Unit 3 Tutorials: Physical Activity
INSIDE UNIT 3
Physical Activity and Fitness
Introduction to Physical Fitness
Benefits of Physical Activity
Physical Activity Guidelines
Health-Related Fitness
Skill Related Fitness
Training Principles
Cardiovascular Training Principles
Cardiovascular Assessment
Resistance Training Principles
Resistance Training Assessment
Principles of Flexibility and Mobility
Flexibility and Mobility Assessment
Exercise Plan
Cardiovascular Training Exercises
Resistance Training Exercises
Flexibility and Mobility Exercises
Injury Prevention, Safety, and Recovery
Your Exercise Program
Introduction to Physical Fitness
by Sophia

WHAT'S COVERED
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Page 1
In this lesson, you will identify the definition and value of physical activity, exercise, and physical fitness.
Specifically, this lesson will cover the following:
1. Physical Activity Versus Exercise
2. NEAT as Physical Activity
3. Physical Fitness
1. Physical Activity Versus Exercise
Physical activity is any body movement that increases metabolism over resting energy expenditure, which can
include daily tasks like housework or occupational duties (Panagiotou et al., 2020).
EXAMPLE Someone who is moving around the house doing chores, playing actively with kids or pets,
carrying things from place to place, or walking to work is being physically active.
Exercise is a subcategory of physical activity that involves doing planned and structured activity with a fitnessbased objective (Panagiotou et al., 2020).
EXAMPLE Someone might go out for a run, bike, or walk because they want to improve their aerobic
fitness, or they might do resistance training because they want to improve their body composition.
Physical activity and exercise can have overlap, such as a person who chooses to bicycle to work. In addition, a
person can have high levels of physical activity without any structured exercise, or someone can do regular
exercise, but be relatively sedentary the rest of the day.
IN CONTEXT
Some of our present-day knowledge on the benefits of regular physical activity stemmed from
landmark large studies from decades ago that investigated people’s occupational physical activity. A
study over 31,000 male transportation workers found that being physically active protected against
coronary artery disease (Morris et al., 1953). Another study on 6,531 longshoremen (a person who
loads and unloads cargo from ships) found that high physical activity was associated with lower death
rate (Paffenbarger & Hale, 1975). These studies and others set the stage for national physical activity
guidelines in later decades.
Compared to decades ago, we have many modern conveniences and less opportunities to be physically active.
Centuries ago, most occupations involved regular physical activity through manual labor, like farming. Today,
with many occupations relying on computer screens and job roles that can be done virtually from home, we are
much more sedentary. Over ¼ of adults report getting no physical activity outside of anything they do at their
job (Centers for Disease Control and Prevention, 2022). A recent study estimated that the resting metabolic
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Page 2
rate has fallen by about 6%, which is the equivalent of about 27 minutes of exercise, since 1820 (Yegian, 2021).
This is likely because of our decreased levels of physical activity.

WATCH
The COVID-19 pandemic triggered a further rise in sedentary behavior with many job roles transitioning to
work-from-home environments. Research notes that work-from-home jobs are associated with higher
sedentary time, specifically, 2 more hours a day of sitting (Streeter et al., 2021). Standing desks have
become more popular to break up sitting time, but are they truly effective?
The increase in sedentary behavior has led to the term “active couch potato.” This describes individuals who do
meet the national physical activity guidelines for regular physical activity, but have extended amounts of
sedentary time during the rest of the day. Research on “active couch potatoes” found that more sedentary time
was associated with greater waist circumference, higher blood pressure, and higher cholesterol (Owen et al.,
2010). Even though regular exercise is important, staying active throughout the day by sitting less is arguably
just as, if not more, important.
In large-scale studies across populations, physical activity is most often measured through instruments like
pedometers or accelerometers (Silfee et al., 2018). A pedometer measures total activity, typically in number of
steps. An accelerometer is more advanced and records not only total activity, but the intensity of the activity
(Rowlands & Eston, 2005). You may own a smart watch that counts steps or records activity for you, or you can
typically track a daily step count through most smartphones.
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IN CONTEXT
With step counts and physical activity, you have probably heard or read about getting 10,000 steps a
day for health. Interestingly, the number 10,000 did not come from research, but came from a 1965
marketing campaign by a Japanese company for their brand of pedometer (Lee et al., 2019). Recent
research has investigated the validity of 10,000 steps, finding that mortality rates improve with more
steps per day, but level off at around 7,500 steps per day (Lee et al., 2019). Staying active beyond
7,500 steps is great, since there may be additional benefits beyond reduced risk of death, but 7,500
steps is a good starting goal to simply move more and sit less.
The bottom line is that both physical activity and exercise are beneficial because they reduce time spent being
sedentary. In addition, moving the body regularly, in the right ways and right amounts, places good stress on
body components that provoke positive adaptations, which you’ll learn about further in future lessons.

REFLECT
Think about how you spent your last 24 hours. Besides time sleeping, how many hours were spent sitting,
such as in the car, watching TV, being on the computer, etc.? How much time was spent moving? What type
of movement did you do during the day—physical activity, exercise, or both?

