hypocortisolism, low levels of cortisol.25,26 It has
also been suggested that reduced levels of cortisol, the primary hormone of stress,
may result in disorders of sleep, physical deconditioning, fatigue, and severe depression.23 Reduced levels of growth hormone (GH) have been reported, as well as reductions in the level of insulin-like growth factor 1 (IGF-1), a secretagogue of GH27,28
in individuals with FM. Side effects of reduced GH and IGF-1 include depression,
exercise intolerance, and fatigue.27 Clearly, changes in the hypothalamic-pituitary
axes may alter physiological function in individuals with FM.
Alterations in the ANS, or dysautonomia, may also explain many of the symptoms
of FM, including pain (Figure 9.1).31 Symptoms that might be altered with dysautonomia may include intolerance to cold, irritable bowel syndrome, lack of restorative
sleep, exercise intolerance, and an inability to stand for prolonged periods of time.12
Data have suggested that individuals with FM have sympathetic hyperactivity at
Deconditioning of
muscles
Autonomic nervous system involvement
1. High sympathetic tone
2. Low parasympathetic tone
Microtrauma
Vasoconstriction
Reduced blood supply
Pain
Inactivity
FIGURE 9.1 A schematic that might explain the relationship between physical inactivity,
pain, and dysautonomia in FM. (With kind permission from Springer Science + Business
Media: Clinical Autonomic Research, A comprehensive study of autonomic dysfunction in
the fibromyalgia patients, 22, 2011, 117–22, Kulshreshtha P, Gupta R, Yadav RK, Bijlani RL,
Deepak KK.)
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rest and sympathetic hypoactivity during a stressor such as standing,32,33 exposure to
cold,34,35 or an acute bout of resistance training (RT)36; however, these findings are
not universal.37 Increased levels of sympathetic activity may also cause an increase in
vascular resistance, resulting in reductions in nutritive blood flow to the muscle and
thus deconditioning and pain (Figure 9.1).38–40 For example, Elvin et al.38 reported
that women with FM had significantly reduced levels of blood flow during static and
dynamic exercise compared to healthy controls. Work by Kim et al.39 showed that
women with FM have greater pulse wave velocity, an indicator of arterial stiffness.
A separate study from the same laboratory reported higher levels of pulse wave
velocity were associated with reductions in quality of life.40 Collectively, these data
suggest that individuals with FM may have alterations in the ANS. However, more
data are needed to better understand the complications associated with dysautonomia in this population.
Diagnosis
In 1990, the American College of Rheumatology defined FM as having pain for
at least 3 months, pain in 3 out of 4 quadrants of the body, and pain on palpation
of 11 out 18 “tender points” (Table 9.1).41 The criteria determined that each tender
point would be deemed “active” if the individual reacted to 4 kg·cm−2 of pressure.41
In 2010, the American College of Rheumatology redefined its diagnostic criteria of
FM.42 The revised criteria necessary for diagnosis have moved away from pain as
the predominant symptom and subsequently removed the tender point examination.
The criteria for diagnosis are now based on a widespread pain index (WPI) and a
symptom severity (SS) scale. The highest score on the WPI is 19, and the SS scale
score ranges from 0 to 12. The SS scale has two distinct parts. One part asks the individuals to identify their general symptoms and, based on the number of symptoms,
TABLE 9.1
Location of Tender Points According to 1990 Fibromyalgia Diagnostic
Criteria
• Low cervical region: (front neck area) at anterior aspect of the interspaces between the transverse
processes of C5-C7.
• Second rib: (front chest area) at second costochondral junctions.
• Occiput: (back of the neck) at suboccipital muscle insertions.
• Trapezius muscle: (back shoulder area) at midpoint of the upper border.
• Supraspinatus muscle: (shoulder blade area) above the medial border of the scapular spine.
• Lateral epicondyle: (elbow area) 2 cm distal to the lateral epicondyle.
• Gluteal: (rear end) at upper outer quadrant of the buttocks.
• Greater trochanter: (rear hip) posterior to the greater trochanteric prominence.
• Knee: (knee area) at the medial fat pad proximal to the joint line.
Source: Adapted from Wolfe, F., Smythe, H. A., Yunus, M. B. et al. Arthritis. Rheum., 33, 160–172, 1998.
J. Derek Kingsley
131
to rate them overall, on a 0–3 scale. The second part of the SS scale focuses on three
distinct issues that plague individuals with FM such as fatigue, waking refreshed,
and cognitive symptoms. Each of these symptoms is independently rated from 0, no
problems, to 3, severe problems. To test positive for FM, an individual must score
7 or greater on the WPI and greater than 5 on the SS scale, or 3–6 on the WPI and
greater than 9 on the SS scale. These revised criteria are valid and reliable and may
allow for a more accurate diagnosis compared to the original criteria.1
Benefits of Resistance Training for Fibromyalgia
When FM was first defined by the American College Rheumatology RT was often
overlooked as a treatment modality. It was thought that the pain associated with FM
was directly related to muscle damage or trauma.53,54 Therefore, the addition of RT
would exacerbate the symptoms and may in turn increase the risk for injury. However,
data have since shown that RT can counteract the deconditioning that is often seen in
individuals with FM as well as can affect many symptoms of the disease.37,48
Over the past few years, the understanding of RT on the symptoms of FM has
flourished (for a summary of studies see Table 9.2).30,36,37,43,45,46,48–50,51 Some studies
report that individuals with FM have lower levels of maximal strength compared to
healthy controls,55,56 but these findings are not universal. One of the most notable
studies examining strength in women with FM reported that women with FM (average age of 46 years) have similar levels of ­isokinetic knee extension and knee flexion
as healthy older women (average age of 71 years) but not the same strength as ageweight-matched controls.57 However, Kingsley et al.37 reported that women with FM
had similar levels of isotonic strength as ­age-weight-matched healthy controls before
starting a RT program. Taken together, these data highlight the need for more data
to understand the effects of FM on maximal strength.
Numerous studies have reported that women with FM have similar gains in
strength to healthy controls when undergoing whole-body RT.37,45,46 In addition,
changes in muscle cross-sectional area have also been shown to be similar between
premenopausal women with FM and healthy controls after 21 weeks of RT.46 For
example, Hakkinen et al. trained participants at 40%–60% of their one-repetition
maximum (1RM) for the first 7 weeks, with 10–20 repetitions per set, using 3–4 sets.
By week 14, the load was progressed to 60%–80% 1RM with five to eight repetitions
and three to five sets. The last 7 weeks consisted of 70%–80% 1RM with five to eight
repetitions across four to six sets. The RT participants with FM had increases that
were similar to the healthy controls and included improvements in isometric force
production and increases in cross-sectional area compared to a group of nonexercising FM controls. Taken together, these data suggest that individuals with FM have
the ability to gain strength and muscle size as healthy controls.
The ability of RT to reduce pain, the predominant symptom of FM, has been
investigated; data are mixed. Studies that have examined pain in individuals with
FM have used a visual analog scale (VAS), the number of active tender points, questionnaires, or the myalgic score, a score used to determine the sensitivity of the
tender points. Hakkinen et al.45 showed reductions in pain (VAS) after 21 weeks of
21 women with FM:
11 RT, 10 CNTL; 12 HC
21 women with FM:
11 RT, 10 CNTL, 10 HC
Hakkinen
et al.
(2002)46
6 exercises for the upper
and lower body on RT
machines
6–8 machines for whole
body
Wall pulley weights for
5 exercises, 1 machine
9 women and 1 man with
FM; 6 HC
Hakkinen
et al.
(2001)45
9 RT machines, 1 BW
10 women with FM; 9 HC
Figueroa
et al.
(2008)30
Geel et al.
(2002)44
Upper and lower body
exercises on RT
machines
26 women with FM:
13 AE, 13 RT
Resistance Type
Bircan
et al.
(2008)43
Subject Characteristics
TABLE 9.2
Summary of Studies on FM and RT
8 weeks, 2× week;
Initially 4–5 reps,
progressing to 12 reps.
Body weight exercises
and free weights
16 weeks, 2× week; 50%
1RM, 8–12 reps, 1 set.
Progressed at 12 reps
8 weeks, 2× week; 60%
1RM, 3 sets of 10 reps.
Increased 1RM to 70% at
4 weeks
21 weeks, 2× week; Began
at 40%–60% 1RM,
15–20 reps, progressed to
70%–80% 1RM,
5–10 reps
21 weeks; 2× week Began
at 40%–70% 1RM,
10–20 reps, 3–4 sets
progressing to 70%–80%
1RM, 5–8 reps, 3–5 sets
Training Prescription
Isometric LE and LF,
CSA, testosterone,
DHEA, IGF-1, GH
MVIC for LE, iEMG,
HAQ, 1RM
FIQ, tender point count,
SCL-90-R, Pi/CrP after
acute wrist exercises
1RM CP and LE, HRV,
BRS, myalgic score
6-minute walk; HAD;
SF-36; tender point
count; VAS for sleep,
pain, and fatigue
Dependent Variables
18% and 13%↑isometric LE and
LF for FM-RT, ↑in CSA for
FM-RT, no change in
Testosterone, DHEA, IGF-1, GH
↑MVIC for LE, ↑iEMG, ↑1RMs,
↓HAQ
↑HRV (total power and
RMSSD), no change in BRS,
↓myalgic score
↓Tender point count, ↓FIQ,
↓SCL-90-R, ↓Pi/CrP after wrist
exercise in FM but not at rest
↓VAS for pain, sleep, and
fatigue; ↓tender point count;
↓HAD; ↑6-minute walk. No
differences between groups
Findings
132
Resistance Training for Fibromyalgia
72 patients with FM:
36 RT, 36 AE
29 women with FM:
15 RT, 14 CNTL
9 women with FM; 15 HC
9 women with FM; 15 HC
9 women with FM; 14 HC
Hooten
et al.
(2012)47
Kingsley
et al.
(2005)48
Kingsley
et al.
(2010)37
Kingsley
et al.
(2010)49
Kingsley
et al.
(2011)50
5 exercises on machines
5 exercises on machines
5 exercises on machines
6 exercises on RT
machines, 3 on cable
machine, 2 BW
Whole-body exercises
using machines
12 weeks, 2× week; 3 sets
of 8–12 reps at
50%–60% 1RM; when
12 reps achieved
increased by 5 lbs
12 weeks, 2× week; 3 sets
of 8–12 reps at
50%–60% 1RM; when
12 reps achieved
increased by 5 lbs
12 weeks, 2× week; 3 sets
of 8–12 reps at
50%–60% 1RM; when
12 reps achieved
increased by 5 lbs
1 set of 10 reps. Loads
increased by 1–3 kg for
upper-body and 3–5 kg
for lower-body; 3 weeks,
2× week
12 weeks, 2× week; Began
40% 1RM, progressed by
5 lbs at 12 reps
Measures of aortic wave
reflection, heart rate,
blood pressure, tender
point count; 1RM for CP,
LE, LF, SR, and LP
Resting forearm blood
flow and peak
vasodilatory capacity
1RM for CP and LE,
tender point count,
myalgic score, FIQ,
functionality measured
CS-PFP
1RM for CP, LE, SR, LF
and LP; tender point
count, myalgic score,
FIQ, HRV
Pain subscale of MPI pain
thresholds, isokinetic and
isometric LE and LF,
HAD
No change in measures of aortic
wave reflection, heart rate, or
blood pressure in either group;
↓tender point count, ↑in all
1RMs
(Continued)
↑In resting forearm blood and
peak vasodilatory capacity in
both groups
↑In all 1RMs, ↓tender point
count and myalgic score, ↓FIQ,
no change in HRV in either
group
↑In 1RMs; no change in tender
point count, myalgic score, or
FIQ; ↑in overall functionality
↑Pain threshold, ↓overall pain,
↑isokinetic and isometric LE
and LF, ↓HAD
J. Derek Kingsley
133
24 women with FM;
15 RT/AE, 11 CNTL
Valkeinen
et al.
(2008)52
Upper and lower body RT
exercises and AE
9 exercises on machines,
1 using BW; RT with
chiro was 2× a week for
chiro
Resistance Type
16 weeks, 2× week; 1 set
of 8–12 reps at 50%
1RM; progressed by
5 lbs at 12 reps; 2× a
week; ended at 100% of
their initial 1RM
21 weeks 2× week; Began
40%–60% 1RM, 10–20
reps, 2–4 sets. Ended
with 70%–80% 1RM,
5–10 reps, 2–6 sets
Training Prescription
VO2 peak; 1RM for LE;
HAQ; VAS for pain,
fatigue, and sleep
1RM for CP and LE,
tender point count,
myalgic score, FIQ,
functionality measured
via CS-PFP
Dependent Variables
No change in VO2peak, ↑in LE,
↓VAS for fatigue, no change in
HAQ or VAS for pain or sleep
↑In CP and LE, ↓tender points,
↓myalgic score, ↓FIQ similar
between groups. ↑in
functionality when RT with
chiro but not with RT alone
Findings
AE, aerobic exercise; BRS, baroreflex sensitivity; CNTL, control; CP, chest press; CSA, cross-sectional area; EMG, electromyography; HAQ, Health Assessment
Questionnaire; HC, healthy control; HRV, heart rate variability; LE, leg extension; LF, leg flexion; LP, leg press; MPI, Multidimensional Pain Inventory; Pi/CrP, ratio of
inorganic phosphate to creatinine phosphate; RM, repetition maximum; RMSSD, root mean square standard deviation; SF-36, Short Form-36 questionnaire; SR, seated row.
21 women with FM;
10 RT, 11 RT with
chiropractic
Panton
et al.
(2009)51
Subject Characteristics
TABLE 9.2 (Continued)
Summary of Studies on FM and RT
134
Resistance Training for Fibromyalgia
J. Derek Kingsley
135
twice a week RT, while Valkeinen et al.52 reported no change in pain after 21 weeks
of RT. RT programs consisting of 8, 12, and 16 weeks have also shown improvements in pain after RT. Bircan et al.43 showed decreases in pain as measured by VAS
and the number of active tender points after only an 8-week training regime. Their
RT regime consisted of starting at 4–5 repetitions and progressing to 12 repetitions
using body weight and free weights. Even though the training was not based on
an individual prescription per say, the responses to the training regime were still
significant. A recent study examined the effects of 3 weeks of RT on pain using a
subscale of the Multidimensional Pain Inventory (MPI).47 The data showed a significant reduction in pain, which was similar to individuals with FM performing aerobic
activity. Overall, the effects of RT on pain are beneficial in individuals with FM if
the workload is kept at a tolerable level. This is imperative, as RT may also have
other effects on symptoms in individuals with FM.
Although pain is the predominant symptom, there are other symptoms that might
be improved by RT. Physical and mental functions are two very important facets that
may be positively altered by RT in individuals with FM. Physical and psychological functions have been assessed in a variety of different ways in individuals with
FM. One questionnaire that is widely used is the Fibromyalgia Impact Questionnaire
(FIQ).58 Other researchers have used objective measures to quantify physical function in addition to the FIQ.48,51,57 As for psychological function, there are a myriad of
different questionnaires that can be used to address concerns such as state and trait
anxiety, pain catastrophizing, depression, and/or overall mood.
The FIQ is a valid and reliable questionnaire to ascertain the impact of FM on
week-to-week quality of life.58 It has been translated into 14 different languages over
its 18-year history. The FIQ uses 21 questions pertaining to how FM affects the ability
to perform ADLs; pain; and a variety of other symptoms including anxiety, depression,
morning stiffness, fatigue, and well-being. The average individual with FM scores a
50, out of 100, while a more severely impacted individual may score 70 or above.58
Numerous reports have shown reductions in the FIQ after RT independent of the
duration of training. Geel et al.44 reported declines in the FIQ by 47% after 8 weeks
of RT consisting of 3 sets of 10 repetitions on 5 exercises using wall pulley weights.
Meanwhile, Kingsley et al.37 reported a 20% drop in the FIQ after 12 weeks of RT
with 3 sets of 5 exercises with 8–12 repetitions. In addition, Panton et al.51 reported
declines in the FIQ after using 1 set of 11 different exercises for the whole body, with
an intensity starting at 50% 1RM and progressing to 80% 1RM over 16 weeks with
8–12 repetitions. Collectively, these data suggest that RT may reduce the impact of
FM on week-to-week quality of life.
In addition to the FIQ and its subjective quantification of ADLs, a few studies have
objectively evaluated the ability to perform ADLs in individuals with FM using the
Continuous Scale-Physical Functional Performance Test (CS-PFP).59 The CS-PFP consists of five different domains: upper body strength, lower body strength, upper body
flexibility, endurance, and a total functional score.59 Kingsley et al.48 showed that 12
weeks of RT significantly increased the ability of women with FM to perform ADLs.
Participants had significantly higher scores for upper body strength, lower body strength,
endurance, and the total functional score (52 ± 15 units to 65 ± 13 units).48 In a followup study, Panton et al.57 reported that women with FM had the same total functional
136
Resistance Training for Fibromyalgia
score as a group of 71-year-old healthy women (FM: 49 ± 15 units; older women: 49
± 13 units), both of which were significantly lower than a group of 46-year-old healthy
women (66 ± 6 units). Additional work from Panton and associates also showed that
16 weeks of whole-body RT did not significantly improve the ability to perform ADLs
in women with FM.51 However, that particular study used a 10-item CS-PFP60 because
many of the participants found the original 16-item CS-PFP too difficult to complete. It
should be noted that although the total score on the CS-PFP increased (55 ± 11 units to
61 ± 14 units), it was not statistically significant. In addition, the participants did have
a significantly higher score on the upper body strength domain.51 Taken together, it is
clear that RT can improve the ability to perform ADLs in women with FM.
It is well documented that individuals with FM have trouble sleeping, which has
been described as difficulty falling asleep, difficulty staying asleep, or more commonly, nonrefreshing sleep.61–65 Using a 100-mm VAS with the end points being
“normal sleep-totally unable to sleep,” Bircan et al.43 have reported a significant
improvement after 8 weeks of RT in 13 participants with FM. Participants trained
twice a week performing 4–5 repetitions initially and gradually progressing toward
12 repetitions with exercises for the lower, upper and trunk muscles using free
weights and body weight. To date, few studies have evaluated the effects of RT on
quality of sleep in individuals with FM, and more data are needed.
It has been suggested that this lack of sleep in individuals with FM may be due
to a significant reduction in sleep stages 3 and 4.63–65 This, in turn, may limit the
production of GH, because 80% of GH is produced during these stages of sleep.
This also may add to the alterations in the hypothalamic-pituitary dysfunction in this
population. To investigate this and other hormones, Hakkinen et al.66 investigated
the effects of 6 months of RT on resting concentrations and acute responses of testosterone, free testosterone, dehydroepiandrosterone (DHEA), IGF-1, and GH. Their
data showed no change after 21 weeks of RT in postmenopausal women with FM
compared to nonexercising women with FM and healthy controls at rest. However, in
that study, participants also underwent an acute RT protocol consisting of 5 sets of
10 repetitions of the participant’s 10RM on the leg press. Hormones were measured
immediately after, 15 and 30 minutes after the acute session. There was no effect of
the acute session on testosterone or free testosterone. Levels of GH acutely increased
immediately after the acute session before RT in women with FM and were maintained for up to 15 minutes in the healthy controls. After the RT was complete, the
women with FM had increases in GH immediately after, 15 and 30 minutes after the
acute session. These data suggest that the hypothalamic-pituitary axis for the release
of GH may become more efficient after RT in women with FM. Furthermore, these
data highlight that women with FM respond similarly to healthy controls in regard
to adaptation to RT.
Data examining the effect of RT on depression in individuals with FM are rare.
It has been reported that 3 weeks of RT can reduce depression, measured using the
hospital anxiety and depression (HAD) scale.47 Using the Beck Depression Index
(BDI), Hakkinen et al.45 showed a significant reduction in depression levels after
21 weeks of RT in women with FM compared to a nonexercising group of women
with FM. Taken together, these data suggest that RT may have the ability to reduce
depression in women with FM, but more data are needed.
J. Derek Kingsley
137
As previously stated, individuals with FM may also suffer from dysautonomia, or
dysfunction of the ANS, at rest. In a healthy individual, RT appears to have no effect
on autonomic function.67 However, in an individual who has autonomic dysfunction,
the results appear to be very different. For instance, 16 weeks of RT in women with
FM increased vagal modulation compared to before training began.30 In this study,
participants completed 1 set of 11 different exercises of 8–12 repetitions starting at
50% of their 1RM and progressing to 85% of their 1RM. However, this finding is
not universal. In a more recent study by Kingsley et al., women with FM underwent
12 weeks of RT using 5 exercises for the whole body with 3 sets of 8–12 repetitions.37
There was no effect of RT on autonomic modulation in women with FM or healthy
controls.37 Whether or not RT alters autonomic function in those with dysautonomia
is still an issue of debate. However, work by Collier et al. using prehypertensive
individuals, a disease also associated with autonomic dysfunction, reported similar
findings.68
It has been postulated that individuals with FM may suffer from lack of nutritive
blood flow because of increases in vasoconstriction through sympathetic hyperactivity.38,69 Although this has not been established to the same degree as the dysautonomia, it makes for a very interesting argument. Kingsley et al.49 showed no
significant differences in resting blood flow or vasodilatory capacity in women with
FM compared to healthy controls using strain-gauge plethysmography (for a review
of this method see Higashi et al.70). In addition, after 12 weeks of RT, both groups
were able to significantly increase their levels of resting blood flow and vasodilatory
capacity.49 These data suggest that women with FM may have similar levels of blood
flow as healthy controls. More importantly, the data highlight that the responses of
the vasculature to RT in women with FM may be very analogous to healthy women.
Designing Resistance Training Programs for Fibromyalgia
When designing RT programs for individuals with FM, there are some very important concepts that need to be addressed. These individuals have a variety of symptoms, despite the pain, that may limit their ability to do a traditional RT regime. As
has been mentioned in section “Benefits of Resistance Training for Fibromyalgia,”
individuals with FM have the ability to gain muscle size and strength similarly to
healthy individuals. However, their regime needs to be very individualized, and care
needs to be taken to minimize exacerbation of symptoms.
Decreasing Peripheral Pain Generators
It is well established that individuals with FM have enhanced levels of pain that contribute to central sensitization. Furthermore, individuals with FM may have other peripheral pain generators that may need to be addressed such as osteoarthritis, bursitis,
tendonitis, and/or plantar fasciitis. Getting treatment for these in the form of injections,
medications, and topical treatments may significantly improve the ability of the individual to maintain an exercise regime. Another method to reduce these pain generators
would be to work on postural alignment. This may include focusing on stretching the
muscles of the upper back and neck. Stretching should always be static, and each stretch
should be held to minor discomfort and should avoid tingling, burning sensations.
138
Resistance Training for Fibromyalgia
Minimize Eccentric Work
It is important to reduce unnecessary work on the muscles in individuals with FM.
One way to reduce this unnecessary work is to reduce the eccentric (lengthening)
phase of the exercise. This may be accomplished by having the individual spend
more time in the concentric (shortening) phase. A general rule of thumb would be
to lift the weight with a 4–6-second count and lower the weight with a 3–4-­second
count. It is also important to use reduced workloads when beginning a training
regime. Most of the studies performed in individuals with FM started the RT at 50%
of their predicted 1RM. Although this might seem light, it allows the individual with
FM to progress at a pace that is comfortable for them. Although the studies in these
individuals started with 50%, many of them ended with the individuals training at
80%–85% of the initial 1RM.
Nonrestorative Sleep and Morning Stiffness
Scheduling a morning workout will be a challenge in this population. Individuals
with FM usually have nonrestorative sleep and suffer from chronic fatigue. In addition to the chronic fatigue, many individuals with FM also suffer from morning stiffness. Many individuals with FM find it easier to exercise once they have been awake
for a few hours, and some of the stiffness has dissipated. Furthermore, care should
be taken to avoid exercise at the end of the day.
Medications
An average individual with FM takes between 8 and 12 different medications a day.
Currently, there are only three medications that are specific for FM and include pregabalin (Lyrica), duloxetine (Cymbalta), and milnacipran (Savella). Although these three
are the only ones specific for FM, there are others that include antidepressants, muscle
relaxants, sleep aids, and opioids. It is imperative that the fitness specialist know what
mediations and supplements that the individual is taking. Not only may these medications alter heart rate and blood pressure, they may also alter the responses to RT. In
addition, some of the medications may be associated with weight gain and malaise.
Depression, Anxiety, and Fear Prevalence
Depression, anxiety, and fear prevalence are well documented in individuals with
FM. Those individuals with FM who have higher levels of depression have been
reported to also have greater fear of pain.71 Fear of pain in response to RT is common
in individuals with FM. A few studies have reported that this feature of FM results in
exercise avoidance and may result in greater levels of deconditioning.72–74 Therefore,
when working with individuals with FM, it is essential that open lines of communication and trust be established on the first day of exercise.
Autonomic Dysfunction
Although not all individuals with FM present with autonomic dysfunction, many
of them do. Therefore, it is important to understand the implications of autonomic
dysfunction and how it directly relates to the RT program. Autonomic dysfunction
may be associated with severe fatigue, orthostatic hypotension (a drop in blood
J. Derek Kingsley
139
pressure on standing), and inability to maintain or regulate body temperature.
Therefore, some accommodations must be made to assist with compliance to the
training regime. Moving from one body position to another might be difficult. The
individual with FM needs a few moments to let their blood pressure stabilize when
moving from lying down to sitting or from sitting to standing. This same idea also
limits the ability of the individual with FM to perform activities that require a lot of
pivoting or fast rotations of the head. In addition, it is important to avoid prolonged
periods of motionless standing that might result in a significant drop in blood pressure. Body temperature regulation can be maintained by making sure the individual
is adequately hydrated and continues to drink water throughout the exercise session.
Avoid Overhead Lifts
The 18 tender points that were initiated in 1990 had the majority of the points on
the upper back and neck.41 Although the revised criterion do not focus on the tender
points per say, many individuals with FM still have significant areas of tenderness
as will be noted in their WPI. Therefore, it is important to keep in mind that lifting
overhead may be a severe limitation in this population.
Energy Conservation
Lifestyle physical activity is a key focus of the American College of Sports Medicine.
The idea is that performing more activity in the day can have positive benefits on
weight and overall health. We encourage people to make changes in their lifestyle so
that they are more active such as taking the stairs instead of the elevator, walking to
the bathroom that is further away, and parking farther away in an effort to burn more
calories. In individuals with FM, this may prove to be very challenging, certainly
at the beginning of the training regime. Individuals with FM, along with their pain,
lack of sleep, and other symptoms, may be better served to conserve energy so that
they have the ability to maintain their RT regime.
Flare-Ups
Flare-ups are an inevitable fact in working with individuals with FM. Some flare-ups
might last only a day or so, while others may last weeks to months. The hardest part
of the flare-up is that the individual with FM will feel discouraged and that the RT is
not working. Although data have shown improvements in overall pain with RT, there
are no data that have shown it decreases flare-ups. This is a critical point that must be
relayed to the individual. If the flare-up is truly bad, reschedule the appointment. If
the individual still wants to come and exercise, a good recommendation is to repeat
the previous workout.
Cognitive Dysfunction
The cognitive dysfunction associated with FM is often referred to as “fibro fog.” This
is a common feature of FM that manifests as decreases in short-term memory and an
inability to concentrate.75 The easiest tactic is to make a standing appointment and to
be understanding if the individual misses an appointment.
140
Resistance Training for Fibromyalgia
Positive Feedback Is Critical
Individuals with FM live in fear of pain and thus as mentioned avoid activity. In
addition, they feel that if they do exercise, they will have a flare-up of symptoms and
will not be able to continue. Therefore, RT must start slowly and progress slowly.
Flare-ups, generally speaking, are going to happen. This, in turn, makes it necessary
to address the individuals’ concerns up front. The program needs to be achievable,
even if a flare-up occurs. Be sure to offer positive feedback on their accomplishments. The data are clear that RT is good for individuals with FM concerning pain,
muscle strength and endurance, lack of sleep, functionality, and most importantly
quality of life. Chronic reassurance of this is important so that the individual with
FM can have a successful, long-term engagement with RT.
REFERENCES
1. McBeth J, Mulvey MR. Fibromyalgia: mechanisms and potential impact of the ACR
2010 classification criteria. Nat Rev Rheumatol 2012;8:108–16.
2. Quintner J, Cohen M. Economic cost and epidemiological characteristics of fibromyalgia. J Rheumatol 2004;31:2311, author reply.
3. Choy E, Perrot S, Leon T et al. A patient survey of the impact of fibromyalgia and the
journey to diagnosis. BMC Health Serv Res 2010;10:102.
4. Yunus MB. The role of gender in fibromyalgia syndrome. Curr Rheumatol Rep
2001;3:128–34.
5. Abeles AM, Pillinger MH, Solitar BM, Abeles M. Narrative review: the pathophysiology of fibromyalgia. Ann Intern Med 2007;146:726–34.
6. Neeck G. Pathogenic mechanisms of fibromyalgia. Ageing Res Rev 2002;1:243–55.
7. Staud R, Cannon RC, Mauderli AP, Robinson ME, Price DD, Vierck CJ, Jr. Temporal
summation of pain from mechanical stimulation of muscle tissue in normal controls and
subjects with fibromyalgia syndrome. Pain 2003;102:87–95.
8. Staud R, Price DD, Robinson ME, Mauderli AP, Vierck CJ. Maintenance of windup
of second pain requires less frequent stimulation in fibromyalgia patients compared to
normal controls. Pain 2004;110:689–96.
9. Staud R, Vierck CJ, Cannon RL, Mauderli AP, Price DD. Abnormal sensitization and
temporal summation of second pain (wind-up) in patients with fibromyalgia syndrome.
Pain 2001;91:165–75.
10. Vierck CJ. A mechanism-based approach to prevention of and therapy for fibromyalgia.
Pain Res Treat 2012;2012:951354.
11. Vierck CJ, Jr., Staud R, Price DD, Cannon RL, Mauderli AP, Martin AD. The effect
of maximal exercise on temporal summation of second pain (windup) in patients with
fibromyalgia syndrome. J Pain 2001;2:334–44.
12. Martinez-Lavin M, Hermosillo AG. Autonomic nervous system dysfunction may explain
the multisystem features of fibromyalgia. Semin Arthritis Rheum 2000;29:197–9.
13. Straub RH, Baerwald CG, Wahle M, Janig W. Autonomic dysfunction in rheumatic diseases. Rheum Dis Clin North Am 2005;31:61–75, viii.
14. Heim C, Ehlert U, Hellhammer DH. The potential role of hypocortisolism in the pathophysiology of stress-related bodily disorders. Psychoneuroendocrinology 2000;25:1–35.
15. Gur A, Cevik R, Nas K, Colpan L, Sarac S. Cortisol and hypothalamic-pituitary-gonadal
axis hormones in follicular-phase women with fibromyalgia and chronic fatigue syndrome
and effect of depressive symptoms on these hormones. Arthritis Res Ther 2004;6:R232–8.
16. Parker AJ, Wessely S, Cleare AJ. The neuroendocrinology in chronic fatigue syndrome
and fibromyalgia. Psychol Med 2001;31:1331–45.
J. Derek Kingsley
141
17. Vierck CJ, Jr. Mechanisms underlying development of spatially distributed chronic pain
(fibromyalgia). Pain 2006;124:242–63.
18. Price DD, Staud R, Robinson ME, Mauderli AP, Cannon R, Vierck CJ. Enhanced temporal summation of second pain and its central modulation in fibromyalgia patients.
Pain 2002;99:49–59.
19. Clauw DJ, Arnold LM, McCarberg BH, FibroCollaborative. The science of fibromyalgia. Mayo Clin Proc 2011;86:907–11.
20. Staud R, Vierck CJ, Robinson ME, Price DD. Effects of the N-methyl-D-aspartate
receptor antagonist dextromethorphan on temporal summation of pain are similar in
fibromyalgia patients and normal control subjects. J Pain 2005;6:323–32.
21. Baraniuk JN, Whalen G, Cunningham J, Clauw DJ. Cerebrospinal fluid levels of opioid peptides in fibromyalgia and chronic low back pain. BMC Musculoskelet Disord
2004;5:48.
22. Harris RE, Clauw DJ, Scott DJ, McLean SA, Gracely RH, Zubieta JK. Decreased central mu-opioid receptor availability in fibromyalgia. J Neurosci 2007;27:10000–6.
23. Geenen R, Jacobs JW, Bijlsma JW. Evaluation and management of endocrine dysfunction in fibromyalgia. Rheum Dis Clin North Am 2002;28:389–404.
24. Neeck G, Crofford LJ. Neuroendocrine perturbations in fibromyalgia and chronic
fatigue syndrome. Rheum Dis Clin North Am 2000;26:989–1002.
25. Sarzi-Puttini P, Atzeni F, Cazzola M. Neuroendocrine therapy of fibromyalgia syndrome: an update. Ann N Y Acad Sci 2010;1193:91–7.
26. Tanriverdi F, Karaca Z, Unluhizarci K, Kelestimur F. The hypothalamo-pituitary-adrenal axis in chronic fatigue syndrome and fibromyalgia syndrome. Stress 2007;10:13–25.
27. Cuatrecasas G, Alegre C, Fernandez-Sola J et al. Growth hormone treatment for sustained pain reduction and improvement in quality of life in severe fibromyalgia. Pain
2012;153:1382–9.
28. Cuatrecasas G, Gonzalez MJ, Alegre C et al. High prevalence of growth hormone
­deficiency in severe fibromyalgia syndromes. J Clin Endocrinol Metab 2010;95:4331–7.
29. Cohen H, Neumann L, Kotler M, Buskila D. Autonomic nervous system derangement in
fibromyalgia syndrome and related disorders. Isr Med Assoc J 2001;3:755–60.
30. Figueroa A, Kingsley JD, McMillan V, Panton LB. Resistance exercise training
improves heart rate variability in women with fibromyalgia. Clin Physiol Funct Imaging
2008;28:49–54.
31. Martinez-Lavin M. Fibromyalgia as a sympathetically maintained pain syndrome. Curr
Pain Headache Rep 2004;8:385–9.
32. Furlan R, Colombo S, Perego F et al. Abnormalities of cardiovascular neural control
and reduced orthostatic tolerance in patients with primary fibromyalgia. J Rheumatol
2005;32:1787–93.
33. Raj SR, Brouillard D, Simpson CS, Hopman WM, Abdollah H. Dysautonomia among
patients with fibromyalgia: a noninvasive assessment. J Rheumatol 2000;27:2660–5.
34. Qiao ZG, Vaeroy H, Morkrid L. Electrodermal and microcirculatory activity in
patients with fibromyalgia during baseline, acoustic stimulation and cold pressor tests.
J Rheumatol 1991;18:1383–9.
35. Vaeroy H, Qiao ZG, Morkrid L, Forre O. Altered sympathetic nervous system response
in patients with fibromyalgia (fibrositis syndrome). J Rheumatol 1989;16:1460–5.
36. Kingsley JD, Panton LB, McMillan V, Figueroa A. Cardiovascular autonomic modulation after acute resistance exercise in women with fibromyalgia. Arch Phys Med Rehabil
2009;90:1628–34.
37. Kingsley JD, McMillan V, Figueroa A. The effects of 12 weeks of resistance
exercise training on disease severity and autonomic modulation at rest and after
acute leg resistance exercise in women with fibromyalgia. Arch Phys Med Rehabil
2010;91:1551–7.
142
Resistance Training for Fibromyalgia
38. Elvin A, Siosteen AK, Nilsson A, Kosek E. Decreased muscle blood flow in fibromyalgia patients during standardised muscle exercise: a contrast media enhanced colour
Doppler study. Eur J Pain 2006;10:137–44.
39. Kim SK, Kim KS, Lee YS, Park SH, Choe JY. Arterial stiffness and proinflammatory
cytokines in fibromyalgia syndrome. Clin Exp Rheumatol 2010;28:S71–7.
40. Lee JH, Cho KI, Kim SM, Lee HG, Kim TI. Arterial stiffness in female patients with
fibromyalgia and its relationship to chronic emotional and physical stress. Korean Circ J
2011;41:596–602.
41. Wolfe F, Smythe HA, Yunus MB et al. The American College of Rhuematology 1990
criteria for classification of fibromyalgia. Report of the Multicenter Criteria Committee.
Arthritis Rheum 1990;33:160–72.
42. Wolfe F, Clauw DJ, Fitzcharles MA et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity.
Arthritis Care Res (Hoboken) 2010;62:600–10.
43. Bircan C, Karasel SA, Akgun B, El O, Alper S. Effects of muscle strengthening versus
aerobic exercise program in fibromyalgia. Rheumatol Int 2008;28:527–32.
44. Geel SE, Robergs RA. The effect of graded resistance exercise on fibromyalgia symptoms and muscle bioenergetics: a pilot study. Arthritis Rheum 2002;47:82–6.
45. Hakkinen A, Hakkinen K, Hannonen P, Alen M. Strength training induced adaptations
in neuromuscular function of premenopausal women with fibromyalgia: comparison
with healthy women. Ann Rheum Dis 2001;60:21–6.
46. Hakkinen K, Pakarinen A, Hannonen P et al. Effects of strength training on muscle
strength, cross-sectional area, maximal electromyographic activity, and serum hormones in premenopausal women with fibromyalgia. J Rheumatol 2002;29:1287–95.
47. Hooten WM, Qu W, Townsend CO, Judd JW. Effects of strength vs aerobic exercise
on pain severity in adults with fibromyalgia: a randomized equivalence trial. Pain
2012;153:915–23.
48. Kingsley JD, Panton LB, Toole T, Sirithienthad P, Mathis R, McMillan V. The effects
of a 12-week strength-training program on strength and functionality in women with
fibromyalgia. Arch Phys Med Rehabil 2005;86:1713–21.
49. Kingsley JD, McMillan V, Figueroa A. Forearm blood flow and vasodilatory capacity in
women with fibromyalgia. Med Sci Sports Exerc 2010;39:S985.
50. Kingsley JD, McMillan V, Figueroa A. Resistance exercise training does not affect
postexercise hypotension and wave reflection in women with fibromyalgia. Appl Physiol
Nutr Metab 2011;36:254–63.
51. Panton LB, Figueroa A, Kingsley JD et al. Effects of resistance training and chiropractic
treatment in women with fibromyalgia. J Altern Complement Med 2009;15:321–8.
52. Valkeinen H, Hakkinen A, Hannonen P, Hakkinen K, Alen M. Acute heavy-resistance
exercise-induced pain and neuromuscular fatigue in elderly women with fibromyalgia
and in healthy controls: effects of strength training. Arthritis Rheum 2006;54:1334–9.
53. Bennett RM. Physical fitness and muscle metabolism in the fibromyalgia syndrome: an
overview. J Rheumatol Suppl 1989;19:28–9.
54. Yunus MB, Kalyan-Raman UP, Kalyan-Raman K, Masi AT. Pathologic changes in muscle in primary fibromyalgia syndrome. Am J Med 1986;81:38–42.
55. Lindh MH, Johansson LG, Hedberg M, Grimby GL. Studies on maximal voluntary muscle contraction in patients with fibromyalgia. Arch Phys Med Rehabil 1994;75:1217–22.
56. Norregaard J, Bulow PM, Vestergaard-Poulsen P, Thomsen C, Danneskiold-Samoe B.
Muscle strength, voluntary activation and cross-sectional muscle area in patients with
fibromyalgia. Br J Rheumatol 1995;34:925–31.
57. Panton LB, Kingsley JD, Cress ME et al. A comparison of physical functional performance and strength in women with fibromyalgia, age and weight matched controls, and
women who are healthy. Phys Ther 2006;86:1479–88.
J. Derek Kingsley
143
58. Burckhardt CS, Clark SR, Bennett RM. The fibromyalgia impact questionnaire: development and validation. J Rheumatol 1991;18:728–33.
59. Cress ME, Buchner DM, Questad KA, Esselman PC, deLateur BJ, Schwartz RS.
Continuous-scale physical functional performance in healthy older adults: a validation
study. Arch Phys Med Rehabil 1996;77:1243–50.
60. Cress ME, Petrella JK, Moore TL, Schenkman ML. Continuous-scale physical f­ unctional
performance test: validity, reliability, and sensitivity of data for the short ­version. Phys
Ther 2005;85:323–35.
61. Anderson RJ, McCrae CS, Staud R, Berry RB, Robinson ME. Predictors of clinical pain
in fibromyalgia: examining the role of sleep. J Pain 2012;13:350–8.
62. Spaeth M, Rizzi M, Sarzi-Puttini P. Fibromyalgia and sleep. Best Pract Res Clin
Rheumatol 2011;25:227–39.
63. Moldofsky H. Rheumatic manifestations of sleep disorders. Curr Opin Rheumatol
2010;22:59–63.
64. Moldofsky H. Management of sleep disorders in fibromyalgia. Rheum Dis Clin North
Am 2002;28:353–65.
65. Moldofsky HK. Disordered sleep in fibromyalgia and related myofascial facial pain
conditions. Dent Clin North Am 2001;45:701–13.
66. Hakkinen K, Pakarinen A, Kraemer WJ, Newton RU, Alen M. Basal concentrations and
acute responses of serum hormones and strength development during heavy resistance
training in middle-aged and elderly men and women. J Gerontol A Biol Sci Med Sci
2000;55:B95–105.
67. Cooke WH, Carter JR. Strength training does not affect vagal-cardiac control or cardiovagal baroreflex sensitivity in young healthy subjects. Eur J Appl Physiol 2005;93:719–25.
68. Collier SR, Kanaley JA, Carhart R, Jr. et al. Cardiac autonomic function and baroreflex
changes following 4 weeks of resistance versus aerobic training in individuals with prehypertension. Acta Physiol (Oxf) 2009;195:339–48.
69. Kasikcioglu E, Dinler M, Berker E. Reduced tolerance of exercise in fibromyalgia may
be a consequence of impaired microcirculation initiated by deficient action of nitric
oxide. Med Hypotheses 2006;66:950–2.
70. Higashi Y, Yoshizumi M. New methods to evaluate endothelial function: method for
assessing endothelial function in humans using a strain-gauge plethysmography: nitric
oxide-dependent and -independent vasodilation. J Pharmacol Sci 2003;93:399–404.
71. Turk DC, Robinson JP, Burwinkle T. Prevalence of fear of pain and activity in patients
with fibromyalgia syndrome. J Pain 2004;5:483–90.
72. Roelofs J, Goubert L, Peters ML, Vlaeyen JW, Crombez G. The Tampa Scale for
Kinesiophobia: further examination of psychometric properties in patients with chronic
low back pain and fibromyalgia. Eur J Pain 2004;8:495–502.
73. de Gier M, Peters ML, Vlaeyen JW. Fear of pain, physical performance, and attentional
processes in patients with fibromyalgia. Pain 2003;104:121–30.
74. Peters ML, Vlaeyen JW, van Drunen C. Do fibromyalgia patients display hypervigilance
for innocuous somatosensory stimuli? Application of a body scanning reaction time
paradigm. Pain 2000;86:283–92.
75. Goldenberg DL, Burckhardt C, Crofford L. Management of fibromyalgia syndrome.
JAMA 2004;292:2388–95.
10
Resistance Training
after Stroke
Richard W. Bohannon
CONTENTS
Introduction............................................................................................................. 149
Resistance Training Regimens................................................................................ 150
Outcomes Associated with Resistance Training Regimens.................................... 150
Conclusions............................................................................................................. 161
References............................................................................................................... 161
INTRODUCTION
Stroke involves the alteration of blood flow to part of the brain with a subsequent loss
of neurological function. One of the major consequences of this pathology, which
strikes almost 800,000 Americans each year,1 is muscle weakness. Although predominant on the side of the body contralateral to the stroke, weakness is also present
on the ipsilateral side.2 The weakness is probably most obvious in the limbs, but it
is present in the trunk as well.3 Given the everyday role that muscle strength plays
in accelerating, maintaining, and decelerating the body and its segments in space,
it should not be surprising that the muscle strength of individuals with stroke is
related to their performance of functional activities such as standing from sitting,4
walking,5–6 and climbing stairs.7 Whether muscle strength was limited before the
stroke, impaired by the stroke itself, or reduced by limited activity following the
stroke, it follows that rehabilitation professionals would seek to increase the muscle
strength of patients who are weak following a stroke. The purpose of this chapter
on r­esistance exercise for patients with stroke, therefore, is to briefly describe and
discuss (1) resistance exercise interventions that have been used and (2) the outcomes
associated with the interventions.
To address the aforementioned purposes, PubMed was searched for relevant
research articles. The search string used was “(strength OR resistance) AND (training
OR exercise) AND stroke.” Additional articles were identified using hand searches.
Apparently, relevant research incorporating interventions other than resistance training (RT) (e.g., constraint-induced therapy) was excluded. Research in which RT was
combined with other interventions (e.g., aerobic conditioning) was excluded as well
unless the added benefits of RT were delineated. As research regarding RT for stroke
prevention was not available, that topic is not covered.
145
146
Resistance Training after Stroke
RESISTANCE TRAINING REGIMENS
Table 10.1 summarizes 28 studies of RT for patients with stroke. Only three ­studies
included patients who were in the acute phase after stroke and only the study by
Åsberg was limited to such individuals.18,24,30 The remaining 25 studies focused
on patients in the subacute or chronic stages after stroke,8–17,19–23,25–29,31–35 during
which muscle strength would be expected to be more stable. The functional status
of patients participating in RT regimens varied, but most patients were described
as ambulatory. As they were participating in RT, all must have had some preserved
force generating capacity in the trained muscle groups.
A single source or multiple sources of resistance were used in the studies. The
most common sources were weights (14 studies), body weight (10 studies), isokinetic
dynamometers (7 studies), pneumatic devices (5 studies), and elastic bands (4 studies), but fixed resistance, manual resistance, springs, and everyday items were also
used. The limbs targeted with the resistance exercise varied. However, the bilateral
lower limbs were targeted most often (16 studies). Four studies targeted either the
paretic lower limb or the paretic upper limb. One or two studies targeted either all
limbs, the paretic upper and lower limbs, or the nonparetic lower limb.
Exercise bouts were generally described on the basis of intensity, sets, and repetitions. Intensities were usually described relative to maximum; when weights were
involved, intensity relative to a 1 or 10 repetition maximum (RM) was most often
described. Bouts were sometimes begun at lower intensities and progressed to higher
intensities. Most studies involved two to three sets of resistance exercise. Ten repetitions per set were most often used, but as few as 5 and as many as 20 repetitions
were sometimes used. Training frequency was daily in some studies but was two or
three times per week in most. The duration of training, with a few exceptions, was
at least 4 weeks.
The exercise regimens described are consistent, by and large, with American
College of Sports Medicine recommendations for older adults participating in RT.36
That is, they usually involve an intensity of 65%–75% of maximum, 1 to 3 sets, 10 to
15 repetitions, and 2 to 4 sessions per week. They, therefore, should be expected to
yield improvements in strength without adverse events over periods of 4 weeks or
more.
OUTCOMES ASSOCIATED WITH RESISTANCE TRAINING REGIMENS
RT programs for patients with stroke described in the literature (Table 10.1) were
almost always accompanied by increases in muscle strength, sometimes in excess
of 100%. However, the increases were not always significant, particularly in com­
parison to alternative treatments. Increases were greatest in the trained activities.
For example, Engardt et al. found concentric isokinetic training of knee extension
to yield greater increases in concentric knee extension torque than in eccentric
knee extension torque.16 This follows from the principle of specificity of train­
ing. Improvements in nonstrength variables after strength training were common
in the studies reviewed. Unfortunately, nonstrength variables rarely improved
more for patients in RT groups than for patients receiving conventional therapy
8
RCT: Upper
limb S vs. RT
Oullette
et al.10
Classification:
Rehabilitation inpatients
N: 133
TSO: < 6 months
Status: Chedoke–
McMaster Stroke
Assessment stage 3, 4,
or 5 for lower limb
Classification:
Community-dwelling
N: 42
TSO: > 6 months
Status: Independently
ambulatory
Classification:
Rehabilitation inpatients
N: 77
TSO: ≤ 3 months
Status: Unable to walk
independently
RCT: FT + S vs.
active exercise +
FT + S vs. RT +
FT + S
RCT: CT vs.
RT + CT
Patients
Design
Moreland
et al.9
Inaba et al.
Study
Resistance: Weights & pneumatic
Exercise: Leg press & three other
(both lower limbs)
Bout: Three sets of 8–10 repetitions
at 70% 1RM
Frequency: Three times per week
Duration: 12 weeks
Resistance: Weights
Exercise: Leg press (paretic lower
limb)
Bout: One set of five repetitions at
50% 10 RM & one set of 10
repetitions at 10 RM
Frequency: NI
Duration: 1–2 months
Resistance: Weights & body weight
Exercise: STS & eight other mostly
functional (both lower limbs)
Bout: Two sets of 10 repetitions at
subjective moderate resistance
Frequency: Three times per week
Duration: Median 62 days
Resistance Training
TABLE 10.1
Summary of Studies Examining Strength Training Regimens for Stroke
Strength: At 12 weeks, RT group increased 11%–67%.
Increase significant for leg press & bilateral knee extension,
ankle plantar flexion, & ankle dorsiflexion in RT group but
not in S group
Other: At 12 weeks, 6-minute walk distance & maximum gait
velocity increased significantly in both groups. Changes in
these variables &stair climb time, STS time & habitual gait
velocity were not significantly different between groups
(Continued)
Strength: At discharge, RT + CT group increased significantly
(79%–300%) relative to baseline
Other: At discharge, no significant difference in length of stay,
or in changes in Disability Inventory or 2-minute walk
distance
Strength: At 1 month, RT + FT + S group increased 101% in
leg press; increase significantly greater than in other groups.
At 2 months, groups did not differ
Other: At 1 month, more in RT + FT + S group (64%) had
significant increases in mobility than in other groups (38% &
30%). At 2 months, groups did not differ
Outcomes
Richard W. Bohannon
147
11
Pretest–posttest
trial
Badics
et al.13
Classification:
Residential
rehabilitation
N: 56 (lower limbs),
36 (upper limbs)
TSO: 3 weeks–10 years
Status: Moderate
weakness
Classification:
Community-dwelling
N: 7
TSO: > 12 months
Status: Unable to stand >
15 seconds on paretic
lower limb
Classification:
Community-dwelling
N: 10
TSO: 6–12 months
Status: Independently
ambulatory
Pretest–posttest
trial
Nonrandom,
self-controlled
trial
Patients
Design
Cramp
et al.12
Weiss et al.
Study
Resistance: Weights & pneumatic
Exercise: Leg press & four other
(both lower limbs)
Bout: Up to three sets of 8–10
repetitions at 70% 1RM
Frequency: Two times per week
Duration: 12 weeks
Resistance: Weights, body weight &
elastic bands
Exercise: Wall squats, step-ups &
three other (both lower limbs)
Bout: Three sets of 10 repetitions
beginning at 20% 1RM and
increasing to 50% 1RM
Frequency: Two times per week
Duration: 6 months
Resistance: Weights
Exercise: Leg press & arm press (all
limbs)
Bout: Three to five sets of 20
repetitions at 20%–50% maximum
Frequency: Two to three times per
week
Duration: Four weeks
Resistance Training
TABLE 10.1 (Continued)
Summary of Studies Examining Strength Training Regimens for Stroke
Strength: At 4 weeks, leg press increased 31.0% & arm press
increased 40.2%
Other: Not applicable
Strength: At 6 months, knee extension torque increased
32%–34% on paretic side & 6%–17% on nonparetic side.
Knee flexion torque increased 0% on paretic & 6% on
nonparetic side. Only paretic knee extension torque increased
significantly at all testing velocities
Other: At 6 months, self-selected gait speed increased
significantly
Strength: At 12 weeks, increases averaged 48% on nonparetic
side & 68% on paretic side. Increases were significant for all
actions except leg press
Other: At 12 weeks, significant improvements in STS time,
Motor Assessment Scale, & Berg Balance Scale but not in
gait or stair speed or unipedal stance time
Outcomes
148
Resistance Training after Stroke
RCT: S vs. RT
Nonrandom,
self-controlled
trial
Nonrandom
trial:
Concentric vs.
eccentric
Kim et al.14
Sharp and
Brouwer15
Engardt
et al.16
Classification: NI
N: 20
TSO: Mean > 26 months
Status: Ambulatory
Classification:
Community-dwelling
N: 15
TSO: > 6 months
Status: Independently
ambulatory
Classification:
Community-dwelling
N: 20
TSO: > 6 months
Status: Independently
ambulatory
Resistance: Isokinetic
Exercise: Extension of knee (both
lower limbs)
Bout: Three sets of 10 repetitions at
submaximum followed by up to 15
sets at maximum
Frequency: Two times per week
Duration: 6 weeks
Resistance: Isokinetic
Exercise: Flexion & extension of
hip, knee & ankle (paretic lower
limb)
Bout: Three sets of 10 repetitions at
maximum
Frequency: Three times per week
Duration: 6 weeks
Resistance: Isokinetic
Exercise: Flexion & extension of
knee (paretic lower limb)
Bout: Three sets of six to eight
repetitions at maximum
Frequency: Three times per week
Duration: 6 weeks
Strength: At 6 weeks, knee extension torque increased
15.8%–19.5% on paretic side & 1.1%–6.4% on nonparetic
side; knee flexion torque increased 37.5%–153.9% on paretic
side & 9.0%–27.2% on nonparetic side. The only significant
increases were paretic knee extension (60°/s & 120°/s) and
paretic knee flexion (120°/s)
Other: At 6 weeks, gait speed & Human Activity Profile
improved significantly but Timed Up & Go & stair climbing
did not
Strength: At 6 weeks, concentric group increased 19.6%–
45.0% in concentric torque & 13.5%–17.7% in eccentric
torque; eccentric group increased 24.4%–28.5% in eccentric
torque & 25.2%–26.8% in concentric torque. All increases
were significant
Other: Weight bearing through paretic lower limb increased
significantly during STS in the eccentric group only
Weight bearing through paretic lower limb did not change
during STS in either group. Walking speed & paretic limb
swing phase duration increased significantly in the concentric
group only
(Continued)
Strength: At 6 weeks, torque increases (composite summed)
were 507% on paretic side & 57% on nonparetic side for RT
group vs. 142% & 22% for S group. The increases in RT
group were not significantly greater
Other: At 6 weeks, changes in walking speed, stair speed &
quality of life were not significantly different between groups
Richard W. Bohannon
149
Design
Randomized
trial:
Recreational
therapy vs.
additional STSs
Nonrandom trial:
CT vs. CT +
additional STSs
Pretest–posttest
trial
RCT: Usual
activity vs. RT
Study
Barreca
et al.17
Åsberg18
Monger
et al.19
Flansbjer
et al.20
Classification:
Community-dwelling
N: 24
Classification:
Community-dwelling
N: 6
TSO: > 1 year
Status: Ambulatory
Classification:
Rehabilitation inpatients
N: 48
TSO: Mean 30.5 days
Status: Chedoke–
McMaster Stroke
Assessment stage ≥ 3
Classification: Hospital
inpatients
N: 63
TSO: 1–2 days
Status: NI
Patients
Resistance: Pneumatic
Exercise: Extension and flexion of
knee (both limbs)
Resistance: Body weight
Exercise: STSs & step-ups (both
lower limbs)
Bout: Three sets of 10 repetitions
graded by ability
Frequency: Daily
Duration: 3 weeks
Resistance: Body weight
Exercise: STSs (both lower limbs)
Bout: One repetition per hour
Frequency: Daily (8 am–8 pm)
Duration: 5–12 days
Resistance: Body weight
Exercise: STSs (both lower limbs)
Bout: Three sets of five repetitions
with assistance if necessary
Frequency: Three times per week
Duration: Mean 46.6 days
Resistance Training
TABLE 10.1 (Continued)
Summary of Studies Examining Strength Training Regimens for Stroke
Strength: At 10 weeks, RT group increased 21.3%–70.1% in
torque on paretic side and 13.9%–43.8% in torque on
nonparetic side. Increases in RT group were significantly
greater than in usual activity group
Strength: NI
Other: At 5–7 days, but not at 10–12 days, proportion of
severely disabled patients was significantly greater in CT
than in CT + STS group. Length of stay did not differ
between groups. During tilting to 70°, CT + RT group had
lesser fall in blood pressure
Strength: Five of six patients showed improvement in STS
performance
Other: Vertical ground reaction force did not increase
significantly through either lower limb. Mean walking speed
increased 27.9%, which was significant
Strength: At discharge, number able to stand twice without
hands was 17 in STS group & 7 in recreation group. Group
proportions were significantly different
Other: At discharge, no significant difference between groups
in number of falls, global rating scale, or COOP scores
Outcomes
150
Resistance Training after Stroke
RCT: BWSTT +
upper-extremity
ergometry vs.
BWSTT +
loaded
lower-extremity
ergometry vs.
BWSTT +
lower extremity
RT
Nonrandom trial:
RT vs. RT +
anabolic steroid
Sullivan
et al.21
Shimodozono
et al.22
Classification:
Rehabilitation inpatients
N: 25
TSO: 4–32 weeks
Status: Able to sit
unsupported but unable
to walk 10 m without
assistive device
Classification:
Community-dwelling
N: 80
TSO: 4–60 months
Status: Ambulatory
TSO: 6–48 months
Status: Independently
ambulatory
Resistance: Isokinetic
Exercise: Extension and flexion of
knee (nonparetic lower limb)
Bout: One set of 25 repetitions at
50%–100% maximum followed by
3 sets of 25 repetitions at 100%
maximum
Frequency: Five times per week
Duration: 6 weeks
Bout: One set of 5 repetitions at
25% maximum followed by two
sets of six to eight repetitions at
80% maximum
Frequency: Two times per week
Duration: 10 weeks
Resistance: Weights, body weight &
elastic bands
Exercise: Flexion & extension of
the hip & knee, dorsiflexion and
plantarflexion of the ankle (paretic
limb)
Bout: Three sets of 10 repetitions at
80% 10 RM
Frequency: Two times per week
Duration: 6 weeks
(Continued)
Strength: At 6 weeks, peak knee torque increased 9%–45% in
RT group and 8%–76% in RT + steroid group
Other: NI
Other: At 10 weeks, the RT group showed improvements in
Timed Up & Go (19.2%), fast gait speed (14.4%) & 6-minute
walk distance (9.6%). All improvements were significant. In
usual activity group, only Timed Up & Go improved.
Perceived participation increased in RT group but the change
did not differ significantly from that in usual activity group
Strength: NI
Other: At 6 weeks, BWSTT + RT group increased
significantly in comfortable gait speed (17.5%), fast gait
speed (12.5%) & 6-minute walk distance (22.7%), but
increases were not significantly different from other groups
Richard W. Bohannon
151
23
RCT: CT vs.
CT + RT
RCT: CT vs.
CT + RT
Cooke et al.25
RCT: RT vs.
control
Design
Donaldson
et al.24
Sims et al.
Study
Classification:
Rehabilitation inpatients
N: 109
TSO: 1–13 weeks
Status: “Some voluntary
muscle contraction in
the paretic lower limb,”
independently mobile
Classification: NI
N: 30
TSO: 7–61 days
Status: “Some voluntary
muscle activity in the
paretic upper limb,” no
overt neglect
Classification:
Community-dwelling
N: 45
TSO: > 6 months
Status: Independently
ambulatory, depressed
Patients
Resistance: Body weight
Exercise: STS & other functional
activities (both lower limbs)
Bout: One to five sets of 10
repetitions
Frequency: Four times per week
Duration: 6 weeks
Resistance: Weights
Exercise: Seated row, lat pull-down,
chest press, leg press, calf raise,
leg extension (all limbs)
Bout: Three sets of 8–10 repetitions
at 80% 1RM
Frequency: Two times per week
Duration: 10 weeks
Resistance: Everyday items
Exercise: Everyday activities (e.g.,
placing food items in bag & lifting
bag onto shelf) (paretic upper
limb)
Bout: One to five sets of 10
repetitions
Frequency: Four times per week
Duration: 6 weeks
Resistance Training
TABLE 10.1 (Continued)
Summary of Studies Examining Strength Training Regimens for Stroke
Strength: At 6 weeks, knee torques increased in group
undergoing RT but no significant added benefit of RT
Other: At 6 weeks, gait speed & symmetry improved in group
undergoing RT but no significant added benefit of RT.
Strength: At 6 weeks, increased 119.6%–174.5% in group
using RT. Increase not significantly different from groups
receiving CT alone
Other: At 6 weeks, Action Research Arm Test & 9 Hole Peg
Test performance improved 67.7% & 466.7%, respectively.
Improvements not significantly different from groups
receiving CT alone
Strength: At 10 weeks, 1RM chest press increased 105% in RT
group & 21% in the control group. Leg press 1RM increased
86% in RT group & 21% in control group
Other: At 10 weeks, depression & well-being improved but
not significantly more in RT group than control group
Outcomes
152
Resistance Training after Stroke
RCT: RT vs.
cycling vs. RT +
cycling vs.
control
RCT: RT vs.
cycling vs. RT +
cycling vs.
control
Nonrandom
self-controlled
trial
Lee et al.26
Lee et al.27
Hill et al.28
Classification:
Community-dwelling
N: 10
TSO: > 6 months
Status: Independently
ambulatory
Classification:
Community-dwelling
N: 48
TSO: ≥ 3 months
Status: Comfortable gait
speed of 15 & 1.4 m/s
Classification:
Community-dwelling
N: 45
TSO: ≥ 3 months
Status: Comfortable gait
speed of 15 & 1.4 m/s
Resistance: Pneumatic, weights,
fixed resistance
Exercise: Lower limb extension,
knee flexion & extension, ankle
dorsiflexion & extension, hip
abduction (both lower limbs)
Bout: Two sets of eight repetitions at
50% 1RM progressing to two sets
of eight repetitions at 80% 1RM
Frequency: Three times per week
Duration: 10–12 weeks
Resistance: Weights, pneumatic &
fixed resistance
Exercise: Lower limb extension,
knee flexion & extension, ankle
dorsiflexion & extension, hip
abduction (both lower limbs)
Bout: Two sets of eight repetitions at
50% 1RM progressing to two sets
of eight repetitions at 80% 1RM
Frequency: Three times per week
Duration: 10–12 weeks
Resistance: Weights, manual
Exercise: Leg press & plantarflexion
(both limbs)
Bout: One set of five repetitions at
50% 1RM followed by four sets of
four repetitions at 85%–95% 1RM
(Continued)
Strength: At 8 weeks, leg press 1RM increased 86% on paretic
side & 75% on nonparetic side. Ankle plantarflexion strength
increased 224% on paretic side & 89% on nonparetic side.
These increases were significantly greater than during control
period
Strength: At 10 weeks, increases in the RT group ranged from
38.0% to 76.7% on paretic side & 2.3% to 84.4% on
nonparetic side. Increases were significant in all actions
except ankle dorsiflexion. Cycling did not result in any
significant increases. RT + cycling did not result in
significantly greater increases than RT alone
Other: NI
Strength: At 12 weeks, increases in strength in the RT group
ranged from 37.5% to 131.0% on paretic side & 26.9% to
110.8% on nonparetic side. Increases were significantly
greater than in the cycling group
Other: At 12 weeks, gait speed, 6-minute walk distance,
stair-climbing power & some aerobic fitness variables
improved in the RT group but not significantly more than in
cycle group
Richard W. Bohannon
153
RCT: Standard
care vs.
functional task
practice vs. RT
vs. functional
task practice +
RT
RCT: No
training vs. RT
Yang et al.29
Design
Winstein
et al.30
Study
Classification: NI
N: 48
TSO: > 1 year
Status: Independently
ambulatory without
device
Classification:
Rehabilitation inpatients
N: 60
TSO: 2–35 days
Status: Admission FIMTM
total score of 40–80
Patients
Resistance: Weights, body weight &
elastic bands
Exercise: Eccentric, isometric &
concentric for shoulder, elbow,
wrist & hand (paretic upper limb)
Bout & Frequency: 1 hour/day at
“high intensity,”
three times per week and “less
resistance & greater speeds two
times per week
Duration: 4 weeks
Resistance: Body weight
Exercise: STS & five other (both
lower limbs)
Bout: 5 minutes at each station with
intensity “graded to each subject’s
functional level”
Frequency: Three times per week
Duration: 4 weeks
Frequency: Three times per week
Duration: 8 weeks
Resistance Training
TABLE 10.1 (Continued)
Summary of Studies Examining Strength Training Regimens for Stroke
Strength: At 4 weeks, increases in strength in RT group ranged
from 12.0% to 47.4% on paretic side & 17.5% to 28.4% on
nonparetic side. Increases were significantly greater for all
six muscle actions in the RT group
Other: At 4 weeks, gait speed, cadence & stride length,
6-minute walk distance, step test performance & Timed Up
& Go time improved. Improvements were significantly
greater than those in no training group
Strength: At 4 weeks, increases in strength in RT group ranged
from 77.3% to 174.7%. Increases were not significantly
greater than in the other groups
Other: At 4 weeks, Fugl-Meyer & Functional Test of
Hemiparetic Upper Extremity scores improved in RT group
but not significantly more than in other groups
Other: At 8 weeks, small improvements (3.1%–7.1%) in
6-minute walk distance, Timed Up & Go & Four Square Step
Test performance were realized after RT. Improvements were
significant for 6-minute walk & Timed Up & Go. Changes
over control and RT periods were not significantly different
for any measure
Outcomes
154
Resistance Training after Stroke
Bourbonnais
et al.33
Tung et al.32
Bütefisch
et al.31
RCT: Upper
limb vs. lower
limb forcefeedback
training
Random
self-controlled
trial: Standard
care + RT vs.
standard care +
nerve
stimulation
RCT: Standard
care +
additional STS
RT vs. standard
care
Classification:
Community-dwelling
N: 25
TSO: mean > 34 months
Status: Chedoke–
McMaster Stroke
Assessment (arm
component) stage 3–6
Classification: NI
N: 27
TSO: 3–19 weeks
Status: No major sensory
deficits, complete hand
paralysis, neglect, aphasia
or peripheral nerve lesions
Classification: NI
N: 32
TSO: 1.6–62.9 months
Status: Berg Balance
Scale score < 50,
independent in STS
Resistance: Dynamometer
Exercise: Sixteen directions for
upper & lower limbs (paretic limbs)
Bout: Upper limb - six to eight
repetitions at 20%–35% maximum,
progressing to 40%–60%
maximum. Lower limb - six to
eight repetitions at 40%–60%
maximum, progressing to
70%–90% maximum
Frequency: Three times per week
Duration: 6 weeks
Resistance: Springs, weights
Exercise: Finger flexion & wrist
extension “against various loads”
(paretic upper limb)
Bout: 15 minutes
Frequency: Two times per day
Duration: 4 weeks
Resistance: Body weight
Exercise: Chair height adjusted STS
(both limbs)
Bout: 15 minutes
Frequency: Three times per week
Duration: 4 weeks
(Continued)
Strength: At 4 weeks, RT group increased 13.7%–22.8% on paretic
side & 11.2%–15.0% on nonparetic side. Increases significant for
hip & knee extension on both sides & ankle plantarflexion on
nonparetic side. Increases not significantly greater than in control
group except for paretic hip extension. Duration for STS
decreased 55.8% in RT group. The decrease was significant &
significantly greater than in standard care group
Other: At 4 weeks, dynamic balance (maximum excursion,
directional control & Berg Balance Scale scores) improved in
the RT group but improvements were not significantly better
than for standard care group
Strength: At 6 weeks, upper limb training was accompanied
by increases of 21%–42% in upper limb. Lower limb training
was accompanied by increases of 39%–81%
Other: At 6 weeks, upper limb tests (Fugl-Meyer, TEMPA,
Box & Blocks, alternating movements) did not improve
significantly more after upper limb training than after lower
limb training. Gait speed & distance did, but Fugl-Meyer &
Timed Up & Go did not improve significantly more after
lower limb training than after upper limb training
Strength: Over 4 weeks of RT, a statistically significant
increases showed for grip strength & wrist extension force &
acceleration. Nerve stimulation was not accompanied by
significant increases
Other: Over 4 weeks of RT, Rivermead Motor Assessment
(arm section) scores increased significantly.
Richard W. Bohannon
155
RCT: Control vs.
resisted
extension,
ballistic
extension vs.
resisted grasp
Trombly
et al.35
Classification:
Rehabilitation inpatients
N: 20
TSO: Mean 3.4–11.1
weeks
Status: Able to grasp
2.5-cm cylinder
Classification:
Community-dwelling
N: 40
TSO: > 6 months
Status: No severe
cognitive deficits
Patients
Resistance: Weights & isokinetic
dynamometer
Exercise: Leg press & seven other
(both lower limbs)
Bout: Two sets of 10 repetitions at
load set by exercise physiologist
and increased over time
Frequency: Three times per week
Duration: 16 weeks
Resistance: Elastic bands
Exercise: Finger flexion or
extension (paretic upper limb)
Bout: One set of 10 repetitions with
maximum number of bands
Frequency: Daily
Duration: Mean 9–12 treatments
Resistance Training
Strength: NI
Other: Following treatment, active range of motion, tapping
rate & grasp-release improved in RT groups. Improvements
were not significantly different than in the other groups
Strength: At 16 weeks, increases in the aerobic training + RT
group ranged from 17.3% to 35.2%. In the aerobic training
group they ranged from 2.1% to 47.8%
Other: At 16 weeks, peak oxygen consumption increased &
total cholesterol decreased significantly in the aerobic
training + RT group but not the aerobic training group.
Fasting blood glucose values decreased in both groups but
not significantly
Outcomes
RCT, randomized controlled trial; N, number; S, stretching; FT, functional training; TSO, time since onset; NI, not indicated; CT, conventional therapy, BWSTT, body
weight supported treadmill training; RM, repetition maximum; STS, Sit-to-stand; RT, resistance training.
Random trial:
Aerobic training
vs. aerobic
training + RT
Design
Carr and
Jones34
Study
TABLE 10.1 (Continued)
Summary of Studies Examining Strength Training Regimens for Stroke
156
Resistance Training after Stroke
Richard W. Bohannon
157
or other interventions. Patients whose RT involved body weight and functional
activities such as sit-to-stand, however, seemed to realize greater improvements in
some aspects of function.17,18,32 This also follows from the principle of specificity
of training.
CONCLUSIONS
Patients with stroke, who are weak, can realize increases in strength through RT.
The optimal training program to achieve increased strength is not yet established,
but it probably will involve functionally specific training.
REFERENCES
1. Roger VL, Go AS, Lloyd-Jones DM, Benjamin EJ, Berry JD, Borden WB, Bravata DM
(writing group). Heart disease and stroke statistics—2012 update: a report from the
American Heart Association. Circulation 2012; 125: e2–e220.
2. Andrews AW, Bohannon RW. Limb muscle strength is impaired bilaterally after stroke.
J Phys Ther Sci 1995; 7: 1–7.
3. Bohannon RW, Cassidy D, Walsh S. Trunk muscle strength is impaired multidirectionally after stroke. Clin Rehabil 1995; 9: 47–51.
4. Bohannon RW. Knee extension strength and body weight determine sit-to-stand independence after stroke. Physiother Theory Pract 2007; 23: 291–297.
5. Suzuki K, Nakamura R, Yamada Y, Handa T. Determinants of maximum walking speed
in hemiparetic stroke patients. Tohoku J Exp Med 1990; 162: 337–344.
6. Bohannon RW. Knee extension power, velocity and torque: relative deficits and relation
to walking performance in stroke patients. Clin Rehabil 1992; 6: 125–131.
7. Bohannon RW, Walsh S. Association of paretic lower extremity muscle strength and
standing balance with stair-climbing ability in patients with stroke. J Stroke Cerbrovasc
Dis 1991; 1: 129–133.
8. Inaba M, Edberg E, Montgomery J, Gillis MK. Effectiveness of functional training,
active exercise, and resistance exercise for patients with hemiplegia. Phys Ther 1973;
53: 28–35.
9. Moreland JD, Goldsmith CH, Huijbregts MP, Anderson RE, Prentice DM, Brunton KB
et al. Progressive resistance strengthening exercises after stroke: a single-blind randomized controlled trial. Arch Phys Med Rehabil 2003; 84: 1433–1440.
10. Ouellette MM, LeBrasseur NK, Bean JF, Phillips E, Stein J, Frontera WR, Fielding RA.
High intensity resistance training improves muscle strength, self-reported function, and
disability in long-term stroke survivors. Stroke 2004; 35: 1404–1409.
11. Weiss A, Suzuki T, Bean J, Fielding RA. High intensity resistance training improves
strength and functional performance after stroke. Am J Phys Med Rehabil 2000;
79: 369–376.
12. Cramp MC, Greenwood RJ, Gill M, Rothwell JC, Scott OM. Low intensity strength
training for ambulatory stroke patients. Disabil Rehabil 2006; 28: 883–889.
13. Badics E, Wittmann A, Rupp M, Stabauer B, Zifko UA. Systematic muscle building
exercises in rehabilitation of stroke patients. Neurorehabilitation 2002; 17: 211–214.
14. Kim CM, Eng JJ, MacIntyre DL, Dawson AS. Effects of isokinetic strength training on walking in persons with stroke: a double-blind controlled pilot study. J Stroke
Cerebrovasc Dis 2001; 10: 265–273.
15. Sharp SA, Brouwer BJ. Isokinetic strength training of the hemiparetic knee: effects on
function and spasticity. Arch Phys Med Rehabil 1997; 78: 1231–1236.
158
Resistance Training after Stroke
16. Engardt M, Knutsson E, Jonsson M, Sternhag M. Dynamic muscle strength training in
stroke patients: effect of knee extension torque, electromyographic activity, and motor
function. Arch Phys Med Rehabil 1995; 76: 419–425.
17. Barreca S, Sigouin CS, Lambert C, Ansley B. Effects of extra training on the ability of
stroke survivors to perform and independent sit-to-stand: a randomized controlled trial.
J Geriatr Phys Ther 2004; 27: 59–64.
18. Åsberg KH. Orthostatic tolerance training of stroke patients in general medical wards.
Scand J Rehabil Med 1989; 21: 179–185.
19. Monger C, Carr JH, Fowler V. Evaluation of a home-based exercise and training
­programme to improve sit-to-stand in patients with chronic stroke. Clin Rehabil 2002;
16: 361–367.
20. Flansbjer U-B, Miller M, Downham D, Lexell J. Progressive resistance training after
stroke: effects on muscle strength, muscle tone, gait performance and perceived participation. J Rehabil Med 2008; 40: 42–48.
21. Sullivan KJ, Brown DA, Klassen T, Mulroy S, Ge T, Azen SP, Winstein CJ. Effects
of task-specific locomotor and strength training in adults who were ambulatory after
stroke: results of the STEPS randomized clinical trial. Phys Ther 2007; 87: 1580–1602.
22. Shimodozono M, Kawahira K, Ogata A, Etoh S, Tanaka N. Addition of an anabolic
steroid to strength training promotes muscle strength in the nonparetic lower limb of
poststroke hemiplegia patients. Int J Neurosci 2010; 120: 617–624.
23. Sims J, Galea M, Taylor N, Dodd K, Jespersen S, Joubert L, Joubert J. Regenerate:
assessing the feasibility of a strength-training program to enhance the physical and mental health of chronic post stroke patients with depression. Int J Geriatr Psychiat 2009;
24: 76–83.
24. Donaldson C, Tallis R, Miller S, Sunderland A, Lemon R, Pomeroy V. Effects of
­conventional physical therapy and functional strength training on upper limb motor
recovery after stroke: a randomized phase II study. Neurorehab Neural Repair 2009;
23: 389–397.
25. Cooke EV, Tallis RC, Clark A, Pomeroy VM. Efficacy of functional strength training
on restoration of lower-limb motor function early after stroke: phase I randomized controlled trial. Neurorehabil Neural Repair 2010; 24: 88–96.
26. Lee M-J, Kilbreath SL, Singh MF, Zeman B, Lord SR, Raymond J, Davis GM.
Comparison of effect of aerobic cycle training and progressive resistance training on
walking ability after stroke: a randomized sham exercise-controlled study. J Am Geriatr
Soc 2008; 56: 976–985.
27. Lee M-J, Kilbreath SL, Singh MF, Zeman B, Davis GM. Effect of progressive r­ esistance
training on muscle performance after chronic stroke. Med Sci Sports Exerc 2010;
42: 23–34.
28. Hill TR, Gjellesvik TI, Moen PMR, Tørhaug T, Fimland MS, Helgerud J, Hoff J.
Maximal strength training enhances strength and functional performance in chronic
stroke survivors. Am J Phys Med Rehabil 2012; 91: 393–400.
29. Yang Y-R, Wang R-Y, Lin K-H, Chu M-Y, Chan R-C. Task-oriented progressive resistance strength training improves muscle strength and functional performance in individuals with stroke. Clin Rehabil 2006; 20: 860–870.
30. Winstein CJ, Rose DK, Tan SM, Lewthwaite R, Chui HC, Azen SP. A randomized
controlled comparison of upper-extremity rehabilitation strategies in acute stroke:
a pilot study of immediate and long-term outcomes. Arch Phys Med Rehabil 2004;
85: 620–628.
31. Bütefisch C, Hummelsheim H, Denzler P, Mauritz K-H. Repetitive training of isolated
movements improves the outcome of motor rehabilitation of the centrally paretic hand.
J Neurol Sci 1995; 130: 59–68.
Richard W. Bohannon
159
32. Tung F-L, Yang Y-R, Wang R-Y. Balance outcomes after additional sit-to-stand training
in subjects with stroke: a randomized controlled trial. Clin Rehabil 2010; 24: 533–542.
33. Bourbonnais D, Bilodeau S, Lepage Y, Beaudoin N, Gravel D, Forget R. Effect of forcefeedback treatments in patients with chronic motor deficits after a stroke. Am J Phys
Med Rehabil 2002; 81: 890–897.
34. Carr M, Jones J. Physiological effects of exercise on stroke survivors. Topics Stroke
Rehabil 2003; 9: 57–64.
35. Trombly CA, Thayer-Nason L, Bliss G, Girard CA, Lyrist LA, Brexa-Hooson A. The
effectiveness of therapy in improving finger extension in stroke patients. Am J Occup
Ther 1986; 40: 612–617.
36. Willoughby DS. ACSM Current Comment. Resistance Training and the Older Adult.
Available at http://www.acsm.org/docs/current-comments/resistancetrainingandtheoa .pdf.
Accessed on February 12, 2012.
11
Effects of Resistance
Training on Depression
and Anxiety
Shawn M. Arent and Brandon L. Alderman
CONTENTS
Introduction............................................................................................................. 165
Resistance Training and Depression....................................................................... 166
Resistance Training, Depression, and Obesity................................................... 167
Resistance Training, Depression, and Dose Issues............................................ 168
Resistance Training and Anxiety............................................................................ 169
Resistance Training and Anxiety: Effects of Training Load.............................. 170
Potential Mechanisms............................................................................................. 174
Conclusions............................................................................................................. 175
References............................................................................................................... 176
INTRODUCTION
Worldwide, over 340 million people are impacted by depression.1 In the United
States alone, 16% of the population will experience major depression at some point
in their lifetime. In fact, depression is considered a leading cause of disability and
is likely to be at least the second leading contributor to worldwide disease burden
by 2020.2 It also appears that depression is linked to increased functional disability
and further exacerbates functional disability in individuals suffering from chronic
­diseases.3 Likewise, anxiety disorders afflict more than 30 million people in the
United States and cost an estimated $42 billion/year. Overall, depression and anxiety
are the two most commonly reported mental health disorders.1,4 To make matters
worse, it appears that at least one-third to two-thirds of depressed patients will not
experience successful alleviation of symptoms with the first antidepressant therapy
prescribed, with as many as 30% being classified as non-responders, that is, not
responding to even multiple interventions.5 Perhaps the more concerning fact is
that antidepressants and anxiolytic drugs are both expensive and accompanied by
a ­number of serious side effects. Fortunately, evidence suggests that a viable alternative low-cost alternative therapy, or at least an important adjunct, exists that has
positive outcomes and is free from the negative side effects: exercise.
A number of large-scale cross-sectional and prospective-longitudinal studies
have demonstrated an inverse association between physical activity and depressive
161
162
Effects of Resistance Training on Depression and Anxiety
and anxiety symptoms.6,7 There has also been an expanding body of meta-analytic
evidence supporting moderate to large reductions in both depression and anxiety
with exercise8–11 with effective magnitude often being on par with other traditional
psychotherapeutic interventions.9,11 Although much of the research included in these
systematic reviews has primarily used aerobic exercise as the treatment modality,
the effects for resistance training (RT) have been shown to be particularly pronounced for depression and both positive and negative moods when included in the
analyses.8,12
RT has the potential to cause significant increases in muscular strength, hypertrophy, and endurance.13,14 From a clinical standpoint, it can also impact numerous
health conditions such as arthritis, type 2 diabetes, and musculoskeletal dysfunction.15 It has become increasingly apparent that RT can also significantly and meaningfully enhance psychological states in addition to the well-reported physiological
outcomes. Although this psychological effect has received considerably more support for aerobic exercise,16 the findings for RT have been encouraging. The purpose
of this chapter is to provide an overview of the research addressing antidepressant
and anxiolytic responses to RT. In addition to summarizing key research findings,
considerations related to the conceptualization of intensity, dose–response issues,
and potential mechanisms underlying the psychological benefits of RT are addressed
where sufficient evidence is available.
RESISTANCE TRAINING AND DEPRESSION
Early work in the area of RT and depression was consistent in finding that this mode
of exercise is effective for reducing depressive symptoms.17–19 Both Doyne et al.17
and Martinsen et al.18 found that RT was as efficacious as traditional aerobic exercise
such as walking or jogging, with effects persisting for up to 1 year post intervention. Unfortunately, one methodological issue that has sometimes plagued this area
of inquiry has been the combination of RT with other exercise modalities, which
makes it difficult to discern the unique impact of RT. For example, despite there
being positive findings for RT efficacy by Martinsen et al., the RT program used in
their study also incorporated coordination and flexibility training. In some cases, the
RT protocol was also fairly weak in its design. However, despite these shortcomings,
research has largely supported the utility of implementing a RT component to reduce
depression.
A recent study20 compared the antidepressant effects of a 10-week combined
moderate-intensity RT and aerobic exercise program to a combined team-sport
and cognitive behavioral therapy (CBT) intervention and a control condition in
84 sedentary males. Both the RT/aerobic and team-sport/CBT groups demonstrated
reductions in depression scores over the 10 weeks compared to the control condition despite the fact that this was an otherwise healthy population. The magnitude
of reduction was somewhat larger in the RT/aerobic exercise group, as was the perception of social support despite the individualized nature of the exercise program.
Unfortunately, the researchers provided very little description of the actual exercise
protocol and the intensity for both RT and aerobic exercise was established solely
based on heart rate.
Shawn M. Arent and Brandon L. Alderman
163
Beniamini and colleagues21 examined the feasibility of implementing a 12-week
high-intensity (defined as 80% one repetition maximum [1RM]) RT program or a
flexibility training program in conjunction with an outpatient cardiac rehabilitation
aerobic exercise program in 38 cardiac patients. Compared to the flexibility intervention, the RT group had significantly greater improvements in total mood disturbance, depression/dejection, and fatigue despite only doing three sets of each of four
total RT exercises twice a week. Additionally, changes in strength were related to
enhanced self-efficacy, mood, and well-being. Perhaps the most important finding,
the authors demonstrated that high-intensity RT is a feasible treatment component
for cardiac patients.
Unlike the combined RT/aerobic exercise protocols employed by Beniamini
et al.21, McGale et al.20, and Kohut et al.22 compared a combined RT and fl
­ exibility
training program to an aerobic exercise program. Older adults (≥64 years) p­ erformed
45 ­minute workouts three times a week for 10 months. Although the RT component
was only performed at moderate intensity and appeared to be fairly low in volume,
both groups had similar improvements in depression scores. Given that meta-­analytic
evidence suggests that yoga and flexibility training have no significant effect on
moods in older adults,12 it is likely that the primary influence on the reductions in
depression were due to the RT. Future research needs to make a more concerted effort
to separate out these effects while also implementing more carefully prescribed RT
protocols, particularly if we hope to establish a causal relationship between RT and
reductions in depression.
Resistance Training, Depression, and Obesity
One of the reasons that RT has begun to receive more attention for its potential
­psychological effects is the burgeoning evidence supporting its physiological b­ enefits.
In addition to the obvious effects of progressive RT programs on reduced sarcopenia
and increased bone density,23 it has also been found to lower cortisol responses to
acute stress24; increase total energy expenditure25; and improve hypertension,26 blood
lipids,27 and glycemic control and glycosylated hemoglobin (HbA1c) levels in individuals with type 2 diabetes.27 Partly because of these beneficial physiological effects
as well as the independent effects for improving body composition by reducing body
fat and increasing lean mass, RT has begun to be implemented as part of obesity
prevention and treatment programs.23 This has particular relevance for the topic of
exercise and depression as obesity has been shown to increase the risk for depression and depression appears to promote obesity.28 From an explanatory perspective,
the link between obesity and depression may be partially attributed to functional
impairments and appearance concerns, two issues that RT is particularly well suited
to help ameliorate. For example, a recent study conducted in our laboratory evaluated the effects of RT on physical self-perceptions in Hispanic adolescents.29 Both
male and female students participated in either a 12-week RT program or attended
physical education classes as the control group. The RT group demonstrated significant improvements in total physical self-perception, physical condition, body attractiveness, and global self-worth compared to the control group. Moreover, the RT
group not only had significant strength gains but also exhibited significant decreases
164
Effects of Resistance Training on Depression and Anxiety
in percentage of body fat and increases in lean body mass relative to the control
group, suggesting a possible connection between increased strength, improved body
composition, and improved physical self-perception.
Importantly, given that one of the major side effects of the commonly prescribed
antidepressant medications is weight gain, the use of RT as an alternative or adjunct
to medication in an already overweight population may be particularly appealing.
This is one reason that the traditional approach of managing either weight or depression without taking into account comorbidities is problematic.28 Exercise, including
RT, may be an appealing and effective solution to this problem. While the existing
research comparing exercise to typical pharmacological treatments has been limited
to aerobic exercise, the results are encouraging and suggest equivalent short-term
improvements but lower relapse rates for exercise.30,31 Considering the physiological
effects of RT, future research comparing this modality of exercise with pharmacological interventions (or in conjunction with pharmacological approaches) is clearly
warranted, particularly in situations of comorbid obesity.
Resistance Training, Depression, and Dose Issues
One key component necessary to establish causation in the exercise–mental
health relationship is the establishment of a dose–response effect.16 In addition to
­epidemiological findings across multiple nations that suggest a dose–response relationship between physical activity and mental health,6 recent experimental evidence
has provided perhaps even more compelling data. Dunn et al.32 compared two different doses of aerobic exercise (7 kcal/kg/week, which is a low dose [LD], or 17.5 kcal/
kg/week, which is a high or public health dose [PHD]) and two different frequencies
(3 or 5 days/week) in individuals with mild to moderate depression. An exercise
placebo group performed 3 days/week of flexibility training for 15–20 minutes per
session. After 12 weeks of training, subjects in the PHD group had significantly
greater reductions in depression than those in the LD or placebo groups. Depression
scores were reduced by 47% in the PHD group, compared to 30% and 29% in the LD
and placebo groups, respectively. The response rate for PHD is at least equivalent to
that seen for other depression treatments, such as pharmacological interventions and
CBT.32 Given that no differences were found for exercise frequency (i.e., 3 days vs.
5 days/week), it appears that total energy expenditure was the critical factor for the
reduction and remission of depressive symptoms. Notably, the adherence rates in this
clinical trial were on par with most pharmaceutical drug trials.33
Although these results were observed for aerobic exercise, there is evidence to
suggest a potential dose–response effect for RT as well. Carek et al.34 have suggested
that early work in this area17 supported an “intensity threshold” for treatment efficacy given the similar antidepressant effects of running and RT. As further ­evidence
for a dose–response relationship for RT intensity, Singh et al.19 conducted a 10 week
randomized controlled trial in 32 subjects aged 60–84 years with depression or
­dysthymia. Subjects were randomized to either a high-intensity (80% 1RM for three
sets of eight repetitions for six exercises) supervised progressive RT program three
times a week or an attention-control group. RT was found to significantly reduce
depression and improve strength in these older adult participants. Further, intensity
Shawn M. Arent and Brandon L. Alderman
165
of training was a significant independent predictor of the improvement in depression
scores. In a follow-up study comparing this dose of exercise to a lower dose, older
adults with clinical depression were randomly assigned to 8 weeks of low-intensity
(20% 1RM for three sets of eight repetitions per exercise) or high-intensity (80%
1RM for three sets of eight repetitions per exercise) progressive RT or a control
condition involving standard care by a general practitioner. High intensity produced
significantly greater improvements in clinical depression compared to low intensity
or standard care by the general practitioner.35 There were no significant differences
between low intensity and standard care. Over 60% of the high-intensity participants
achieved what the authors classified as significant clinical responses (a 50% reduction in therapist-rated depression, compared to 29% of the low-intensity and 21% of
the standard care participants). Additionally, 95%–100% compliance was achieved
in both RT groups. Strength gains were directly related to the magnitude of reductions in depression, which is notable because these results were achieved using only
six total RT exercises per session.
Despite the encouraging findings and potential support for a causal model based on
preliminary dose–response effects, it is important to recognize that implementation
of such protocols in a real-world setting are not without its challenges in a depressed
population. This is particularly true if depression is accompanied by other comorbidities. Individuals with major depression often report feeling a lack of energy to
perform basic and essential daily activities. To facilitate implementation and adherence to an RT program, lifestyle interventions are thus likely to be necessary.28 This
could mean incorporating such things as goal setting, self-monitoring, and social
support,36 as well as providing appropriate instruction for RT technique and program
design. If appearance concerns are also present, perhaps in conjunction with obesity,
it may be difficult to get the individuals to join a gym or fitness facility. In this case,
it would be important to design and monitor in-home RT programs. Sparrow et al.37
successfully implemented a home-based RT program in older adults using a telecommunications system (telephone-linked computer-based long-term interactive fitness
trainer). Improvements in strength, balance, and depression were seen with this intervention, suggesting that it may have broader application in this population. It will
also be important to adequately educate physicians and psychologists on the benefits
of RT as well as proper programmatic design variables to facilitate the most effective
delivery of treatment. Special care and programmatic adaptations would need to be
taken with depressed individuals who also suffer from functional limitations.
RESISTANCE TRAINING AND ANXIETY
Relative to the literature on exercise and depression, much less research has been
conducted to examine the effects of aerobic or resistance exercise on clinical anxiety
disorders. However, an extensive body of research supports the anxiolytic benefits
of exercise in healthy volunteers10,36 and exercise also results in significant improvements in various transitory psychological states, including feelings of basic pleasure, moods, and positive affects.38,39 Indeed, reductions in state anxiety following
acute aerobic exercise are one of the most commonly reported psychological benefits
within the exercise psychology literature.10,40–42 State anxiety is characterized by
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Effects of Resistance Training on Depression and Anxiety
transient feelings of tension, apprehension, or worry lasting anywhere from moments
to hours in duration. Conversely, trait anxiety refers to a more general predisposition
to respond across many situations with apprehension, worry, and nervousness. Acute
aerobic exercise has been consistently linked with meaningful reductions in state
anxiety,10,16 whereas meta-analytic findings support the beneficial effect of chronic
exercise interventions on trait anxiety.10 These reductions in anxiety following aerobic exercise have been found regardless of how anxiety was operationalized, whether
self-report or neurophysiological measures of anxiety were used, and across studies varying widely in methodological rigor. While the anxiolytic effect of exercise
has received considerably more support using acute bouts of aerobic exercise, more
recent findings for RT have been encouraging.
Many of the earliest studies examining the effects of acute RT on mood and wellbeing focused on changes in state anxiety. Results from these early studies indicated
that acute RT resulted in either little to no change or, in some cases, transient elevations in state anxiety. For instance, Raglin et al.41 examined anxiety responses to
acute bouts of RT and stationary cycling in a sample of intercollegiate athletes. The
RT bouts consisted of three sets of 6–10 repetitions at 70%–80% of individual 1RM
with a 1–2 minute rest interval between sets for six to seven different strength training exercises. On a separate day, stationary cycling was performed for 30 minutes
at 70%–80% of age-predicted maximum heart rate. Their results were interpreted
as an increase in anxiety immediately following RT and a significant postexercise
reduction in anxiety only emerging at 60 minutes following the stationary cycling
condition. However, these two acute bouts of exercise did not represent comparable
intensities of exercise and the RT was likely performed at a much higher intensity,
thus confounding the findings for mode of exercise with intensity-related effects.
Consistent with these findings, Koltyn et al.43 found no change in state anxiety
following a 50 minute bout of RT performed at self-selected intensity in college
students. Garvin et al.44 similarly found no significant changes in state anxiety following an acute bout of RT performed at 70% of 1RM in college-aged males. These
early nonsignificant findings led some researchers to prematurely conclude that
acute RT was not associated with anxiolytic benefits.40 Adding further complexity
to the issue, some studies have even found pronounced anxiogenic effects of RT. For
example, increases in state anxiety have been observed immediately following acute
RT performed with loads > 70% of 1RM.45,46 A number of studies, however, have
observed improvements in state anxiety and other relevant psychological states following acute RT.45–48 Many of these studies have indicated that factors such as the
type of RT routine performed, training load, and intensity may influence the psychological responses accompanying acute RT. These important programmatic variables
and subject characteristics might help to explain the mixed findings inherent in the
early work in this area of investigation.
Resistance Training and Anxiety: Effects of Training Load
Kraemer and Ratamess14 stated that “altering the training load can significantly
affect the acute metabolic, hormonal, neural, and cardiovascular responses to training.” Consistent with this notion, the mixed findings in the literature of acute RT
Shawn M. Arent and Brandon L. Alderman
167
and anxiety could be explained by the use and manipulation of RT intensity. For
instance, O’Connor et al.49 examined changes in state anxiety following bouts of RT
performed at 40%, 60%, and 80% of 10 repetition maximum (10RM). They found
that RT for 30 minutes at 60% of 10RM (across six exercises), but not 40% or 80%
10RM, resulted in reductions in state anxiety at 90 and 120 minutes following exercise cessation. Focht and Koltyn48 examined the effects of acute bouts of RT characterized by different loads and rest intervals, with participants completing either
12–20 repetitions/set at 50% of their 1RM incorporating a 45–75 second rest interval
between sets or 4–8 repetitions at 80% of 1RM with a 2–2.5 minute rest interval.
Significant reductions in state anxiety only emerged following the 50% 1RM condition. However, transient postexercise increases in fatigue were also observed following this dose of exercise. The higher repetition range and shorter rest intervals,
which characterized the 50% 1RM condition, may have contributed to the transitory
postexercise increase in fatigue. Bibeau et al.50 conducted a similar study examining
resistance exercise of varying intensities and rest intervals. Participants (N = 104,
Mage = 20.5 years) from a university weight training class were randomly assigned
to one of five treatment conditions in which load (50%–55% 1RM vs. 80%–85%
1RM) and rest intervals (30 vs. 90 seconds) were manipulated. All load/rest combinations resulted in increased state anxiety immediately post exercise, although this
was most pronounced in the high-load short-rest condition (i.e., the highest intensity).
All conditions resulted in significant reductions in state anxiety at 20 and 40 minutes
post exercise. The authors did acknowledge that they might not have adequately
implemented a high-intensity RT protocol, which may explain the pattern of anxiety
and affective responses. One notable limitation of this study was the use of only four
exercises (chest press, seated row, leg press, and hamstring curl), which is inconsistent with current recommendations on proper RT program design.
Focht et al.51 compared a traditional multiple-set RT condition to a circuit RT
­condition. The circuit RT condition consisted of performing one set of 10–20 repetitions at 50% of 1RM for 12 different exercises with a 30–45 second interval between
exercises, whereas the traditional multiple-set routine consisted of three sets of
6–10 repetitions at 75% of 1RM for four different exercises with 1–2 m
­ inutes of
rest between sets. The acute session of circuit RT was shown to significantly reduce
state anxiety at 120 and 180 minutes post exercise. On the other hand, the traditional
multiple-set routine yielded no significant changes in state anxiety, but did result in
immediate improvements in body awareness and systolic blood pressure. Ratings of
perceived exertion were also found to be significantly higher during the traditional
multiple-set routine relative to the circuit training exercise. It should be noted that in
several of the aforementioned studies,46,48,49 some of the postexercise psychological
assessments were obtained after individuals were permitted to leave the laboratory
setting and resume normal daily activities. Although perhaps increasing external
validity, factors other than RT may have contributed to the observed psychological
responses and this possibility should be considered when interpreting the findings
of such investigations.16 For instance, Arent et al.52 found that allowing research subjects to leave the testing environment following the completion of an RT session
performed at 50% of the participants’ 1RM produced different patterns of affective
responses relative to those required to stay in the environment for up to 120 minutes
168
Effects of Resistance Training on Depression and Anxiety
post exercise, although both groups demonstrated favorable affective responses
within 60 minutes post exercise.
Transient increases in state anxiety have been found immediately following
20 minutes of acute RT performed at 75%–85% of 1RM.45 However, 20 minutes of
RT at 40%–50% of 1RM resulted in a significant reduction in state anxiety that was
observed within 20 minutes post exercise. Unfortunately, a notable methodological problem in this study limits the interpretability of these findings. The investigators used a time limit to control the RT protocol, likely resulting in a different
number of exercises and total sets for each condition. Without adequate control and
manipulation of volume, attempting to make conclusions regarding load or intensity
(as defined by percentage 1RM) is difficult at best. Based on the extant literature,
it is apparent that differences in methodology and inadequate assignment of program design variables have been a hallmark of this area and have limited the ability to make direct comparisons across studies. It is also important to acknowledge
that several acute RT studies incorporated programmatic characteristics that likely
resulted in participants having to complete at least some sets to the point of momentary muscular failure.41,44,45,48 This methodological detail could clearly impact how
individuals respond to acute RT participation. Overall, current findings suggest that
load assignment is an important programmatic factor that influences state anxiety
and psychological responses to acute resistance exercise. Moreover, this factor may
be even more important if the concept of “momentary failure” is taken into account
as an indicator of overall intensity.47
Prior investigations in the acute RT and anxiety literature have been characterized by marked differences in load determination and assignment, total volume,
repetition ranges, and rest intervals between sets. As Arent et al.47 have noted,
the inconsistency in prescription and lack of control over volume load evident in the
literature precludes the ability to draw firm conclusions regarding dose–response
effects of acute RT and psychological responses, including anxiety. In an attempt
to directly examine the role of intensity while controlling for volume, Arent et al.47
examined state anxiety and affective responses to acute RT performed at 40%, 70%,
and 100% of predetermined 10RM in a sample of 31 college-aged men and women.
State anxiety; positive and negative affect; and feelings of energy, calmness, tiredness, and tension were assessed prior to and several times for 60 m
­ inutes following
each acute RT session. Results revealed that the moderate-intensity bout (70% of
10RM) resulted in the greatest improvements in state anxiety, positive and negative
affect, energy, and calmness. These responses emerged immediately following the
70% of 10RM condition and persisted for 1 hour post exercise. Additionally, the
high-intensity condition (100% of 10RM) was accompanied by unfavorable psychological responses including transient increases in state anxiety, negative affect,
and tension. These findings demonstrate that, when properly defining intensity and
controlling for RT volume, acute moderate-intensity RT results in more favorable
psychological responses compared to either a low or a high dose of RT (based on
intensity). Furthermore, these intensity considerations are consistent with the recent
American College of Sports Medicine53 definitions of RT intensity, which also
focus on ratings of perceived exertion. This study represents an ideal dose–response
Shawn M. Arent and Brandon L. Alderman
169
investigation of psychological responses to acute RT and should be used to guide
the design of future research studies aimed at examining the role of intensity in the
acute RT–anxiety relationship.
In comparison to the literature on acute resistance exercise and anxiety, very little
research has been conducted to date on the potential anxiolytic effects of chronic
exercise, particularly in clinically anxious individuals. A recent meta-analytic
review of randomized clinical trials examining the efficacy of exercise interventions
on anxiety revealed that exercise training resulted in significant reductions in anxiety scores among patients with a chronic illness.54 Exercise training programs lasting no more than 12 weeks and those with durations of at least 30 minutes resulted
in the largest effects. To date, the effects of chronic RT on outcome measures of
anxiety have received surprisingly little research. However, several randomized controlled trials have included RT as a modality of exercise in studies of healthy adults,55
elderly,56 and among patient populations.57 These studies have provided preliminary
support for RT effects on anxiety symptoms and may help to guide future investigations aimed at clarifying the dose–response and mechanistic effects of the resistance
exercise and anxiety relationship.
In one of the few studies conducted to date on chronic exercise and anxiety,
Jazaieri et al.57 conducted a randomized controlled trial of mindfulness-based stress
reduction (MBSR) versus aerobic exercise among adults with social anxiety disorder.
A standard MBSR program was used comprising 8-weekly 2.5 hour group classes, a
1-day meditation retreat, and daily home practice. For the exercise condition, participants were provided with 2 month gym memberships and were required to complete
at least two individual bouts of aerobic exercise at moderate intensity and one group
aerobic exercise session per week during the 8-week intervention. Both MBSR and
exercise were found to be associated with significant reductions in social anxiety
and depression and increases in subjective well-being immediately post intervention
and at 3 months post intervention relative to an untreated control group. It is notable
that these effects for exercise emerged since intensity of exercise was not monitored
and participants received no direct instruction on how to properly use the gym equipment, two factors that could influence psychological outcomes to exercise.
In the previous randomized controlled trials investigating the effects of RT on
anxiety, resistance exercise resulted in small but statistically significant reductions in
anxiety, although the effect sizes have generally been larger for studies using healthy
adult volunteers. Furthermore, similarly to the acute RT and anxiety literature,
the improvement in anxiety symptoms has been shown to be best after moderate-­
intensity RT (defined as 50–60% of 1RM) compared with a higher intensity training
(~80% of 1RM).56,58 The evidence to date supports the conclusion that chronic RT
also reduces symptoms of anxiety among healthy adults, although teasing apart the
effects of exercise on state versus trait forms of anxiety awaits further investigation.
Future research studies need to investigate the effects of RT on patient samples suffering from anxiety, determine which specific forms of anxiety (e.g., generalized
anxiety disorder, specific phobias, social anxiety disorder, etc.) benefit most from
RT programs, and compare the efficacy of RT as an alternative or adjunct to other
established psychotherapeutic interventions for anxiety disorders.
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Effects of Resistance Training on Depression and Anxiety
POTENTIAL MECHANISMS
Various biological and psychological mechanisms have been advanced as potential explanations for the antidepressant and anxiolytic effects of exercise. As with
issues related to dose–response models, it is imperative that plausible mechanisms
be identified to establish causal relationships.16 Whereas some of the hypotheses or
concepts that have been studied to date have shown promise as viable mechanisms,
others have not. For example, the notion of exercise primarily serving as a distraction, social support, or placebo has generally been discounted.16,35 On the other hand,
there is potential utility to the self-esteem and mastery effects that exercise may
provide,29 though most of the support for the effects on depression has been correlational in nature. Direct experimental evidence is largely lacking, and well-designed
studies should examine this possibility.
Several biological mechanisms have emerged that appear to hold promise in this
area. Depression and stress-related disorders have been shown to produce maladaptive structural changes in the hippocampus, amygdala, frontal cortex, and other brain
areas that are interconnected and critical to depression and anxiety.34,59 Neuronal
degradation and decreases in hippocampal volume are particularly notable in these
stress-related disorders.60,61 The restoration of these brain regions through plasticity
and neurogenesis appears to be one mechanism through which antidepressants exert
their effects.62 A similar effect has been seen with exercise, suggesting that it may
share common biological pathways with pharmaceutical interventions.61 At least part
of this response may be due to the upregulation of brain-derived neurotrophic factor
(BDNF), which has been shown to support glutamatergic neurons and promote antidepressive and anxiolytic actions.59 BDNF has been shown to increase with certain
antidepressants as well as exercise at specific intensities.61,63 Other neurotransmitters
that have been implicated in mood-altering effects of exercise are serotonin (5-HT)
and norepinephrine (NE). Depressed patients typically exhibit decreased secretion
of serotonin as well as NE and its precursor, dopamine, in the brain.64,65 Certain antidepressants (i.e., SSRIs, MAOIs, and tricyclics) function by reregulating serotonin
and/or NE levels through reduced degradation or prevention of re-uptake by neurons.
Research has found that exercise can result in serotonergic, monoaminergic, and
noradrenergic effects similar to those seen with antidepressants.66
Exercise has also been associated with an increase in endogenous opioids (most
notably β-endorphin and β-lipotropin) and endocannabinoids, both of which have
demonstrated analgesic and anxiolytic properties.67,68 Peripheral β-endorphin has
been found to be elevated with long-duration aerobic exercise69 and high-­intensity
RT.70 However, it is uncertain at this time whether or not peripherally derived
endorphins exert central effects on the brain because of the impermeability of the
blood–brain barrier to these substances. Nonetheless, the possibilities are intriguing,
although it is unlikely that either endorphins or endocannabinoids play a solitary role
in either antidepressive or anxiolytic responses to exercise.16 Instead, they may be
contributors to the overall neurophysiological response.
Although the aforementioned potential mechanisms have been proposed to explain
the psychological benefits of exercise, empirical support for these concepts generally
remains sparse, particularly as it pertains to RT. One mechanism that has received
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171
increasing support in recent research, however, is the ­hypothalamic-pituitary-adrenal
(HPA) axis hypothesis. Hypercortisolism due to a dysregulation of the HPA axis is
a hallmark of depression71 as well as anxiety and other stress-related disorders.72
The end result is often an inappropriate systemic response to stress, which only
serves to further exacerbate existing symptomology.73 It has been established that
rectification of control of the HPA axis is instrumental in the alleviation of both
depression and anxiety and that failure to do so greatly increases the chance of
relapse.71 In fact, HPA reregulation appears to be how the more effective antidepressants exert their primary effect. Ironically, chronically elevated cortisol has
been found to increase the risk of overweight and obesity,74 which, as noted previously, might serve to exacerbate the effects of depression. Optimal, controlled
stimulation of stress response and adaptations of the HPA axis with training are
likely means through which exercise produces improvements in anxiety and depression.16,75 Consistent with this hypothesis, Arent et al.47 demonstrated that autonomic
and HPA axis responses are important mechanisms underlying affective responses
to acute RT. Their findings may also explain why anxiogenic responses have been
seen with high-intensity RT,45 due to increases in corticotropin-releasing hormone
(CRH) and cortisol. Future research needs to systematically examine the viability of
these mechanisms and begin to adequately apply RT as an exercise modality given
its clearly promising utility for reducing depression and anxiety.
CONCLUSIONS
After an extensive review of the RT literature related to depression and anxiety, it
is clear that much more research is needed. The current body of research generally
lacks a progressive coherency that would enable a systematic examination of these
topics, with conflicting results likely attributable to the variability in methodologies.76 The general approach to examining the impact of RT on mental health needs
to be more logical. For example, if the effects of training duration are being studied,
only the duration of an existing intervention should be varied while holding other
variables constant. Changing the intensity, population, load, frequency, and outcome
measures along with the duration is not conducive to advancing the knowledge base
in this area or establishing causal models. It is worth noting that the complexity of
RT prescription far exceeds that of aerobic exercise. There are significantly more
variables to consider when structuring an appropriate RT bout or program. These
variables include, but are not limited to, repetitions, sets, load, rest intervals, exercise
order, eccentric versus concentric emphasis, speed of movement, body part training
split, and frequency. It is exactly due to this complexity, though, that there must be
a more systematic approach to the examination of the mental health effects of RT.
Despite the limitations of the available literature, there is encouraging evidence
for the antidepressive and anxiolytic effects of RT. Regardless of the shortcomings, it
is apparent that this modality of exercise is a useful tool for improving both physical
and psychological health. Further research in this area and on the unique benefits of
RT is clearly warranted. However, there must be a concerted effort to systematically
advance the RT studies being conducted in these areas. The approach to this point
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Effects of Resistance Training on Depression and Anxiety
has been largely atheoretical and disjointed.76 It is imperative that we examine the
mechanisms underlying the effects of RT on stress-related disorders if we hope to
move toward causation. With further work on dose–response and plausible biological
mechanisms, we may finally be able to formulate recommendations that can guide
public policy.
REFERENCES
1. Kessler RC, Berglund P, Demler O et al. The epidemiology of major depressive disorder: results from the National Comorbidity Survey Replication (NCS-R). J Am Med
Assoc 2003;289:3095–105.
2. Lopez AD, Murray CC. The global burden of disease, 1990–2020. Nat Med
1998;4:1241–3.
3. Egede LE. Major depression in individuals with chronic medical disorders: prevalence,
correlates and association with health resource utilization, lost productivity and functional disability. Gen Hosp Psychiatry 2007;29:409–16.
4. Kessler RC, Chiu WT, Demler O, Merikangas KR, Walters EE. Prevalence, severity,
and comorbidity of 12-month DSM-IV disorders in the National Comorbidity Survey
Replication. Arch Gen Psychiatry 2005;62:617–27.
5. Berlim MT, Fleck MP, Turecki G. Current trends in the assessment and somatic treatment of resistant/refractory major depression: an overview. Ann Med 2008;40:149–59.
6. Abu-Omar K, Rütten A, Lehtinen V. Mental health and physical activity in the European
Union. Soz Praventivmed 2004;49:301–9.
7. Dunn AL, Trivedi MH, O’Neal HA. Physical activity dose-response effects on outcomes
of depression and anxiety. Med Sci Sports Exerc 2001;33:S587–97; discussion 609–10.
8. North TC, McCullagh P, Tran ZV. Effect of exercise on depression. Exerc Sport Sci Rev
1990;18:379–415.
9. Craft LL, Landers DM. The effect of exercise on clinical depression and depression
resulting from mental illness: a meta-analysis. J Sport Exercise Psy 1998;20:339–57.
10. Petruzzello SJ, Landers DM, Hatfield BD, Kubitz KA, Salazar W. A meta-analysis on
the anxiety-reducing effects of acute and chronic exercise. Outcomes and mechanisms.
Sports Med 1991;11:143–82.
11. Rethorst CD, Wipfli BM, Landers DM. The antidepressive effects of exercise: a metaanalysis of randomized trials. Sports Med 2009;39:491–511.
12. Arent SM, Landers DM, Etnier JL. The effects of exercise on mood in older adults:
a meta-analytic review. J Aging Phys Activ 2000;8:407–30.
13. Feigenbaum MS. Rationale and review of current guidelines. In Graves JE, Franklin
BA Resistance training for health and rehabilitation. Champaign, IL: Human Kinetics
Publishers; 2001:13–32.
14. Kraemer WJ, Ratamess NA. Fundamentals of resistance training: progression and exercise prescription. Med Sci Sports Exerc 2004;36:674–88.
15. Graves JE, Franklin BA. Resistance Training for Health and Rehabilitation. Champaign,
IL: Human Kinetics Publishers, 2001.
16. Landers DM, Arent SM. Physical activity and mental health. In Tenenbaum G, Eklund
R. Handbook of sport psychology. Hoboken, NJ: Wiley; 2007:469–91.
17. Doyne EJ, Ossip-Klein DJ, Bowman ED, Osborn KM, McDougall-Wilson IB, Neimeyer
RA. Running versus weight lifting in the treatment of depression. J Consult Clin Psychol
1987;55:748–54.
18. Martinsen EW, Hoffart A, Solberg O. Comparing aerobic with nonaerobic forms of
exercise in the treatment of clinical depression: a randomized trial. Compr Psychiatry
1989;30:324–31.
Shawn M. Arent and Brandon L. Alderman
173
19. Singh NA, Clements KM, Fiatarone MA. A randomized controlled trial of progressive
resistance training in depressed elders. J Gerontol A-Biol 1997;52:M27.
20. McGale N, McArdle S, Gaffney P. Exploring the effectiveness of an integrated exercise/
CBT intervention for young men’s mental health. Brit J Health Psych 2011;16:457–71.
21. Beniamini Y, Rubenstein JJ, Zaichkowsky LD, Crim MC. Effects of high-intensity
strength training on quality-of-life parameters in cardiac rehabilitation patients.
Am J Cardiol 1997;80:841–6.
22. Kohut ML, McCann DA, Russell DW et al. Aerobic exercise, but not flexibility/resistance exercise, reduces serum IL-18, CRP, and IL-6 independent of beta-blockers, BMI,
and psychosocial factors in older adults. Brain Behav Immun 2006;20:201–9.
23. Braith RW, Stewart KJ. Resistance exercise training: its role in the prevention of cardiovascular disease. Circulation 2006;113:2642–50.
24. Fabbri A, Giannini D, Aversa A et al. Body-fat distribution and responsiveness of the
pituitary-adrenal axis to corticotropin-releasing-hormone stimulation in sedentary and
exercising women. J Endocrinol Invest 1999;22:377–85.
25. Nelson ME, Fiatarone MA, Morganti CM, Trice I, Greenberg RA, Evans WJ. Effects
of high-intensity strength training on multiple risk factors for osteoporotic fractures.
A randomized controlled trial. J Am Med Assoc 1994;272:1909–14.
26. Cornelissen VA, Fagard RH. Effect of resistance training on resting blood pressure:
a meta-analysis of randomized controlled trials. J Hypertens 2005;23:251–9.
27. Honkola A, Forsén T, Eriksson J. Resistance training improves the metabolic profile in
individuals with type 2 diabetes. Acta Diabetol 1997;34:245–8.
28. Markowitz S, Friedman MA, Arent SM. Understanding the relation between obesity and
depression: causal mechanisms and implications for treatment. Clin Pscychol: Sci Pr
2008;15:1–20.
29. Velez A, Golem DL, Arent SM. The impact of a 12-week resistance training program on
strength, body composition, and self-concept of Hispanic adolescents. J Strength Cond
Res 2010;24:1065–73.
30. Blumenthal JA, Babyak MA, Moore KA et al. Effects of exercise training on older
patients with major depression. Arch Intern Med 1999;159:2349–56.
31. Babyak M, Blumenthal JA, Herman S et al. Exercise treatment for major depression:
maintenance of therapeutic benefit at 10 months. Psychosom Med 2000;62:633–8.
32. Dunn AL, Trivedi MH, Kampert JB, Clark CG, Chambliss HO. Exercise treatment for
depression: efficacy and dose response. Am J Prev Med 2005;28:1–8.
33. Cantrell CR, Eaddy MT, Shah MB, Regan TS, Sokol MC. Methods for evaluating
patient adherence to antidepressant therapy: a real-world comparison of adherence and
economic outcomes. Med Care 2006;44:300–3.
34. Carek PJ, Laibstain SE, Carek SM. Exercise for the treatment of depression and anxiety.
Int J Psychiatry Med 2011;41:15–28.
35. Singh NA, Stavrinos TM, Scarbek Y, Galambos G, Liber C, Fiatarone Singh MA.
A ­randomized controlled trial of high versus low intensity weight training versus general
practitioner care for clinical depression in older adults. J Gerontol A Biol Sci Med Sci
2005;60:768–76.
36. Ströhle A. Physical activity, exercise, depression and anxiety disorders. J Neural Transm
2009;116:777–84.
37. Sparrow D, Gottlieb DJ, Demolles D, Fielding RA. Increases in muscle strength and
balance using a resistance training program administered via a telecommunications system in older adults. J Gerontol A Biol Sci Med Sci 2011;66:1251–7.
38. Ekkekakis P, Petruzzello SJ. Acute aerobic exercise and affect: current status, problems
and prospects regarding dose-response. Sports Med 1999;28:337–74.
39. Thayer RE. Calm Energy: How People Regulate Mood with Food and Exercise. New York,
NY: Oxford University Press; 2003.
174
Effects of Resistance Training on Depression and Anxiety
40. Raglin JS. Anxiolytic effects of physical activity. In Morgan WP. Physical Activity and
Mental Health. Washington, DC: Taylor & Francis; 1997:107–26.
41. Raglin JS, Turner PE, Eksten F. State anxiety and blood pressure following 30 min of leg
ergometry or weight training. Med Sci Sports Exerc 1993;25:1044–8.
42. Markowitz SM, Arent SM. The exercise and affect relationship: evidence for the
dual-mode model and a modified opponent process theory. J Sport Exerc Psychol
2010;32:711–30.
43. Koltyn KF, Raglin JS, O’Connor PJ, Morgan WP. Influence of weight training on state
anxiety, body awareness and blood pressure. Int J Sports Med 1995;16:266–9.
44. Garvin AW, Koltyn KF, Morgan WP. Influence of acute physical activity and relaxation on state anxiety and blood lactate in untrained college males. Int J Sports Med
1997;18:470–6.
45. Bartholomew JB, Linder DE. State anxiety following resistance exercise: the role of
gender and exercise intensity. J Behav Med 1998;21:205–19.
46. Focht BC. Pre-exercise anxiety and the anxiolytic responses to acute bouts of selfselected and prescribed intensity resistance exercise. J Sports Med Phys Fitness
2002;42:217–23.
47. Arent SM, Landers DM, Matt KS, Etnier JL. Dose-response and mechanistic issues in
the resistance training and affect relationship. J Sport Exercise Psy 2005;27:92–110.
48. Focht BC, Koltyn KF. Influence of resistance exercise of different intensities on state
anxiety and blood pressure. Med Sci Sports Exerc 1999;31:456–63.
49. O’Connor PJ, Bryant CX, Veltri JP, Gebhardt SM. State anxiety and ambulatory blood
pressure following resistance exercise in females. Med Sci Sports Exerc 1993;25:516–21.
50. Bibeau WS, Moore JB, Mitchell NG, Vargas-Tonsing T, Bartholomew JB. Effects of
acute resistance training of different intensities and rest periods on anxiety and affect.
J Strength Cond Res 2010;24:2184–91.
51. Focht BC, Koltyn KF, Bouchard LJ. State anxiety and blood pressure responses following different resistence exercise sessions. Int J Sport Psychol 2000;31:376–90.
52. Arent SM, Alderman BL, Short EJ, Landers DM. The impact of the testing environment on affective changes following acute resistance exercise. J Appl Sport Psychol
2007;19:364–78.
53. Ratamess NA, Alvar BA, Evetoch TK et al. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Med Sci Sports
Exerc 2009;41:687–708.
54. Herring MP, O’Connor PJ, Dishman RK. The effect of exercise training on anxiety
symptoms among patients: a systematic review. Arch Intern Med 2010;170:321–31.
55. Sjögren T, Nissinen KJ, Järvenpää SK, Ojanen MT, Vanharanta H, Mälkiä EA. Effects
of a physical exercise intervention on subjective physical well-being, psychosocial functioning and general well-being among office workers: a cluster randomized-controlled
cross-over design. Scand J Med Sci Sports 2006;16:381–90.
56. Tsutsumi T, Don BM, Zaichkowsky LD, Takenaka K, Oka K, Ohno T. Comparison of
high and moderate intensity of strength training on mood and anxiety in older adults.
Percept Mot Skills 1998;87:1003–11.
57. Jazaieri H, Goldin PR, Werner K, Ziv M, Gross JJ. A randomized trial of MBSR versus
aerobic exercise for social anxiety disorder. J Clin Psychol 2012.
58. Cassilhas RC, Viana VA, Grassmann V et al. The impact of resistance exercise on the
cognitive function of the elderly. Med Sci Sports Exerc 2007;39:1401–7.
59. Bjørnebekk A, Mathé AA, Brené S. The antidepressant effect of running is associated with increased hippocampal cell proliferation. Int J Neuropsychopharmacol
2005;8:357–68.
60. Bremner JD, Narayan M, Anderson ER, Staib LH, Miller HL, Charney DS. Hippocampal
volume reduction in major depression. Am J Psychiatry 2000;157:115–8.
Shawn M. Arent and Brandon L. Alderman
175
61. Ernst C, Olson AK, Pinel JP, Lam RW, Christie BR. Antidepressant effects of exercise:
evidence for an adult-neurogenesis hypothesis? J Psychiatry Neurosci 2006;31:84–92.
62. Duman RS, Nakagawa S, Malberg J. Regulation of adult neurogenesis by antidepressant
treatment. Neuropsychopharmacol 2001;25:836–44.
63. Russo-Neustadt A, Ha T, Ramirez R, Kesslak JP. Physical activity-antidepressant treatment combination: impact on brain-derived neurotrophic factor and behavior in an
­animal model. Behav Brain Res 2001;120:87–95.
64. Jacobs BL. Serotonin, motor activity and depression-related disorders. Am Sci
1994;82:456–63.
65. Dunn AL, Reigle TG, Youngstedt SD, Armstrong RB, Dishman RK. Brain norepinephrine and metabolites after treadmill training and wheel running in rats. Med Sci Sports
Exerc 1996;28:204–9.
66. Dishman RK, Berthoud HR, Booth FW et al. Neurobiology of exercise. Obesity
2006;14:345–56.
67. Dietrich A, McDaniel WF. Endocannabinoids and exercise. Brit J Sports Med
2004;38:536–41.
68. Dishman RK. Brain monoamines, exercise, and behavioral stress: animal models. Med
Sci Sports Exerc 1997;29:63–74.
69. Hoffman P. The endorphin hypothesis. In Morgan WP. Physical Activity and Mental
Health. Washington, DC: Taylor & Francis; 1997:163–77.
70. Kraemer WJ, Dziados JE, Marchitelli LJ et al. Effects of different heavy-resistance exercise protocols on plasma beta-endorphin concentrations. J Appl Physiol 1993;74:450–9.
71. Holsboer F. The corticosteroid receptor hypothesis of depression. Neuropsychopharmacol
2000;23:477–501.
72. Burrows HL, Nakajima M, Lesh JS et al. Excess corticotropin releasing hormone-­
binding protein in the hypothalamic-pituitary-adrenal axis in transgenic mice. J Clin
Invest 1998;101:1439–47.
73. Modell S, Yassouridis A, Huber J, Holsboer F. Corticosteroid receptor function is
decreased in depressed patients. Neuroendocrinology 1997;65:216–22.
74. Ottosson M, Lönnroth P, Björntorp P, Edén S. Effects of cortisol and growth hormone on
lipolysis in human adipose tissue. J Clin Endocrinol Metab 2000;85:799–803.
75. Wittert GA, Livesey JH, Espiner EA, Donald RA. Adaptation of the hypothalamopituitary adrenal axis to chronic exercise stress in humans. Med Sci Sports Exerc
1996;28:1015–9.
76. Arent SM, Golem DL. Resistance Training and Mental Health. The Psychology of Strength
Training and Conditioning: International Perspectives. Routledge, London; 2012.
12
Progressive Resistance
Training for Individuals
with Chronic Obstructive
Pulmonary Disease
Simone D. O’Shea and Nicholas F. Taylor
CONTENTS
Introduction............................................................................................................. 182
Rationale for Progressive Resistance Training....................................................... 182
Evidence That Progressive Resistance Training Is Beneficial for Individuals
with COPD.............................................................................................................. 182
Summary of Outcomes for Systematic Review Update.......................................... 183
Program Content and Environmental Factors.................................................... 184
Personal Factors................................................................................................. 184
Body Structure and Function............................................................................. 192
Muscle Function (Strength)........................................................................... 192
Body Composition......................................................................................... 192
Respiratory Function, Maximal Exercise Capacity, and Psychological
Function......................................................................................................... 192
Dyspnea......................................................................................................... 193
Activity............................................................................................................... 194
Participation....................................................................................................... 194
Long-Term Outcomes of Progressive Resistance Exercise................................ 194
Synthesis of Evidence for Progressive Resistance Training for Individuals
with COPD.............................................................................................................. 195
Implementing Progressive Resistance Training in the Clinical Setting.................. 197
Who Is Suitable?................................................................................................ 197
What Equipment?............................................................................................... 198
What Exercises?................................................................................................. 198
Special Consideration—Continence..................................................................200
What Setting?..................................................................................................... 201
Monitoring Progress........................................................................................... 201
Adherence to Progressive Resistance Training..................................................202
Conclusions............................................................................................................. 203
References............................................................................................................... 203
177
178
Progressive Resistance Training for Individuals with COPD
INTRODUCTION
Chronic obstructive pulmonary disease (COPD) is characterized by ongoing and predominantly irreversible airflow limitation that is associated with chronic inflammatory responses in the airways. As the disease progresses, chronic inflammation leads
to thickening of airway walls and pulmonary vasculature, as well as destruction of
lung parenchyma.1 Changes in pulmonary structure and function are associated with
common symptoms such as dyspnea (shortness of breath), chronic cough with or
without sputum production, wheeze, fatigue, as well as reduced exercise tolerance.1
COPD is one of the leading causes of mortality and morbidity worldwide and is
associated with significant disease burden. Although statistics on prevalence, mortality, morbidity and burden of this disease vary between countries and different studies,
overall COPD was ranked as the fourth leading cause of death worldwide in 2008.2
RATIONALE FOR PROGRESSIVE RESISTANCE TRAINING
Traditionally seen as a disease primarily of the lungs, it is now widely accepted
that COPD has many systemic or extrapulmonary complications that can contribute
greatly to morbidity and mortality. Specifically, changes in skeletal muscle structure
and function (muscle atrophy and weakness), independent of ventilatory limitations,
have been shown to influence exercise tolerance,3,4 risk of exacerbation/hospitalization,5,6 and prognosis.7–11 Mechanisms purported to contribute to skeletal muscle
changes in COPD include deconditioning due to reduced physical activity levels,
hypoxia, hypercapnia, chronic inflammation, poor nutrition, and steroid-induced
myopathy.3 In addition, skeletal muscle changes may be further complicated by agerelated reductions in muscle mass and strength.12–14
Reductions in muscle mass and strength, especially in the muscles of ambulation
(compared with matched healthy controls), are commonly seen in people with COPD
(particularly in those with moderate to severe disease). Reductions in strength of
20%–30% have been reported compared with healthy subjects,15–17 and the degree of
muscle weakness correlates with the severity of disease.15
As changes in muscle structure and function represent a potentially modifiable
aspect of the disease process,18 muscle conditioning programs as part of pulmonary
rehabilitation have gained greater recognition in the past 10–15 years. In particular,
the relationship between muscle strength and morbidity/prognosis in COPD provides
a strong rationale for the inclusion of progressive resistance training in the rehabilitation of this population.
EVIDENCE THAT PROGRESSIVE RESISTANCE TRAINING
IS BENEFICIAL FOR INDIVIDUALS WITH COPD
Systematic reviews and meta-analytic methods collate empirical evidence to answer a
clinical question. The review method uses explicit, systematic methods to help minimize bias in the findings.19 Systematic reviews can therefore help clinicians prescribing
progressive resistance training programs for individuals with COPD by providing them
with the best available synthesis of information on effectiveness, safety and feasibility.
Simone D. O’Shea and Nicholas F. Taylor
179
Our systematic review of the role of progressive resistance training for individuals
with COPD included 18 trials and concluded that short-term resistance training programs could lead to moderate increases in the ability to generate muscle force. There
was also some preliminary evidence that increased muscle strength could improve
the ability to complete daily activities such as sitting, standing, and stair walking.20
However, the search strategy for our review only included trials published up until
April 2008 and included a number of studies that were not randomized controlled
trials. In this chapter, we present the results of an updated systematic review, limited
to randomized controlled trials, with the aim of providing up-to-date high-level evidence for progressive resistance training for individuals with COPD.
We conducted electronic database searches to update the search of the previous
review until October 26, 2011. Search terms combined synonyms for the population,
COPD, with synonyms for the intervention of progressive resistance training.
Trials were only included if the intervention conformed to American College of
Sports Medicine’s progressive resistance training guidelines21 and if they allowed
for the independent effects of participation in progressive resistance training to be
evaluated. Additionally, only trials employing a randomized controlled trial design
were included to provide the highest level of evidence with the least risk of bias.
Risk of bias in individual trials was examined by two independent researchers
using the physiotherapy evidence database (PEDro) scale, which contains ­assessment
items relating to major threats to bias including blinding, concealment of treatment
allocation, and intention-to-treat analysis.22
During the review, outcomes of progressive resistance training were described
within the framework of the International Classification of Functioning, Disability
and Health (ICF), which was developed by the World Health Organization to measure how people function within a particular health condition.23 Three broad categories are defined in the ICF including body structure and function (physical, cognitive,
psychological), activity (tasks or actions), and participation (broader function in life
situations). It is recognized within the ICF model that all three levels of functioning
interact and can be influenced by contextual factors from within the person or the
environment.
To compare the results between trials, standardized mean differences (effect sizes)
and 95% confidence intervals (CI) were calculated using web-based ­meta-analysis
software.24 Where features of study design were similar for an o­ utcome measure, and
the degree of heterogeneity between the obtained effect sizes were not statistically
significant (Q statistic, p > .1), overall effects (δ) were calculated using the random
effects model for meta-analysis.25
SUMMARY OF OUTCOMES FOR SYSTEMATIC REVIEW UPDATE
After completing all electronic database searches, a further 317 potential trials
were identified for the updated review. Application of the inclusion criteria to titles,
abstracts, and full text led to the identification of 5 additional randomized controlled
trials,26–30 which when added to the randomized controlled trials included in our
2009 review resulted in 20 trials for final review. A median PEDro score of 5 out of
10 (range: 3–8) was obtained for the 20 randomized controlled trials.
180
Progressive Resistance Training for Individuals with COPD
Features of trial design varied between the investigations included in the review
(Table 12.1). Ten trials compared progressive resistance training with a no-­intervention
control group, four trials compared progressive resistance training with another intervention such as endurance training or rehabilitation, and the final six trials combined
progressive resistance training with another intervention such as endurance training
and compared it with another intervention such as endurance training alone. Any
between-group differences observed in this final trial design could be attributed to
the unique contribution of the intervention of progressive resistance training.
Program Content and Environmental Factors
The key features of progressive resistance training programs are summarized in
Table 12.1. The majority of progressive resistance training programs were conducted
in outpatient clinics (14 trials). Resistance training was typically conducted using
machine weights (15 trials), as is usually found in a gymnasium. Four trials used either
pulleys alone to provide resistance29 or used a combination of gymnasium equipment.30,37,40 A single trial46 provided resistance with elasticized bands, equipment that
could be used in the completion of exercises at home as well as in the outpatient clinic.
Training duration was typically 12 weeks (range: 6–26 weeks), and exercises were
performed two or three times per week in all trials. A median of five resisted exercises
(range: 1–8) were performed during each exercise session, with a range of exercises
for the lower limbs, upper limbs, and trunk described. Each training session generally
comprised of 3 sets (range: 1–4 sets for each session) of 8–12 repetitions (range: 5–20
for each set) of each exercise, at intensities ranging from 50%–90% of 1 repetition
maximum (1RM). Alternatively, training intensity required participants to complete
between 8 and 20 repetitions of each exercise (8 to 20RM) until muscular fatigue.
Personal Factors
The characteristics of participants included in trials of progressive resistance training
for individuals with COPD are summarized in Table 12.2. From the data provided, a
total of 721 participants have been enrolled in randomized controlled trials of resistance training for COPD. The weighted mean age of participants completing the
interventions was 65 years (range: 49–72 years), and men represented 64% of the total
review population. Participants had a weighted mean body mass index (BMI) of 25.6.
Participants with significant comorbidities, such as cardiovascular disease, pulmonary
hypertension, cancer, and neurological or orthopedic problems, limiting exercise performance were often excluded from participation in trials of progressive resistance training.
Severity of COPD was generally described using spirometric measures, with
18 of the 20 trials reporting the percentage predicted of the forced expiratory volume in 1 second (FEV1%pred). The weighted mean FEV1%pred across studies was
45.2%. A further 14 trials described the ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) and reported a weighted mean of 44.2%.
Therefore, ­participants in trials of progressive resistance training, on average, demonstrated severe airflow limitation, classified as GOLD 3 severe COPD according to
the Global Initiative for Chronic Obstructive Lung Disease guidelines.1
4 Groups
Plbo
test
Plbo/RT
test/RT
As per
Casaburi
et al.31
2 Groups
control
RT
2 Groups
control
RT
Casaburi
et al.31
Chavoshan
et al.27
Clark et al.32
Hoff et al.33
Trial Design
References
Lab
O/P clinic
O/P clinic
O/P clinic
Setting
Alone
Group
Not stated
Not stated
Program
Frequency Duration
Machine
Machine
Machine
Machine
3/week for 8 weeks
2/week for
12 weeks
3/week for
10 weeks
3/week for
10 weeks
Progressive Resistance Training vs. Control
Type of Weights
4 sets
5 reps
4 weeks
3 sets
12 reps
6 weeks
4 sets
8–10 reps
4 weeks
3 sets
12 reps
6 weeks
4 sets
8–10 reps
3 sets
10 reps
Sets Reps
Progressive Resistance Exercise (RT)
85%–90%
1RM
↑ load 2.5
kg > 5RM
70% 1RM
60% 1RM
↑ load
80% 1RM
↑ load
60% 1RM
↑ load
80% 1RM
↑ load
Load
(Continued)
Usual activities. Moderate
exercise recommend by
physician
Usual activities
No training
No training
Comparison Intervention
TABLE 12.1
Features of Progressive Resistance Training and Comparison Interventions of Trials Included in the 2011 Systematic
Review Update
Simone D. O’Shea and Nicholas F. Taylor
181
Ike et al.29
2 Groups
control
RT
2 Groups
control
RT
O’Shea
et al.46
Simpson
et al.37
Lewis et al.35
Kongsgaard
et al.34
Trial Design
2 Groups
control
RT
2 Groups
RT
control
As per
Casaburi
et al.31
References
Setting
O/P clinic
O/P clinic
& home
O/P clinic
Not stated
Not stated
Program
Not stated
Group &
alone
Not stated
Not stated
Not stated
Free/machine
Thera-Band®
Machine
Machine
Pulley
Type of Weights
3/week for
8 weeks
3/week for
12 weeks
3/week for
10 weeks
2/week for
12 weeks
3/week for 6 weeks
Frequency Duration
3 sets
10 reps
4 weeks
3 sets
12 reps
6 weeks
4 sets
8–10 reps
3 sets
8–12 reps
4 sets
8 reps
3 sets
8 reps
Sets Reps
Progressive Resistance Exercise (RT)
8–12RM
↑ load
(band
color) at
12RM for
2 sessions
50%–85%
1RM
60% 1RM
↑ load
80% 1RM
↑ load
80% 1RM
80%1RM
Load
Not stated
Usual exercise. Monitored
every 6/52
No training
Bronchial hygiene,
respiratory function
re-education
Unsupervised breathing
ex (PEP)
Comparison Intervention
TABLE 12.1 (Continued )
Features of Progressive Resistance Training and Comparison Interventions of Trials Included in the 2011 Systematic
Review Update
182
Progressive Resistance Training for Individuals with COPD
2 Groups
control
RT
3 Groups
LGT
RT
LGT/RT
2 groups
Rehab
Rehab/UL
RT
4 groups
Control
RT
AT
AT/RT
Wright
et al.38
Dourado
et al.28
JanaudisFerreira
et al.30
Ortega et al.
200239
Group
Machine
2/week for
2 weeks
3/week for 10 weeks
2 weeks
2–3 sets
12 reps
5 weeks
2–4 sets
10 reps
5 weeks
2–4 sets
8–10 reps
Submax
Max
Max
O/P clinic
I/P or O/P
clinic
Not stated
Group
Rehab –
group
UL –
alone
Group
Machine
Free weights/
Machine
Machine
3/week for
12 weeks
3/week for 6 weeks
3/week for 12 weeks
2–4 sets
6–8 reps
2 sets
12 reps
3 sets
12 reps
70–85%
1RM
10 – 12RM
50%–80%
1RM
Progressive Resistance Training vs. Other Intervention (i.e., Rehab or Aerobic Training)
O/P clinic
(Continued)
Self-paced walk
30 minutes
Low-intensity UL/LL ex
using free weights/mat
work/parallel bars
20–25 reps
3 METs
AT (walk/treadmill)
60%–80% 6MWT speed
LL ex 15–20RM
Sham UL flexibility ex
Breathing ex
Education
Cycle:
40 min
70% Wpk
Not stated
Simone D. O’Shea and Nicholas F. Taylor
183
Trial Design
2 groups
RT
AT
2 groups
Rehab
Rehab/RT
2 groups
AT/RT
RT
References
Spruit et al.40
Alexander
et al.26
Arnardottir
et al.41
Setting
Program
Not stated
Machine/pulley
Type of Weights
Frequency Duration
3/week for
12 weeks
Sets Reps
3 sets
8 reps
Load
70% 1RM
↑ 5% 1RM
weekly
O/P clinic
Group
Machine
AT 1/week
RT 2/week
8 weeks
1 set
15–20
reps
15–20RM
↑ load at
20RM
Concurrent Progressive Resistance & Aerobic Training vs. other Intervention
O/P clinic
Group
Machine
2/week for 8 weeks
1 set
50%1RM
Rehab ex before or
12 reps
RPE 11–13
after RT
↑ load 3–5
lb after 2
sessions
12RM
O/P clinic
Progressive Resistance Exercise (RT)
AT (UL ergo, treadmill,
cycle, stepper)
20–40 min
3METs, SOB 1–5, RPE
11–13, ↑HR 20–40 bpm
7 UL ex 1 × 8 –15 reps
1–10 lb dumbbell
Cycle (IT)
6 min 20%–30% Wpk
10 × 3 min (30%–50% to
80% Wpk)
Callisthenics:
UL ex, Cx sp/Tx sp mob
PLB
Cycling: 30% Wpk 10min
75% Wpk 25 min
Walk: 60% 6MWT speed
10 – 25 min
UL ergo: BORG 5–6
4–9 min
Stairs (both):
3–6 min
Comparison Intervention
TABLE 12.1 (Continued )
Features of Progressive Resistance Training and Comparison Interventions of Trials Included in the 2011 Systematic
Review Update
184
Progressive Resistance Training for Individuals with COPD
2 groups
AT
AT/RT
2 groups
AT
AT/RT
2 groups
rehab
control
Mador et al.43
Phillips
et al.44
Troosters
et al.45
O/P clinic
O/P clinic
O/P clinic
O/P clinic
Group
Group
Group
Group
Machine
Machine
Machine
Machine
3/week for
3 months
2/week for
3 months
2/week for
8 weeks
3/week for
8 weeks
(24 sessions)
3/week for
12 weeks
3 sets
10 reps
1 set
10 reps
1 set
10 reps
↑ to 3 sets
10 reps
2–3 sets
8–10 reps
60%
1RM
50% 1RM
or 10RM
↑ load
5–10% >
10RM
60%1RM
↑ load (5lb)
at 3 × 10
reps
60%–80%
1RM
Cycling
80%Wpk
For 30 min
DBE & relaxation for
45 min
Cycle: 50% Wmax 20 min
SOB < 5, ↑ W10%
Treadmill: 15 min,
SOB < 5, ↑ speed/
gradient
UL, cycle, stepper +
treadmill
20–40 min
3 METs, RPE <13,
SOB < 3, SpO2 > 90%
Low-intensity resistance
1 × 16–18RM
Not stated
reps, repetitions; AT, aerobic training; O/P, outpatient clinic; Wpk, work rate peak; ex, exercise; UL, upper limb; Cx sp, cervical spine; Tx sp, thoracic spine; PLB, pursed
lip breathing; DBE, deep breathing exercise; Plbo, placebo injections; Test, testosterone injections; LGT, low-intensity general training; IT, interval training; RPE, rate
of perceived exertion; W, watt; HRR, heart rate reserve; METs, metabolic equivalents.
Note: Casaburi et al. (2004), data for groups receiving testosterone not included; Ortega et al. (2002), control group data not provided; therefore RT compared with AT
group; Dourado et al. (2009), information for group receiving combined training not included.
2 groups
AT
AT/RT
Bernard
et al.42
Simone D. O’Shea and Nicholas F. Taylor
185
26
Mador et al.43
Ike et al.29
Janaudis-Ferreira
et al.30
Kongsgaard
et al.34
Lewis et al.35
Hoff et al.33
Dourado et al.28
Clark et al.32
Chavoshan et al.27
Casaburi et al.31
Arnardottir
et al.41
Bernard et al.42
Alexander et al.
References
N = 13
(13/0)
N = 19
(from Casaburi cohort)
N = 24
N = 36
(28/8)
N = 24
(24/0)
N = 19 (from Casaburi
cohort)
N = 43
(25/18)
N = 24
(19/5)
N = 12
(8/4)
N = 12 (9/3)
N = 36 (21/15)
N = 20
(14/6)
N = 42 (21/21)
Sample (M/F)
27.6
26.8
68.1
71
25.5
24.6
26.8
26.5
25.2
26
25.7
26.9
25
22.9
26.6
BMI† (kg/m2)
72
69.1
67
61.7
63.4
48.5
68.3
68.3
65.5
66.5
69
Age (mean)
1.39
1.41
1.49
—
0.8
1.08
1.25
2.34
1.23
1.2
1.1
1.00
0.97
FEV1 (L)
42
41.3
46
32.6
35.2
36.2
58.6
77
38
37.3
42
37.5
34.2
FEV1%pred
TABLE 12.2
Characteristics of Participants Included in Trials of Progressive Resistance Training
25%
Not stated
28%
25%
13.9%
0%
29.4%
0%
Not stated
11.3%
20%
33%
25.9%
Attrition Rate
>90%
Not stated
Not stated
Not stated
77.8%
100%
>85% reported
Not stated
Not stated
83%
94%
Not stated
Not stated
ST Exercise Adherence
186
Progressive Resistance Training for Individuals with COPD
N = 33
(28/5)
N = 54
(21/33)
N = 19
(5/14)
N = 28
(15/13)
N = 30
(26/4)
N = 70
(61/9)
N = 28
(12/16)
55.7
61.5
63.5
71.5
70.5
67.7
66
—
24.5
25
24.7
27.3
26.7
—
—
—
—
—
0.93
1.16
1.13
55.9
42
40.5
39.4
37.4
50.6
40.5
36% 6 months
34% 18 months
Not stated
37.5%
17.6%
21%
24%
9.1%
≈89%
77%
78%
90%
100%
85%
Not stated
M/F, male/female; attrition rate, percentage of participants withdrawing from trials; exercise adherence, percentage of completed exercise sessions.
Wright et al.38
Troosters et al.47
Spruit et al.40
Simpson et al.37
Phillips et al.44
O’Shea et al.46
Ortega et al.39
Simone D. O’Shea and Nicholas F. Taylor
187
188
Progressive Resistance Training for Individuals with COPD
The average noncompletion rate (calculated from 17 trials) for participants with
COPD included in progressive resistance training trials was 21%. The main reasons
reported for participant withdrawal in the included trials were death, hospitalization
due to COPD exacerbation, refusal to exercise, lack of motivation, surgery, changes
in treatment, comorbid medical conditions, and injury unrelated to training. There
were no reports of participants withdrawing from trials as a direct result of adverse
events related to resistance training. However, two trials reported minor injuries
limiting the performance of some exercises.30,46 The weighted mean percentage of
training sessions attended by individuals with COPD who did not withdraw from the
program was 84%.
Body Structure and Function
Muscle Function (Strength)
The average increase in knee extensor strength was 30% for participants completing
progressive resistance training, compared with 12% for participants in the comparison groups. Average increases in muscle strength for other lower limb muscle groups
ranged from 23% (leg press strength) to 59% (knee flexors). Average increases in
muscle strength for upper limb muscles ranged from 17% (shoulder abductors) to
31% (elbow extensors).
The meta-analysis of data from nine trials demonstrated that resistance ­training
had a positive medium-sized effect on knee extensor strength (δ = 0.61, 95%
CI: 0.36–0.85). The meta-analysis of data from six trials demonstrated that resistance training had a large positive effect on leg press strength (δ = 0.82, 95%
CI: 0.19–1.45) (Figure 12.1). The meta-analysis of data from eight trials demonstrated a moderate to large effect favoring resistance training for pectoral muscle
strength (δ = 0.76, 95% CI: 0.15–1.36). A meta-analysis of five trials evaluating
latissimus dorsi strength demonstrated a moderate effect favoring resistance training
(δ = 0.66, 95% CI: 0.29–1.02).
Body Composition
The review update yielded no new data on the influence of progressive resistance
training on any measures of body composition. From our previous review, limited
evidence was found for changes in measures of muscle cross-sectional area and
­muscle fiber density post progressive resistance training for individuals with COPD.20
Respiratory Function, Maximal Exercise Capacity,
and Psychological Function
The review update yielded no new data on the influence of progressive resistance training on respiratory function measures, maximal exercise capacity, or psychological functioning. From our previous review, changes in respiratory function after progressive
resistance training appear unlikely. Progressive resistance training also had no effect
on measures of maximal oxygen consumption (VO2 max), measured with incremental
bicycle ergometry or treadmill tests, or on psychological function, as measured by
the Chronic Respiratory Disease Questionnaire, the Hospital Anxiety and Depression
Scale, and components of the St. George Respiratory Disease Questionnaire.20
Simone D. O’Shea and Nicholas F. Taylor
189
Knee extensors
O’Shea et al. (2007) N = 54
d = 0.42 (–0.12, 0.96)
Clark et al. (2000) N = 43
d = 1.11 (0.45, 1.76)
Troosters et al. (2000) N = 62
d = 0.47 (–0.04, 0.98)
Bernard et al. (1999) N = 36
d = 0.66 (–0.02, 1.34)
Mador et al. (2004) N = 24
d = 0.60 (–0.22, 1.42)
Simpson et al. (1992) N = 28
d = –0.02 (–0.76, 0.76)
Ortega et al. (2002) N = 33
d = 0.77 (0.07, 1.48)
Kongsgaard et al. (2004) N = 13
d = 0.49 (–0.62, 1.59)
Dourado et al. (2009) N = 24
d = 1.45 (0.55, 2.36)
Overall N = 317
δ = 0.61 (0.36, 0.85) Q = 8.7 p = 0.37
Leg press
Casaburi et al. (2004) N = 24
d = 0.81 (–0.02, 1.64)
Hoff et al. (2007) N = 12
d = 0.19 (–0.95, 1.32)
Simpson et al. (1992) N = 28*
d = 0.52 (–0.24, 1.27)
Alexander et al. (2009) N = 20
d = 0.23 (–0.65, 1.11)
Kongsgaard et al. (2004) N = 13
d = 1.7 (0.43, 2.97)
Phillips et al. (2006) N = 19
d = 2.25 (1.1, 3.4)
Overall N = 116
δ = 0.82 (0.19, 1.45) Q = 9.4 p = 0.09
Knee flexors
Mador et al. (2004) N = 24
d = 0.23 (–0.57, 1.04)
Ortega et al. (2002) N = 33
d = 1.79 (0.98, 2.60)
Hip abductors
O’Shea et al. (2007) N = 54
d = 0.27 (–0.27, 0.8)
–0.5
0
Favors comparison
0.5
1.0
1.5
2.0
2.5
Favors progressive resistance training
FIGURE 12.1 Standardized mean differences with 95% confidence intervals for lower limb
muscle strength.
Dyspnea
Despite dyspnea being a key symptom for individuals with COPD, only five t­ rials
included outcome measures for shortness of breath. In two trials where progressive
resistance training was compared with no intervention, a trend favoring improvements in ratings of dyspnea was seen after progressive resistance training30,46
(Figure 12.2). However, where progressive resistance training was c­ompared
with aerobic training39 or performed concurrently with aerobic training and compared with aerobic training alone,42,43 no differences were found for the ratings of
dyspnea.
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Progressive Resistance Training for Individuals with COPD
Dyspnea
O’Shea et al. (2007) N = 54
d = 0.49 (–0.05, 1.03)
Janaudis-Ferreira et al. (2011) N = 31
d = 0.34 (–0.38, 1.06)
Mador et al. (2004) N = 24
d = –0.56 (–1.38, 0.26)
Bernard et al. (1999) N = 36
d = –0.12 (–0.79, 0.54)
Ortega et al. (2002) N = 33
d = –0.09 (–0.77, 0.59)
–2.0
–1.0
Favors comparison
0
1.0
2.0
Favors progressive resistance training
FIGURE 12.2 Standardized mean differences with 95% confidence intervals for dyspnea.
Activity
There was a trend favoring progressive resistance training for improved walking
distance when compared with no intervention (δ = 0.31, 95% CI: −0.02–0.64)37,45,46
but not when compared with aerobic training, or concurrent progressive resistance
training and aerobic training compared with aerobic training alone (Figure 12.3).
When compared with no intervention, meta-analysis of five trials demonstrated a
large effect favoring progressive resistance training for improved cycling endurance
(δ = 0.87, 95% CI: 0.29–1.44) but not when compared with aerobic training.20
For a variety of daily tasks such as arm lifting activities and timed mobility tasks
(e.g., timed up and go test), meta-analysis did not demonstrate significant effects
favoring progressive resistance training. However, a trend favoring progressive resistance training was observed for improvement in sit to stand tasks (δ = 0.68, 95%
CI: −0.09–1.46), and a single trial reported a large increase in stair climbing speed
favoring progressive resistance training (d = 1.31, 95% CI 0.11–2.51).34 Changes in
activity were also measured in several trials using questionnaires such as the activity
section of the St George respiratory questionnaire. Findings suggested that progressive resistance training had no effect on self-reported activity performance.
Participation
The limited data does not provide evidence to support the proposition that progressive
resistance training improves societal participation in individuals with COPD28,41,46
Long-Term Outcomes of Progressive Resistance Exercise
The longer term outcomes of progressive resistance exercise were examined in four
trials39,41,45,46 with follow-up periods ranging from 12 weeks to 12 months. Generally,
there were no differences between groups at follow-up. However, there is some evidence that increased muscle strength may be maintained for a short period of up to
12 weeks after training stops.39
191
Simone D. O’Shea and Nicholas F. Taylor
Resistance v nointervention
O’Shea et al. (2007) N = 54
6MWT d = 0.32 (–0.22, 0.86)
Troosters et al. (2000) N = 62
6MWT d = 0.26 (–0.25, 0.76)
Simpson et al. (1992) N = 28
6MWT d = 0.45 (–0.31, 1.19)
Overall N = 144
δ = 0.31 (–0.02, 0.64) Q = 0.15 p = .93
Resistance v aerobic
Spruit et al. (2002) N = 30
6MWT d = –0.06 (–0.78, 0.65)
Ortega et al. (2002) N = 33
ISWT d = 0.28 (–0.41, 0.97)
Dourado et al. (2009) N = 24
6MWT d = 0.69 (–0.14, 1.51)
Overall N = 87
δ = 0.26 (–0.17, 0.69) Q = 1.68 p = .43
Concurrent v
aerobic
Bernard et al. (1999) N = 36
6MWT d = 0.76 (0.07, 1.44)
Mador et al. (2004) N = 24
6MWT d = –0.04 (–0.84, 0.76)
Phillips et al. (2006) N = 19
6MWT d = –0.13 (–1.03, 0.77)
Alexander et al. (2009) N = 20
6MWT d = –0.09 (–0.97, 0.79)
Overall N = 99
δ = 0.20 (–0.20, 0.60) Q = 3.6 p = 0.30
Resistance v
concurrent
Arnadottir et al. (2007) N = 42
12MWT d = –0.36 (–0.97, 0.25)
–1.0
Favors comparison
0
1.0
2.0
Favors progressive resistance exercise
FIGURE 12.3 Standardized mean differences with 95% confidence intervals for walking
distance.
SYNTHESIS OF EVIDENCE FOR PROGRESSIVE RESISTANCE
TRAINING FOR INDIVIDUALS WITH COPD
There have been 20 randomized controlled trials conducted on the effects of progressive resistance training for individuals with COPD, providing a body of evidence
with a relatively low risk of bias.
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Progressive Resistance Training for Individuals with COPD
It is clear that progressive resistance training can produce increases in arm and
leg muscle strength with moderate to large effect sizes. Progressive resistance training may also improve exercise endurance as shown by improvements in cycling
endurance and performance in field walking tests of exercise capacity. Progressive
resistance exercise protocols appeared feasible and safe for people with COPD when
performed under supervision in an outpatient clinic, with few reported adverse
events. Despite moderate withdrawal rates from trials, high levels of training adherence were reported with short-term interventions.
However, the carryover effect of increased muscle strength into improved ability
to do daily tasks has yet to be convincingly demonstrated. Individual trials have demonstrated improvements in activities such as stair climbing and timed sit to stand,
but meta-analyses have not demonstrated improvements when results from trials are
combined. One reason for the lack of carryover into the ability to do daily tasks may
be due to a lack of specificity of training, that is, if the aim is to increase strength
to do a functional task the training should as much as possible closely resemble that
functional task.
The effects of progressive resistance training on measures of body composition,
psychological function, dyspnea, and societal participation remain inconclusive,
although individual trials have reported favorable results. Also, as expected, progressive resistance training did not lead to improvements in maximal exercise capacity
or respiratory function.
There is as yet limited information on whether benefits obtained from training
are maintained after the training stops, but the available evidence suggests that a
detraining effect starts relatively quickly and that increases in muscle strength after
the training stops are maintained only in the short term.
The findings of the current systematic review are consistent with clinical practice guidelines. Both the ACCP/AACVPR Evidence-Based Clinical Practice
Guidelines48 and the ATS & ERS Pulmonary Rehabilitation Guidelines49 recommend the inclusion of progressive resistance training to pulmonary rehabilitation for
individuals with COPD because it is a relatively safe intervention that can increase
muscle strength, although little is known about its longer term outcomes and how
it influences morbidity and prognosis. The ATS & ERS Pulmonary Rehabilitation
Guidelines49 further note that progressive resistance training may have some advantages over endurance training for some individuals with COPD because the shorter
duration of training sessions may make it easier to control breathing and lead to less
dyspnea.
The Canadian Thoracic Society Clinical Practice Guidelines on pulmonary rehabilitation50 recommend that combined (strength and endurance) training results in
better outcomes for increasing muscle strength and may result in more functional
gains than endurance training. In the current systematic review, we included six trials that combined progressive resistance training with endurance training compared
with endurance training alone with any differences assigned to the effect of adding
progressive resistance training.26,41–45 In general, the effect of combined training on
muscle strength and functional gains appeared similar to those trials that employed
progressive resistance training alone. The benefit from adding endurance training
to progressive resistance training may be in the improvements in endurance and
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193
aerobic fitness. Progressive resistance training alone does not provide a sufficient
stimulus to increase aerobic fitness.
Therefore, current evidence supports the recommendations that adding progressive resistance training to pulmonary rehabilitation for individuals with COPD is
safe, is feasible, increases muscle strength, and may help to improve walking endurance. The extent to which progressive resistance training can improve the ability to
do functional daily tasks remains inconclusive; but if it does, it may have a relatively
smaller effect and be related to how closely associated the resistance exercise is to
the daily task.
IMPLEMENTING PROGRESSIVE RESISTANCE
TRAINING IN THE CLINICAL SETTING
Who Is Suitable?
Progressive resistance training is particularly appropriate for individuals with COPD
presenting with reductions in muscle mass and strength and where this lack of
strength is assessed to be contributing to changes in functional performance. These
changes of atrophy and muscle weakness are often observed as the disease becomes
more severe.
In addition, clinical practice guidelines recommend that progressive resistance
training should be incorporated into pulmonary rehabilitation so that muscle
strengthening may be appropriate for most individuals with COPD.48,49 In particular, for people with COPD with severe dyspnea, anxiety, and decreased confidence
associated with physical activity, shorter intervals of exercise interspersed with rest
periods can provide an achievable and tolerable method for introducing exercise
training.
There is now a large body of evidence suggesting that progressive resistance
training is safe and feasible for individuals with COPD. The contraindications to
resistance training for individuals with COPD are the same as those for other groups
and include conditions such as unstable cardiac conditions. When uncertain of the
risks with an individual, obtaining medical clearance before starting training is sensible. To check whether it is necessary to gain medical clearance, some clinicians
may use a screening tool such as the Physical Activity Readiness Questionnaire.51
Orthopedic and neurological conditions that could make it more difficult to exercise
are often listed as exclusion criteria, but in many cases exercises can be adapted so
that individuals with these comorbidities can successfully participate in resistance
training. There is high-level evidence that progressive resistance training can also be
an effective intervention for people with orthopedic and neurological conditions.52
One issue not addressed by the trials included in the review in this chapter is the
effect of starting progressive resistance training during hospitalization for an acute
exacerbation of COPD. Pulmonary rehabilitation is often only commenced when
medical management has been optimized for people with COPD. Starting the exercise component of pulmonary rehabilitation during hospitalization for an exacerbation may have the advantage of minimizing the degree of physical deconditioning,
facilitating discharge back to the community and help to set up exercise patterns that
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Progressive Resistance Training for Individuals with COPD
may improve long-term adherence. However, there are also concerns that getting
individuals with compromised breathing to exercise at an intense level may further
compromise their respiratory system and lead to adverse events.
Two recent randomized controlled trials have investigated the starting of very
early progressive resistance training for individuals with COPD during an acute
exacerbation.47,53 Troosters et al.47 demonstrated that a quadriceps resistance training program implemented during an acute exacerbation with COPD could prevent
muscle deterioration without increasing inflammation. Tang et al.53 found that an
exercise program that included progressive resistance training, which commenced
the day after admission with an exacerbation of COPD, was safe and feasible with
no difference in adverse events observed between the exercise groups and the usual
care control group. Therefore, there is preliminary evidence that it may be safe to
start progressive resistance training during an acute exacerbation with COPD during
hospitalization, without waiting for referral to a pulmonary rehabilitation program
after discharge from the hospital to home.
What Equipment?
A variety of equipment options are available for progressive resistance training including machine weights, free weights, pulleys, and elasticized resistance bands. Machine
weights provide greater stability and control of the desired movement and therefore
are suitable for novice trainers or for the very frail. However, machine weights are
expensive and are usually only available in gymnasiums so that access issues including cost and travel may become barriers for some individuals with COPD.
Free weights (e.g., dumbbells) are a cheaper and a more portable option, with
training able to be completed in a gymnasium and also at home. However, resistance training with free weights with sufficient load to get a strengthening effect
involves the control and stabilization of other body parts. Also, because the weights
are free there is more of a risk of injury by dropping the weight on a body part
because of lack of control. For these reasons, close supervision is required if starting
training with free weights and, if possible, clinicians should consider progressing to
free weight training after an initial period of training with machine weights.
Elasticized resistance bands are another option of providing resistance for progressive resistance training. They have the advantage of being cheap, and are very
portable, so that training can be prescribed for the home setting. A disadvantage is
that it is not very easy to quantify the amount of resistance. Similar to free weights,
elasticized bands encourage increased trunk control and balance; but this means that
it is easier to have “poor form” when completing the exercise, which could lead to an
increased risk of injury.
What Exercises?
The choice of exercises should be based on individual client assessment and areas
of specific strength and functional need. Common areas of muscle weakness for
individuals with COPD include lower limb muscles for walking (especially the quadriceps) and upper limb muscles involved in lifting tasks.
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195
One consideration is the choice of multijoint versus single-joint exercises. It
would be expected that there should be greater performance gains if muscles are
trained in the way they will be used, favoring multijoint exercises. However, multijoint and more functional exercises impose a greater ventilatory demand. Therefore,
for individuals with severe dyspnea and/or anxiety associated with physical activity, exercises involving single-joint movement (e.g., quadriceps extension) may allow
training with higher loads; make training more achievable; and improve confidence
with exercise, allowing for gradual progression to more functional exercises involving movements of a number of joints.
The choice of whether exercises should be an open or a closed kinetic chain
should be based on the purpose of the exercise and the functional requirements of
the muscles being trained. Closed kinetic chain exercises make sense if the purpose
is to increase lower limb muscle strength with the aim of improving functional tasks
such as walking. As well as encouraging functional muscle action, the closed kinetic
chain exercises if carefully planned can have the added benefit of facilitating balance
responses to training. In contrast, many upper limb activities involve an open kinetic
chain, which increases ventilatory demand in individuals with COPD because the
accessory muscles cannot be used to assist breathing. Training upper limb muscles
in this way if done well can be very beneficial in improving perceptions of dyspnea
and exercise capacity,48 but because of the greater challenge it can be distressing for
individuals with COPD if breathing control is not emphasized.
The training protocols suitable for individuals with COPD conform to guidelines
for healthy older adults published by the American College of Sports Medicine.54
Briefly, these guidelines recommend that for improvements in muscle strength,
training should aim for 1–3 sets per exercise with 60%–80% of 1RM for 8–12 repetitions with 1–3 minutes of rest between sets for 2–3 days a week. The effort for
progressive resistance training should be moderate to high with ratings of perceived
exertion ranging from 5 to 8 on a 0–10 scale55 or from 13 to 15 on the 15-point (6–20)
Borg rating of perceived exertion.56 The training protocols of the 20 trials included
in our review (see Table 12.1) confirm that this sort of training regimen is safe, feasible, and effective for individuals with COPD.
However, implementing this sort of protocol with individuals with COPD can
involve clinician skill and supervision. For frailer clients with COPD with no experience of progressive resistance training, it is a good idea to start training at lower
training intensities (lower number of sets) and progress gradually (i.e., increase the
number of sets and then the load) ensuring good technique. This could be seen as
a familiarization phase during the first 2–3 weeks of training, where emphasis is
placed on learning correct exercise and breathing technique. For progression of
training load, guidelines recommend that training load be increased by 2%–10%
when the individual can perform the current workload for one to two repetitions over
the set number for one to two sessions.54 Practically, individuals with COPD can be
progressed to the next available weight when they can do 12 repetitions of the number of sets they are training at for two sessions in a row.
Since progressive resistance exercise involves training at a relatively high intensity it is important that sufficient recovery periods be built in both between sets and
between sessions. This is especially important for individuals who as well as needing
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Progressive Resistance Training for Individuals with COPD
time to recover from muscle fatigue will need time to recover from the ventilatory
demand of exercising. There should be a rest period of 2–3 minutes between sets, and
training should be on nonconsecutive days with preferably 48 hours between sessions.
Training with good form is often emphasized in progressive resistance training
and involves joints going through the available range of motion with good control, as
well as good postural control within the supporting segments. Of particular importance in progressive resistance training for individuals with COPD is incorporating
and teaching breathing control during exercise. Breathing control includes timing
expiration with concentric muscle contraction to facilitate contraction of the stabilizing muscles of the trunk and avoiding breath holding (the Valsalva maneuver)
during exercise. We have found that teaching breathing control works best after the
person can perform an exercise with good form, highlighting the importance of good
supervision in the first few weeks of training to gradually incorporate these quality components of progressive resistance training. The skills in breathing control
during exercise can be quite powerful for individuals with COPD, helping to build
confidence and reduce anxiety and improving levels of perceived dyspnea. There is
potential for the skills in breathing control to be applied when doing physical tasks
during daily activities. The ability to practice and master breathing control during
resistance training is an advantage of this form of exercise over other forms of exercise, such as endurance training.
Special Consideration—Continence
The potential for coexisting continence problems in people with COPD have received
greater recognition in recent years. While little prevalence data for continence problems in people with COPD exists, estimates of 10% of men and between 30% and 68%
of women have been reported.57,58 People with COPD may be at higher risk of stress
urinary incontinence where a chronic cough exists because repeated increases in
intra-abdominal pressure place stress on the pelvic floor muscle mechanism.57 From
our own experience, and supported by the findings of a recent study,59 people with
COPD often report symptoms of urgency and urge incontinence during episodes of
breathlessness. Shortness of breath and urgency are further intensified with increasing feelings of anxiety associated with these symptoms. The mechanisms behind
this phenomenon are not clear but could be associated with various factors including
altered mechanics in muscles of the thorax, abdomen, and pelvis (core muscles) due
to hyperinflation; high work associated with airflow limitation and active expiration
utilizing the abdominals; as well as changes in autonomic nervous system function,
those in psychological function (anxiety), and those associated with the aging process.
The implication for prescription of progressive resistance exercises in this population is the potential for worsening continence problems if repeated strain is placed
on a continence mechanism lacking adequate muscular support. We recommend
that clinicians screen for continence problems during assessment, referring on if
required. Consistent with encouraging core stability during progressive resistance
training, we also encourage teaching people with COPD how to perform pelvic floor
muscle contractions and, where appropriate, incorporating pelvic floor muscle exercises into training programs.
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What Setting?
Most studies on COPD have conducted training under supervision either in clinics
or in gymnasiums. Supervision helps to ensure that training loads and progressions
are applied correctly and that participants train with correct form and breathing
control, providing encouragement and helping to solve any problems. However,
there are costs involved in having all sessions supervised, which could affect program feasibility for some individuals with COPD. Only one trial included in our
review included a training program with a home-based, unsupervised component
for 2 days each week. This trial46 demonstrated that training at home is a relatively safe and feasible option for resistance training for this population, provided a
supervision component is built into training, especially during the familiarization
phase.
Monitoring Progress
Assessment of muscle strength should be included in general assessment of individuals with COPD, to document specific impairments of muscle strength, and as part of
pulmonary rehabilitation to monitor any changes and the effects of interventions.60
Reassessment of muscle strength can also help to motivate the client and can inform
progression of loads for resistance training.
Methods of assessing muscle strength in the clinical setting need to be simple, cost
and time effective, reliable, and valid. Manual muscle testing, where the strength of
the muscle is graded from 1 to 5 based on whether it can move against gravity and
clinicians’ resistance, is commonly applied in the clinic to assess muscle strength.61
However, despite the ease of testing, manual muscle tests are relatively insensitive to
change, particularly at higher grades.62,63
More objective measures of muscle strength include isokinetic dynamometry and
handheld dynamometry. Mathur et al.64 found that the Cybex II isokinetic dynamometer demonstrated high levels of retest reliability (intraclass correlation coefficient [ICC] > .88) in a group with moderately severe COPD.64 However, isokinetic
strength testing can be time consuming and not well related to functional task performance and the equipment is expensive so that it might not be feasible in many
clinical settings.
Handheld dynamometers are a simple, portable, and relatively inexpensive way
of objectively measuring isometric muscle strength for individuals with COPD.
A study on a group with moderately severe COPD found that a handheld dynamometer could measure upper and lower limb muscle strengths with high levels of
reliability (ICC > .79). Group changes between 4% and 18% could be ascribed to
true change over and above measurement error, whereas individual changes would
need to exceed between 34% and 58%.36 This suggests that handheld dynamometry
may be sufficiently reliable to monitor change and test hypotheses in groups of
people with COPD but may not be sufficiently reliable to monitor change in most
individuals with COPD. A further consideration with handheld dynamometers is
that they measure isometric muscle strength so that the measures may not relate
well to dynamic muscle performance during functional tasks.
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Progressive Resistance Training for Individuals with COPD
Another common method of measuring muscle strength and one that has been utilized in many of the trials included in our review is 1RM, the amount of weight that
can be lifted through full range just once. One-repetition maximum is a relatively safe
method of measuring dynamic muscle strength in this population and is highly associated with both isometric and isokinetic measures of strength.34,65 If the clinician has
concerns about applying the load involved with 1RM, then submaximal repetitions (usually between 4 and 12 repetition maximum) can also be used as a strength assessment.
Adherence to Progressive Resistance Training
One of the challenges of progressive resistance training in individuals with COPD
is adherence to the program. Adherence is defined as the degree to which an individual follows the prescribed training program.66 Results of the systematic review
suggest that about one in five (21%) of those with COPD who participated in the
trials did not complete their prescribed program of progressive resistance training.
Noncompletion rates for pulmonary rehabilitation programs appear to be as high, if
not higher than for progressive resistance training programs, ranging from 23%67 to
31%.68 Therefore, the problem with adherence is not just about progressive resistance
training but about exercise in general.
Factors that can facilitate adherence to progressive resistance training for individuals with COPD include an expectation that the exercise program would be beneficial, having supervision while exercising, documenting training progress through
a logbook, and having group support.20 Therefore, clinicians setting up resistance
training programs should seek to optimize these factors that can facilitate adherence.
One strategy is to provide clear information about expected benefits such as
increased muscle strength, increased exercise endurance, and the opportunity to
improve breathing control at the start of a program and to reinforce these benefits
by providing feedback on progress during training to reinforce pretraining exercise
beliefs. We found that having a group component to exercising was perceived positively by participants. As well as providing participants with increased enjoyment,
confidence, and peer support, exercising in a group, at least weekly, also provided
participants with an incentive to exercise by benchmarking their performance against
others. However, the long-term effect of group training is not clear with some reports
that home-based training can lead to higher longer term adherence rates to exercise
than center-based training.69,70 In pulmonary rehabilitation programs difficulty in
getting to the programs because of poor mobility and lack of transport is perceived
as a barrier to exercise,71 which might explain why training at home might be an
option for some individuals with COPD. A central factor in providing information
and feedback, and to organize group training, is to have supervision of training by a
health-care professional. In addition, exercise supervisors are important for monitoring exercise techniques and progression, acknowledging achievements, and helping
participants to set new goals. Although supervisors can play a key role in facilitating
adherence to an exercise program, there are costs involved in maintaining this supervision in the long term. Strategies such as refresher sessions, or follow-up assessment
sessions may be relative cost-effective and feasible ways of maintaining supervisor
input to assist with long-term adherence.
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An important barrier restricting participation in resistance training for individuals with COPD is their health.20 This factor has also been identified as a key barrier
for people taking up or not completing pulmonary rehabilitation.71 The results of the
review reported in this chapter confirmed this: the main reasons given for failure to
complete a training program were related to health, including hospitalization due to
COPD exacerbation, surgery, changes in treatment, comorbid medical conditions,
and injury unrelated to training. Fluctuating health status, poor physical function,
and comorbid health conditions are often present72 so that in this population strategies to assist in the resumption of training need to be incorporated into programs.
Another factor that is an important barrier to resistance training for individuals with COPD is the weather. A relationship has been demonstrated between levels of particulate matter in the air and adverse health outcomes in COPD.73 Also,
cold weather can induce increased bronchoconstriction in individuals with COPD.74
Being aware of the effect that the weather can have as a barrier to exercise for people
with COPD may help clinicians and supervisors to provide advice about maintaining
or adapting resistance training during times of weather change.
Given the barriers to exercise and the interruptions and setbacks that can be
almost inevitable, a key skill for the clinician supervising the program is to teach
people how to deal with these setbacks, to restore confidence, and to help participants learn how to adjust and rebuild their training loads again.
Knowledge of potential factors that may influence adherence to resistance training in people with COPD is important to maximize the benefits of training. However,
factors influencing adherence need to be explored, understood, and monitored with
each individual client. Promoting facilitators such as being clear about the benefits
of exercise and having a supervisor and minimizing the effects of barriers through
supporting participants through setbacks to training due to exacerbation of their condition are practical ways in which we can strive to increase adherence to resistance
training for individuals with COPD.
CONCLUSIONS
There is high-quality evidence that progressive resistance training is a safe exercise
intervention for individuals with COPD, which can lead to increased muscle strength
that may carry over into improved exercise endurance and an increased ability to
do daily tasks. Resistance training guidelines for individuals with COPD, including
intensity and dosage, are similar to those for other groups including healthy adults.
However, skill and leadership is required to prescribe and facilitate training in this
group where barriers such as being unwell can affect adherence to training.
REFERENCES
1. Global strategy for the diagnosis, management and prevention of COPD. Global
Initiative for Chronic Obstructive Lung Disease. 2011. (Accessed 6 February 2012,
2011, at http://www.goldcopd.org/.)
2. World Health Report. 2000. (Accessed 8 February 2012, at http://www.int/whr/2000/en/
statistics.htm.)
200
Progressive Resistance Training for Individuals with COPD
3. ATS/ERS. Skeletal muscle dysfunction in chronic obstructive pulmonary disease:
a joint statement of the American Thoracic Society and European Respiratory
Society. American Journal of Respiratory & Critical Care Medicine 1999;
159:S1–40.
4. Thomas A. Chronic obstructive pulmonary disease: the contribution of skeletal muscle
dysfunction to exercise intolerance. Physical Therapy Reviews 2006;11:62–6.
5. Vilaro J, Ramirez-Sarmiento A, Martinez-Llorens J et al. Global muscle dysfunction
as a risk factor of readmission to hospital due to COPD exacerbations. Respiratory
Medicine 2010;104:1896–902.
6. Garcia-Aymerich J, Farrero E, Felez MA, Izquierdo J, Marrades RM, Anto JM. Risk
factors of readmission to hospital for a COPD exacerbation: a prospective study. Thorax
2003;58:100–5.
7. Kim HC, Mofarrahi M, Hussain SNA. Skeletal muscle dysfunction in patients with
chronic obstructive pulmonary disease. International Journal of Chronic Obstructive
Pulmonary Disease 2008;3:637–58.
8. Swallow EB, Reyes D, Hopkinson NS et al. Quadriceps strength predicts mortality
in patients with moderate to severe chronic obstructive pulmonary disease. Thorax
2007;62:115–20.
9. Decramer M, Gosselink R, Troosters T et al. Peripheral muscle force is a determinant of
survival in COPD (abstract). European Respiratory Journal 1998;12:261S.
10. Decramer M, Gosselink R, Troosters T, Verschueren M, Evers G. Muscle weakness is
related to utilisation of health care resources in COPD patients. European Respiratory
Journal 1997;10:417–23.
11. Marquis K, Debigare R, Lacasse Y et al. Midthigh muscle cross-sectional area is a
better predictor of mortality than body mass index in patients with chronic obstructive pulmonary disease. American Journal of Respiratory & Critical Care Medicine
2002;166:809–13.
12. Larsson L, Grimby G, Karlsson J. Muscle strength and speed of movement in relation to
age and muscle morphometry. Journal of Applied Physiology 1990;46:451–6.
13. Lynch NA, Metter EJ, Lindle RS et al. Muscle quality. I. Age-associated difference
between arm and leg muscle groups. Journal of Applied Physiology 1999;86:188–94.
14. Hopp JF. Effects of age and resistance training on skeletal muscle: a review. Physical
Therapy 1993;73:361–73.
15. Bernard S, LeBlanc P, Whittom F et al. Peripheral muscle weakness in patients with
chronic obstructive pulmonary disease. American Journal of Respiratory & Critical
Care Medicine 1998;158:629–34.
16. Franssen FME, Broekhuizen R, Janssen PP, Wouters EF, Schols A. Effects of wholebody exercise training on body composition and functional capacity in normal-weight
patients with COPD. Chest 2005;125:2021–8.
17. Gosselink R, Troosters T, Decramer M. Peripheral muscle weakness contributes to exercise limitation in COPD. American Journal of Respiratory & Critical Care Medicine
1996;153:976–80.
18. Remels AH, Gosker HR, van der Velden J, Langen RC, Schols AM. Systemic inflammation and skeletal muscle dysfunction in chronic obstructive pulmonary disease: state of
the art and novel insights in regulation of muscle plasticity. Clinics in Chest Medicine
2007;28:537–52.
19. Higgins JPT, Green S (Eds.). Cochrane Handbook for Systematic Reviews of
Interventions Version 5.1.0. The Cochrane Collaboration, 2011. (Accessed 28 October
2011, at www.cochrane-handbook.org).
20. O’Shea SD, Taylor NF, Paratz JD. Progressive resistance exercise improves muscle
strength and may improve elements of performance of daily activities for people with
COPD: a systematic review. Chest 2009;136:1269–83.
Simone D. O’Shea and Nicholas F. Taylor
201
21. Kraemer WJ, Adams K, Cafarelli E et al. American College of Sports Medicine position
stand: progression models in resistance training in healthy adults. Medicine & Science in
Sports & Exercise 2002;34:364–80.
22. The physiotherapy evidence database (PEDro) scale items. 1999. (Accessed 17 September
2009, at http://www.pedro.org.au/scale_item.html.)
23. International Classification of Functioning, Disability and Health. World Health
Organization. 2002. (Accessed 3 March 2003, at http://apps.who.int/classifications/
icfbrowser/).
24. Schwarzer R. 1989. Meta-analysis programs. Version 5.1. Free University of Berlin.
(Accessed 24 April 2003, at http://userpage.fu-berlin.de/~health/meta_e.htm).
25. Hedges L, Olkin I, eds. Statistical Methods for Meta-Analysis. Orlando, FL: Academic
Press; 1985.
26. Alexander JL, Phillips WT, Wagner CL. The effect of strength training on functional
fitness in older patients with chronic lung disease enrolled in pulmonary rehabilitation.
Rehabilitation Nursing 2008;33:91–7.
27. Chavoshan B, Fournier M, Lewis MI et al. Testosterone and resistance training
effects on muscle nitric oxide synthase isoforms in COPD men. Respiratory Medicine
2012;106(2):269–275.
28. Dourado VZ, Tanni SE, Antunes LC et al. Effect of three exercise programs on patients
with chronic obstructive pulmonary disease. Brazilian Journal of Medical and Biological
Research 2009;42:263–71.
29. Ike D, Jamami M, Marino DM, Ruas G, Pessoa BV, Amorim Pires V. Effects of the
resistance exercise in upper limb on peripheral muscular strength and functionality of
COPD patient. Fisioterapia Em Movimento 2010;23:429–37.
30. Janaudis-Ferreira T, Hill K, Goldstein RS et al. Resistance arm training in patients with
COPD: a randomized controlled trial. Chest 2011;139:151–8.
31. Casaburi R, Bhasin S, Cosentino L et al. Effects of testosterone and resistance training
in men with chronic obstructive pulmonary disease. American Journal of Respiratory &
Critical Care Medicine 2004;170:870–8.
32. Clark CJ, Cochrane LM, Mackay E, Paton B. Skeletal muscle strength and endurance
in patients with mild COPD and the effects of weight training. European Respiratory
Journal 2000;15:92–7.
33. Hoff J, Tjonna AE, Steinshamn S, Høydal M, Richardson RS, Helgerud J. Maximal
strength training of the legs in COPD: a therapy for mechnical inefficiency. Medicine &
Science in Sports & Exercise 2007;39:220–6.
34. Kongsgaard M, Backer V, Jorgensen K et al. Heavy resistance training increases muscle size, strength and physical function in elderly male COPD patients: a pilot study.
Respiratory Medicine 2004;98:1000–7.
35. Lewis MI, Fournier M, Storer TW et al. Skeletal muscle adaptations to testos­
terone and resistance training in men with COPD. Journal of Applied Physiology
2007;103:1299–310.
36. O’Shea SD, Taylor NF, Paratz JD. Measuring muscle strength for people with chronic
obstructive pulmonary disease: retest reliability of hand-held dynamometry. Archives of
Physical Medicine and Rehabilitation 2007;88:32–6.
37. Simpson K, Killian K, McCartney N et al. Randomised controlled trial of weightlifting
exercise in patients with chronic airflow limitation. Thorax 1992;47:70–5.
38. Wright PR, Heck H, Langenkamp H, Franz KH, Weber U. Influence of a resistance
training on pulmonary function and performance measures of patients with COPD.
Pnemonologie 2002;56:413–7.
39. Ortega F, Toral J, Cejudo P et al. Comparison of effects of strength and endurance
training in patients with chronic obstructive pulmonary disease. American Journal of
Respiratory & Critical Care Medicine 2002;166:669–74.
202
Progressive Resistance Training for Individuals with COPD
40. Spruit MA, Gosselink R, Troosters T et al. Resistance versus endurance training in
patients with COPD and peripheral muscle weakness. European Respiratory Journal
2002;19:1072–8.
41. Arnardottir RH, Sorenson S, Ringqvist I et al. Two different training programmes for
patients with COPD: a randomised study with 1-year follow up. Respiratory Medicine
2006;100:130–9.
42. Bernard S, Whittom F, LeBlanc P et al. Aerobic and strength training in patients with
chronic obstructive pulmonary disease. American Journal of Respiratory & Critical
Care Medicine 1999;159:896–901.
43. Mador MJ, Bozkanat E, Aggarwal A et al. Endurance and strength training in patients
with COPD. Chest 2004;125:2036–45.
44. Phillips WT, Benton MJ, Wagner CL, Riley C. The effect of single set resistance training on strength and functional fitness in pulmonary rehabilitation patients. Journal of
Cardiopulmonary Rehabilitation 2006;26:330–7.
45. Troosters T, Gosselink R, Decramer M. Short- and long-term effects of outpatient rehabilitation in patients with chronic obstructive pulmonary disease: a randomised trial.
American Journal of Medicine 2000;109:207–12.
46. O’Shea SD, Taylor NF, Paratz JD. A predominantly home-based progressive resistance exercise program increases knee extensor strength in the short-term in people
with chronic obstructive pulmonary disease: a randomised controlled trial. Australian
Journal of Physiotherapy 2007;53:229–37.
47. Troosters T, Probst VS, Crul T et al. Resistance training prevents deterioration in quadriceps muscle function during acute exacerbations of chronic obstructive pulmonary
disease. American Journal of Respiratory & Critical Care Medicine 2010;181:1072–7.
48. Ries AL, Bauldoff GS, Carlin BW et al. Pulmonary rehabilitation: joint ACCP/AACVPR
evidence-based clinical practice guidelines. Chest 2007;131:4S–42S.
49. ATS, ERS. ATS/ERS statement on pulmonary rehabilitation. American Journal of
Respiratory & Critical Care Medicine 2006;173:1390–413.
50. Marciniuk DD, Brooks D, Butcher S et al. Optimizing pulmonary rehabilitation in
chronic obstructive pulmonary disease—practical issues: a Canadian Thoracic Society
clinical practice guideline. Canadian Respiratory Journal 2010;17:159–68.
51. PAR - Q: Physical activity readiness questionnaire. Canadian Society for Exercise
Physiology. 2002. (Accessed 1 July 2012, at http://www.csep.ca/cmfiles/publications/
parq/par-q.pdf.)
52. Taylor NF, Dodd KJ, Damiano DL. Progressive resistance exercise in physical therapy:
a summary of systematic reviews. Physical Therapy 2005;85:1208–23.
53. Tang CY, Blackstock FC, Clarence M, Taylor NF. Early rehabilitation exercise program
for inpatients during an acute exacerbation of chronic obstructive pulmonary disease
(COPD): a randomized controlled trial. Journal of Cardiopulmonary Rehabilitation &
Prevention 2012;32:163–9.
54. ACSM. Progression models in resistance training for healthy adults. Medicine & Science
in Sports & Exercise 2009;41:687–708.
55. Nelson ME, Rejeski WJ, Blair SN et al. Physical activity and public health in older
adults: recommendations from the American College of Sports Medicine and American
Heart Association. Medicine & Science in Sports & Exercise 2007;39:1435–45.
56. Borg G. Psychophysical basis of perceived exertion. Medicine & Science in Sports &
Exercise 1982;14:377–81.
57. Hirayama F, Binns CW, Lee AH, Senjyu H. Urinary incontinence in Japanese women
with COPD: review. Journal of Physical Therapy Science 2005;17:119–24.
58. Schnell K, Weiss CO, Lee T et al. The prevalence of clinically-relevant comorbid con­
ditions in patients with physician-diagnosed COPD: A cross-sectional study using data
from NHANES 1999–2008. BMC Pulmonary Medicine 2012;12:26.
Simone D. O’Shea and Nicholas F. Taylor
203
59. Hirayama F, Lee AH, Hiramatsu T, Tanikawa Y. Breathlessness is associated with urinary
incontinence in men: A community-based study. BMC Pulmonary Medicine 2010;10:2.
60. Robles PG, Mathur S, Janaudis-Fereira T, Dolmage TE, Goldstein RS, Brooks D.
Measurement of peripheral muscle strength in individuals with chronic obstructive pulmonary disease: a systematic review. Journal of Cardiopulmonary Rehabilitation and
Prevention 2011;31:11–24.
61. Clarkson HM, Gilewich GB, eds. Musculoskeletal Assessment: Joint Range of Motion
and Manual Muscle Strength. Baltimore, MD: Williams & Wilkins; 1999.
62. Beasley WC. Influence of method on estimates of normal knee extensor force among
normal and post polio children. Physical Therapy Reviews 1956;36:21–41.
63. Bohannon RW. Measuring knee extensor muscle strength. American Journal of Physical
Medicine & Rehabilitation 2001;80:13–8.
64. Mathur S, Makrides L, Hernandez P. Test-retest reliability of isometric and isokinetic
torque in patients with chronic obstructive pulmonary disease. Physiotherapy Canada
2004;56:94–101.
65. Vilaro J, Rabinovich R, Gonzalez-deSuso JM et al. Clinical assessment of peripheral
muscle function in patients with chronic obstructive pulmonary disease. American
Journal of Physical Medicine & Rehabilitation 2009;88:39–46.
66. Sabate E. (Ed.) Adherence to long term therapies: Evidence for Action. World Health
Organisation. 2003. (Accessed 4 April 2006, at http://www.who.int/chp/knowledge/
publications/adherence_full_report.pdf).
67. Fischer MJ, Scharloo M, Abbink JJ et al. Drop-out and attendance in pulmonary
rehabilitation: the role of clinical and psychosocial variables. Respiratory Medicine
2009;103:1564–71.
68. Garrod R, Marshall J, Barley E, Jones PW. Predictors of success and failure in pulmonary rehabilitation. European Respiratory Journal 2006;27:788–94.
69. Strijbos JH, Postma DS, van Altena R, Ginemo F, Koeter GH. A comparison between an
outpatient hospital-based pulmonary rehabilitation program and a home-care pulmonary
rehabilitation program in patients with COPD. Chest 1996;109:366–72.
70. Ashworth NL, Chad KE, Harrison EL, Reeder BA, Marshall SC. Home versus centrebased physical activity programs in older adults. Cochrane Database of Systematic
Reviews 2005;1:CD004017.
71. Keating A, Lee A, Holland AE. What prevents people with chronic obstructive pulmonary disease from attending pulmonary rehabilitation: a systematic review. Chronic
Respiratory Disease 2011;8:89–99.
72. Seemungal TAR, Donaldson GC, Bhowmik A, Jeffries DJ, Wedzicha JA. Time course
and recovery of exacerbations in patients with chronic obstructive pulmonary disease.
American Journal of Respiratory & Critical Care Medicine 2000;161:1608–13.
73. Yang Q, Chen Y, Krewski D, Burnett RT, Shi Y, McGrail KM. Effect of short-term exposure to low levels of gaseous pollutants on chronic obstructive pulmonary disease hospitalizations. Environmental Research 2005;99:99–105.
74. Koskela HO, Koskela AK, Tukiainen HO. Bronchoconstriction due to cold weather in
COPD. Chest 1996;110:632–6.
13
Benefits of Resistance
Training for HIV/AIDS
Jacob J. van den Berg and Joseph T. Ciccolo
CONTENTS
Introduction.............................................................................................................209
HIV-Associated Complications...............................................................................209
Exercise and HIV.................................................................................................... 210
Resistance Training Studies.................................................................................... 210
Conclusion and Future Directions.......................................................................... 215
References............................................................................................................... 215
INTRODUCTION
Globally, over 34 million people were living with human immunodeficiency virus
(HIV) at the end of 2011. Worldwide, 2.5 million people became newly infected with
HIV in 2011.1 In the United States, the Centers for Disease Control and Prevention has
estimated that over 1.1 million people are currently living with HIV, with approximately 18% of those individuals being unaware of their infection and another 50,000
becoming newly infected each year.2 Approximately two-thirds of Americans with
HIV identify as a racial or ethnic minority, and in 2007, HIV ranked as the fifth leading cause of death among persons aged 35–44.3 Today, the life expectancy for HIVinfected Americans has increased dramatically in comparison to earlier years of the
epidemic. Advances in antiretroviral (ARV) therapy have significantly contributed
to extending the lives of those living with HIV in the United States. Predictions of
life expectancy for a young HIV-positive person living in the United States beginning ARV therapy following today’s combination treatment regimen can anticipate
living on average to the age of 69.4 As such, HIV infection is now treated as a chronic
illness, and individuals with HIV are increasingly at risk for diseases associated with
aging, including cardiovascular disease and type 2 diabetes.5,6
HIV-ASSOCIATED COMPLICATIONS
Despite the beneficial advances in medical treatment, the impact of HIV and the
side effects of ARV therapy are significant. These may include muscle wasting,7
peripheral insulin resistance,8 hypertriglyceridemia,9 hypercholesterolemia,10 central adiposity,11 peripheral lipoatrophy,12 and osteopenia.13 Pharmacologic agents can
be used to treat the majority of these conditions, but the financial costs, potential
205
206
Benefits of Resistance Training for HIV/AIDS
toxicity, and high pill burden ultimately create a barrier to use and adherence.14 As
such, nondrug therapies and treatments are promoted as an alternative to medication,
and exercise, in particular, is regularly recommended given its potential to reduce
the impact of the various metabolic and morphologic abnormalities experienced by
HIV-infected individuals.15
EXERCISE AND HIV
The earliest studies testing the effects of exercise on persons with HIV centered on
issues of safety, efficacy, and physiological adaptation. Research was designed to
determine whether individuals were fully capable of completing and adapting to various intensities and types of exercise (e.g., aerobic and resistance training [RT]). The
results of these studies indicated that exercise could stimulate a number of significant
physical and mental health benefits and that these effects could occur without any
significant negative impact on the disease or its progression. For example, studies
showed that exercise was linked to improvements in aerobic fitness16, increases in
muscular strength17, and a reduction in the levels of fatigue, as well as depression
and anxiety.18–19 Moreover, none of these studies found significant negative effects on
immune and disease markers (e.g., CD4+ cell count and viral load), supporting the
safety of exercise for this population.
As outlined in the earlier chapters of this book, regular RT can independently and
significantly increase muscle mass, reduce the risks and effects of cardiovascular
and metabolic diseases, and decrease anxiety and depression. Given that muscle
wasting, metabolic complications, and mental health are issues for those with HIV/
AIDS, RT may be an ideal therapy to include as part of the treatment needed to manage HIV/AIDS and its medication side effects. The research on the benefits of RT for
this population is detailed in the section “Resistance Training Studies.”
RESISTANCE TRAINING STUDIES
Using an electronic search (PubMed, PsycINFO, and Web of Science), studies testing
a RT-only intervention for individuals with HIV/AIDS published in print or online by
December 2012 were collected. A total of 19 published articles were identified,19–37 with
8 of these describing different aspects of the same study, resulting in 11 independent
projects. Table 13.1 provides a summary of all the trials that compared RT to a non-RT
control group, which excluded 5 of the 11 independent trials identified in the search.
The first published study to investigate RT in an HIV-infected population was released
early in the epidemic and was conducted by Spence et al.20 At that time, azidothymidine
(AZT) was the primary medication used to treat HIV infection, and it only gradually
slowed the progression of the disease to AIDS. For the majority of those infected with
HIV, metabolic dysfunction, nervous system disorders, and myopathy led to significant
muscle and tissue wasting.38 Given the known effects of RT in the general population,
the authors hypothesized that RT would safely improve muscle function and lean body
mass for those with HIV. Participants were 24 males (mean age = 32) randomly assigned
to a RT (n = 12) or nonexercising control (n = 12) group. The RT group completed a
supervised, full-body program three times per week for 6 weeks (18 sessions) using
3 groups: AE; RT;
stretching and
flexibility (FLEX)
Lox et al.19,21
Sattler
2 groups: weekly
et al.24,25;
injections of
Schroeder et nandrolone
al.26,27;
(NAN); weekly
Jaque
injections of
et al.28
nandrolone
combined and
resistance training
(NAN + RT)
2 groups: RT;
nonexercise
control (CON)
Study Design
Spence
et al.20
Reference
Males with HIV/AIDS
(38.8)
Males with HIV/AIDS
previously recovered from
Pneumocystis carinii
pneumonia (32)
Males with HIV/AIDS (36)
Participant Characteristics
(Mean Age in Years)
3 sessions/week; 12
weeks
3 sessions/week; 12
weeks
33 (AE = 11;
RT = 12;
FLEX = 10)
30 (15 per
group)
3 sessions/week; 6
weeks
Frequency/Length
of Training
24 (12 per
group)
Sample Size
TABLE 13.1
Summary of Studies Testing Resistance Training in HIV/AIDS
3 sets; 8
reps
3 sets/10
reps
3 sets/15
reps
Sets/Reps
Intensity
AE did
50%–80%
of HRR;
RT did
60% of
1RM
80% 1RM
Light to
heavy
Outcomes
(Continued)
Sig. ↑ in BW and
strength for RT; sig. ↓
in BW and MS for
CON
Sig. ↑ in MS for RT; sig.
↑ in VO2max for AE; sig.
↑ in BW and mood/life
satisfaction for AE and
RT; no Δ in CD4+ for
any group
Sig. ↑ in BW, LBM, MS
for both groups; sig. ↓
in FM in NAN + RT; no
Δ in CD4+ for either
group
Jacob J. van den Berg and Joseph T. Ciccolo
207
4 groups: placebo,
no exercise (PNE);
testosterone, no
exercise (TNE);
placebo, exercise
(PE); testosterone,
exercise (TE)
3 groups: whey
protein (PRO);
RT; combined
whey protein and
resistance training
(PRO + RT)
2 groups: AE; RT
Study Design
HIV-infected males with
lipodystrophy (49.5)
Females with HIV (40.9)
HIV-infected males (41.8)
Participant Characteristics
(Mean Age in Years)
3 sessions/week;
14 weeks
3 sessions/week;
16 weeks
20 (AE = 10;
RT = 10)
3 sessions/week;
16 weeks
Frequency/Length
of Training
30 (10 per
group)
61 (PNE = 14;
TNE = 17;
PE = 15;
TE = 15)
Sample Size
3–4 sets;
8–12
reps
3 sets;
8–10
reps
3–4 sets;
12–15
reps
Sets/Reps
Intensity
Outcomes
Sig. ↑ in MS for all
groups; Sig. ↑ in BW,
LBM, FM for PRO; sig.
↑ in LBM for PRO +
RT; sig. ↓ in FM in RT;
Sig. ↑ in MS for TNE,
PE, TE; sig ↑ in BW for
TNE and PE; sig ↑ in
LBM in TNE and TE;
no Δ in HIV status for
any group
AE did interval Sig. ↑ IMGU, HDL in
training,
both groups; Sig. ↓ FFA
50%–100%
in both groups; AE had
VO2max;
sig. ↓ in TC, LDL,
RT did
CRP; RT had sig. ↓ in
50%–80%
TG; RT had sig. ↓ fat
1RM
mass versus AE
75% 1RM
60%–90%
1RM
1RM, one-repetition maximum; VO2max, maximum oxygen uptake; BW, body weight; MS, muscular strength; LBM, lean body mass; FM, fat mass; IMGU, insulin-mediated
glucose uptake; FFA, free fatty acids; TC, total cholesterol; CRP, C-reactive protein; TG, triglycerides
Lindegaard
et al.34
Agin
et al.22,23
Bhasin
et al.29
Reference
TABLE 13.1 (Continued)
Summary of Studies Testing RT in HIV/AIDS
208
Benefits of Resistance Training for HIV/AIDS
Jacob J. van den Berg and Joseph T. Ciccolo
209
hydraulic equipment. The load and volume were progressively increased from 1 set of 10
repetitions to 3 sets of 15 repetitions at higher settings (i.e., increased resistance) on various machines. At the 6-week time point, the RT group improved on 13 of the 15 study
variables when compared to the control. This included a statistically significant change
in body weight (mean increase = 1.7 kg) for the RT group, when compared to the control
(mean decrease = 1.9 kg). Upper and lower body muscular strength also significantly
increased in the RT group, whereas it decreased in the control group.
The positive results of Spence et al. eventually spurred other investigations into
the benefits of RT for HIV-infected individuals, particularly as medical treatment
advanced. In 1995, Lox et al.19,21 randomized 33 males (mean age = 36) into a
12-week intervention consisting of aerobic exercise (AE) (n = 11), RT (n = 12), and
a stretching/flexibility group (n = 10). Participants in AE and RT groups engaged in
three, supervised 45 minute sessions per week, while the control group was given a
home-based stretching program. The AE group exercised on a bicycle ergometer to
a target heart rate of 50%–80% of their estimated heart rate reserve (HRR), and the
RT group participated in a full-body program consisting of 3 sets of 10 repetitions,
at 60% of their one-repetition maximum (1RM). The weight used by the RT group
was progressively increased (by 2–4 kg) with the successful completion of all three
sets. Using Cohen’s d, effect size differences were reported for each group (classified
as small = 0.20; moderate = 0.50; and large, = 0.80).39 When compared to the AE
and control groups, results indicated larger positive effects for the RT group in total
body weight (RT = 0.31; AE = −0.04; control = −0.29), lean body mass (RT = 0.51;
AE =0.11; control = −0.30), upper body strength (RT = 1.90; AE = 0.10; control =
−0.40), and lower body strength (RT = 2.01; AE = 0.59; control = −27). The AE
group had larger positive change (1.05) in maximal oxygen uptake (VO2max) when
compared to the RT (0.28) and control (−0.08) groups. In addition, there were no
statistically significant changes in total CD4+ cells in the AE or RT groups, supporting the safety of exercise for those with HIV. Results also showed that participants
in the AE and RT groups had significant increases in positive mood states and life
satisfaction, whereas there was no change in the control group.
The findings from the above trials encouraged more research in this area. Shifting
away from using an all-male sample, Agin et al.22,23 conducted one of the first studies
with a female-only sample. The goal of the research was to determine whether whey
protein supplementation (PRO) (recommended for HIV at the time) would augment
gains in body weight and muscle mass when combined with RT. A total of 30 women
(mean age = 40.9) were randomized into one of three groups: PRO ( n = 10), resistance exercise (RE) (n = 10), or whey protein and resistance exercise (PRE) (n = 10).
Participants acted as their own controls and took part in a 6-week, nonintervention
assessment period prior to the 14-week experimental period. The PRO and PRE
groups were instructed to consume 1.0 g·kg−1 of whey protein powder to body weight
daily. The RE and PRE groups completed a full-body progressive program 3 days
per week. A total of 3 sets of 8–10 repetitions were prescribed, with loads set at 75%
of the baseline 1RM. Thereafter, adjustments in load were made to accommodate for
changes in strength. As determined by dual-energy x-ray absorptiometry, the PRO
group had a significant increase in body weight, lean body mass, and fat mass; the
RE group had no change in body weight or lean body mass, but did reduce fat mass;
210
Benefits of Resistance Training for HIV/AIDS
and the PRE group had no change in body weight, an increase in lean body mass, and
no change fat mass. In addition, all three groups had significant increases in upper
and lower body strength. It was concluded that RT was beneficial overall, but that
protein supplementation has independent positive effects.
Around the same time as Agin et al. study, investigations into the clinical ­benefits
that might be gained from combining RT with pharmacotherapy began. Sattler
et al.24 (and later Sattler et al.25, Schroder et al.26, Schroder et al.27, Jaque et al.28)
hypothesized that nandrolone decanoate, an anabolic steroid, would increase lean
body tissue, muscle mass, and strength in men with HIV and that these effects would
be enhanced with RT. A total of 30 male participants (mean age = 38.8) were randomly assigned to receive weekly injections of nandrolone alone (n = 15) or in combination with supervised RT (n = 15). Full-body RT sessions with free weights were
conducted three times per week for 12 weeks. Participants performed three sets of
eight repetitions for nine different exercises at 80% of the 1RM, with the final set
performed to failure. In addition, the 1RM was assessed once every 2 weeks to adjust
for changes in strength and maintain the 80% load. Total body weight and lean body
mass increased significantly in both groups, but lean body mass increased significantly more in the RT group. Gains in muscular strength were also greater in the
RT group, even when controlling for body mass. These results were similar to other
research investigating the effects of anabolic agents.29,30 For instance, Bhasin et al.29
examined the effects of testosterone replacement on muscle strength and body composition after 16 weeks of RT in a sample of HIV-infected men with low testosterone
levels and previous weight loss. Results indicated that testosterone and RT could be
helpful for changes in body weight, lean muscle mass, and muscular strength.
The mounting evidence was making it clear that RT was safe and beneficial for
those with HIV. Additional studies showed that RT could effectively increase muscle
mass and strength,31 and it seemed to be particularly advantageous for men suffering from wasting.32,33 As HIV/AIDS medical treatments advanced, however, muscle
wasting became less common, and a new focus on treating the metabolic complications resulting from ARV therapy came to the forefront. Peripheral insulin resistance,
hypertriglyceridemia, hypercholesterolemia, central adiposity (i.e., ­lipodystrophy), and
increased risks for cardiovascular disease were becoming the most common challenges
faced by those with HIV. Research in non-HIV-infected populations showed that both
AE and RT could positively affect these conditions; thus, Lindegaard et al.34 sought to
determine the differential effects of an AE and RT program for HIV-infected men with
an altered metabolic profile (i.e., dyslipidemia and presence of central adiposity). A
total of 20 males (mean age = 49) were randomized to AE or RT three times per week
for 16 weeks. The AE condition consisted of eight different routines with 35 minutes
of interval training. For the first 8 weeks, participants trained at a heart rate of 65%
of their baseline VO2max and at 75% for the last 8 weeks. The RT group engaged in a
full-body, progressive program, completing 3–4 sets of 8–12 repetitions with loads at
50%–80% of 1RM. Results indicated that both groups had a similar and significant
increase in high-density lipoprotein (HDL) cholesterol and insulin-mediated glucose
uptake (IMGU). Each group also experienced independent effects. Specifically, the AE
group had significant reductions in total cholesterol and low-density lipoprotein (LDL),
and the RT group had a significant increase in lean body mass, along with significant
Jacob J. van den Berg and Joseph T. Ciccolo
211
reductions in total and regional fat mass (trunk and limb), and triglycerides. The authors
concluded that although both types of exercise were beneficial, only RT was found to
reduce fat mass in this population (i.e., HIV-infected men with central adiposity).
Most recently, Souza et al.35,36 investigated the effects of a 12-month RT program on
strength, body composition, and physical fitness in a sample of 32 older adults (mean
age = 65). Participants with HIV infection (n = 11) were compared to an a­ ge-and
­gender-matched, non-HIV-infected control group (n = 21). The training ­program was
full-body and consisted of five different exercises: (1) leg press, (2) seated row, (3) lumbar extension, (4) chest press, and (5) seated abdominal. All participants exercised twice
per week, and exercises were done in 3 sets of 12, 10, and 8 repetitions at light, moderate, and heavy loads, respectively. Variations in the loads were adjusted bimonthly to
accommodate increases in strength as the program progressed. From baseline to end
of treatment (i.e., 12 months), there were significant changes in strength for all muscle
groups in both arms of the study, with no major effect of age, gender, HIV infection,
HIV/AIDS pathology, or HIV medication. Neither group had significant changes in
body composition, bone mass, or blood lipids. The authors concluded that RT was a
safe and effective intervention to increase strength in older adults with HIV.
CONCLUSION AND FUTURE DIRECTIONS
To date, there is satisfactory evidence to support the use of RT for individuals with
HIV/AIDS, as clinical improvements in muscle strength, lean body mass, body
weight, body composition, blood lipids, and health-related quality of life have been
reported. These effects, importantly, have occurred without a reduction in CD4+
cell count or HIV viral load, even in samples with significant disease progression.
Caution is needed, however, as these findings are limited by a small number of studies over a greater than 20-year period. In addition, eligibility criteria for enrollment
have varied widely across the research conducted thus far, despite the uniformly
small sample sizes and focus on middle-aged males. Furthermore, only one intervention has been longer than 16 weeks, and there has been very little variation in the type
of RT completed or the progression model/prescription used. Future RT research
will be needed to reflect the current HIV/AIDS population by including much larger
samples and far greater numbers of women, minorities, low-income groups, substance abusers, individuals with hepatitis C, children, adolescents, and older adults.
More studies will also be needed to test individuals at various stages of the disease,
and with more sophisticated RT programming. Finally, as survivor rates continue to
grow, studies will be needed to investigate how RT can be used to prevent and treat
illness in the newer population of HIV-infected individuals who are now at risk for,
or are currently suffering from, cardiovascular disease, type 2 diabetes, and obesity.
REFERENCES
1. UNAIDS. Global report. UNAIDS report on the global AIDS epidemic 2012. Geneva,
Switzerland: WHO Library; 2012.
2. Centers for Disease Control and Prevention (CDC). HIV Surveillance Report. 2010;
vol. 22. Available at http://www.cdc.gov/hiv/topics/surveillance/resources/reports/.
Accessed 2/5/2013.
212
Benefits of Resistance Training for HIV/AIDS
3. CDC. National Vital Statistics System. Death, percent of total deaths, and death rates
for the 15 leading causes of death in 10-year age groups, by race and sex: United States,
1999–2007. Atlanta, GA: CDC; 2011. Available at http://www.cdc.gov/nchs/nvss/­
mortality/lcwk2.htm. Accessed 2/5/2013.
4. Antiretroviral Therapy Cohort Collaboration. Life expectancy of individuals on
­combination antiretroviral therapy in high-income countries: a collaborative analysis of
14 cohort studies. Lancet. 2008;372:293–9.
5. Petoumenos K, Worm SW. HIV infection, aging and cardiovascular disease: epidemiology and prevention. Sex Health. 2011;8:465–73.
6. Tebas P. Insulin resistance and diabetes mellitus associated with antiretroviral use
in HIV-infected patients: pathogenesis, prevention, and treatment options. J Acquir
Immune Defic Syndr. 2008;49 Suppl 2:S86–92.
7. Dudgeon WD, Phillips KD, Carson JA, Brewer RB, Durstine JL, Hand GA. Counteracting
muscle wasting in HIV-infected individuals. HIV Med. 2006;7:299–310.
8. Rao MN, Lee GA, Grunfeld C. Metabolic abnormalities associated with the use of protease inhibitors and non-nucleoside reverse transcriptase inhibitors. Am J Infect Dis.
2006;2:159–66.
9. Banerjee S, McCutchan JA, Ances BM et al. Hypertriglyceridemia in combination
­antiretroviral-treated HIV-positive individuals: potential impact on HIV sensory polyneuropathy. AIDS. 2011;25:F1–6.
10. Fellay J, Boubaker K, Ledergerber B et al. Prevalence of adverse events associated with
potent antiretroviral treatment: Swiss HIV Cohort Study. Lancet. 2001;358:1322–7.
11. Scherzer R, Heymsfield SB, Lee D et al. Decreased limb muscle and increased central adiposity are associated with 5-year all-cause mortality in HIV infection. AIDS.
2011;25:1405–14.
12. Bastard JP, Caron M, Vidal H et al. Association between altered expression of
­adipogenic factor SREBP1 in adipocyte differentiation and insulin resistance. Lancet.
2002; 359:1026–31.
13. Chew NS, Doran PP, Powderly WG. Osteopenia and osteoporosis in HIV: pathogenesis
and treatment. Curr Opin HIV AIDS. 2007;2:318–23.
14. Kaplan JE, Benson C, Holmes KH, Brooks JT, Pau A, Masur H. Guidelines for prevention and treatment of opportunistic infections in HIV-infected adults and adolescents.
MMWR Recomm Rep. 2009;58:1–207.
15. Wanke CA, Falutz JM, Shevitz A, Phair JP, Kotler DP. Clinical evaluation and management of metabolic and morphologic abnormalities associated with human immunodeficiency virus. Clin Infect Dis. 2002;34:248–59.
16. Nixon S, O’Brien K, Glazier RH, Tynen AM. Aerobic exercise interventions for adults
living with HIV/AIDS. Cochrane Database Syst Rev. 2005;3:1796.
17. O’Brien K, Nixon S, Glazier RH, Tynan AM. Progressive resistive exercise intervention
for adults living with HIV/AIDS. Cochrane Database Syst Rev. 2004;4:CD004248.
18. Smith BA, Neidig JL, Nickel JT, Mitchell GL, Para MF, Fass RJ. Aerobic exercise:
effects on parameters related to fatigue, dyspnea, weight and body composition in HIVinfected adults. AIDS. 2001;15:693–701.
19. Lox CL, McAuley E, Tucker RS. Exercise as an intervention for enhancing subjective
well-being in an HIV-1 population. J Sport Exerc Psyc. 1995;17:345–62.
20. Spence DW, Galantino ML, Mossberg KA, Zimmerman SO. Progressive resistance
exercise: effect on muscle function and anthropometry of a select AIDS population.
Arch Phys Med Rehabil. 1990;71:644–8.
21. Lox CL, McAuley E, Tucker RS. Physical training effects on acute exercise-induced
feeling states in HIV-1-positive individuals. J Health Psych. 1996;1:235–40.
Jacob J. van den Berg and Joseph T. Ciccolo
213
22. Agin D, Gallagher D, Wang J, Heymsfield SB, Pierson RN Jr, Kotler DP. Effects of
whey protein and resistance exercise on body cell mass, muscle strength, and quality of
life in women with HIV. AIDS. 2001;15:2431–40.
23. Agin D, Kotler DP, Papandreou D et al. Effects of whey protein and resistance exercise
on body composition and muscle strength in women with HIV infection. Ann N Y Acad
Sci. 2000;904:607–9.
24. Sattler FR, Jaque SV, Schroeder ET et al. Effects of pharmacological doses of
nandrolone decanoate and progressive resistance training in immunodeficient
patients infected with human immunodeficiency virus. J Clin Endocrinol Metab.
1999;84:1268–76.
25. Sattler FR, Schroeder ET, Dube MP et al. Metabolic effects of nandrolone ­decanoate and
resistance training in men with HIV. Am J Physiol Endocrinol Metab. 2002;283:1214–22.
26. Schroeder ET, Jaque SV, Hawkins SA et al. Regional DXA in assessment of muscle
adaptation to anabolic stimuli. Clin Exerc Physiol. 2001;3:199–206.
27. Schroeder ET, Terk M, Sattler FR. Androgen therapy improves muscle mass and
strength but not muscle quality: results from two studies. Am J Physiol Endocrinol
Metab. 2003;285:E16–24.
28. Jaque SV, Schroeder ET, Azen SP et al. Magnitude and timing of regional body composition changes during anabolic therapies in HIV-positive men. Clin Exerc Physiol.
2002;4:50–9.
29. Bhasin S, Storer TW, Javanbakht M et al. Testosterone replacement and resistance
exercise in HIV-infected men with weight loss and low testosterone levels. JAMA.
2000;283:763–70.
30. Strawford A, Barbieri T, Van Loan M et al. Resistance exercise and supraphysiologic
androgen therapy in eugonadal men with HIV-related weight loss: a randomized controlled trial. JAMA. 1999;281:1282–90.
31. Yarasheski KE, Tebas P, Stanerson B et al. Resistance exercise training reduces hypertriglyceridemia in HIV-infected men treated with antiviral therapy. J Appl Physiol.
2001;90:133–8.
32. Roubenoff R, McDermott A, Weiss L et al. Short-term progressive resistance training
increases strength and lean body mass in adults infected with human immunodeficiency
virus. AIDS. 1999;4:231–9.
33. Roubenoff R, Wilson IB. Effect of resistance training on self-reported physical functioning in HIV infection. Med Sci Sport Exerc. 2001;33:1811–17.
34. Lindegaard B, Hansen T, Hvid T et al. The effect of strength and endurance training
on insulin sensitivity and fat distribution in human immunodeficiency virus-infected
patients with lipodystrophy. J Clin Endocrinol Metab. 2008;93:3860–9.
35. Souza PM, Jacob-Filho W, Santarém JM, Zomignan AA, Burattini MN. Effect of progressive resistance exercise on strength evolution of elderly patients living with HIV
compared to healthy controls. Clinics (Sao Paulo). 2011;66:261–6.
36. Souza PM, Jacob-Filho W, Santarém JM, Silva AR, Li HY, Burattini MN. Progressive
resistance training in elderly HIV-positive patients: does it work? Clinics (Sao Paulo).
2008;63:619–24.
37. Sakkas GK, Mulligan K, Dasilva M et al. Creatine fails to augment the benefits from
resistance training in patients with HIV infection: a randomized, double-blind, placebocontrolled study. PLoS One. 2009;4:e4605.
38. Weinroth SE, Parenti DM, Simon GL. Wasting syndrome in AIDS: pathophysiologic
mechanisms and therapeutic approaches. Infect Agents Dis. 1995;4:76–94, Review.
39. Cohen J. Statistical power analysis for the behavioral sciences (2nd edn.). Hillsdale, NJ:
Lawrence Erlbaum; 1988.
14
Resistance Training
for Individuals with
Orthopedic Disease
and Disability
CONTENTS
Introduction............................................................................................................. 220
Scope of Orthopedic Disease and Disability...................................................... 220
Quality of Life: Pain, Strength, and Physical Function..................................... 220
Pain..................................................................................................................... 221
Strength and Physical Function.......................................................................... 221
Chronic Low Back Pain.......................................................................................... 222
Overview............................................................................................................ 222
Prevention........................................................................................................... 223
Treatment........................................................................................................... 223
Stability System and Spinal Stability................................................................. 223
Movement System and Back Extension Strength..............................................224
Osteoarthritis........................................................................................................... 225
Overview............................................................................................................ 225
Prevention........................................................................................................... 226
Treatment........................................................................................................... 226
Rheumatoid Arthritis............................................................................................... 227
Overview............................................................................................................ 227
Prevention........................................................................................................... 227
Treatment........................................................................................................... 228
Osteoporosis............................................................................................................ 229
Overview............................................................................................................ 229
Prevention........................................................................................................... 229
Mechanical Loading and Bone Mineral Density............................................... 230
Muscular Strain and Bone Mineral Density....................................................... 230
Treatment........................................................................................................... 231
Adherence Issues.................................................................................................... 232
Overview............................................................................................................ 232
Pain, Kinesiophobia, and Catastrophizing......................................................... 232
215
216
Resistance Training for Individuals with Orthopedic Disease and Disability
Individual Differences........................................................................................ 233
Readiness for Change......................................................................................... 233
Individual Preference......................................................................................... 234
Motivation Type................................................................................................. 234
Conclusion.............................................................................................................. 235
References............................................................................................................... 236
Mark D. Faries
INTRODUCTION
Scope of Orthopedic Disease and Disability
Orthopedic disease and disability encompasses conditions that inflict the musculoskeletal system and is considered a leading cause of disability in the United States.1 The
years 2002–2011 were proclaimed as the United States Bone and Joint Decade, with
national recognition to the burden of musculoskeletal diseases (BMUS). As a result, a
collaborative movement sanctioned by the World Health Organization was ­developed
to raise awareness, advance understanding of prevention, and improve on the burden
of musculoskeletal disease in the United States (http://www.boneandjointburden.org).
Over 110 million U.S. adults reported some form of musculoskeletal condition
in the 2008 National Health Interview Survey, which represented nearly one out of
every two adults (from BMUS). Data from the same survey show that orthopedic
disease and disability becomes more widespread with age, accounting for more than
50% of all chronic conditions in individuals 50 years of age or older.2 Because age,
muscle weakness, and obesity are the three important risk factors for musculoskeletal
disease and disability, these numbers will continue to escalate parallel with the growing population of older adults, sedentary lifestyles, and obese individuals. In addition
to the burden of these three risk factors, the individual with an orthopedic disease or
disability now has the added burden of the condition and its outcomes, such as pain,
weakness, stress, depression, and decrements in well-being, physical function, work
abilities, and activities of daily living (ADL). As a result, many suffer a tremendous
reduction in quality of life (QOL) and increased risk of premature death.
Evidence-based understanding is still trying to catch up to the growing burden
of orthopedic diseases and disability. However, current research sheds more light
on the specific role of resistance training on the most widely discussed conditions,
which are highlighted in this chapter: chronic low back pain (CLBP), osteoarthritis
(OA), rheumatoid arthritis (RA), and osteoporosis.
Quality of Life: Pain, Strength, and Physical Function
Musculoskeletal diseases and disabilities provide a unique avenue to stretch the
understanding and impact of resistance exercise, moving beyond the traditional mold
Mark D. Faries
217
of three sets of ten with common weight room type lifts. However, when dealing with
resistance training and health, such as these orthopedic disorders, proper prescription takes into account the specificity of the program variables, individual goals, and
condition status.3 For instance, one of the main goals of resistance exercise in all
orthopedic conditions is to improve the individual’s QOL. As such, the specificity of
prescription provides a unique exploration of functionality and goals that can deviate
from many common goals associated with resistance training.
Despite the known benefits of resistance exercise, there are currently no confirmed
prescription standards for the orthopedic conditions highlighted in this chapter. Without
the standardized prescriptions, the emphasis on specificity and progressive resistance
training becomes even more important. Resistance programs should be designed to
meet the needs of the individual, and this chapter is only to be used as a guide and not
as the exact prescription for every individual with an orthopedic disease and disability.
With this understanding, it is also important to understand the three most common
outcomes from resistance training to impact one’s QOL: pain, strength, and function.
Pain
Pain reduction is a significant outcome from within orthopedic disorders. Every condition discussed within this chapter can have perpetual pain associated with it, and
resistance training offers a valuable intervention to aid in the reduction. The experience with pain can be debilitating for the individual, preventing physical activity, and
subsequently negatively affecting other important areas in their life, such as functional
capacity for ADL and psychological health. For example, knee OA, that is sufficiently
severe to consider joint replacement, may represent a minority of all individuals with
knee pain4; however, this means that the majority of the inflicted are going about their
day-to-day functions in pain and have to cope with the pain and decreased function
associated with the condition. Coping with the pain is beyond the scope of this chapter,
but is extremely important in the long-term management of the condition. Resistance
exercise can play an important role, even as a coping mechanism in some individuals.
Interestingly, the discomfort resulting from resistance training (e.g., exerciseinduced discomfort, fatigue, soreness) may be perceived by the individual as a worsening of the orthopedic condition, which is discussed later in the Adherence Issues
section. The pain may also lead to kinesiophobia and/or catastrophizing in individuals with an orthopedic concern. Catastrophizing is the overly negative, even irrational, thoughts making a situation and the future much worse than it actually is (i.e., a
catastrophe). So, as the goal of resistance training prescription is to provide reduction
in acute and chronic pain, the benefits far exceed pain reduction into the enhancement
of QOL, coping, and a reduction in kinesiophobic and catastrophic thought processes.
Strength and Physical Function
Pain and muscle weakness work as a notorious tag team to inhibit physical function
in the orthopedic population. The inability to function physically at a level to meet
the demands of daily life is a very important reason for resistance exercise should
be used in this population. Muscle weakness is a common risk factor and symptom
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Resistance Training for Individuals with Orthopedic Disease and Disability
across all musculoskeletal disorders discussed in this chapter. Most research has
focused on the ability of resistance training to improve strength, which is commonly
tested isometrically or isokinetically. In these cases, strength is considered as a force
that can be generated under a maximal contraction or load. However, the role of
resistance training on muscle weakness moves well beyond the ability to produce
isolated maximum muscle force. In regards to orthopedic disorders, strength should
be seen as a functional concept, or its ability to translate to and meet the demands of
the particular needs, functions, and goals of the individual.
In this population, strength may be better operationalized as simply the ability of
a muscle or group of muscles to generate force. Individuals with orthopedic concerns
are not necessarily in need of maximal exertion, rather strength to perform their
ADL, such as standing from a chair, walking up stairs, opening a jar, lifting a child,
or preventing falls. Strength, as seen in this manner, is intrinsic to daily function.
Thus, progressive resistance training programs in this population may be more specifically and better designed to enhance “functional strength,” which will also dictate
the training variables that would be prescribed (e.g., intensity, volume, rest, stability).
Improving general muscle strength is important, but the subsequent impact on
physical functioning and QOL may be the more impactful goal to be kept in mind
with progressive resistance training prescriptions. With this specificity, there may
be a distinction between the optimal prescription and the individual’s condition
and needed level of physical functioning. For instance, high-impact, dynamic resistance exercise may be an optimal prescription for increasing bone mass, but it is
commonly contraindicated in clinically diagnosed osteoporotic individuals due to
increased risk of fracture. Resistance exercise should never worsen the orthopedic
condition, so prescription (even if not optimal) should first accommodate the contraindications of the condition, and then be progressive to meet the functional demands
and symptomatology of the individual.
CHRONIC LOW BACK PAIN
Overview
CLBP syndrome is one of, if not the most widely experienced, the orthopedic conditions in the world, and the National Institute of Neurological Disorders and Stroke
rates CLPB only second to headaches as the most common neurological ailment in the
United States. Reports estimate that 70%–80% of Americans experience back pain
at some time in their life, with CLBP being a leading cause of absenteeism from the
workplace. Americans spend at least $50 billion each year on low back pain (LBP),
with total cost estimations of $100 to $200 billion annually. Although many experience
LBP, most recover within a few months of onset, unless slowed by complicating issues
(e.g., sciatica, bulging disk, spinal degeneration, spinal stenosis, spondylitis, fibromyalgia, or osteoporosis). In addition, recurrence of LBP is extremely common. The case
becomes clinically classified as CLBP when it persists for more than 3 months. CLBP
is commonly progressive and has causes that may be difficult to determine.
Anatomically speaking, the low back includes the five lumbar vertebrae (L1–L5),
­­
which support the weight of the upper body. The pain experienced with CLBP may
Mark D. Faries
219
stem from several sources, but the most common suggestions are from the result of
trauma (e.g., lifting injury), a disorder (e.g., OA), age-related wear and tear, body
weight status, sedentary lifestyle, muscle weakness and spinal instability, and imbalances resulting in postural deficiencies. More specifically with the spine, the muscles
that keep the spine stable and stiff can become weak, less elastic, and lose strength
and endurance. CLBP may also reflect nerve damage, muscle irritation and/or lesions
on the bone. These issues can subsequently cause the intervertebral disks to lose
fluid and flexibility subsequently affecting the disks’ ability to cushion the vertebrae.
Symptoms may range from aching pain to intense stabbing pain and may involve
radiating pain or numbness, such as down the leg.
Prevention
CLBP syndrome can occur in males and females, across all ages, although occurs
most in middle-aged to older adults. The sedentary lifestyle promotes a reduction in
muscle quality, strength, and postural stress on the low back. Of course, dynamic
progressive resistance training is able to positively impact muscle quality and counter many of the effects of an inactive lifestyle. From a prevention standpoint, resistance training can provide the adequate strength and functionality needed to prevent
or delay the onset of CLBP.
Another potential consideration for the prevention of LBP stems from healthy
individuals performing particular resistive exercises incorrectly, with too much spinal flexion or posterior pelvic tilting, and choosing exercises that may put them at
risk for low back injury, such as bent knee sit-ups.5 In addition, the effect of resistance exercise on improving the ability of the musculature to stabilize the spine may
be an important preventive measure for LBP. Because of the multifactorial etiology
of CLBP and potential for “buckling” of the spine, preventive resistive exercise may
be more advantageous to focus on the endurance capacity of the trunk musculature,
rather than strengthening alone.
Treatment
Trunk muscle weakness and lumbar instability are often considered significant factors in CLBP. Resistance exercise is effective in improving muscular strength and
reducing self-reported pain in patients with CLBP, by focusing on both the strength
and endurance of the trunk musculature, including abdominals and low back. More
specifically, the prescription of resistance exercise varies by which muscular “core”
system is to be trained.
The core musculature is generally defined as the 29 pairs of muscles that support
the lumbo–pelvic–hip complex to stabilize the spine and pelvis. To ensure the stability of the spine for force production and injury prevention, these core muscles must
have sufficient strength, endurance, and recruitment patterns. The core consists of
two systems, the local and the global systems. The separation of these two systems is
important, as the specific system should dictate the resistance exercise prescription
(for a review, see the study by Faries and Greenwood6).
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Resistance Training for Individuals with Orthopedic Disease and Disability
Stability System and Spinal Stability
The local or “stabilization” system describes the deeply placed muscles that are
designed to stabilize the spine before and during movement. The spine is inherently
unstable and requires the stabilization system musculature to protect against external
forces and compression loads. Segmental instability of the vertebrae describes a loss
of stiffness, so that a particular force will produce greater displacement than what
would occur normally. The type I fatigue-resistant muscles of the stability system,
such as the multifidus and transversus abdominis (TrA), have shorter muscle lengths,
and are activated at low resistance levels (e.g., 30%–40% of maximal voluntary contraction). These muscles contract isometrically, attempt to provide support for the
spine through segmental stiffness (i.e., multifidus), and act as a corset to increase
intra-abdominal pressure (i.e., TrA).
In healthy individuals without CLBP, these muscles are able to activate before
movement of the limbs to help stabilize the spine. However, in individuals with
CLBP, these muscles show weakness and delayed activation with limb movement,
resulting in ineffective ability to stabilize the spine.7 Resistance exercise is able to
improve the functionality of this musculature, especially when focused on endurance-based exercises with little to no movement of the spine, such as a quadruped,
supine, prone, and side bridging (i.e., stabilization exercises).
Many of these stabilization exercises are also performed with abdominal hollowing, which is the co-contraction of only the local system muscles and is accomplished by isometrically contracting and drawing in the abdominal wall or navel
without movement of the spine or pelvis. This technique limits the activation of the
superficial global muscles, such as the rectus abdominis and external obliques, while
emphasizing the activation of the TrA to improve sacroiliac joint laxity.8 Isometric
exercises with abdominal hollowing, and abdominal hollowing alone, have been
used as an effective treatment by reducing pain and functional disability levels in
patients with CLBP and confirmed diagnosis of spondylolysis or spondylolisthesis.9
However, there has been concern about the abdominal hollowing technique
being performed during other more dynamic exercises, because of the inability to
receive the added benefit of intra-abdominal pressure from the co-contraction of
the global system muscles (i.e., abdominal bracing). Abdominal hollowing limits
activation of many global system muscles that are normally active during dynamic
movements, thus preventing the natural abdominal co-contraction of all musculature. However, if dynamic resistive exercise is being performed, then there will be
a shift in specificity from the stabilization system to the movement system. There is
common consideration that the local system should be trained before advancement
into larger movements for the movement system with individuals with CLBP.
Movement System and Back Extension Strength
The global or “movement” system includes the rectus abdominis, external oblique,
and erector spinae. Although these muscles can provide aid in intra-abdominal pressure for spinal stability, their primary action is to move the spine. Extensor muscle
weakness has been linked with CLBP, and back extension machine exercises are
Mark D. Faries
221
the most common resistive modality for increasing the low back extension strength.
Prescription typically centers on a moderate to high intensity of 8–15 repetition maximum (RM) and a frequency of one to two times per week. One lumbar extension
training session per week at 80% of maximum isometric force was shown to be just
as effective as two sessions per week for strength gains and reductions in perceived
pain.10
A key to the effectiveness of back extension exercise is maintaining pelvic stabilization. Pelvic stabilization involves a pad against the posterior hips and a strap
around the upper thigh to keep the pelvis secure against the seat of the back extensor
machine. Resistive back extension exercises without pelvic stabilization have been
shown to be ineffective in improving muscular strength or reducing LBP.11,12
There is an ongoing discussion of the preferred use of machine versus free-weight
modalities, isolation versus multijoint, stable versus unstable surfaces, and unilateral versus bilateral for improving the function of the trunk musculature and overall
functional abilities (e.g., Behm et al.13). In short, the greater the muscle activity and
lesser the force production, the more unstable and unilateral the modality, such as
using free weights over machines, replacing a chest press bench with a stability ball,
or performing a unilateral shoulder press instead of two arms at the same time.
Further research is needed on the ability of these various methods to improve pain,
disease, and functional outcomes in CLBP, and any possible changes to muscle activation and force production as a result of training adaptations.
Thus, in patients with CLBP, it appears that the best combination for treatment
and improvement in pain reduction, increases in strength, and improvements in
functionality may be a concurrent use of local-system core low-intensity, endurance
training (e.g., bridging) and global system high-intensity machine lumbar extension
training with pelvic stabilization. Danneels et al.14 found that combining s­ tabilization
system exercises with dynamic-static progressive resistance training was far superior
than the modalities used alone, for increasing the cross-sectional area of the lumbar
multifidus in patients with CLBP. More general, progressive resistance training, with
the use of unstable surfaces, unilateral and free-weight exercises need to be further
examined for efficacy in CLBP. As with all other orthopedic conditions, the individual status and needs should dictate the progression and specificity of resistance
training prescription.
OSTEOARTHRITIS
Overview
Arthritis is a general term for joint inflammation and is a considerable growing
­public health problem in the United States. Arthritis afflicts 22% or approximately
50 million adults of age 18 or older.15 Older adults have a higher prevalence of arthritis, at approximately 50% of those aged 65 or older. Arthritis is a common cause of
disability and joint replacement (e.g., hip and knee), and it is complicated by age,
decreased physical activity and obesity. Approximately 9.4%, or 21 million adults,
have arthritis-attributable activity limitation, and an increased percentage of obese
individuals (33.8% of women and 25.2% of men) have doctor-diagnosed arthritis.15
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Resistance Training for Individuals with Orthopedic Disease and Disability
In addition, because of the high levels of obesity and inactivity, there is a high prevalence of cardiovascular risk factors, including hypertension, dyslipidemia, and diabetes in individuals with OA.16
“Wear and tear” arthritis is the most common form of OA. With OA, there is a
wearing down of the protective cartilage, with the most common areas being the
knee and the hip joints. The prevalence of OA increases with age and is associated
with joint pain, physical disability, decreased functionality, and poor health status.
The ­progression in OA can be quite rapid and is a common reason for knee and hip
replacement surgery. The pain, gait impairment, and decreased functionality can
also lead to an increase in fall risk. Arnold and Faulkner17 found that 45% of adults
with hip OA have reported at least one fall over the previous year, with 77% ­reporting
near falls. Falls in the older adult population can lead to severe injuries, including
fractures, traumatic brain injury, and early death. Nonfatal falls can lead to high
medical costs, disability, and fear of falling, which can in turn limit physical activities, reduced mobility, and loss of physical fitness.
Prevention
The etiology of OA is multifactorial, complex, and not fully understood. Risk factors
do include increasing age, gender (women are more at risk), previous joint injuries,
repetitive occupational tasks that wear on the joints, sedentary lifestyle, and obesity.
As little as 11 pounds of weight loss reduced the risk of developing OA in women
by 50%18. Despite no clear prevention being available, factors such as muscle weakness, joint laxity, sedentary lifestyle, and obesity, alongside the systemic factor of
decreased bone mineral density (BMD), make a strong argument for the use of resistance training for the prevention of OA.
Treatment
A main outcome of treatment within this population is to promote an improved
QOL through reduction in pain, stiffness, swelling and improved strength, joint
stability, and functional status for ADL. Resistance exercise has been shown to
improve on all these outcomes. There is also hopeful evidence of the positive effects
of RT on the disease progression of OA.19 In addition, there appears to be little to no
direct evidence for contraindication concerns for resistance training in individual
with OA.20
The research on knee and hip OA treatment has focused on progressive isotonic
training modalities with machines, free weights, Therabands, and items around the
home.21 Positive results have been shown across all modalities, but individual access
may dictate which modality is used. Most protocols focus on the quadriceps and
hamstring exercises, such as knee extension, flexion, body weight squats, and leg
presses. Strength measures are usually specific to the training modality. Although
not as common, other modes, such as isokinetic, eccentric only, and water-based
resistance exercise can provide benefit.
Mark D. Faries
223
The mixed use of intensity, duration, and volume in research methodologies has
heavily contributed to the current inability to establish more concrete norms of prescription in arthritis. With knee OA, resistance training prescription is typically light
to moderate (40%–60%), but higher intensities (>60% of maximum) appear to be
tolerable and provide further benefit.22 However, these trends for the use of higher
intensities must be specified to the needs and abilities of the population. If the intensities are too high, then greater pain and disability may result. Thus, higher intensity
should be chosen relatively to reduce pain and enhance functional outcomes, but
limited to not negatively affect the OA condition.
The low to moderate intensities translate within the literature to anywhere from
3 to 20 repetitions. Durations have normally ranged from 10 to 60 minutes per
­session, at an average volume of three sets per exercise or muscle group (range
= 1–10 sets). Frequency tends to remain around 2–3 days per week, but may be
­tolerable at higher frequencies. Without an established dose–response relationship of intensity, duration, or frequency on OA outcomes, all individuals should
be properly progressed across all variables on an individualized manner. Until
standards are established, a professional qualified to work with these individuals, and who understands the nuances associated with arthritis, should supervise
prescriptions.
Perhaps, the largest impact of resistance training on OA is the impact on functional capacity, with most studies reporting significant improvements in self-reported
levels of physical debility.21 Improved function could be a result of the increased
strength, reduced pain, improved mental states, and enhanced self-efficacy following
resistance training. For many individuals stricken with OA, the ability to go about
daily functions that were once delimitated due to pain and lack of functional strength
is an important reason for a progressive resistance training prescription.
RHEUMATOID ARTHRITIS
Overview
RA is a long-term autoimmune disease, where the body attacks healthy ­tissue,
resulting in inflammation of joints and surrounding tissue, deformities, joint
­
­destruction, pain, and functional impairments. Risk factors typically include age,
gender, family history, and smoking. There can be extreme complications with
RA (e.g., rheumatoid lung, rheumatoid vasculitis, cardiovascular incidents), so
consultation with a rheumatologist should be sought before resistance training
participation.
In general, individuals with RA can maintain an active lifestyle, with resistance
exercise being highly promoted for improvements in strength, pain, and functional
abilities. RA can impact bone health and function leading to osteoporosis, so resistance training can provide this added benefit in individuals with RA.
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Resistance Training for Individuals with Orthopedic Disease and Disability
Prevention
RA can impact any age and all areas of the body, but the most attention has focused
on the lack of strength in the hands. Risk factors are unclear, but are thought to
include genetics and environmental triggers. Subsequently, there is not a clear link
between resistance exercise and the prevention of RA. However, strengthening exercises may be quite beneficial in the prevention of the progression of the disease,
deformities, loss of function, and strength of the hands. With no known prevention,
many of the medical treatments that are subsequently used can also cause serious
side effects.
Treatment
Resistance training as treatment for RA remains somewhat controversial, as historically, there was worry that higher intensity exercise could increase disease activity
and accelerate joint damage. However, longitudinal, randomized trials using full
body, dynamic resistance training for up to 5 years (50%–70% 1 RM, 2 sets per
exercise at 8–12 repetitions) were able to increase strength and physical functioning without negative effects on RA disease activity in the hands and feet.23,24 Even
higher intensity, full-body resistive (50%–70% of max), and concurrent endurance
interventions show promising results for individuals with RA.25,26 A more recent
review found moderate- to high-intensity, weight-bearing exercise to be safe in RA,
considering disease activity and no additional radiologic damage of the hands and
feet.27 Even low-intensity progressive resistance training using isokinetic knee extension exercises at 50% of maximal voluntary contraction did not exacerbate knee joint
inflammation in RA patients.28 Of course, all prescriptions should be individualized,
and there is a general understanding that “flare-ups” in RA may dictate rest from
resistance training.
Much of the research on the treatment of RA with resistance training has focused
on the hands, specifically the improvement of grip strength and perceived functional capacity. Resistance exercise prescriptions for the hands commonly consist of
combinations of isotonic and isometric modalities, and functional levels of strength
can occur without changes in muscle volume or size.29 Grip strengthening exercises
involve a Digiflex apparatus; rubber ball squeezes; or hand putty exercises, such as
squeezing, rolling, or folding, and it can provide strengthening of the entire hand
and wrist. These exercises are usually light to moderate in intensity of 2–10 sets,
and isometric grip exercises may range from 10- to 30-second holds. Improvements
in RA outcomes have been seen in studies lasting from 8 weeks to 2 years. Strength
in the hands should not be taken lightly, as decrements in grip strength with aging
is positively related to falls in older adults, alongside predictability of the number of falls, development of disability, and likelihood of premature mortality.30
Thus, maintaining grip strength may be a crucial step in the prevention of falls and
disability.
Other areas, such as psychological outcomes (e.g., depression), have been scarcely
studied,19,25 but hold important implications to the RA patient. Pain from RA can
be overwhelming and extremely debilitating in many individuals, which results in
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225
catastrophizing, psychological disorder and depression. A meta-analytic review has
shown that depression is more common in RA patients than healthy individuals.31
This depression may be highly attributable to the pain experienced in this population.
Resistance training has been previously shown to improve depressive symptoms,
with strength gain being directly related to reduction in symptoms. For example,
Singh et al.32 found that high-intensity progressive resistance exercise (80% of max)
was far more effective in reducing self-reported depression than both l­ow-intensity
resistance exercise (20% of max) and general practitioner care for clinical depression in adults aged 60 years or older. Approximately 61% of the high-intensity group
observed a 50% reduction in depression scores, as compared to only 29% and 21%
in the low-intensity resistance training and general practitioner care groups, respectively. Because pain, decreased function, and psychological health issues are interrelated in individuals with RA, progressive resistance training provides an ideal
prescription.
OSTEOPOROSIS
Overview
Osteoporosis is the most common bone disease, describing the porous thinning of
bone tissue, resulting in loss of BMD, increased frailty, and heightened fracture risk.
Osteoporotic fractures can result with no major trauma, such as from a minor fall,
twisting, reaching, coughing, or even sneezing. Falls are common in the osteoporotic
population, alongside sarcopenia, muscle weakness, cognitive decline, depression, and
decrements in balance and perceived functionality. Fractures in this population, which
are most common in the hip (femoral neck) and vertebrae, are responsible for a decreased
QOL, admission to long-term care, and an increase in morbidity and mortality.
Clinical levels of osteoporosis are a step beyond opsteopenia or low bone mass.
Based on dual-energy x-ray absorptiometry, the World Health Organization defines
osteopenia as a BMD of 1.0–2.5 standard deviations below the BMD of a young
healthy adult (T-score of −1.0 to −2.5), and osteoporosis as a BMD more than
2.5 standard deviations below this young normal adult BMD (T-score of <−2.5).
According to the 2005–2008 National Health and Nutrition Examination Survey,33
approximately 9% of adults aged 50 years or older had osteoporosis. The prevalence
does differ across age and gender, with it being higher in women and older adults. In
the United States, approximately 0.8 million (2%) of men and one out of every five
women (4.5 million, 10%) aged 50 years and older have osteoporosis.
Prevention
Physically active individuals typically hold a greater BMD than sedentary individuals, and thus are at a reduced risk of osteoporosis. However, age-related decrements
in bone-forming cell activity occur in all populations after ~35 years, thus the goal
of prevention is to maintain or increase BMD. The evidence supports the ability to
increase BMD at younger ages, but maintenance of bone mass may be the focus in
middle-aged and older adults. As stated, decreased BMD is one of the most important
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risk factors for osteoporosis and subsequent osteoporotic-related fracture, because of
its effect on the strength of the bone. In other words, the higher the BMD, the stronger
the bone. However, there appears to be more evidence in the preventive advantages of
age-related decline in bone mass, compared to that on menopause-related declines.
The potential preventive effect of resistance training through BMD is seen at
younger ages. Elite junior weight lifters (~17 years) were shown to have significantly
higher BMD at the lumbar spine and femoral neck than adult men reference data
of ages 20–39 years.34 Peak bone mass will be reached by the early adult years,
and children participating in activities involving resistance and high-impact forces
show greater bone mass than those who are active, but with less resistive, nonweightbearing exercise (e.g., walking, swimming).
Resistance training has a direct impact on BMD, mainly by two mechanisms:
(1) mechanical loading of the skeletal system and (2) strain placed on the bone from
contracting musculature. Both these mechanisms promote site-specific increases in
BMD, whereas a global (i.e., systemic) increase in BMD is also possible. Mechanical
loading places strain on the bone and promotes remodeling of the bone structure
to handle the excess load, mainly by an increase in BMD through action of a team
of bone cells. In actuality, the bone is not a static structure, rather is constantly
remodeling with the help of osteoclasts and osteoblasts to resorb and refill bone,
respectively.
Mechanical Loading and Bone Mineral Density
Weight-bearing high-impact activities, such as jumping with the large ground reaction forces and high-intensity resistance exercise, may promote an ideal stimulus
for greater gains in bone mass. These activities are dynamic in nature and stimulate remodeling through variable mechanical loadings and gravitational load on the
skeleton. Subsequently, this mechanical loading may be an effective way to delay
or prevent the onset of osteoporosis. Such high-impact training and weight-bearing
resistance training have been shown effective in increasing site-specific bone density in both premenopausal and postmenopausal women up to 4%–7% (Wallace and
Cumming35). There is some evidence that the same type of high-impact exercise can
increase and prevent the decline of total body BMD. For example, Nelson et al.36
showed that as little as 2 days per week of high-intensity strength training increased
femoral and lumbar BMD, while preventing the decline of total body BMD in sedentary, estrogen-deplete postmenopausal women.
This type of weight-bearing resistance exercise may also be extremely advantageous for individuals with small frames and low body mass. Simply carrying their
body weight around through walking or running may not be enough to stimulate the
remodeling process to the point of increasing BMD. Thus, the extra load from the
high-impact and/or high-intensity resistance exercise can provide the needed stimulus for more advanced osteogenic effects. As the magnitude of intensity increases
with resistance exercise, so does the bone-loading forces and subsequent potential
for bone stimulation. This positive relationship is important to note, because of no
exact recommendations for resistance exercise in the population.
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227
Muscular Strain and Bone Mineral Density
The stress that contracting muscle places on the skeletal system can also promote
increase in BMD at the site of strain. A main source of strain on the skeletal system
comes from the contractions of the muscles that attach to it. As the muscles become
stronger, they exert greater force on the bone, which in turn will stimulate boneremodeling processes. As with mechanical loading, only the sites that are exposed to
overload are going to be triggered into bone-remodeling processes. This site specificity becomes important when prescription is made, such as for very specific areas
(e.g., femoral neck, lumbar vertebrae). The resistance exercises should then be chosen for their ability to improve on the osteopenic areas.
Generally, overload above and beyond the stimulus that the bone is used to will
promote some degree of bone turnover. However, low load and high-repetition resistance training does not consistently show an improvement in BMD. As the intensity
increases to higher loads, site-specific increases in BMD are found. This improvement in BMD is typically lost, if the exercise is discontinued. The bone will respond
to the resistance stimulus, so when the stimulus is removed the bone has little reason
to maintain the same BMD. Conceptually, resistance exercise that can incorporate
both mechanical loading and musculature strain will have the best chance of improving both site-specific and total body BMD changes. Also, the more dynamic this
prescription, the better promotion of BMD changes.
Subsequently, the American College of Sports Medicine has suggested an exercise prescription recommendation for the preservation of bone health during adulthood.37 This position stand suggests resistance exercise with “moderate to high
bone-loading forces,” but are unclear on the exact intensity. The general recommendation is that higher intensities, as a percent of 1 RM, will parallel bone-­loading
forces, and common prescriptions for high intensities exceed 70% of maximal
effort. Volume and tempo prescriptions follow the same conceptual understanding
that increases in volume or tempo length will parallel increases in or maintenance
of bone mass.
Treatment
The goal of any progressive resistance training program as treatment for ­osteoporosis
would be to prevent the decline or possibly increase BMD, muscular strength, and
improve functionality, so as to prevent fractures and enhance one’s QOL. However,
unlike prevention, there is an added caution of fracture, due to the characteristic
thinning and weakening of bone. Even though high-intensity, high-impact, and
higher volume prescriptions are typically required to induce osteogenesis and prevent bone mass loss, this same overload is commonly contraindicated in an individual with osteoporosis due to the risk of fracture. In addition, exercises that used
forceful bending forward (e.g., sit-ups, crunches, toe touches) and twisting the spine
should also be avoided in this population.
Thus, in osteoporotic individuals, it is extremely important to note the relative
nature of the intensity prescription. For example, if 70% of max in one individual
is not the same as 70% of max in another individual. In addition, 70% of max may
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promote fracture in one individual, but not in another. The speed of the contraction
or tempo of the exercise may show the same individual differences within those
with osteoporosis. Resistance exercise should be progressive to the higher relative
loads, as opposed to overloading them from the beginning of their training. Common
progressions of resistance training can be followed to allow safe increases in load
to reach the desired level of intensity, with constant caution for the risk of fractures.
Because the majority of those with osteoporosis are older adults, the individualized progressive prescription should follow those provided by the Aging and Older
Adults chapter in this book, along with the additional suggestions for other modalities beyond traditional weight training machines and exercises (e.g., aquatic, band
training). Since the main goal with older adults is to maintain or slow the degradation of BMD, less intensities are needed, as compared to that needed for the bone
remodeling and subsequent increases in BMD. Also, fracture prevention is of high
priority, as is the preservation of functional capacity and QOL.
ADHERENCE ISSUES
Overview
An interesting finding from the orthopedic research is that despite variation, adherence to most resistance training prescriptions is moderate at best. Individuals with
orthopedic diseases and disabilities experience all the common concerns and barriers
to resistance training, such as perceived lack of time, poor efficacy beliefs, fatigue,
soreness, injury, travel constraints, lack of motivation, loss of interest, embarrassment,
lack of social support, self-presentational concerns, and cost. However, individuals
with orthopedic conditions must also deal with the added pain, discomfort, and disabilities stemming from their condition, associated medications, and/or additional
complications (e.g., obesity or comorbidities). Mikesky et al.19 used an adherence strategy with their participants, including a check-in system, contact on missed session,
and incentives. Despite these efforts, participants still only attended less than half
of the 24 sessions. Thus, adherence to resistance training may be more difficult for
individuals with orthopedic conditions, and specific issues should be accounted for.
Pain, Kinesiophobia, and Catastrophizing
Orthopedic-related pain can occur before, during, and after exercise, all providing
various impacts on willingness to participate in exercise.38 One first consideration is
that individuals may be in pain before the resistance exercise ever begins. In many,
this pain may motivate the individual to avoid exercise, rather than attempt it. Even
if there is no pain, there is concern that the exercise avoidance role of anticipation
and fear of pain, which predict physical performance and can even persist after healing.39 Similarly, individuals with orthopedic conditions can experience kinesiophobia (fear of movement), which can lead to decreased activity, complications with
disuse, declines in physical functioning, and even resultant depression.
These perceptions may also tie into the risk of catastrophizing in individuals
with orthopedic condition. As previously mentioned, catastrophizing is the overly
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negative, even irrational, thoughts making a situation and the future much worse
than it actually is (i.e., a catastrophe). Catastrophizing plays an important role in the
management of an orthopedic condition and has been shown to be predictive of pain
intensity, disability, and psychological distress.40,41 These individuals commonly
anticipate the worst and focus on all the things that will go wrong. These thoughts
can be a self-fulfilling prophecy, when individuals begin to give up on their efforts,
because they hold a consistent negative belief of the outcomes.
Many patients with an orthopedic condition may interpret the pain experienced
during resistance exercise as pain stemming from their condition or perceive the pain
is a result of the exercise making their condition worse. This exercise-induced discomfort can act as a barrier purely from the dislike of the feelings, but is amplified if
perceived as something negative or worsening their condition. The individual should
have the knowledge and efficacy to handle such discomfort, alongside trust that the
exercise specialist is providing them with the proper prescription. Law et al.42 found
that despite RA patients being aware of the advantages of exercise, there existed a
perception that health professionals lack certainty and clarity on what the specific
recommendations are.
These concerns filter into postexercise pain, soreness, and fatigue. The individual
should be educated on the source and reasons for their postexercise pain, so they do
not associate discomfort with worsening of their condition or to their lack of physical
ability, both of which may impact one’s motivation to return to resistance exercise,
kinesiophobia, and catastrophizing. There is a fine line between pain that is common
to exercise and pain that stems from the orthopedic condition, and this can be an
understandably difficult situation for the individual. Special care should be taken by
the exercise specialist to work closely with the individual to ensure confidence that
they are being safely progressed through the resistance training program.
Individual Differences
Despite orthopedic diseases and disabilities occurring at any age, the majority of
individuals affected will be middle-aged or older adults. Common barriers will exist
between both age groups, such as lack of time, lack of confidence, lack of energy or
motivation, social embarrassment, and unpleasantness of exercise. However, individual differences on the concerns and barriers to exercise may exist between the
age groups, and with the aging process. For instance, older adults commonly report
barriers associated with transportation problems, safety and bad weather, whereas
middle-aged adults may not. On the other hand, middle-aged adults may report
perceived barriers involving caregiving duties and physical appearance to a greater
extent than older adults. The motivation to exercise may also differ by weight class,
as high-intensity exercise has been reported as a more unpleasant, painful, and exerting experience in obese individuals as compared to the reports of normal weight or
overweight individuals (e.g., see study by Ekkekakis et al.43). Individual differences
may also span gender, activity level, ethnicity, environmental conditions, and cultural influences.44,45
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Readiness for Change
One may assume that individuals with any health condition should be automatically motivated to ameliorate their symptoms; however, individual differences will
exist between the readiness to adopt treatment for management of their condition.
The stages of change, or transtheoretical model, describe the 5–6 stages of behavior
change that individuals progress through: precontemplation, contemplation, preparation, action, maintenance, and termination.46 The goal of progression is to reach
maintenance or termination, but any relapse in behavior can cause the reentering
into an earlier stage. When dealing with individuals with an orthopedic condition
and adoption of a self-management program, such as a resistance training program,
there should be an understanding of that individual’s readiness for change.
For example, Keefe et al.47 found that nearly half (44%) of a sample of RA and OA
patients were in a precontemplation stage when it came to adopting a s­ elf-­management
program for their arthritis. In other words, these patients were not even considering
a change or adopting a self-management program to help their disease, reporting
that medical treatment was the only effective method to manage the arthritis condition. Although not the majority, 11% of this sample was contemplative, meaning that
they were considering the thought of a self-management program for their arthritis.
However, the simple identification of an individual’s stage of change is not enough to
promote movement to the next stage.
Just as individual differences exist on the readiness for change, the implementation of appropriate “processes of change” may aid in the adoption and adherence of
resistance as a treatment for orthopedic conditions. Processes of change are tactics
designed specifically for each stage to help aid the individual move from one stage
to the next. For instance, “consciousness raising” can be used for those individuals
who are precontemplative and describes tactics to help the individual initiate the
seeking of new information, understanding, and feedback on resistance training and/
or the orthopedic condition. Another process is “environmental reevaluation”, which
promotes the individual to consider and assess how the resistance training behaviors and/or orthopedic condition affects their physical and social environments, such
as watching a documentary or including family interventions. The transtheoretical
model also emphasizes self-efficacy, decisional balance, and temptations for movement through the stages, as well as understanding relapse. Although promising, more
research is needed on the transtheoretical model to help guide resistance exercise
interventions in individuals with orthopedic conditions.
Individual Preference
Resistance training modalities can take many forms based on the specific orthopedic condition of interest. Subsequently, there may be varied preferential responses
from the individual, such as the simple like or dislike of certain modalities. For
example, there may be varied preferences and responses to a strengthening exercise
routine with hand putty for a case of RA, compared to a core strengthening program
in LBP, or a full-body aquatic workout for a fibromyalgia patient. There may also
be the consideration of preference for group versus individual resistance training,
Mark D. Faries
231
such as preferring a group aquatic resistance exercise to individualized Theraband
exercise at home. Thus, concerns may exist and vary between individual- versus
group-based programs, or with the type of exercise choice (e.g., machines, free
weights, Theraband, aquatic). If the orthopedic outcomes can be positively impacted
across several modalities and settings, then it may be advisable to prescribe based
on preferences of the individual to help promote higher levels of intrinsic and/or
­self-­determined motivation, and subsequent adherence to the resistance training.
Motivation Type
Just as individuals may differ on the stage of their motivation for change, they may
also differ on the type of motivation that they have. Self-determination theory48 distinguishes between three different types of motivation, with very different implications on the initiation and maintenance of a resistance training prescription. In short,
intrinsic motivation describes one’s motivation to engage in a behavior for the sheer
enjoyment and/or challenge of that behavior.
On the other hand, extrinsic motivation describes doing a behavior, because it
is necessary to achieve a desired external reward or goal, such as many of the outcomes discussed in the chapter (e.g., pain relief or improved physical function).
Extrinsic motivation can be experienced in two different ways, as controlled or
­self-­determined. When controlled, one could feel urged or forced to do the behaviors by external forces, such as feeling pressure from a doctor, a fitness professional,
therapist, or a family member. This controlled form of motivation may be common in orthopedic patients, and unfortunately, it is not considered ideal for longterm maintenance of a behavior. However, with self-determined motivation, the
individual is still pursuing a behavior for the outcomes discussed, but the reasons
for choosing the behavior are determined by the individual and are autonomous.
Because the majority of individuals with an orthopedic condition are resistance
training for the specific outcomes, the aim may be to help individuals achieve a
more self-determined motivation.
Despite the heightened use of self-determination theory in the adoption and maintenance of physical activity,49 there is an unfortunate dearth of research on its use with
resistance training or in patients with orthopedic conditions. However, the theory states
that prescriptions that foster the three basic psychological needs of autonomy, competence, and relatedness will foster more intrinsic, ­high-quality forms of ­motivation,
creativity, performance, and persistence (­ http://www.­selfdeterminationtheory.org).
As mentioned earlier, preference to the resistance training modality and environment could be harnessed to provide autonomy and independence in choice. The progressive nature of individualized resistance training provides a prime opportunity to
guide the development of competence with the exercise prescription, its implementation, and individual efficacy in performance. Relatedness describes the perceptions
of connectedness, similarity, and understanding among others. This relatedness can
be experienced between the orthopedic individual and the exercise specialist who is
providing the prescription. In a clinical setting, the specialist must be able to connect
with and provide understanding to the patient during the resistance training treatment, to help maintain their motivation to continue in the treatment. Because it is a
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basic psychological need, individuals with an orthopedic condition may also seek to
be a part of exercise groups that contain other individuals with similar conditions.
As with preference, some individuals may be more motivated in a group setting than
in an individual, in-home program.
CONCLUSION
Despite the positive impact on their condition and QOL, adherence to resistance
training is a concern for individuals with orthopedic diseases and disabilities.
In addition to common barriers and orthopedic-related pain, there will be individual differences in the abilities and motivation to adhere to resistance training.
Remember, even this best resistance training programs become ineffective if no
one completes them. Adherence to general exercise has been widely studied, and
despite a growing understanding, still remains elusive. Less research has been
observed with orthopedic conditions and rehabilitation. We are however improving our understanding of rehabilitation psychology with dedicated research and
journals, such as the Rehabilitation Psychology Journal. In addition to the already
discussed self-determination and stage of change theories, there is also great potential for other common health theories, such as self-regulation, positive psychology,
religion/spirituality, theory of planned behavior, and social cognitive theory for
enhancing adherence in the prevention and treatment of individuals with orthopedic conditions. At a minimum, we must be aware of the adherence concerns in
orthopedic diseases and disabilities, and provide progressive, individualized resistance training prescriptions that are tailored to balance improvement of the condition and its symptomatology, with the adoption and maintenance of the exercise
prescription.
REFERENCES
1. Jacobs JJ. Burden of musculoskeletal diseases in the United States. Rosemont, IL:
American Academy of Orthopaedic Surgeons. 2008.
2. The Consensus Document. The Bone and Joint Decade 2000–2010. Inaugural Meeting
17 and 18 April 1998, Lund, Sweden. Acta Orthop Scand 1998; 69 Suppl 281:67–86.
3. Kraemer WJ, Ratamess NA, French DN. Resistance training for health and performance. Curr Sport Med Rep. 2002; 1: 165–71.
4. Peat G, McCarney R, Croft P. Knee pain and osteoarthritis in older adults: a review
of community burden and current use of primary health care. Ann Rheum Dis. 2001;
60: 91–7.
5. McGill SM. Low back stability: from formal description to issue for performance and
rehabilitation. Exerc Sport Sci Rev. 2001; 29: 26–31.
6. Faries MD, Greenwood M. Core training: stabilizing the confusion. Strength Cond J.
2007; 29: 10–25.
7. Hodges PW, Richardson CA. Inefficient muscular stabilization of the lumbar spine associated with low back pain: a motor control evaluation of transversus abdominis. Spine.
1996; 21: 2640–50.
Mark D. Faries
233
8. Richardson CA, Snijders CJ, Hides JA et al. The relation between the transversus
abdominis muscles, sacroiliac joint mechanics, and low back pain. Spine. 2002; 27:
399–405.
9. O’Sullivan PB, Phyty DMG, Twomey LT et al. Evaluation of specific stabilizing exercise in the treatment of chronic low back pain with radiologic diagnosis of spondylolysis
or spondylolisthesis. Spine. 1997; 22: 2959–67.
10. Bruce-Low S, Smith D, Burnet S et al. One lumbar extension training session per week
is sufficient for strength gains and reductions in pain in patients with chronic low back
pain ergonomics. Ergonomics 2012; 55: 500–7.
11. Graves JE, Webb DC, Pollock ML et al. Pelvic stabilization during resistance training:
its effects on the development of lumbar extension strength. Arch Phys Med Rehabili.
1994; 75: 210–5.
12. Smith D, Bissell G, Bruce-Low S et al. The effect of lumbar extension training with and
without pelvic stabilization on lumbar strength and low back pain. J Back Musculoskelet
Rehabil. 2011; 24: 241–9.
13. Behm DG, Drinkwater EJ, Willardson JM et al. The use of instability to train the core
musculature. Appl Physiol Nutr Metab. 2010; 35: 91–108.
14. Danneels LA, Vanderstraeten GG, Cambier DC et al. Effects of three different training
modalities on the cross sectional area of the lumbar multifidus muscle in patients with
chronic low back pain. Br J Sports Med. 2001; 35: 186–91.
15. Cheng YJ, Hootman JM, Murphy LB et al. Prevalence of doctor-diagnosed arthritis and
arthritis-attributable activity limitation—United States, 2007–2009. Morb Mortal Wkly
Rep (MMWR). 2010; 59: 1261–5.
16. Singh G, Miller JD, Lee FH et al. Prevalence of cardiovascular disease risk factors
among US adults with self-reported osteoarthritis: data from the Third National Health
and Nutrition Examination Survey. Am J Manag Care. 2002; 8: 383–91.
17. Arnold AM, Faulkner RA. The history of falls and the association of the time up and
go test to falls and near-falls in older adults with hip osteoarthritis. BMC Geriatr.
2007; 7: 17.
18 Felson DT, Chaisson, CE. 2 Understanding the relationship between body weight and
osteoarthritis. Baillière’s Clinical Rheumatology. 1997; 11: 671–81.
19. Mikesky AE, Mazzuca SA, Brandt KD et al. Effects of strength training on the incidence
and progression of knee osteoarthritis. Arthritis Rheum. 2006; 55: 690–9.
20. Roddy E, Zhang W, Doherty M et al. Evidence-based recommendations for the role of
exercise in the management of osteoarthritis of the hip or knee—the MOVE consensus.
Rheumatology. 2005; 44: 67–73.
21. Lange AK, Vanwanseele B, Fiatarone Singh MA. Strength training for treatment osteoarthritis of the knee: a systematic review. Arthritis Rheum. 2008; 59: 1488–94.
22. Jan MH, Lin JJ, Liau JJ et al. Investigation of clinical effects of high- and low-resistance
training for patients with knee osteoarthritis: a randomized control trial. Phys Ther.
2008; 88: 427–36.
23. Hakkinen A, Sokka T, Kotaniemi A et al. A randomized two-year study of the effects of
dynamic strength training on muscle strength, disease activity, functional capacity, and
bone mineral density in early rheumatoid arthritis. Arthritis Rheum. 2001; 44: 515–22.
24. Hakkinen A, Sokka T, Kotaniemi A et al. Sustained maintenance of exercise induced
muscle strength gains and normal bone mineral density in patients with early rheumatoid arthritis: a 5 year follow up. Ann Rheum Dis. 2004; 63: 910–6.
25. De Jong Z, Munneke M, Zwinderman AH et al. Is a long-term high-intensity exercise
program effective and safe in patients with rheumatoid arthritis? Results of a randomized controlled trial. Arthritis Rheum. 2003; 48: 2415–24.
26. Strasser B, Leeb G, Strehblow C et al. The effects of strength and endurance training in
patients with rheumatoid arthritis. Clin Rheumatol. 2011; 30: 623–32.
234
Resistance Training for Individuals with Orthopedic Disease and Disability
27. De Jong A, Vliet Vlieland TPM. Safety of exercise in patients with rheumatoid arthritis.
Curr Opin Rheumatol. 2005; 17: 177–82.
28. Lynberg KK, Ramsing, BU, Nawrocki A et al. Safe and effective isokinetic knee extension training in rheumatoid arthritis. Arthritis Rheum. 1994; 37: 623–8.
29. Speed CA, Campbell R. Mechanisms of strength gain in a handgrip exercise programme
in rheumatoid arthritis. Rheumatol Int. 2012; 32: 159–63.
30. Bohannon RW. Hand-grip dynamometry predicts future outcomes in aging adults.
J Geriatr Phys Ther. 2008; 31: 3–10.
31. Dickens C, McGowan L, Clark-Carter D et al. Depression in rheumatoid arthritis: a systematic review of the literature with meta-analysis. Psychosom Med. 2002; 64: 52–60.
32. Singh NA, Stavrinos TM, Scarbek Y et al. A randomized controlled trial of high versus
low intensity weight training versus general practitioner care for clinical depression in
older adults. J Gerontol Biol Sci Med Sci. 2005; 60: 768–76.
33. Looker AC, Borrud LG, Dawson-Hughes B, Shepherd JA, Wright NC. Osteoporosis
or low bone mass at the femur neck or lumbar spine in older adults: United States,
­2005–2008. NCHS data brief no 93. Hyattsville, MD: National Center for Health
Statistics. 2012.
34. Conroy BP, Kraemer WJ, Maresh CM et al. Bone mineral density in elite junior Olympic
weightlifters. Med Sci Sports Exerc. 1993; 25: 1103–9.
35. Wallace BA, Cumming RG. Systematic review of randomized trials of the effect of
exercise on bone mass in pre- and postmenopausal women. Calcif Tissue Int. 2000;
67: 10–18.
36. Nelson ME, Fiatarone MA, Morganti CM et al. Effects of high-intensity strength training on multiple risk factors for osteoporotic fractures. JAMA. 1994; 272: 1909–14.
37. Kohrt WM, Bloomfield SA, Little KD et al. Physical activity and bone health: American
College of Sports Medicine position stand. Med Sci Sports Exerc. 2004; 36: 1985–96.
38. Wilcox S, Der Ananian C, Abbott J et al. Perceived exercise barriers, enablers, and benefits among exercising and nonexercising adults with arthritis: results from a qualitative
study. Arthritis Rheum. 2006; 55: 616–27.
39. Al-Obaidi S, Nelson RM, Al-Awadhi S et al. The role of anticipation and fear of pain
in the persistence of avoidance behavior in patients with chronic low back pain. Spine.
2000; 25: 1126–31.
40. Peters ML, Vlaeyen JWS, Weber WEJ. The joint contribution of physical ­pathology,
pain-related fear and catastrophizing to chronic back pain disability. Pain. 2005;
113: 45–50.
41. Severeijns R, Vlaeyen JWS, van den Hout MA et al. Pain catastrophizing predicts pain
intensity, disability, and psychological distress independent of the level of physical
impairment. Clin J Pain. 2001; 17: 165–72.
42. Law RJ, Breslin A, Oliver EJ et al. Perceptions of the effects of exercise joint health in
rheumatoid arthritis patients. Rheumatology. 2010; 49: 2444–51.
43. Ekkekakis P, Lind E, Vazou S. Affective responses to increasing levels of exercise
intensity in normal-weight, overweight, and obese middle-aged women. Obesity. 2009;
18: 79–85.
44. King AC, Castro C, Wilcox S. Personal and environmental factors associated with physical inactivity among different racial-ethnic groups of U.S. middle-aged and older-aged
women. Health Psychol. 2000; 19: 354–64.
45. Mathews AE, Laditka SB, Laditka JN et al. Older adults’ perceived physical activity
enablers and barriers: a multicultural perspective. J Aging Phys Act. 2010; 18: 119–40.
46. Prochaska JO, Velicer WF. The transtheoretical model of health behavior change.
Am J Health Promot. 1987; 12: 38–48.
47. Keefe FJ, Lefebvre JC, Kerns RD et al. Understanding the adoption of arthritis self-­
management: Stages of change profiles among arthritis patients. Pain. 2000; 87: 303–13.
15
Resistance Training
for Older Adults
Michael G. Bemben, Christopher
A. Fahs, Jeremy P. Loenneke, Lindy
M. Rossow, and Robert S. Thiebaud
CONTENTS
Introduction.............................................................................................................240
Age-Related Loss of Muscle Mass: Sarcopenia................................................240
Decreases in Muscle Strength and Functional Abilities.....................................240
Basic Resistance Training....................................................................................... 241
Current Strength Training Recommendations and Considerations.................... 241
Effects of Resistance Training on Muscle Size and Architecture...................... 242
Effects of Resistance Training on Muscular Strength........................................ 242
Effects of Resistance Training on Muscular Endurance.................................... 243
Effects of Resistance Training on Muscular Power...........................................244
Effects of Resistance Training on Physical Function.........................................244
Effects of Resistance Training on Muscle Quality............................................. 245
Nontraditional Resistance Training........................................................................ 245
Difficulties of Using Traditional Resistance Equipment.................................... 245
Alternatives to Weight Machines and Free Weights........................................... 247
Body Weight Exercises: Benefits.................................................................. 247
Body Weight Exercise: Disadvantages..........................................................248
Elastic Band Training: Benefits.....................................................................248
Elastic Band Training: Disadvantages........................................................... 249
Aquatic Resistance Training: Benefits.......................................................... 249
Aquatic Resistance Exercise: Disadvantages................................................ 250
Low-Load Resistance Exercise with Blood Flow Restriction: An Alternative
to Traditional Resistance Exercise.......................................................................... 250
Historical Perspective of Low-Load Resistance Training with Blood Flow
Restriction.......................................................................................................... 250
Basic Theory Behind Blood Flow Restricted Exercise...................................... 251
Mechanisms................................................................................................... 251
Standard Protocols......................................................................................... 252
Restriction Pressure Recommendations........................................................ 252
Potential Safety Concerns............................................................................. 252
235
236
Resistance Training for Older Adults
Studies Demonstrating Efficacy......................................................................... 253
Blood Flow Restriction without Exercise...................................................... 253
Blood Flow–Restricted Walking and Cycling............................................... 253
Blood Flow Restriction with Resistance Exercise......................................... 254
Blood Flow Restriction and Bone Health...................................................... 255
Conclusion.............................................................................................................. 255
References............................................................................................................... 256
INTRODUCTION
Age-Related Loss of Muscle Mass: Sarcopenia
Over the life span of an individual, many changes occur in the human body that can
affect both physical fitness and function. One particular change intrinsic to the aging
process is a normal age-related loss of skeletal muscle mass. In 1989, Rosenberg1 suggested that the age-related loss of muscle mass be termed “sarcopenia.” Sarcopenia
is noted by a 1%–3% decrease in total muscle cross-sectional area (CSA) per year
after the age of 50.2 Furthermore, the loss of muscle mass can produce significant
decreases in muscle strength and functional abilities.3
Loss of muscle mass with age is thought to be mainly due to decreased muscle
protein synthesis, including mixed muscle proteins, myosin heavy chains, and mitochondrial proteins.4 Baumgartner et al.5 suggested that sarcopenia be assessed by
determining a person’s height-adjusted appendicular skeletal muscle mass in kilograms per square meter. If a person’s height-adjusted muscle mass is below two
standard deviations from the young adult mean value, that person is classified as
sarcopenic.5 This classification system is similar to what is used to diagnose osteoporosis, and muscle mass is typically assessed using dual x-ray absorptiometry. With
respect to resistance training recommendations, quantifying degree of muscle mass
loss may be less important than determining functional limitations and areas of
weakness in which resistance training could be most beneficial.
Decreases in Muscle Strength and Functional Abilities
Recent work has highlighted the fact that the age-related loss of muscle mass does
not follow the age-related loss of strength.6 Thus, it is suggested that the term “sarcopenia” only refer to the age-related loss of muscle mass, whereas a new term, “dynapenia,” be used to refer to the age-related loss of muscular strength.6,7 With regard to
the ability to perform activities of daily living, maintaining muscular strength may
matter more than maintaining muscle mass with age. In fact, low muscular strength
is associated in 90% of poor physical performance or disability cases compared to
low muscle mass, which only accounts for 35% of poor physical performance or disability.6 Thus, improving muscle strength and abilities rather than mass, to improve/
maintain functionality and performance of physical activities of daily living, should
be the main focus of a resistance exercise program for older adults.
Loss of muscular strength with age is thought to be driven by factors intrinsic to
the muscle as well as by neural factors. Within the muscle, excitation–contraction
coupling functions less efficiently, possibly due to the consequences of a decreased
Michael G. Bemben et al.
237
number of dihydropyridine receptors or decreased expression of junctophilin subtype 45 (JP-45), a sarcoplasmic reticulum junctional face membrane protein that
effects the expression of dihydropyridine receptor subunits.6 Deficiencies in dihydropyridine receptors or JP-45 can ultimately lead to a decrease in calcium release
from the sarcoplasmic reticulum and therefore result in a decrease in contractile
force. Additionally, intramuscular and intermuscular fat appear to increase with
age, impairing the force-generating ability of the muscle. Also, muscle fiber lengths
shorten due to decreased sarcomeres in series, whereas muscle fiber pennation angles
decrease due to decreased sarcomeres in parallel.8
Neural factors are likely the primary contributors to muscle strength loss with
age. Aging leads to declines in function from the motor cortex to the neuromuscular
junction, since the ability to manipulate firing rate and to recruit additional neurons
for force generation decreases.6 In addition, type II muscle fibers tend to selectively
lose neural innervations. Consequently, these fibers may then be reinnervated to
become type I muscle fibers, leading to an increase in fiber type homogeneity within
a muscle and a reduction in force-generating ability.8 Due to these age-related decrements, achieving neural gains via strength training is essential for the older adult.
BASIC RESISTANCE TRAINING
Current Strength Training Recommendations and Considerations
Resistance training is beneficial, safe, and recommended for older adults. Improvements
in muscle function have been shown to translate into improvements in overall health in
older adults. Although differences exist in the neuromuscular systems of older adults,
these differences are not so great as to preclude older adults from responding effectively to a resistance training program.
The American College of Sports Medicine (ACSM),9 in its position stand
“Exercise and Physical Activity for Older Adults,” recommends that older adults
resistance train at least 2 days per week at moderate to vigorous intensities. Moderate
intensity is defined as a rating between 5–6, and vigorous intensity is defined as a
rating between 7 and 8 on a scale of 0 to 10 (Borg 10 Point Scale). Another ACSM
position stand providing evidence-based recommendations for exercise for adults
of all ages specifies that older adults should exercise at 40%–50% of one-repetition
maximum (1RM) to improve strength.10 Thus, older adults may choose to base exercise intensity on either exertion level or a percentage of 1RM.
Accurate 1RMs are notoriously difficult to obtain in older adults,11 and the
­possibility of injury exists during a maximal effort on equipment with which one
has minimal experience. Basing workloads on perceived exertion level, while
more subjective than 1RM, at least provides a relative indicator of how hard an
­individual is working. It must be recognized, when prescribing exercise intensity,
that ­unfamiliarity with equipment and fear of injury may lead some older adults to
overestimate the intensity of the exercise. Thus, the real possibility of injury versus
the necessity to challenge the exerciser to make training gains must be balanced. If
a ­percentage of 1RM is used to prescribe exercise, several 1RM practice sessions
should be p­ erformed prior to actual assessment.
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Resistance Training for Older Adults
The ACSM recommends traditional methods of progressive resistance training
or weight bearing calisthenics (8–10 exercises, involving the major muscle group, of
8–12 repetitions each), and other strengthening activities that use the major muscle
groups.9 The goal of this training is often different from that for a younger individual; the younger individual may want to improve sports performance, overall health,
and/or physical appearance, whereas the older individual may be seeking more functional improvements along with improvements in general health.
Effects of Resistance Training on Muscle Size and Architecture
Muscle mass in older adults begins to decline from around age 40 with accelerated
loss occurring after age 65–70 with the largest decreases occurring in the lower body.9
Resistance training, however, is able to improve the muscle size of older adults, and
older men and women generally appear as able as younger men and women to achieve
relative increases in muscle CSA in response to resistance training,12 although this
finding is not universal.13 Most studies reporting training-induced increases in total
muscle CSA (5%–10%) involve a training program of 10–12 weeks.4 Since sarcopenia
is thought to be primarily driven by a decreased protein synthetic responsiveness to
an anabolic stimulus rather than an increase in muscle protein catabolism, the ability
of resistance training to increase muscle protein synthesis is of interest.14 Current evidence suggests that resistance exercise is able to significantly increase muscle protein
synthesis in older adults.15 Even frail elderly adults aged up to 92 years responded with
an increase in mixed muscle protein synthesis to resistance training.16 The increase
in protein synthesis to resistance training can increase both type I and type II muscle
fiber sizes in older adults4; however, it appears that variability within the training
program as well as individual variability may influence training adaptations, as large
variations in the degree of fiber size increases are observed.17
As previously stated, muscle architecture changes as both fascicle length and fascicle
angle of insertion decrease with age; these changes suggest loss of sarcomeres in series
and in parallel, respectively.18 Resistance training in older adults has been shown to
counteract these changes. Following a 14 week strength training program in men and
women aged over 70 years, resting fascicle length and pennation angle of vastus lateralis
were increased by 8%–10% and 28%–35%, respectively.19 Also, in this same study, optimal fascicle length increased by 11% following training and tendon stiffness increased
by 69%.19 These changes would influence the length–force relationship, resulting in
greater force production; furthermore, they show that muscle architecture and tendon
stiffness are still adaptable and responsive to resistance training in older individuals.
Effects of Resistance Training on Muscular Strength
Increases in muscular strength with resistance training may be due to a combination of
morphological and neurological factors. The morphological changes in skeletal muscle
leading to increased muscle strength primarily are due to changes in whole muscle and
individual fiber size.20 Increases in muscle fiber number (hyperplasia), changes in muscle fiber type and myosin heavy-chain composition, and changes in muscle architecture
may also contribute to increased muscular strength, but evidence suggests these factors
Michael G. Bemben et al.
239
do not contribute greatly.20 Increases in both motor unit activation and rate of discharge
contribute to increases in muscular strength with resistance training. Thus, the increase
in strength with resistance training may exceed the increase in muscle size.
In older individuals, resistance training causes substantial changes in neuromuscular function, leading to an increase in muscle strength.21 Following resistance
training, there is an increase in the degree of motor unit activation during a maximal
voluntary contraction,22 as well as an increase in the maximum motor neuron firing
frequency.23 Likewise, a decrease in antagonist muscle coactivation typically occurs
following resistance training in older individuals.22
Following a resistance training program, increases in strength typically range
between 25% and 100% in older individuals. Evidence conflicts as to whether the
magnitude of improvement in strength is similar between younger and older individuals. Initial strength gains may be similar between younger and older individuals
beginning a strength training program, whereas the rate of strength gain may diminish or become slower in older individuals as the training continues.24 However, older
men and women of various ages can improve strength with resistance training.25
Even individuals 80–90 years old are capable of increasing muscle strength following a resistance training program.26
Many resistance program variables influence the magnitude of the strength adaptation; however, resistance training intensity (i.e., load) appears to be the biggest factor influencing strength gains with high-intensity (>80% 1RM) resistance training,
producing greater increases in strength compared to low-intensity (<60% 1RM) or
moderate-intensity (60%–80% 1RM) resistance training.25 For example, in 60- to
72-year-old men, 12 weeks of high-intensity (80% 1RM) knee flexor and extensor
exercise resulted in >100% and >200% increases in knee extensor and flexor dynamic
strength, respectively.27 With high-intensity training, an increase in dynamic muscle
strength of 5% per exercise session, similar to strength increases reported in studies
performed in younger men, has been shown to occur in older men.27 Studies examining the effect of resistance exercise volume (one-set versus three-set protocols) in
older adults have also demonstrated superior strength adaptations with higher volume
resistance training programs.28 In contrast, resistance training frequency does not
influence the magnitude of strength gain following short-term resistance training in
older adults.29 Although progressive increases in training load are recommended for
older individuals,9 progressive increases in other training variables (e.g., frequency
and volume) may be necessary to facilitate further strength adaptations.
Effects of Resistance Training on Muscular Endurance
The ability to exert muscle force repeatedly becomes increasingly important as one
ages and may determine functional independence in older adults. Any resistance
training program that increases muscle size and/or strength may increase muscular
endurance by reducing motor unit activation for submaximal tasks along with other
metabolic and biochemical adaptations that occur within the muscle.
In younger individuals, resistance training utilizing low to moderate exercise loads
(<50% 1RM) with a greater number of repetitions per set (i.e., 10–20) is generally
recommended for improving muscular endurance.30 In older adults, moderate- to
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Resistance Training for Older Adults
high-load (50%–80% 1RM) resistance exercise causes robust increases in muscular endurance.31 In fact, higher load (50%–80% 1RM) exercise improves muscular
endurance to a greater extent compared to lower load (<50% 1RM) resistance exercise training in older adults.32 However, when exercise volume is equivalent, low-load
(40% 1RM) and high-load (80% 1RM) resistance exercise training produce similar
increases in muscular endurance in older adults.31 The increase in muscular endurance
following training may be due to an increase in strength capacity. Therefore, in older
adults, any resistance training program designed to increase muscular strength should
also increase muscular endurance to an extent. Changes at the cellular level, which
affect cross-bridge cycling, may also contribute to changes in muscular endurance.
For example, half-relaxation time increases following resistance training in older
adults, which prolongs the length of time tension is produced from a single action
potential.33 This allows greater muscle force to be produced at a lower motor neuron
firing rate and may also contribute to a reduction in fatigue at submaximal loads.
Effects of Resistance Training on Muscular Power
Muscular power is the product of force and velocity; power can be increased by performing the same amount of work in a shorter time or by increasing the amount of
work performed during the same period of time. In older adults, the ability to generate power, especially at low velocities, becomes increasingly important for performing everyday tasks such as getting out of a chair and climbing stairs.
Any training program that increases muscular strength may also increase muscular
power. In older adults, the increase in power following a resistance training program
has been attributed to an increase in strength.34 Thus, an improvement in power parallels an increase in strength with more robust increases in both observed during the
initial weeks (~4 weeks) of resistance training and a diminished increase with longer
training periods. Increases in upper and lower body muscular power may be similar
between younger and older individuals initially during a high-intensity (80% 1RM)
resistance training program.35 However, traditional slower movement ­resistance training may increase strength more than power in older adults. In fact, the improvement
in muscle power at low velocities following high-load, low-­velocity resistance training may be beneficial to older adults because these improvements may translate to
improvements in functional ability. However, to optimize muscular power adaptations
in older adults, high-velocity explosive-type resistance training may be more effective.
High-load (70% 1RM) training performed with the concentric phase of each repetition completed as fast as possible increases peak power to a greater extent than traditional (2 seconds concentric) resistance training despite similar increases in strength.36
In addition, increases in muscle power may be s­ pecific to the training load.24
Effects of Resistance Training on Physical Function
Although resistance training improves measures of muscular fitness in older adults,
the translation of these benefits to improvements in physical function is not always
clear. Many resistance training programs may produce modest increases in physical
function, but these improvements may only be observed when the training mimics
the functional outcome measured (e.g., stair climb, chair rise, and walking).
Michael G. Bemben et al.
241
Resistance training intensity does not influence the magnitude of functional
improvement despite the fact that higher intensity resistance training improves
strength to a greater extent than lower intensity training in older adults.37 Both lowand high- intensity resistance training can improve functional abilities such as stair
climbing.31 It appears that below a minimum strength threshold, functional ability
is compromised in older adults.38 Likewise, a modest increase in strength produces
a large increase in functional ability with greater increases in strength producing
negligible increases in functional ability.38
Functional ability is more related to power than strength. Thus, explosive power
training may improve functional ability to a greater extent than traditional slow
resistance training. However, evidence appears inconsistent with regard to whether
traditional or explosive power training provides greater improvements in functional
ability.37 Resistance training mimicking everyday tasks (e.g., walking and stair
climbing) has been proposed to be the most effective for improving functional ability in older adults. However, limited evidence exists at this time to determine if
task-oriented resistance training improves physical function more than traditional
free-weight or machine-type resistance training (Table 15.1).37
Effects of Resistance Training on Muscle Quality
Muscle quality is the ratio of function (strength) to mass (area or volume). Decreases
in muscle quality with age may exceed decreases in muscle mass. Conversely,
resistance training in older adults generally improves muscle function more than
mass. Thus, resistance training improves muscle quality. For example, in older
adults, vastus lateralis muscle hypertrophy and increases in pennation angle do not
match the increase in isometric force indicating an increase in m
­ uscle ­quality.39
Replacement of intramuscular adipose tissue with muscle tissue, an increased
packing density of contractile elements, increases in force per cross-bridge, an
increase in myocyte membrane excitability, selective hypertrophy of type II fibers,
and an increase in neural drive are all potential factors increasing muscle quality. Increases in muscle quality are usually attributed to either a greater increase
in type II fiber area33 or an increase in neural activation17 following resistance
training. In addition, resistance training may also improve tendon stiffness, which
can improve muscle quality by increasing the rate of torque development in older
individuals.40
NONTRADITIONAL RESISTANCE TRAINING
Difficulties of Using Traditional Resistance Equipment
Resistance exercise training has proven to be a very effective tool against sarcopenia as well as for improving muscular strength, power, endurance, and functional
ability. However, several problems arise in the actual implementation of resistance exercise training with an older population. One problem could be inadequate
transportation to facilities or gyms where resistance exercise machines can be
used.41 Also, motivation may be low to attend a gym due to a lack of adequate
242
Resistance Training for Older Adults
TABLE 15.1
Traditional Resistance Training
Effect of Aging
Effect of Resistance
Training
Muscle size
↓ Type I and II fiber CSA
↓ In whole muscle size
↑ Type I and II fiber CSA
↑ In whole muscle size
Muscle
architecture
↓ Fascicle length
↓ Pennation angle
↑ Fascicle length
↑ Pennation angle
Muscle strength
↓ Strength
↓ Motor unit activation
and firing frequency
↑ Strength
↑ Motor unit activation
and firing frequency
Muscle
endurance
↓ Endurance
↑ Endurance
Muscle power
↓ Power
↑ Power
Physical
function
↓ Functional ability
↑ Functional ability
Muscle quality
↓ Muscle quality
↑ Muscle quality
Attribute
Comment
Wide variation in
magnitude of muscle
hypertrophy observed
Muscle stiffness
Changes contribute to
an improvement in the
force–length
relationship
Resistance exercise load
(i.e., >80% 1RM) is
most important for
improving strength
Moderate to high loads
(i.e., 40%–80% 1RM)
can effectively
increase endurance
Both high-velocity
low-load and
low-velocity high-load
resistance trainings are
effective
High-velocity power
training can improve
functional ability more
than slow-movement
resistance training
Greater improvements
in muscle strength
compared to muscle
mass result in
improved muscle
quality
funds or the gym environment.41 Furthermore, purchasing a weight machine can
be e­ xpensive and may make the option of resistance exercise at home difficult to
achieve. Finally, older individuals may have joint or other health problems that
prevent them from using traditional free weights. Because of these problems,
alternative and ­effective forms of resistance exercise training are needed. Several
alternative forms of t­ raditional resistance exercise training may help combat sarcopenia and its effects: these include body weight exercises or calisthenics, elastic
band e­ xercises, and aquatic resistance exercises (Table 15.2).
243
Michael G. Bemben et al.
TABLE 15.2
Nontraditional Resistance Training
Resistance Exercise
Body weight
Elastic bands
Aquatic resistance training
Advantages
Disadvantages
Inexpensive
↑ Strength
↑ Functional ability
Numerous exercises for
upper and lower body
Easily transported
Limited amount of exercises
Limited progression
↔ Muscle size
Improper technique limits usefulness
↑ Strength
↑ Functional ability
↑ Balance
↓ Stress on joints
↑ Strength
↑ Functional ability
↑ Muscle CSA
↑ Fat-free mass
Cannot use predetermined 1RM to
quantify intensity
Possibility of bands snapping
Requires access to a pool
Requires special equipment
Difficulty controlling intensity
↔ Bone mineral density
Alternatives to Weight Machines and Free Weights
Body Weight Exercises: Benefits
One alternative to traditional weight training may be the use of body weight exercises or
calisthenics. Body weight exercises focus on using one’s own body weight for resistance
and can include exercises such as wall push-ups, sit-ups, body squats, stair stepping,
chair rises, and walking. These exercises do not require expensive equipment and can
be done easily at home. Furthermore, these exercises focus on functional tasks performed during daily activities such as rising up and down from a chair. When first investigating the effects of physical activity in older adults, researchers had older men (69–74
years old) perform static and dynamic exercises using only body weight with a focus on
the lower limbs. After exercising three times a week for 12 weeks, they found significant
increases in knee extension isometric and isokinetic strength.42 However, despite these
strength gains, type II muscle fiber area did not increase significantly, and the authors
suggested that the increase in strength was most likely due to neurological adaptations.
Another study by Krebs et al.43 also examined the effect of using body weight on
strength and functional ability. The authors designed a body weight training program focused on using functional activities to improve strength and functional ability in older subjects (62–85 years old) with some lower limb impairment. Exercises
included chair rises, forward walking, side step walking, step up/step forward and
down, marching, stooping/squatting, and forward and upward reach type activities.
Progression included having participants hold objects during walking, increasing
speed or number of repetitions of an exercise, changing step height or combining
tasks. After participating in this intervention three times a week for 6 weeks, significant increases in lower body strength were found for this group similar to an exercise
244
Resistance Training for Older Adults
group who used elastic bands for resistance. Additionally, functional ability also
significantly increased.43 The results of these studies show that body weight can be
used to produce a stimulus that can increase strength and functional ability, which is
important in combating the effects of sarcopenia.
Body Weight Exercise: Disadvantages
However, some disadvantages exist with body weight exercises. For one, increases in
muscle size may not occur.42 Also, progression may be difficult without adding some
type of resistance such as carrying household items.43 Despite these disadvantages, if
traditional resistance exercise equipment options are not available, then body weight
exercises offer a beneficial alternative.
Elastic Band Training: Benefits
Another alternative form of resistance training is elastic band resistance training,
which involves performing an exercise with elastic bands or elastic tubing. The
intensity of the exercise depends on how far the band is stretched and how thick
the band is. Elastic bands require more force to stretch the band as the length of the
band increases. The ability of elastic bands to easily alter intensity makes them very
adaptable to individuals. Light resistance bands (smaller thicknesses) can be used
for weaker individuals, and stronger individuals can increase the intensity by either
changing the elastic band thickness or doubling up bands. Furthermore, elastic bands
tend to be relatively affordable and can be transported easily or used at home.44
Many studies have examined the use of elastic bands to improve functional ability
and strength in the elderly and have shown positive results. One study examined how
the elastic band training of dorsiflexors and plantar flexors would change strength
and functional ability in institutionalized elderly (72–87 years old).45 After training
three times a week for 6 weeks with supervision, participants significantly increased
both dorsiflexor and plantar flexor strength, but no significant change was found
in the control group. Also, balance and functional mobility significantly increased
with elastic band training but not in the control group.45 Another study had men
and women 65 years and older perform six upper body and six lower body elastic
band exercises three times a week for 12 weeks with one supervised session and
two home training sessions.45 After 12 weeks, isokinetic eccentric and knee flexion
strength significantly increased. Similarly, another supervised elastic band t­raining
program found that following 16 weeks of training, women between the ages of
60 and 81 significantly increased the strength of their biceps and quadriceps.46
Rogers et al.47 also found that older inner-city African–American women increased
lower body strength and endurance by 19% and increased balance and mobility by
10% after using elastic bands. When elastic band exercises are properly performed
with supervision, significant increases in strength and functional ability can result.
Evidence also exists that a home-based program using elastic bands not requiring supervision can be effective in increasing strength. Jette et al.48 had participants
exercise with elastic bands at home for over a 6 month period and found that strength
significantly increased in the lower body (6%–12%) and disability status was significantly reduced (15%–18%) compared to a control group.48 In support of these
Michael G. Bemben et al.
245
findings, Zion et al.49 found that the elderly (ages of 63–81) with orthostatic hypotension who performed elastic band exercises at home significantly increased chest
press, quadriceps, and leg press strength. Also, seven of eight subjects improved their
walking speed for the timed-up-and-go (TUG) test. In this study though, subjects
returned at weeks 2 and 4 to have their form monitored and resistance increased.
Overall, elastic bands provide a strong enough stimulus when used correctly to significantly increase strength and improve functional ability in the elderly.
However, some have questioned the benefits of elastic band training compared
with traditional weight training equipment. To investigate the effectiveness of elastic
bands compared with traditional weight machines in middle-aged women, one study
had participants perform similar exercises with weights or with elastic bands. After
exercising two times a week for 10 weeks, both groups significantly increased upper
body endurance and lower body power without significant differences between
groups.50 Another piece of evidence supporting that elastic bands can provide a resistance similar to traditional weight machines is the finding that muscle activity is
similar between elastic band and dumbbell exercises.51 Elastic bands can provide a
similar stimulus to normal weight training equipment in older adults.
Elastic Band Training: Disadvantages
When performing elastic band exercises, it is important that proper technique and
progression be used to maximize its benefits. A disadvantage of elastic bands could
be the lack of proper form used when performing exercises at home without supervision. The user needs to control the movement of the elastic band so that the elastic
band is not controlling them or returning back to its original shape without any resistance. One way to address improper form is to familiarize the user on proper form
and then send a video or instruction manual with pictures home with the exerciser.
Jette et al.48 found that using a video or giving written instructions to participants
resulted in significant strength gains over a 6 month period.
Another disadvantage may be the difficulty of exercisers to monitor intensity during exercise compared to using a predetermined percentage of 1RM.50 One method
that has been used to address the intensity of elastic band exercises is the OMNI
resistance for active muscles (OMNI-RES AM) scale. This scale allows exercisers to
quantify their physical exertion throughout the exercise session and training period.
When used with elastic band training, it has proved to be a successful model for
progression resulting in strength gains.50,52
Aquatic Resistance Training: Benefits
Another alternative to traditional resistance exercise training that may be useful in
combating the effects of sarcopenia is aquatic resistance training. Aquatic resistance
training can increase functional fitness and contains both an aerobic and an anaerobic component, depending on the type of exercises used.53 Water resists limb movements and as the velocity of the body part increases the drag force increases, thereby
creating a resistance component. To optimize the water resistance, the motion of
the exercise needs to oppose the upward buoyancy force during the range of movement. Both upper body and lower body exercises can be done, but specific types of
water-resistance products, like water noodles or cuff devices, are needed to provide
246
Resistance Training for Older Adults
more resistance. This type of training may be especially beneficial to individuals
with arthritis, osteoporosis, or joint problems because the water provides a buoyant
component that decreases the stress on the joints.
Not only can aquatic resistance training be beneficial for decreasing stress on the joints
but also evidence demonstrates that this type of training can improve strength. Following
12 weeks of aquatic resistance exercise training, arm and leg strength increased significantly in older women (~69 years old).54 Another study found that after 24 weeks of
aquatic resistance training, three-repetition maximum of elderly women increased by
29% in the knee extension, 30% in the leg press, and 26% in the chest press and was significantly higher than a control group.55 Furthermore, the same study found that isometric torque, which is a key indicator of functional ability in the elderly,56,57 significantly
increased for knee extension (11%), knee flexion (13%), and handgrip (13%).55 Because
loss of muscular strength occurs with sarcopenia, aquatic resistance training provides
another effective alternative to traditional weight training that elderly subjects may enjoy
because of the low stress on joints and the psychological benefits of exercising in a group.
Other benefits of aquatic resistance training include increased functional capacity
and increased muscle CSA and fat-free mass.58,59 When individuals over the age of 65
performed aquatic resistance training for a period of 8 weeks, TUG test times and 5 m
maximum walking speed significantly improved.60 In support of this finding, Tsourlou
et al.55 found that TUG performance improved by 20% and squat jump performance
increased by 25% after 24 weeks of aquatic exercise. Deveraux et al.61 found that
women over the age of 65 had significant increases in dynamic standing balance after
10 weeks of aquatic exercise. The aquatic environment provides a stimulus that challenges the balance system, and improvements in functional ability and balance result.
Aquatic Resistance Exercise: Disadvantages
Despite the benefits of countering sarcopenia with aquatic resistance training, several disadvantages are apparent. First of all, access to a pool and need for special
aquatic resistance equipment could limit its use with an older population. This may
not be feasible for some who do not have transportation to pools in general, or when
pools may be closed during the winter, if indoor pools are not available. Another
problem is controlling the intensity of the exercise. Different weights can be used,
but speeding or slowing down movements change the resistance, so it is important
for subjects to quantify their intensity by possibly using a scale such as the OMNIRES AM scale.59 Also, because aquatic resistance exercise does not place much
stress on the bones or joints, this type of exercise does not enhance bone strength.
LOW-LOAD RESISTANCE EXERCISE WITH BLOOD FLOW
RESTRICTION: AN ALTERNATIVE TO TRADITIONAL
RESISTANCE EXERCISE
Historical Perspective of Low-Load Resistance Training with
Blood Flow Restriction
The concept of heavy resistance training is not new but dates back to ancient
Greece. Legends tell Milo of Croton who lifted a bull-calf daily until it was fully
Michael G. Bemben et al.
247
grown, which is now known as progressive overload. Since that time, it has been
observed that ­lifting heavy weights repeatedly with some form of progressive overload is capable of increasing skeletal muscle hypertrophy, muscular strength, and
muscular endurance. Furthermore, the majority of scientific literature suggests that
­meaningful muscle hypertrophy does not occur with loads less than 70% 1RM. Also,
this heavy loading needs to be applied to the skeletal muscle at least two to three
times a week for continued improvement in muscle mass and strength.30 Although
numerous positive effects have been observed from heavy resistance training, some
­populations (e.g., elderly and rehabilitating patients) might be advised not to perform
heavy resistance training and may be limited to performance of lower load resistance
exercise. Blood flow restriction (BFR) in combination with low-load exercise may be
an attractive form of training for those who are unable to lift heavier loads.
The idea of BFR is credited to Yoshiaki Sato, who started developing this method
of training in the fall of 1966 following numbness in his calf from kneeling at
a Buddhist ceremony. Sato realized that this was a similar feeling as to what he
received following heavy calf-raise resistance exercise and theorized that this muscle
swelling and altered sensation was associated with reduced blood flow to the muscle.
With this, he set out to develop an equipment (initially bicycle tubing) to test his
initial theory that this stimulus could effectively produce positive muscular adaptation. Following numerous modifications, he completed the basic training manual for
BFR approximately 4 years following his initial idea. Numerous laboratories across
the world have researched this method of training and found it to be very useful for
increasing muscle size and function.62
Basic Theory Behind Blood Flow Restricted Exercise
Mechanisms
The physiologic mechanisms behind BFR are not completely known, but a prominent mechanism is likely the stimulation of muscle protein synthesis, which has
been observed following low-load BFR resistance exercise.63 This may occur from
a reduced-oxygen (not anoxic) environment and through metabolic accumulation,
which may increase the recruitment of higher threshold (type II) muscle fibers through
the stimulation of group III and IV afferent fibers.64 It is thought that increases in
metabolites may also facilitate the increase in growth hormone observed following resistance exercise with BFR.65 However, metabolic accumulation and increased
fiber recruitment are not always present with BFR walking nor BFR alone, which
are conditions that have both previously been shown to increase or maintain strength
and muscle mass. Therefore, it has been hypothesized that the application of BFR
may induce muscle cell swelling through a combination of blood pooling and reactive hyperemia following the removal of BFR, which may contribute to skeletal muscle adaptations that occur with BFR.66,67 However, a recent study has demonstrated
that the reactive hyperemia following BFR is not responsible for increases observed
in muscle protein synthesis.68 In addition, when BFR is combined with resistance
exercise, the effects on both muscle hypertrophy and strength are augmented by
increases in the previously mentioned mechanisms (e.g., fiber type recruitment and
elevations in anabolic hormones). Evidence also indicates that markers of protein
248
Resistance Training for Older Adults
breakdown and myostatin expression are decreased following low-load resistance
exercise in combination with BFR.69
Standard Protocols
The typical protocol includes the application of cuffs to the proximal portion of
the limb that is being exercised. However, there is some evidence that increases in
muscular adaptation can also occur in muscles that are not under the restriction of
blood flow. This suggests that BFR is not only a local response but also systemic.70
Research has typically focused on single-joint resistance exercises, although benefits have also been observed with more complex movements (i.e., bench press and
squat). In addition, walking at low intensities with BFR has been shown to result in
increased muscle mass and strength, despite subjects only walking at 50 m·min−1.71
The traditional loading for BFR resistance training is approximately 20%–30%
1RM for four sets of exercise with 30 seconds rest between the sets. The first set is
30 repetitions with the last three being 15 repetitions. The first set contains more
repetitions as it is designed to stimulate and maintain the metabolic buildup throughout the duration of exercise. With BFR walking, the typical protocol is around
50–60 m·min−1 of walking for approximately 20 minutes. Some, but not all, walking
protocols include rest intervals where subjects will walk for 2 minutes and then rest
(stand) for 1 minute. This 1 minute standing rest period may diminish muscle pump
activity and further facilitate venous pooling.
Restriction Pressure Recommendations
In the literature, a wide range of restrictive cuff pressures have been used, from
50 to 300 mmHg. However, the pressure should be set to allow venous occlusion from
the working muscle and moderate arterial restriction into the working muscle. Some
studies have used arbitrary pressures for everyone or have tried to make it relative to
the individual by using a percentage of brachial systolic blood pressure (most often
130% of brachial systolic blood pressure). Complicating things further, different
sized cuffs are used in different studies, making it hard to compare outcomes across
different investigations. Traditionally, the lower body elastic cuff is 5 cm wide and
the upper body cuff is approximately 3 cm wide. However, some investigations have
used a much wider cuff (13.5 cm) interchangeably with a narrower cuff (5 cm). This
is problematic in that a wide cuff requires less pressure to restrict blood flow than a
narrow cuff and if pressures are used interchangeably some subjects may actually be
without arterial blood flow during the inflation. Research indicates that regardless of
cuff size, cuff pressure should largely be determined by thigh circumference.72
Potential Safety Concerns
Low-intensity exercise in combination with BFR appears to offer a safe alternative
to higher intensity exercise. One of the major concerns with restricting blood flow is
deep vein thrombosis; however, investigations have found that coagulation activity
does not appear to increase following BFR exercise.73 Moreover, the restriction of
blood flow actually appears to enhance the fibrinolytic potential,73 an effect similar
to that observed with higher intensity exercise. A study investigating Japanese facilities utilizing this technique found that the incidence rate for venous thrombosis was
249
Michael G. Bemben et al.
TABLE 15.3
Blood Flow–Restricted Resistance Training
Advantages
↓ Mechanical stress to joint
↑ Muscle size at low external loads
↑ Muscular strength at low external loads
↑ Bone formation markers (bone-specific alkaline
phosphatase)
Attenuates ↓ muscle size during periods of unloading
Attenuates ↓ muscle strength during periods of unloading
Disadvantages
Access to pressure cuffs
Slightly greater discomfort than
traditional resistance training
Not recommended for those with an
elevated thromboembolism risk
only 0.06% out of 30,000 training sessions, which is actually lower than the general
Asian population risk of 0.2%–0.26%.74
Peripheral and central changes in the cardiovascular system have also demonstrated
positive outcomes from chronic BFR training. Blood flow appears to be enhanced following this mode of training, and there appears to be no lasting negative effect on systolic
or diastolic blood pressure.75–77 In addition, muscular benefits with low-load BFR resistance training are observed without measurable changes in markers of muscle damage or
oxidative stress,65,71 making it an attractive alternative for populations who are contraindicated to performing damaging exercise (i.e., high-load resistance exercise; Table 15.3).
Studies Demonstrating Efficacy
Several studies have found that exercise in combination with BFR provides s­keletal
muscle adaptations that are similar to those observed with higher intensity e­ xercise
(Figure 15.1). Although numerous studies have shown benefits of BFR in younger
subjects, the studies highlighted in this section used an older population or provided
evidence directly applicable to the elderly.
Blood Flow Restriction without Exercise
Evidence indicates that BFR in the absence of exercise may provide a means to attenuate muscle atrophy and declines in strength during a period of muscular unloading.
Studies were completed using a series of 5 minute inflations followed by 3 minutes
of deflation, for a total of five complete series completed twice daily.78–80 This is
directly applicable to individuals of advancing age who may be inactive due to an
injury or illness as BFR may provide a means to maintain lean mass until they are
again capable of physical activity.
Blood Flow–Restricted Walking and Cycling
Low-intensity walking with BFR has been shown to result in skeletal muscle hypertrophy and strength gain, which is only typically observed following resistance training.81 These improvements are observed while walking as slow as 50 m·min−1. In
addition to the increased size, strength, and functional capacity with BFR walking,
250
Resistance Training for Older Adults
Muscle hypertrophy effect size
1.5
1
0.5
0
–0.5
Absence of exercise
Low intensity
walking
Low load
resistance training
–1
–1.5
–2
Blood flow restriction
No blood flow restriction
FIGURE 15.1 The effects of blood flow restriction (BFR) on muscle hypertrophy ­compared
to the same conditions without BFR: the application of BFR in the absence of exercise
­attenuates atrophy. However, when BFR is combined with low-intensity/-load exercise there
are significant increases in muscle hypertrophy. Effect size for muscle size was calculated
(Posttest mean—Pretest mean/Pretest SD). (From data presented by Takarada, Takazawa
and Ishii (2000) and a meta-analysis in Eur J Appl Physiol. 2012 May; 112(5): 1849–59.
All images created by Jacob M. Wilson, PhD.)
improvements in arterial and venous compliance have also been observed. Walking
with BFR may provide an additional mode of exercise for increasing or maintaining
muscle mass, particularly for those who are unable or not willing to perform resistance training. Interestingly, evidence in younger subjects indicates that BFR may be
utilized with more than one type of aerobic modality, as increases in muscle hypertrophy and strength have been observed following BFR cycling at 40% of their aerobic
capacity.82
Blood Flow Restriction with Resistance Exercise
Low-load resistance exercise with BFR has proved beneficial with older populations for increasing lower and upper body strength and size. These results have been
observed at loads representing approximately 20%–50% 1RM. A study performed
in postmenopausal women found that 16 weeks of low-load BFR resistance exercise
increased the size and strength of elbow flexors.83 In addition, evidence from studies
in older men found that the increases in strength are similar to those observed with
Michael G. Bemben et al.
251
higher load resistance training (80% 1RM), highlighting its potential role in skeletal muscle accretion or maintenance.84 In younger adults, the increases in muscle
size and strength have also been found to occur in muscles proximal to the actual
BFR stimulus.85 For example, applying BFR to the arms and performing low-load
bench press exercise results in increased muscle hypertrophy of the pectoralis major,
despite not being under BFR. Further studies are warranted; but these findings suggest that although BFR is applied only to the limbs, benefits are observed in musculature proximal to the cuff, making the BFR stimulus also applicable to muscles of
the trunk.
Blood Flow Restriction and Bone Health
Although the focus is on maintaining skeletal muscle hypertrophy, it is also important to talk about the actual skeleton as well, particularly when exercising at lower
loads or intensities. Long-term research on this topic has not been completed, but
short-term studies suggest that both walking and resistance exercise in combination
with BFR positively affects serum bone markers. Walking has been found to increase
markers of bone formation, whereas research on low-load resistance ­training with
BFR has found increases in bone formation as well as decreases in bone resorption.
These studies suggest that although very low loads and intensities are used with BFR
exercise, positive adaption in bone is likely occurring, providing further rationale for
the use of BFR when higher loading is not possible.86,87
CONCLUSION
Aging brings about the inevitable consequences of a loss of muscle mass and concomitant changes in muscle function. This decline in skeletal muscle mass can
severely affect even the simplest activities of normal daily living. The reasons for the
age-related loss of muscle mass are numerous and varied, but most occur due to the
normal aging process. Therefore, being able to identify critical time periods during
aging where individuals are most susceptible to change is essential for being able to
design appropriate resistance training programs to help slow the loss of muscle mass
or even increase muscle mass through muscle hypertrophy.
In general, resistance training can be beneficial, is safe, and is often recommended for older adults, if approved by their personal physicians. Minimally,
­resistance training should be performed twice weekly at an intensity that is moderate to intense, with specific recommendations offered in the ACSM’s position stand
in 2009.
If traditional resistance exercises with free weights or machine weights are not
available or desired, then other modes of exercise can also prove to be effective for
improving muscle function. Exercises that incorporate body weight, elastic bands, or
aquatic resistance can provide effective interventions. Finally, another novel approach
that is currently being investigated in a number of laboratories in the United States
is the use of BFR during low-load resistance training. This method appears to be
safe and effective, but more research is needed before adopting this technique as an
alternative form of resistance training for older individuals.
252
Resistance Training for Older Adults
REFERENCES
1. Rosenberg IH. Summary comments. Am J Clin Nutr. 1989; 50: 1231–3.
2. Frontera WR, Hughes VA, Fielding RA, Fiatarone MA, Evans WJ, Roubenoff R. Aging
of skeletal muscle: a 12-yr longitudinal study. J Appl Physiol. 2000; 88: 1321–6.
3. Buchman AS, Wilson RS, Boyle PA, Tang Y, Fleischman DA, Bennett DA. Physical
activity and leg strength predict decline in mobility performance in older persons. J Am
Geriatr Soc. 2007; 55: 1618–23.
4. Vandervoort AA. Aging of the human neuromuscular system. Muscle Nerve. 2002; 25:
17–25.
5. Baumgartner RN, Koehler KM, Gallagher D et al. Epidemiology of sarcopenia among
the elderly in New Mexico. Am J Epidemiol. 1998; 147: 755–63.
6. Manini TM, Clark BC. Dynapenia and aging: an update. J Gerontol A Biol Sci Med Sci.
2012; 67: 28–40.
7. Clark BC, Manini TM. Sarcopenia dynapenia. J Gerontol A Biol Sci Med Sci. 2008; 63:
829–34.
8. Narici MV, Maffulli N. Sarcopenia: characteristics, mechanisms and functional significance. Br Med Bull. 2010; 95: 139–59.
9. Chodzko-Zajko WJ, Proctor DN, Fiatarone Singh MA et al. American College of Sports
Medicine position stand. Exercise and physical activity for older adults. Med Sci Sports
Exerc. 2009; 41: 1510–30.
10. Garber CE, Blissmer B, Deschenes MR et al. American College of Sports Medicine
position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc. 2011; 43: 1334–59.
11. Ploutz-Snyder LL, Giamis EL. Orientation and familiarization to 1RM strength testing
in old and young women. J Strength Cond Res. 2001; 15: 519–23.
12. Roth SM, Ivey FM, Martel GF et al. Muscle size responses to strength training in young
and older men and women. J Am Geriatr Soc. 2001; 49: 1428–33.
13. Welle S, Totterman S, Thornton C. Effect of age on muscle hypertrophy induced by
resistance training. J Gerontol A Biol Sci Med Sci. 1996; 51: M270–5.
14. Breen L, Phillips S. Skeletal muscle protein metabolism in the elderly: interventions to
counteract the ‘anabolic resistance’ of ageing. Nutr Metab. 2001; 8: 68.
15. Porter MM. The effects of strength training on sarcopenia. Can J Appl Physiol. 2001;
26: 123–41.
16. Yarasheski KE, Pak-Loduca J, Hasten DL, Obert KA, Brown MB, Sinacore DR.
Resistance exercise training increases mixed muscle protein synthesis rate in frail
women and men >/=76 yr old. Am J Physiol. 1999; 277: E118–25.
17. Grimby G, Aniansson A, Hedberg M, Henning GB, Grangard U, Kvist H. Training can
improve muscle strength and endurance in 78- to 84-yr-old men. J Appl Physiol. 1992;
73: 2517–23.
18. Narici MV, Maganaris CN, Reeves ND, Capodaglio P. Effect of aging on human muscle
architecture. J Appl Physiol. 2003; 95: 2229–34.
19. Reeves ND, Maganaris CN, Narici MV. Effect of strength training on human patella
tendon mechanical properties of older individuals. J Physiol. 2003; 548: 971–81.
20. Folland JP, Williams AG. The adaptations to strength training: morphological and neurological contributions to increased strength. Sports Med. 2007; 37: 145–68.
21. Aagaard P, Suetta C, Caserotti P, Magnusson SP, Kjaer M. Role of the nervous system in
sarcopenia and muscle atrophy with aging: strength training as a countermeasure. Scand
J Med Sci Sports. 2010; 20: 49–64.
Michael G. Bemben et al.
253
22. Hakkinen K, Kraemer WJ, Newton RU, Alen M. Changes in electromyographic activity, muscle fibre and force production characteristics during heavy resistance/power
strength training in middle-aged and older men and women. Acta Physiol Scand. 2001;
171: 51–62.
23. Kamen G, Knight CA. Training-related adaptations in motor unit discharge rate in
young and older adults. J Gerontol A Biol Sci Med Sci. 2004; 59: 1334–8.
24. Izquierdo M, Hakkinen K, Anton A et al. Maximal strength and power, endurance performance, and serum hormones in middle-aged and elderly men. Med Sci Sports Exerc.
2001; 33: 1577–87.
25. Peterson MD, Rhea MR, Sen A, Gordon PM. Resistance exercise for muscular strength
in older adults: a meta-analysis. Ageing Res Rev. 2010; 9: 226–37.
26. Kryger AI, Andersen JL. Resistance training in the oldest old: consequences for muscle
strength, fiber types, fiber size, and MHC isoforms. Scand J Med Sci Sports. 2007; 17:
422–30.
27. Frontera WR, Meredith CN, O'Reilly KP, Knuttgen HG, Evans WJ. Strength conditioning in older men: skeletal muscle hypertrophy and improved function. J Appl Physiol.
1988; 64: 1038–44.
28. Galvao DA, Taaffe DR. Resistance exercise dosage in older adults: single- versus multiset
effects on physical performance and body composition. J Am Geriatr Soc. 2005; 53: 2090–7.
29. DiFrancisco-Donoghue J, Werner W, Douris PC. Comparison of once-weekly and
twice-weekly strength training in older adults. Br J Sports Med. 2007; 41: 19–22.
30. Ratamess NA, Alvar BA, Evetoch TK et al. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Med Sci Sports
Exerc. 2009; 41: 687–708.
31. Vincent KR, Braith RW, Feldman RA et al. Resistance exercise and physical performance in adults aged 60 to 83. J Am Geriatr Soc. 2002; 50: 1100–7.
32. de Vos NJ, Singh NA, Ross DA, Stavrinos TM, Orr R, Fiatarone Singh MA. Optimal
load for increasing muscle power during explosive resistance training in older adults.
J Gerontol A Biol Sci Med Sci. 2005; 60: 638–47.
33. Brown AB, McCartney N, Sale DG. Positive adaptations to weight-lifting training in the
elderly. J Appl Physiol. 1990; 69: 1725–33.
34. Ferri A, Scaglioni G, Pousson M, Capodaglio P, Van Hoecke J, Narici MV. Strength and
power changes of the human plantar flexors and knee extensors in response to resistance
training in old age. Acta Physiol Scand. 2003; 177: 69–78.
35. Jozsi AC, Campbell WW, Joseph L, Davey SL, Evans WJ. Changes in power with resistance training in older and younger men and women. J Gerontol A Biol Sci Med Sci.
1999; 54: M591–6.
36. Fielding RA, LeBrasseur NK, Cuoco A, Bean J, Mizer K, Fiatarone Singh MA. Highvelocity resistance training increases skeletal muscle peak power in older women. J Am
Geriatr Soc. 2002; 50: 655–62.
37. Steib S, Schoene D, Pfeifer K. Dose-response relationship of resistance training in older
adults: a meta-analysis. Med Sci Sports Exerc. 2010; 42: 902–14.
38. Buchner DM, Larson EB, Wagner EH, Koepsell TD, de Lateur BJ. Evidence for a nonlinear relationship between leg strength and gait speed. Age Ageing. 1996; 25: 386–91.
39. Narici MV, Reeves ND, Morse CI, Maganaris CN. Muscular adaptations to resistance
exercise in the elderly. J Musculoskelet Neuronal Interact. 2004; 4: 161–4.
40. Maganaris CN, Narici MV, Reeves ND. In vivo human tendon mechanical properties:
effect of resistance training in old age. J Musculoskelet Neuronal Interact. 2004; 4: 204–8.
41. Schutzer KA, Graves BS. Barriers and motivations to exercise in older adults. Prev Med.
2004; 39: 1056–61.
254
Resistance Training for Older Adults
42. Aniansson A, Gustafsson E. Physical training in elderly men with special reference to
quadriceps muscle strength and morphology. Clin Physiol. 1981; 1: 87–98.
43. Krebs DE, Scarborough DM, McGibbon CA. Functional vs. strength training in disabled elderly outpatients. Am J Phys Med Rehabil. 2007; 86: 93–103.
44. Mikesky AE, Topp R, Wigglesworth JK, Harsha DM, Edwards JE. Efficacy of a homebased training program for older adults using elastic tubing. Eur J Appl Physiol Occup
Physiol. 1994; 69: 316–20.
45. Ribeiro F, Teixeira F, Brochado G, Oliveira J. Impact of low cost strength training of
dorsi- and plantar flexors on balance and functional mobility in institutionalized elderly
people. Geriatr Gerontol Int. 2009; 9: 75–80.
46. Bemben MG, Bemben DA, Fields D, Walker L. The effects of 16 weeks of resistance
training on strength and flexibility in elderly women. Issues on Aging. 1996; 19: 10–4.
47. Rogers ME, Sherwood HS, Rogers NL, Bohlken RM. Effects of dumbbell and elastic
band training on physical function in older inner-city African-American women. Women
Health. 2002; 36: 33–41.
48. Jette AM, Lachman M, Giorgetti MM et al. Exercise—it’s never too late: the strong-forlife program. Am J Public Health. 1999; 89: 66–72.
49. Zion AS, De Meersman R, Diamond BE, Bloomfield DM. A home-based resistancetraining program using elastic bands for elderly patients with orthostatic hypotension.
Clin Auton Res. 2003; 13: 286–92.
50. Colado JC, Triplett NT. Effects of a short-term resistance program using elastic bands
versus weight machines for sedentary middle-aged women. J Strength Cond Res. 2008;
22: 1441–8.
51. Andersen LL, Andersen CH, Mortensen OS, Poulsen OM, Bjornlund IB, Zebis MK.
Muscle activation and perceived loading during rehabilitation exercises: comparison of
dumbbells and elastic resistance. Phys Ther. 2010; 90: 538–49.
52. Colado JC, Garcia-Masso X, Pellicer M, Alakhdar Y, Benavent J, Cabeza-Ruiz R.
A comparison of elastic tubing and isotonic resistance exercises. Int J Sports Med. 2010;
11: 810–7.
53. Wood RH, Reyes R, Welsch MA et al. Concurrent cardiovascular and resistance training
in healthy older adults. Med Sci Sports Exerc. 2001; 33: 1751–8.
54. Takeshima N, Rogers ME, Watanabe E et al. Water-based exercise improves healthrelated aspects of fitness in older women. Med Sci Sports Exerc. 2002; 34: 544–51.
55. Tsourlou T, Benik A, Dipla K, Zafeiridis A, Kellis S. The effects of a twenty-four-week
aquatic training program on muscular strength performance in healthy elderly women.
J Strength Cond Res. 2006; 20: 811–8.
56. Lauretani F, Russo CR, Bandinelli S et al. Age-associated changes in skeletal muscles
and their effect on mobility: an operational diagnosis of sarcopenia. J Appl Physiol.
2003; 95: 1851–60.
57. Rantanen T, Era P, Heikkinen E. Maximal isometric strength and mobility among
75-year-old men and women. Age Ageing. 1994; 23: 132–7.
58. Valtonen A, Poyhonen T, Sipila S, Heinonen A. Effects of aquatic resistance training on
mobility limitation and lower-limb impairments after knee replacement. Arch Phys Med
Rehabil. 2010; 91: 833–9.
59. Colado JC, Triplett NT, Tella V, Saucedo P, Abellan J. Effects of aquatic resistance training
on health and fitness in postmenopausal women. Eur J Appl Physiol. 2009; 106: 113–22.
60. Katsura Y, Yoshikawa T, Ueda SY et al. Effects of aquatic exercise training using waterresistance equipment in elderly. Eur J Appl Physiol. 2010; 108: 957–64.
61. Devereux K, Robertson D, Briffa NK. Effects of a water-based program on women
65 years and over: a randomised controlled trial. Aust J Physiother. 2005; 51: 102–8.
62. Sato Y. 2005. The history and future of KAATSU Training. Int J KAATSU Training Res.
2005; 1: 1–5.
Michael G. Bemben et al.
255
63. Fry CS, Glynn EL, Drummond MJ et al. Blood flow restriction exercise stimulates
mTORC1 signaling and muscle protein synthesis in older men. J Appl Physiol. 2010;
108: 1199–209.
64. Yasuda, T, Abe T, Brechue WF et al. Venous blood gas and metabolite response to lowintensity muscle contractions with external limb compression. Metabolism. 2010; 59:
1510–9.
65. Takarada Y, Nakamura Y, Aruga S, Onda T, Miyazaki S, Ishii N. Rapid increase in
plasma growth hormone after low-intensity resistance exercise with vascular occlusion.
J Appl Physiol. 2000; 88: 61–5.
66. Loenneke JP, Fahs CA, Rossow LM, Abe T, Bemben MG. The anabolic benefits of
venous blood flow restriction training may be induced by muscle cell swelling. Med
Hypotheses. 2012; 78: 151–4.
67. Loenneke JP, Thrower AD, Balapur A, Barnes JT, Pujol TJ. Blood flow-restricted walking does not result in an accumlation of metabolites. Clin Physiol Funct Imaging. 2012;
32: 80–2.
68. Gundermann D, Fry C, Dickinson J et al. Reactive hyperemia is not responsible for
stimulating muscle protein synthesis following blood flow restrictive exercise. J Appl
Physiol. 2012; epub ahead of print.
69. Laurentino GC, Ugrinowitsch C, Roschel H et al. Strength training with blood flow
restriction diminishes myostatin gene expression. Med Sci Sports Exerc. 2012; 44:
406–12.
70. Yasuda T, Ogasawara R, Sakamaki M, Bemben MG, Abe T. Relationship between limb
and trunk muscle hypertrophy following high-intensity resistance training and blood flowrestricted low-intensity resistance training. Clin Physiol Funct Imaging. 2011; 31: 347–3.
71. Abe T, Kearns CF, Sato Y. Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training. J Appl
Physiol. 2006; 100: 1460–6.
72. Loenneke JP, Fahs CA, Rossow LM et al. Effects of cuff width on arterial occlusion:
implications for blood flow restricted exercise. Eur J Appl Physiol. 2011; epub ahead of
print.
73. Clark BC, Manini TM, Hoffman RL et al. Relative safety of 4 weeks of blood flowrestricted resistance exercise in young, healthy adults. Scand J Med Sci Sports. 2011;
21: 653–62.
74. Nakajima T, Kurano M, Iida H et al. Use and safety of KAATSU training: results of a
national survey. Int J KAATSU Training Res. 2006; 2: 5–13.
75. Patterson SD, Ferguson RA. Enhancing strength and postocclusive calf blood flow in older
people with training with blood-flow restriction. J Aging Phys Act. 2011; 19: 201–13.
76. Fahs CA, Rossow LM, Loenneke JP et al. Effect of different types of lower body resistance training on arterial compliance and calf blood flow. Clin Physiol Funct Imaging.
2012; 32: 45–51.
77. Rossow LM, Fahs CA, Sherk VD, Seo DI, Bemben DA, Bemben MG. The effect of
acute blood-flow-restricted resistance exercise on postexercise blood pressure. Clin
Physiol Funct Imaging. 2011; 31: 429–34.
78. Kubota A, Sakuraba K, Koh S, Ogura Y, Tamura Y. Blood flow restriction by low compressive force prevents disuse muscular weakness. J Sci Med Sport. 2011; 14: 95–9.
79. Kubota A, Sakuraba K, Sawaki K, Sumide T, Tamura Y. Prevention of disuse muscular
weakness by restriction of blood flow. Med Sci Sports Exerc. 2011; 40: 529–34.
80. Takarada Y, Takazawa H, Ishii N. Applications of vascular occlusion diminish disuse
atrophy of knee extensor muscles. Med Sci Sports Exerc. 2000; 32: 2035–9.
81. Ozaki H, Sakamaki M, Yasuda T et al. Increases in thigh muscle volume and strength by
walk training with leg blood flow reduction in older participants. J Gerontol A Biol Sci
Med Sci. 2011; 66: 257–63.
256
Resistance Training for Older Adults
82. Abe T, Fujita S, Nakajima T et al. Effects of low-intensity cycle training with restricted
leg blood flow on thigh muscle volume and VO2max in young men. J Sports Sci Med.
2010; 9: 452–8.
83. Takarada Y, Takazawa H, Sato Y, Takebayashi S, Tanaka Y, Ishii N. Effects of resistance
exercise combined with moderate vascular occlusion on muscular function in humans.
J Appl Physiol. 2000; 88: 2097–106.
84. Karabulut M, Abe T, Sato Y, Bemben MG. The effects of low-intensity resistance training with vascular restriction on leg muscle strength in older men. Eur J Appl Physiol.
2010; 108: 147–55.
85. Yasuda T, Fujita S, Ogasawara R, Sato Y, Abe T. Effects of low-intensity bench press
training with restricted arm muscle blood flow on chest muscle hypertrophy: a pilot
study. Clin Physiol Funct Imaging. 2010; 30: 338–43.
86. Bemben DA, Palmer IJ, Abe T, Sato Y, Bemben MG. Effects of a single bout of low
intensity KAATSU resistance training on markers of bone turnover in young men. Int
J KAATSU Training Res. 2007; 3: 21–6.
87. Karabulut M, Bemben DA, Sherk VD, Anderson MA, Abe T, Bemben MG. Effects of
high-intensity resistance training and low-intensity resistance training with vascular
restriction on bone markers in older men. Eur J Appl Physiol. 2011; 111: 1659–7.
16
Resistance Training
for Children and
Adolescents
Avery D. Faigenbaum
CONTENTS
Introduction............................................................................................................. 261
Safety and Efficacy of Youth Resistance Training.................................................. 262
Mechanisms of Strength Development in Youth..................................................... 263
Persistence of Training-Induced Strength Gains.....................................................264
Potential Health and Fitness Benefits..................................................................... 265
Cardiovascular and Metabolic Health.....................................................................266
Bone Health............................................................................................................266
Motor Skills and Sports Performance..................................................................... 267
Youth Resistance Training Guidelines.................................................................... 268
Program Design Variables....................................................................................... 269
Choice and Order of Exercises............................................................................... 270
Training Intensity and Volume................................................................................ 270
Rest Intervals.......................................................................................................... 271
Repetition Velocity.................................................................................................. 271
Program Variation................................................................................................... 272
Special Considerations for Overweight Youth........................................................ 272
Summary................................................................................................................. 273
References............................................................................................................... 273
INTRODUCTION
A growing number of children and adolescents are participating in resistance training programs to improve their health and fitness. Despite outdated concerns that
resistance training would be ineffective or potentially injurious for school-age youth,
the safety and efficacy of youth resistance training are now well documented, and the
qualified acceptance of youth resistance training by medical and fitness organizations has become widespread.1–5 Physical education curricula now include activities
that enhance muscular strength and rehabilitation programs specifically designed to
improve the muscular fitness of children and adolescents with medical conditions are
becoming part of clinical practice.6–9
257
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Resistance Training for Children and Adolescents
Learning how resistance training can improve the health and well-being of children
and adolescents with different needs, abilities, and medical conditions is a growing area
of interest among clinicians, fitness professionals, and pediatric researchers. Parents
want to know if it is safe for their children to lift weights, and health professionals
are often asked to provide information on age-appropriate resistance training guidelines. Furthermore, since physical activity early in life helps to prevent chronic diseases
such as diabetes and cardiovascular disease later in life, health and fitness professionals need to develop lesson plans and training sessions that are purposely designed to
prepare boys and girls for a lifetime of health and fitness. Although much of what we
understand about the stimulus of resistance exercise has been gained by exploring the
responses of adults to various training protocols, research into the long-lasting effects
of physical activity on youth continue to highlight the importance of enhancing muscular strength during childhood and adolescence.10–12
The purpose of this chapter is to evaluate the safety and efficacy of youth resistance training and to discuss the potential benefits and concerns associated with
resistance exercise. In addition, program design considerations for youth with different needs, goals, and abilities will be reviewed. In this chapter, the term children
refers to boys and girls who have not yet developed secondary sex characteristics
(approximately up to the age of 11 in girls and 13 in boys). This period of life is
often referred as preadolescence. The term adolescence refers to a period of time
between childhood and adulthood and includes girls 12 to 18 years and boys 14 to
18 years. The term youth is broadly defined in this chapter to include both children
and adolescents.
SAFETY AND EFFICACY OF YOUTH RESISTANCE TRAINING
Although early researchers failed to show an increase in strength in children who participated in a resistance training program, the lack of significance could be explained
by methodological shortcomings (e.g., short study duration) or inadequate training
program (e.g., low training volume). In 1978, Vrijens concluded in a frequently cited
report that strength development was closely related to sexual maturation and that
resistance training could only be effective during the postpubescent age.13 However,
more recent investigations using higher training intensities and greater training volumes have convincingly found that children can indeed enhance muscular strength
above and beyond growth and maturation, provided appropriate training guidelines
are followed.14–16 Moreover, observations from physicians, physical therapists, and
sport coaches provide compelling evidence that children can make significant gains
in muscular strength beyond what is normally the result of growth and maturation.
Research findings indicate a relatively low risk of injury in children and adolescents who follow age-appropriate resistance training guidelines that include qualified
supervision and instruction.15–17 In the vast majority of research studies, the injury
occurrence in children and adolescents was either very low or nil and the resistance
training stimulus was well tolerated by the subjects. Of note, injury to the growth
cartilage has not been reported in any prospective youth resistance training research
study, and there is no evidence to suggest that resistance training will negatively
impact growth and development during childhood and adolescence.15,16
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259
Different combinations of sets and repetitions have been found to be effective
for school-age youth, although data from a recent meta-analysis on youth resistance
training suggest that multiple set protocols with moderate loads are most common
during the initial adaptation period.14 While differences in the program design, quality of instruction, and training experience of the subjects can influence the degree of
adaptation, strength gains of roughly 30% are typically observed in youth following
short-term resistance training programs (8–12 weeks). At the start of any resistance
training program, the window of adaptation (i.e., opportunity for change) is relatively
large and therefore impressive gains in measures of muscular strength are probable.
However, following several months of resistance training, the window of adaptation
is reduced and training-induced gains in muscular strength will be reduced.
Children as young as 5 and 6 years have participated in resistance training programs,18,19 and there is no clear evidence of any difference in strength between preadolescent boys and girls.20 Although few studies have compared the training response
in different age groups, it appears that relative strength gains achieved during preadolescence are quantitatively greater than (or at least similar to) gains made by
older populations.21,22 In terms of absolute strength gain (e.g., total force measured in
kilogram), it appears that adolescents make greater gains than children22 and adults
make greater gains than young adolescents.23 Although children can develop the
same force per unit muscle cross-sectional area as adults,24 it is somewhat unrealistic
to expect a child to make the same absolute gains in strength as a larger adolescent
or adult who probably has at least twice the absolute strength of a young boy or girl.
MECHANISMS OF STRENGTH DEVELOPMENT IN YOUTH
Since children lack adequate level of circulating androgens to stimulate increases
in muscle hypertrophy, training-induced strength gains appear to be more related
to neuromuscular mechanisms than morphological factors during preadolescence.
Studies examining whole muscle hypertrophy in youth have usually used anthropometric techniques and have provided no evidence of training-induced hypertrophy in
children consequent to a resistance training program (up to 20 weeks).25,26 However,
the results from smaller studies that used more sensitive measurement techniques
(magnetic resonance imaging and ultrasound) do put forth the possibility that muscle hypertrophy is possible in children following resistance training.27,28 Thus, it is
possible that more intensive training programs and sensitive measuring techniques
that are ethically appropriate for the pediatric population may be needed to partition the effects of training on fat-free mass from expected gains due to growth and
development.
At present, the available data indicate that neurological adaptations (i.e., a trend
toward increased motor unit activation and changes in motor unit coordination,
recruitment, and firing) and possibly intrinsic muscle adaptations (as evidenced by
increases in twitch torque) appear to be primarily responsible for training-induced
strength gains during preadolescence.25,26 Improvements in motor skill performance
and the coordination of the involved muscle groups may also play a significant role,
because measured increases in training-induced strength are typically greater than
changes in neuromuscular activation. Given that the optimization of intra-muscular
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Resistance Training for Children and Adolescents
coordination depends on prior physical activity and experience in a specific task,29
it is reasonable to conclude that multi-faceted neuromuscular adaptations are largely
responsible for training-induced gains in muscle strength in untrained preadolescents. During and after puberty, gains in muscle strength following resistance training may be associated with changes in the cross-sectional area of muscle in males
since testosterone and other hormonal influences on muscle hypertrophy would be
operant.16 Smaller amounts of testosterone in females limit the magnitude of training-induced gains in muscle hypertrophy.
PERSISTENCE OF TRAINING-INDUCED STRENGTH GAINS
Children and adolescents may undergo periods of reduced training because of program design factors, school vacations, injury, or illness. Therefore, it is important to
evaluate changes in strength following the temporary or permanent withdrawal of
the training stimulus which is referred to as detraining. This is an interesting topic
to explore in youth because of the concomitant growth-related increases in muscle
strength during the detraining (or reduced training) time period.
The phenomenon of detraining in youth is characterized by different adaptations and regressions in strength and power. Some of the mechanisms that underpin
changes in performance during this period are likely influenced by the design of
the training program and the amount and type of activity that take place during
the detraining period. A majority of the data indicate that training-induced strength
gains in children are impermanent and tend to regress toward untrained control
group values during the detraining period.30–34 In one report, the effects of an 8-week
resistance training program followed by an 8-week detraining period were evaluated
in boys and girls of ages 7 to 12 years.30 While significant gains in upper and lower
body strength were observed following the training period, strength gains regressed
toward untrained control group values during the detraining period at a rate of 3%
per week. Changes in neuromuscular functioning and possibly a loss of motor coordination could be at least partly responsible for the detraining response observed in
children. The mechanisms responsible for the detraining response during adolescence may be more complicated because strength gains during this developmental
period are often associated with training-induced gains in muscle size.
Only a limited number of studies have evaluated the effects of training frequency
on strength maintenance in youth. A 1-day-a-week maintenance program was just
as sufficient as a 2-day-a-week maintenance program in retaining the strength
gains made after 12 weeks of training in a young male athletes.35 Others observed
that children who completed a 10-week training program were able to maintain
­training-induced gains in muscle power following 8 weeks of reduced training which
included soccer practice.36 Although additional research is needed before specific
maintenance training recommendations can be made for children and adolescents,
it seems reasonable for health and fitness professionals to encourage participation in
some type of maintenance training program in order to maintain training-induced
gains in muscular strength. This is particularly important for clinicians who prescribe resistance exercise as part of therapy and are expected to prepare youth for
participation in health-enhancing physical activity.
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261
POTENTIAL HEALTH AND FITNESS BENEFITS
The promotion of exercise habits during the growing years should be based, at least
in part, on the idea that habitual physical activity established early in life may reduce
the risk of developing adult-diseases later in life. In the landmark Pathobiological
Determinants of Atherosclerosis in Youth (PDAY) study, strong relationships were
found between risk factors and the severity and extend of atherosclerosis measured
after death in 15 to 34 year olds who died accidentally of external causes.37 While
there was a striking increase in the severity and extent of disease as the number of
risk factors increased in the PDAY study, it is noteworthy that the absence of risk
factors was found to be associated with a virtual absence of advanced atherosclerotic
lesions.37 Since pathological processes that become clinically manifested during
adulthood typically originate during the pediatric years, desirable patterns of physical activity should be established early in life and sustained throughout adulthood.
Consequently, the potential health and fitness benefits of resistance exercise should
be considered along with the nature of the physical activity experience and whether
long-term adherence can be expected in order to reduce the risk of adverse health
outcomes later in life.
Resistance training can offer unique health and fitness benefits to children and
adolescents provided that appropriate training guidelines are followed. In addition to
enhancing muscular strength and motor performance skills, the proper prescription
of resistance exercise has been shown to favorably influence cardiovascular risk, metabolic health, body composition, bone mineral density, resistance to sports-related
injuries, and psychological health.38–42 These health- and fitness-related benefits will
likely enhance the quality of life for children and adolescents by enabling them to
perform life’s daily activities with more energy and vigor. Furthermore, children
who are exposed to environments with opportunities to enhance motor skill proficiency (e.g., jumping, throwing, and balancing) may be more active later in life.43,44
Since muscle strength is an essential component of motor skill performance,45 youth
who regularly perform resistance exercise may be more likely to develop the prerequisite motor skills and perceived confidence that form the foundation for a lifetime
of physical activity. A summary of the potential health and fitness benefits associated
with youth resistance training is presented in Table 16.1.
TABLE 16.1
Potential Benefits of Youth Resistance Training
•
•
•
•
•
•
•
•
•
Increase muscle strength and power
Enhance motor skill performance
Increase bone mineral density
Improve body composition
Improve insulin sensitivity
Reduce cardiovascular risk
Reduce risk of sport-related injuries
Enhance psychological health
Stimulate a more positive attitude toward lifetime physical activity
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Resistance Training for Children and Adolescents
CARDIOVASCULAR AND METABOLIC HEALTH
The prevalence of pediatric obesity has more than doubled for adolescents and it has
more than tripled for children over the past three decades.46 As the prevalence of
pediatric obesity continues to increase, weight-related cardiovascular and metabolic
problems will likely be seen at an increased rate in school-age youth. Of note, data
from a cross-sectional sample of adolescents aged 12 to 19 years found that 49% of
overweight and 61% of obese adolescents had at least one cardiovascular risk factor
in addition to their weight status.47 In the future, the number of children and adolescents with chronic health conditions will likely increase and innovative strategies
will be needed to manage these chronic conditions.
A growing body of scientific evidence indicates that resistance exercise can
improve the metabolic health and body composition of overweight and obese
youth.48–51 In one report, researchers examined the effects of 16 weeks of resistance
training (1 to 3 sets, 3 to 15 repetitions, 62 to 97% 1 repetition maximum [RM]) on
insulin sensitivity and body composition in overweight adolescent males.48 These
researchers reported that participation in a resistance training program significantly
decreased body fat and significantly increased insulin sensitivity. Since the increase
in insulin sensitivity remained significant after adjustment for changes in total fat
mass and total lean tissue, it seems that resistance training produced qualitative
changes in skeletal muscle that contributed to enhanced insulin action. Since other
researchers found that resistance training without weight loss improved insulin sensitivity and muscle mass in obese adolescents,50 preventive strategies that enhance
muscle strength may provide a desirable approach for enhancing metabolic health in
overweight and obese youth.
Although decreasing resting blood pressure and improving blood lipids following
exercise training in youth may be due to favorable changes in body composition and
nutritional intake, it is likely that a comprehensive lifestyle modification program
which includes physical activity may offer the most benefit. Limited data suggest
that resistance training may be an effective nonpharmacologic intervention that may
prevent the return of blood pressure to preintervention levels in hypertensive adolescents.52 Others reported that resistance-trained youth demonstrate favorable changes
in their blood lipid profiles.53,54
BONE HEALTH
Traditional fears that resistance training would be harmful to the developing skeleton have been replaced by current findings which suggest that childhood may be the
opportune time for the bone modeling and remodeling process to respond to weightbearing physical activity.39 Since low peak bone mass is a risk factor for osteoporosis and associated fractures later in life, participation in weight-bearing physical
activities including high strain eliciting sports such as gymnastics and weightlifting
should be encouraged during the pediatric years for normal bone growth and development.55,56 If sensible training guidelines are followed and nutritional recommendations (e.g., adequate calcium and vitamin D) are adhered to, beginning resistance
training at a young age may reduce the risk of osteoporotic fractures later in life.
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These observations are supported by data from a 20-year follow-up study which
found that the main physical fitness component at adolescence related to adult bone
mineral content was muscular fitness.57
Muscular forces that have the greatest osteogenic effects on the growing skeleton
are those characterized by a considerable loading magnitude applied at a rapid rate.39
In addition to the direct effect of weight-bearing physical activity on bone, resistance
exercise can stimulate bone growth indirectly by increasing muscle strength and
muscle mass, which in turn could increase the generation of forces placed on bone.
Although weight-bearing physical activity plays a critical role in bone mass acquisition during the growing years, health and fitness professionals should consider the
importance of participating in such activities before the pubertal growth spurt in
order to optimize lifespan skeletal health.39 Maintaining participation in weightbearing activities should not be overlooked, because training-induced gains in bone
health may be lost if the program is not continued.58
MOTOR SKILLS AND SPORTS PERFORMANCE
Regular participation in a youth resistance training program has the potential to
enhance motor skills and sports performance.5,59–61 Several studies have noted significant improvements in selected motor performance skills (e.g., long jump, vertical
jump, sprint speed, and balance) in children and adolescents following resistance
training.22,62–65 Since training adaptations are specific to the movement pattern,
velocity of movement, contraction type, and contraction force, training programs
that include movements that are specific to the test may be more likely to result in
favorable changes in motor performance. Indeed, researchers have reported that the
combination of resistance training and plyometric training may actually be synergistic with their combined effect being greater than each program performed alone.66,67
Although it is intuitively attractive to assume that regular participation in a
well-designed youth resistance training program can improve sports performance, scientific evaluations of this observation are difficult because success in
sport is influenced by a wide variety of factors including genetics, motivation,
coaching, nutrition, and sleep. Nevertheless, limited direct and indirect evidence
suggests that regular participation in a well-designed resistance training program
will not have a negative effect on youth sports performance, and in all likelihood,
it will result in some degree of improvement.4,61 Moreover, one of the greatest
benefits of resistance training may be its ability to enhance the physical fitness of
children and adolescents so that they are better prepared for sports practice and
competition.
In a growing number of cases, it appears that some young athletes are ill-­prepared
for the demands of sport training. While the total elimination of sports-related injuries is an unrealistic goal, regular participation in a preseason conditioning program that includes resistance exercise may reduce the likelihood of sports-related
injuries in young athletes.68 However, only a minority of young athletes participate
in multicomponent conditioning programs before sports training and competition.69 Clinicians and fitness professionals should not overlook the value of targeting deficits in strength and neuromuscular control as a preventative health measure.
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Resistance Training for Children and Adolescents
Comprehensive conditioning programs that included resistance training have proven
to be an effective strategy for reducing sports-related injuries in young athletes.70–73
Since a youngster’s participation in physical activity should not start with sports
practice and competition, there is an ongoing need for school- and community-­
center involvement to ensure that participation in interscholastic sports evolves out
of preparatory conditioning and instructional practice sessions that are gradually
progressed over time.
YOUTH RESISTANCE TRAINING GUIDELINES
Youth resistance training programs need to be carefully prescribed and progressed
due to interindividual differences in training experience, fitness goals, and stress
tolerance. In addition, cautionary measures including qualified supervision, health
screening, and an uncluttered training environment need to be considered before
children and adolescents participate in any type of resistance training. Of note, youth
programs should be designed and supervised by qualified professionals who have an
understanding of youth resistance training guidelines and who are knowledgeable
of the physical and psychosocial uniqueness of children and adolescents. Although
a preparticipation medical examination is not required for apparently healthy children and adolescents, medical clearance is recommended for youth with preexisting
medical conditions such as hypertension and seizure disorders.74
In general, if children are ready for participation in some type of sports training (about age 7 or 8 years), then they may be ready to resistance train. In any case,
all participants should have the emotional maturity to accept and follow directions
and should be aware that they could get hurt if they do not follow coaching instructions. All youth resistance training programs should be characterized by qualified
instruction, correct exercise technique, a safe training environment, and a gradual
progression of training loads. Participants should be given an opportunity to understand basic training principles and establish a solid strength base before progressing
to more intense training regimens. A basic level of technical competency along with
an understanding of youth resistance training guidelines and safety procedures (e.g.,
sensible starting weights, proper spotting, and the proper storage of equipment) are
reasonable expectations during an introductory training program.
When introducing youth to resistance training it is always better to underestimate
their physical abilities than overestimate their abilities and risk an injury. This is
particularly important during the first few weeks of training when the focus of the
program should be on learning proper form and technique on a variety of exercises and reinforcing proper training procedures. Without qualified supervision and
instruction, youth are more likely to attempt to lift weights that exceed their abilities
or perform an excessive number of repetitions with improper exercise technique.
Furthermore, young lifters who do not receive instruction from qualified professionals on proper program design may spend too much time training their so-called
“mirror muscles” (i.e., biceps and chest) and not enough time (or no time at all)
strengthening the musculature on the posterior side of their body. Modifiable injury
risk factors associated with youth resistance training are outlined in Table 16.2.
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Avery D. Faigenbaum
TABLE 16.2
Modifiable Injury Risk Factors Associated with Youth Resistance Training
Which Can Be Reduced or Eliminated with Qualified Supervision and
Instruction
Risk Factor
Unsafe exercise environment
Improper equipment storage
Unsafe use of equipment
Inappropriate progression
Poor exercise technique
Muscle imbalances
Previous injury
Inadequate recuperation
Modification by Qualified Professional
Adequate training space and proper equipment layout
Secure storage of exercise equipment
Instruction on safety rules in the training area
Prescription and progression of training program driven by
technical performance of prescribed exercise movement
Clear instruction and feedback on exercise movements
Training program includes agonist and antagonist exercises
Communicate with treating clinician and modify program
Incorporate active rest and consider lifestyle factors such as proper
nutrition and adequate sleep
Since enjoyment has been shown to mediate the effects of youth physical activity
programs,75 the importance of creating an enjoyable exercise experience for children
and adolescents should not be overlooked. This is where the art and science of developing a youth resistance training program come into play, because the principles of
training specificity and progressive overload need to be balanced with individual
needs and abilities in order to optimize gains, prevent boredom, and provide a stimulating program that gives participants a more positive attitude toward resistance
training and physical activity. However, the addition of more intense and voluminous
training to the total exercise picture needs to be carefully considered because resistance training adds to the chronic repetitive stress placed on the developing musculoskeletal system. Thus, each child must be treated as an individual and observed for
signs and symptoms such as decreased performance, chronic joint and muscle pain,
or general apathy that would require a modification of the training program. Clearly,
developing resistance training programs for youth involves balancing the demands
for training with the need for recovery.
PROGRAM DESIGN VARIABLES
The systematic structuring of program variables along with individual effort will
determine the training-induced adaptations that take place. The acute program
variables that should be considered when designing a resistance training program include the following: (1) choice and order of exercise, (2) training intensity,
(3) training volume, (4) rest intervals, and (5) repetition velocity. Table 16.3 summarizes general youth resistance training guidelines. More detailed information on
developing resistance training programs for children and adolescents is available
elsewhere.76,77
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Resistance Training for Children and Adolescents
TABLE 16.3
General Youth Resistance Training Guidelines
•
•
•
•
•
•
•
•
•
Provide qualified instruction and close supervision
Ensure that the exercise environment is safe and free of hazards
Focus on developing proper exercise technique
Perform 1 to 3 sets of 6 to 15 repetitions on strength exercises
Perform 1 to 3 sets of 6 or less repetitions on power exercises
Perform exercises for the upper body, lower body, and midsection
Include exercises that require balance and coordination
Resistance train two to three times per week on nonconsecutive days
Keep the program fresh and challenging by systematically varying the training program.
CHOICE AND ORDER OF EXERCISES
It is important to select exercises that are appropriate for a child’s body size, fitness
level, and exercise technique experience. Weight machines (both child sized and
adult sized) as well as free weights (barbells and dumbbells), elastic bands, medicine balls, and body weight exercises have been used by children and adolescents in
­clinical- and school-based exercise programs. It is desirable to start with relatively
simple movements and gradually progress to more advanced exercises that require
balance and coordination. Also, it is important to include strengthening exercises for
the pelvis, abdomen, trunk, and hip. While exercises such as curl-ups, back extensions, and prone bridges are beneficial, the training program should progress to
include multidirectional exercises that involve rotational movements and diagonal
patterns (with one’s body weight or a medicine ball) on stable and unstable surfaces
to improve trunk stability during dynamic activities.
Most youth will perform total body workouts several times per week that involve
multiple exercises stressing all major muscle groups each session. In this type of
workout, multiple-joint exercises should be performed before single-joint exercises.
Following this exercise order will allow heavier weights to be used on the multiplejoint exercises because fatigue will be less of a factor. It is also helpful to perform
more challenging exercises earlier in the workout when the neuromuscular system is
less fatigued. Thus, if a child is learning how to perform a back squat exercise, this
type of exercise should be performed early in the training session so that the child
can practice the exercise without undue fatigue.
TRAINING INTENSITY AND VOLUME
Training intensity typically refers to the amount of weight used for an exercise,
whereas training volume generally refers to the total amount of work performed in
a training session. While both are important training variables, training intensity
is one of the more important factors in the design of a resistance training program. During the initial adaptation period (first 8 weeks), lighter loads and higher
repetitions (e.g., 10–15 RM) appear to be most beneficial for enhancing muscular
Avery D. Faigenbaum
267
strength in untrained youth.18,78 However, since different combinations of sets and/
or repetitions may be needed to promote long-term gains in muscular fitness, the
best approach may be to start resistance training with one or two sets of 10 to 15
repetitions with a moderate load and then gradually progress the training program
to include heavier loads (e.g., 6–10 RM) depending on training goals and objectives. Of note, due to the relatively complex nature of weightlifting movements
(e.g., modified cleans, pulls, and presses), fewer than 6 to 8 repetitions per set are
typically performed, because these exercises require a high degree of technical
skill.
The number of repetitions performed per set, the number of sets performed per
exercise, and the weight lifted all influence the training volume. For example, if a
child performs 1 set of 10 repetitions with 50 kg on the leg press exercise, the training volume for this exercise would be 500 kg (1 × 10 × 50 = 500). It is important to
remember that every training session does not need to be characterized by the same
number of sets, repetitions, and exercises. In general, it is reasonable to begin resistance training with one or two sets on 6 to 10 different exercises and then gradually
progress to two- or three-set protocols following the first few weeks of resistance
training. Although long-term training studies are needed to explore the effects of
different resistance training programs on youth, multiple set training protocols have
proven to be effective in children and adolescents.14
REST INTERVALS
The length of the rest interval between sets and exercises is an important training
variable since acute force and power production may be compromised if the rest
interval is too short. While a rest interval of 2 to 3 minutes for primary, multijoint exercises is typically recommended for adults, this recommendation may not
be consistent with the needs and abilities of younger populations due to growth and
maturation-related differences in the response to physical exertion.79 It appears that
children and adolescents can resist fatigue to a greater extent than adults during several repeated bouts of resistance exercise.80 Consequently, a shorter rest interval (e.g.,
about 1 minute) between sets and exercises may suffice in children and adolescents
when performing moderate intensity resistance training.
REPETITION VELOCITY
The velocity or cadence at which a strength exercise is performed can affect the
adaptations to a training program. Since beginners need to learn how to perform
each exercise correctly with a relatively light load, it is generally recommended that
untrained youth perform resistance exercises with a light to moderate load in a controlled manner at a moderate velocity. However, different training velocities may be
used depending on the choice of exercise (e.g., weight machine exercise or medicine
ball toss) and program goals. It is likely that the performance of different training
velocities within a training program may provide the most effective resistance training stimulus.
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Resistance Training for Children and Adolescents
PROGRAM VARIATION
Long-term performance gains will be optimized and the risk of overuse injuries
may be reduced by periodically varying program variables over time.81 Since it is
impossible for youth to continually improve at the same rate over a long-term training program, the systematic manipulation of program variables (primarily intensity
and volume) will allow participants to make even larger gains because the body will
be challenged to adapt to the increased demands placed upon them. In addition, systematically changing the training program can help to prevent training plateaus that
are common after the first 8 to 12 weeks of resistance training. Although untrained
youth will respond to most training protocols, trained youth require more advanced
training procedures in order to continually achieve higher levels of fitness and prevent boredom.
The use of periodization concepts has traditionally been applied to elite athletes
as well as adults in recreational and rehabilitative setting. Although more data on
younger populations are needed, youth who participate in periodized resistance
training programs are more likely to optimize gains in muscular strength and power.
In the long term, program variation with adequate recovery between training sessions will allow children and adolescents to achieve higher levels of muscular fitness
while limiting training plateaus. Moreover, it is reasonable to suggest that youth
who participate in well-designed periodized programs and continue to improve their
health and fitness may be more likely to adhere to an exercise program for the long
term. Although there is not one model of periodization that is appropriate for all
youth, the general concept is to prioritize training goals and then develop a longterm plan that varies throughout the year. Detailed information on periodization
and lifestyle factors that can influence athletic performance in youth are available
elsewhere.82,83
SPECIAL CONSIDERATIONS FOR OVERWEIGHT YOUTH
Many overweight and obese youth may lack the motor skills and confidence to be
physically active and they may actually perceive physical activity to be discomforting and embarrassing. Not surprisingly, these youth may feel uncomfortable or incapable of participating if the focus of the program is on performance rather than
participation and having fun. Additionally, excess body weight hinders the performance of weight-bearing physical activities such as jogging and increases the risk
of musculoskeletal overuse injuries. Conversely, overweight and obese youth seem
to enjoy resistance training, because it is typically characterized by short periods of
physical activity interspersed with brief rest periods between sets as needed.84
The first step in encouraging overweight and obese youth to exercise is to increase
their confidence in their ability to be physically active, which in turn may lead to
an increase in regular physical activity, an improvement in body composition and,
hopefully, exposure to a form of exercise that can be carried over into adulthood.
Teaching youth about their bodies, promoting safe training procedures, and providing a rewarding program that gives participants a more positive attitude toward physical activity are important considerations. Because overweight and obese youth tend
Avery D. Faigenbaum
269
to be the strongest students in class, participation in a resistance training p­ rogram
gives youth with a high percentage of body fat a chance to “shine” and gain confidence in their abilities to be physically active. This is where the art and science of
developing a youth resistance training program come into play, because the principles of training specificity and progressive overload need to be balanced with individual needs, goals, and abilities in order to optimize gains, prevent boredom, and
promote resistance training as an ongoing lifestyle choice.
SUMMARY
Despite traditional concerns regarding the safety and efficacy of resistance training
for children and adolescents, a compelling body of scientific evidence along with
clinical observations indicate that regular participation in a resistance training program has the potential to offer observable health and fitness value to children and
adolescents provided that age-appropriate training guidelines are followed. In addition to performance-related benefits, the effects of resistance training on selected
health-related measures including bone strength, body composition, metabolic
health, cardiovascular risk factors, and sports-injury reduction should be recognized
by clinicians and fitness professionals who work with youth. Public health objectives
now aim to incorporate resistance training into lifelong physical activity programs
for all boys and girls, especially those who need physical activity the most.
REFERENCES
1. American College of Sports Medicine. ACSM’s Guidelines for Exercise Testing and
Prescription. 8th ed. Baltimore, MD: Lippincott, Williams and Wilkins; 2010.
2. Australian Strength and Conditioning Association. Resistance training for children and
youth: A position stand from the Australian Strength and Conditioning Association.
www.strengthandconditioning.org (accessed 21 June 2012) 2007.
3. Behm D, Faigenbaum A, Falk B, Klentrou P. Canadian Society for Exercise Physiology
position paper: Resistance training in children and adolescents. Applied Physiology,
Nutrition and Metabolism 2008;33:547–61.
4. Faigenbaum A, Kraemer W, Blimkie C et al. Youth resistance training: Updated position
statement paper from the National Strength and Conditioning Association. Journal of
Strength and Conditioning Research 2009;23:S60–79.
5. Lloyd R, Faigenbaum A, Myer A et al. UKSCA position statement: Youth resistance
training. Professional Strength and Conditioning 2012;Summer:26–39.
6. Davis J, Ventura E, Shaibi G et al. Interventions for improving metabolic risk in overweight Latino youth. International Journal of Pediatric Obesity 2010;5:451–5.
7. Huang T, Ness K. Exercise interventions in children with cancer: A review. International
Journal of Pediatrics 2011; doi: 10.1155/2011/461512.
8. National Association for Sport and Physical Education. Physical Education for Lifetime
Fitness. 3rd ed. Champaign, IL: Human Kinetics; 2011.
9. Verschuren O, Ada L, Maltais D, Gorter J, Scianni A, Ketelaar M. Muscle strengthening
in children and adolescents with spactic cerebral palsy: Considerations for future resistance training protocols. Physical Therapy 2011;91:1130–9.
10. Ortega F, Ruiz J, Castillo M, Sjostrom M. Physical fitness in children and adolescence:
A powerful marker of health. International Journal of Obesity 2008;32:1–11.
270
Resistance Training for Children and Adolescents
11. Strong WB, Malina RM, Blimkie CJ et al. Evidence based physical activity for school-age
youth. Journal of Pediatrics 2005;146:732–7.
12. Tremblay M, Darren E, Warburton R et al. New Canadian physical activity guidelines.
Applied Physiology, Nutrition and Metabolism 2011;36:36–46.
13. Vrijens F. Muscle strength development in the pre and post pubescent age. Sports
Medicine 1978;11:152–8.
14. Behringer M, vom Heede A, Yue Z, Mester J. Effects of resistance training in children
and adoelscents: A meta-analysis. Pediatrics 2010;126:e1199–210.
15. Faigenbaum A, Myer G. Resistance training among young athletes: Safety, efficacy and
injury prevention effects. British Journal of Sports Medicine 2010;44:56–63.
16. Malina R. Weight training in youth—growth, maturation and safety: An evidenced
based review. Clinical Journal of Sports Medicine 2006;16:478–87.
17. Hamill B. Relative safety of weight lifting and weight training. Journal of Strength and
Conditioning Research 1994;8:53–7.
18. Faigenbaum A, Westcott W, Loud R, Long C. The effects of different resistance training protocols on muscular strength and endurance development in children. Pediatrics
1999;104:e5.
19. Weltman A, Janney C, Rians C et al. The effects of hydraulic resistance strength training
in pre-pubertal males. Medicine and Science in Sports and Exercise 1986;18:629–38.
20. Faigenbaum AD, Milliken LA, Westcott WL. Maximal strength testing in healthy children. Journal of Strength and Conditioning Research 2003;17:162–6.
21. Pfeiffer R, Francis R. Effects of strength trianing on muscle development in prepubescent,
pubescent and postpubescent males. Physician and Sports Medicine 1986;14:134–43.
22. Lillegard WA, Brown EW, Wilson DJ, Henderson R, Lewis E. Efficacy of strength training in prepubescent to early postpubescent males and females: Effects of gender and
maturity. Pediatric Rehabilitation 1997;1:147–57.
23. Sailors M, Berg K. Comparison of responses to weight training in pubescent boys and
men. Journal of Sports Medicine and Physical Fitness 1987;27:30–7.
24. Rowland T. Children’s Exercise Physiology. 2nd ed. Champaign, IL: Human Kinetics;
2007.
25. Ozmun JC, Mikesky AE, Surburg PR. Neuromuscular adaptations following prepubescent strength training. Medicine and Science in Sports and Exercise 1994;26:510–4.
26. Ramsay JA, Blimkie CJ, Smith K, Garner S, MacDougall JD, Sale DG. Strength
training effects in prepubescent boys. Medicine and Science in Sports and Exercise
1990;22:605–14.
27. Fukunga T, Funato K, Ikegawa S. The effects of resistance training on muscle area
and strength in prepubescent age. The Annals of Physiological Anthropology 1992;
11:357–64.
28. Mersch F, Stoboy H. Strength training and muscle hypertrophy in children. In: Oseid
S, Carlsen K, eds. Children and Exercise XIII. Champaign, IL: Human Kinetics;
1989:165–82.
29. Folland J, Williams A. The adaptations to strength training: Morphological and neurological contributions to increased strength. Sports Medicine 2007;37:145–68.
30. Faigenbaum A, Westcott W, Micheli L et al. The effects of strength training and detraining on children. Journal of Strength and Conditioning Research 1996;10:109–14.
31. Ingle L, Sleap M, Tolfrey K. The effect of a complex training and detraining programme
on selected strength and power variables in early prepubertal boys. Journal of Sport
Sciences 2006;24:987–97.
32. Tsolakis CK, Vagenas GK, Dessypris AG. Strength adaptations and hormonal responses
to resistance training and detraining in preadolescent males. Journal of Strength and
Conditioning Research 2004;18:625–9.
Avery D. Faigenbaum
271
33. Granacher U, Muehlbauer T, Doerflinger B, Strohmier R, Gollhofer A. Promoting
strength and balance in adolescents during physical education: Effects of a short
term resistance training program. Journal of Strength and Conditioning Research
2011;25:940–949.
34. Faigenbaum A, Farrell A, Fabiano M et al. Effects of detraining on fitness performance in
7-year old children. Journal of Strength and Conditioning Research 2013;27:323–330.
35. DeRenne C, Hetzler RK, Buxton B, Ho KK. Effects of training frequency on strength
maintenance in pubescent baseball players. Journal of Strength and Conditioning
Research 1996;10:8–14.
36. Diallo O, Dore E, Duche P, Van Praagh E. Effects of plyometric training followed by
a reduced training program on physical performance in prepubescent soccer players.
Journal of Sports Medicine and Physical Fitness 2001;41:342–8.
37. Strong J, Malcom G, McMahan C et al. Prevalence and extent of atherosclerosis in
adolescents and young adults: Implications for prevention from the Pathobiological
Determinants of Atherosclerosis in Youth Study. Journal of the American Medical
Association 1999;281:495–501.
38. Faigenbaum A, Myer G. Pediatric resistance training: Benefits, concerns and program
design considerations. Current Sports Medicine Reports 2010;9:161–8.
39. Gunter K, Almstedt H, Janz K. Physical activity in childhood may be the key to optimizing lifespan skeletal health. Exercise and Sports Science Reviews 2011;40:13–21.
40. Gutin B, Owens S. The influence of physical activity on cardiometabolic biomarkers in
youths: A review. Pediatric Exercise Science 2011;23:169–85.
41. Myer G, Faigenbaum A, Ford K, Best T, Bergeron M, Hewett T. When to initiate integrative neuromuscular training to reduce sports-related injuries and enhance health in
youth? Current Sports Medicine Reports 2011;10:157–66.
42. Padilla-Moledo C, Ruiz J, Ortega F, Mora J, Castro-Pinero J. Associations of muscular
fitness with psychological positive health, health complaints, and health risk behaviors
in Spanish children and adolescents. Journal of Strength and Conditioning Research
2012;26:167–73.
43. Lopes V, Rodrigues L, Maia J, Malina R. Motor coordination as predictor of physical activity in childhood. Scandinavian Journal of Medicine and Science in Sports
2011;21:663–9.
44. Barnett L, Van Beurden E, Morgan P, Brooks L, Beard J. Childhood motor skill proficiency as a predictor of adolescent physical activity. Journal of Adolescent Health
2009;44:252–9.
45. Malina R, Bouchard C, Bar-Or O. Growth, Maturation and Physical Activity. 2nd ed.
Champaigm, IL: Human Kinetics; 2004.
46. Ogden C, Carroll M, Kit B, Flegal K. Prevalance of obesity and trends in body mass
index among US children and adolescents, 1999–2010. Journal of the American Medical
Association 2012;epub ahead of print.
47. May A, Kuklina E, Yoon P. Prevalence of cardiovascular disease risk factors among US
adolescents, 1999–2008. Pediatrics 2012;129:1035–41.
48. Shaibi GQ, Cruz ML, Ball GD et al. Effects of resistance training on insulin sensitivity
in overweight Latino adolescent males. Medicine and Science in Sports and Exercise
2006;38:1208–15.
49. Sothern M, Loftin J, Udall J et al. Safety, feasibility and efficacy of a resistance training program in preadolescent youth. The American Journal of the Medical Sciences
2000;319:370–5.
50. Van der Heijden G, Wang Z, Chu Z et al. Strength exercise improves muscle mass and
hepatic insulin sensitivity in obese youth. Medicine and Science in Sports and Exercise
2010;42:1973–80.
272
Resistance Training for Children and Adolescents
51. McGuigan MR, Tatasciore M, Newton RU, Pettigrew S. Eight weeks of resistance training can significantly alter body composition in children who are overweight or obese.
Journal of Strength and Conditioning Research 2009;23:80–5.
52. Hagberg J, Ehsani A, Goldring D, Hernandez A, Sinacore D, Holloszy J. Effect of weight
training on blood pressure and hemodynamics in hypertensive adolescents. Journal of
Pediatrics 1984;104:147–51.
53. Sung RY, Yu CW, Chang SK, Mo SW, Woo KS, Lam CW. Effects of dietary intervention and strength training on blood lipid level in obese children. Archives of Disease in
Childhood 2002;86:407–10.
54. Weltman A, Janney C, Rians C, Strand K, Katch F. Effects of hydraulic-resistance
strength training on serum lipids in prepubertal boys. American Journal of Diseases in
Children 1987;141:777–80.
55. Conroy BP, Kraemer WJ, Maresh CM et al. Bone mineral density in elite junior Olympic
weightlifters. Medicine and Science in Sports and Exercise 1993;25:1103–9.
56. Ward K, Roberts S, Adams J, Mughal M. Bone geometry and density in the skeleton of
prepubertal gymnasts and school children. Bone 2005;26:1012–8.
57. Barnekow-Bergkvist M, Hedberg G, Pettersson U, Lorentzon R. Relationships between
physical activity and physical capacity in adolescent females and bone mass in adulthood. Scandinavian Journal of Medicine and Science in Sports 2006;16:447–55.
58. Gustavsson A, Olsson T, Nordstrom P. Rapid loss of bone mineral density of the femoral neck after cessation of ice hockey training: A 6-year longitudinal study in males.
Journal of Bone and Mineral Research 2003;18:1964–9.
59. Behringer M, vom Heed A, Metthews M, Mester J. Effects of strength training on motor
performance skills in children and adolescents: A meta-analysis. Pediatric Exercise
Science 2011;23:186–206.
60. Johnson B, Salzberg C, Stevenson D. A systematic review: Plyometric training programs
for young children. Journal of Strength and Conditioning Research 2011;25:2623–33.
61. Harries S, Lubans D, Callister R. Resistance training to improve sports performance in
adolescent athletes: A systematic ereview and meta-analysis. Journal of Science and
Medicine in Sport 2012;15:532–540.
62. Faigenbaum A, Farrel A, Fabiano M et al. Effects of integrative neuromuscular training
on fitness performance in children. Pediatric Exercise Science 2011;23:573–84.
63. Filipa A, Byrnes R, Paterno M, Myer G, Hewett T. Neuromuscular training improves
performance on the star excursion balance test in young female athletes. Journal of
Orthopedic and Sports Physical Therapy 2010;40:551–8.
64. Hetzler R, DeRenne C, Buxton B, Ho K, Chai D, Seichi G. Effects of 12 weeks of
strength training on anaerobic power in prepubescent male athletes. Journal of Strength
and Conditioning Research 1997;11:174–81.
65. Myer G, Ford K, Palumbo J, Hewett T. Neuromuscular training improves performance and lower-extremity biomechanics in female athletes. Journal of Strength and
Conditioning Research 2005;19:51–60.
66. Faigenbaum A, McFarland J, Keiper F et al. Effects of a short term plyometric and
resistance training program on fitness performance in boys age 12 to 15 years. Journal
of Sports Science and Medicine 2007;6:519–25.
67. Santos E, Janeira M. Effects of complex training on explosive strength in adolescent
male basketball players. Journal of Strength and Conditioning Research 2008;22:903–9.
68. Valovich McLeod T, Decoster L, Loud K et al. National Athletic Trainers’ Association
position statement: Prevention of pediatric overuse injuries. Journal of Athletic Training
2011;46:206–20.
69. Brooks M, Schiff M, Koepsell T, Rivara F. Prevalence of preseason conditioning among
high school athletes in two spring sports. Medicine and Science in Sports and Exercise
2007;39:241–7.
Avery D. Faigenbaum
273
70. Heidt R, Swetterman L, Carlonas R, Traub J, Tekulve F. Avoidance of soccer injuries
with preseason conditioning. American Journal of Sports Medicine 2000;28:659–62.
71. Hewett T, Riccobene J, Lindenfeld T, Noyes F. The effects of neuromuscular training on
the incidence of knee injury in female athletes. American Journal of Sports Medicine
1999;27:699–706.
72. Mandelbaum B, Silvers H, Watanabe D, Knarr J, Thomas S, Griffin L et al. Effectiveness
of a neuromuscular and proprioceptive training program in preventing anterior cruciate ligament injuries in female athletes. American Journal of Sports Medicine
2005;33:1003–10.
73. LaBella C, Huxford M, Grissom J, Kim K-Y, Peng J, Christoffel LK. Effects of neuromuscular warm-up on injuries in female soccer and basketball athletes in urban public
high schools. Archives of Pediatric and Adolescence Medicine 2011;165:1033–40.
74. American Academy of Pediatrics. Strength training by children and adolescent.
Pediatrics 2008;121:835–40.
75. Dishman R, Motl R, Saunders R et al. Enjoyment mediates effects of a schoolbased ­physical activity intervention. Medicine and Science in Sports and Exercise
2005;37:478–87.
76. Faigenbaum A, Westcott W. Youth Strength Training. Champaign, IL: Human Kinetics;
2009.
77. Kraemer W, Fleck S. Strength Training for Young Athletes. Champaign, IL: Human
Kinetics; 2005.
78. Faigenbaum A, Zaichkowsky L, Westcott W, Micheli L, Fehlandt A. The effects of
a twice per week strength training program on children. Pediatric Exercise Science
1993;5:339–46.
79. Falk B, Dotan R. Child-adult differences in the recovery from high-intensity exercise.
Exercise and Sport Science Reviews 2006;34:107–12.
80. Faigenbaum A, Ratamess N, McFarland J et al. Effect of rest interval length on bench
press performance in boys, teens, and men. Pediatric Exercise Science 2008;20:457–69.
81. Ratamess N, Alvar B, Evetoch T et al. Progression models in resistance training in
healthy adults. Medicine and Science in Sports and Exercise 2009;41:687–708.
82. Bompa T, Haff G. Periodization—Theory and Methodology of Training. Champaign, IL:
Human Kinetics; 2009.
83. Jeffreys I. Coaches Guide to Enhancing Recovery: A Multidimentional Approach to
Developing the Performance Lifestyle. Monterey, CA: Coaches Choice; 2008.
84. Faigenbaum A, Westcott W. Resistance training for obese children and adolescents.
President’s Council on Physical Fitness and Sports 2007;8:1–8.
SportS NutritioN
Resistance Training
for the Prevention
and Treatment of
Chronic Disease
Current evidence supports the use of resistance training as an
independent method to prevent, treat, and potentially reverse the
impact of numerous chronic diseases. With physical inactivity one of the
top risk factors for global mortality, a variety of worldwide initiatives
have been launched, and resistance training is promoted by numerous
organizations including the World Health Organization and the Centers
for Disease Control and Prevention. Despite this, most books do not
provide a detailed focus on resistance training.
An up-to-date and comprehensive resource, Resistance Training for
the Prevention and Treatment of Chronic Disease is an evidencebased guide that presents an in-depth analysis of the independent and
positive effects that can result from resistance training. Written by some
of the world’s leading exercise physiologists and resistance training
researchers and experts, the chapters provide detailed descriptions
of the benefits of resistance training for specific clinical populations.
They also include guidelines on how to construct a tailored resistance
training prescription for each population when appropriate.
The book covers resistance training for effective prevention or treatment
of numerous diseases including cardiovascular disease, cancer, type 2
diabetes, renal failure, multiple sclerosis, Parkinson’s disease, fibromyalgia,
stroke, depression and anxiety, pulmonary disease, HIV/AIDS, and
orthopedic disease. The authors also address resistance training for
older adults and for children and adolescents.
K14384
ISBN-13: 978-1-4665-0105-8
90000
9 781466 501058