TERMS TO KNOW
Physical Activity
Any body movement that increases metabolism over resting energy expenditure, which can include
daily tasks like housework or occupational duties.
Exercise
A subcategory of physical activity that involves doing planned and structured activity with a fitnessbased objective.
2. NEAT as Physical Activity
In the lesson titled “Nutrition Basics for Weight Loss”, you learned about the three components of metabolism,
where physical activity is the most variable component since we can influence it regularly. While exercise is a
type of physical activity, non-exercise activity thermogenesis (NEAT) is the energy we expend throughout the
day from any activities besides planned exercise, sleeping, and eating (Levine, 2002). Therefore, NEAT is a
component of our total physical activity, and adding up NEAT throughout the day can not only reduce our
sedentary time but can contribute to weight loss goals and provide other benefits.
According to research, NEAT is highly variable among individuals—up to a 2,000-calorie difference per day!
(Levine et al., 2006). Therefore, increasing NEAT increases the total daily amount of physical activity, even
without doing planned and structured exercise.
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IN CONTEXT
Let us consider an example of NEAT (based on research by Levine et al., 2006). Kirby and Leo both
have desk jobs in a large office for an automotive company, and both report that they typically do not
get any physical activity outside of what they do at work. However, Leo has a BMI that indicates
obesity, while Kirby’s BMI indicates being at a healthy weight, even though both are considered
sedentary. Studying Kirby and Leo’s daily workplace habits reveals some significant differences when
it comes to NEAT.
Kirby gets up and talks to colleagues when there are questions or meetings, which can involve walking
multiple flights of stairs and down long hallways. Kirby also does a lot of fidgeting during desk work
and gets up frequently to pace and think. Meanwhile, Leo always takes the elevator to meetings, and
communicates with colleagues by email or chat software; only leaving the desk chair when it is
absolutely necessary.
Research on NEAT compared individuals like Kirby and Leo, finding that sedentary individuals with
obesity tended to be seated for 2.5 hours per day more than their sedentary colleagues at healthy
weights (Levine et al., 2006). While NEAT is certainly not the only factor in body weight, increasing
NEAT throughout the day is one strategy to support weight loss or weight maintenance efforts.
According to national recommendations, all adults should avoid inactivity. Some physical activity is better than
none, and even small amounts of physical activity can provide health benefits, as you saw with NEAT. In the
study we referenced before that investigated the validity of 10,000 steps, the researchers found that even
getting 4,400 steps per day reduced mortality by 41% (Lee et al., 2019). The following are a few starting ideas
for ways to increase NEAT, and therefore become more physically active, throughout your day:
Walk around the room or house during TV commercials
Take short breaks for active household tasks, like organizing inside or weeding outside
Park further away from your destination to get in a short walk
Pace around the house during phone calls
Do active hangouts with friends rather than watching TV or movies, such as bowling or walking
Set a timer for mini-movement breaks when doing computer work or schoolwork, such as a 5-minute break
every hour or half hour

THINK ABOUT IT
What other opportunities are there for NEAT during your regular activities?

TERM TO KNOW
Non-Exercise Activity Thermogenesis (NEAT)
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Energy expended throughout the day from any activities besides planned exercise, sleeping, and
eating.
3. Physical Fitness
Physical fitness is the ability and health of your body to work efficiently and perform activities of daily living with
the least effort possible (Corbin et al., 2022). Physical fitness consists of five health-related components and six
skill-related components, which we’ll cover later in this Challenge.
There is no single “best way” to measure physical fitness, since it has multiple components and since “activities
of daily living” may look different depending on the individual. In general, a person with a good level of physical
fitness can meet the demands of normal responsibilities with low physical effort, like doing household tasks and
being mobile enough to live independently (Corbin et al., 2022). Understandably, improving physical fitness for
an elderly adult would likely look quite different from improving physical fitness for a younger person with a
very active occupation, such as first responders or military personnel. However, regardless of the population,
physical fitness also promotes characteristics that lower one’s risk of hypokinetic diseases, which are diseases
associated with sedentary lifestyles.
IN CONTEXT
“Hypo” means less, and “kinetic” means movement, so hypokinetic diseases tend to develop when
we are moving less. Examples of hypokinetic diseases include cardiovascular disease, diabetes,
hypertension, and obesity (Cardinal, 2016). While there are other behaviors that impact these types of
diseases, such as nutritional habits, being physically active can prevent or reduce the risk of these
diseases.

TERMS TO KNOW
Physical Fitness
The ability and health of your body to work efficiently and perform activities of daily living with the least
effort possible.
Hypokinetic Diseases
Diseases associated with sedentary lifestyles.

SUMMARY
In this lesson, you learned about the difference between physical activity and exercise, where physical
activity is any activity beyond resting expenditure, and exercise is a subset of physical activity involving
planned and structured movement with a fitness-based objective. NEAT as physical activity is valuable
because moving more throughout the day means less time being sedentary. Physical fitness is the
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
Page 6
ability and health of the body to work and perform with the least effort possible, and improving physical
fitness also reduces the risk of hypokinetic diseases.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE.
Disclaimer: The use of any CDC and United States government materials, including any links to the materials on
the CDC or government websites, does not imply endorsement by the CDC or the United States government of
us, our company, product, facility, service, or enterprise.
REFERENCES
Cardinal B. J. (2016). Toward a greater understanding of the syndemic nature of hypokinetic diseases. Journal of
Exercise Science and Fitness, 14(2), 54–59. doi.org/10.1016/j.jesf.2016.07.001
Centers for Disease Control and Prevention (2022). Adult physical inactivity prevalence maps by race/ethnicity.
www.cdc.gov/physicalactivity/data/inactivity-prevalence-maps/index.html
Corbin, C.B., Castelli, D.M., Sibley, B.A., & Le Masurier, G.C. (2022). Fitness for Life: 7th Edition. Human Kinetics.
ISBN: 978-1-718-20870-4.
Lee, I. M., Shiroma, E. J., Kamada, M., Bassett, D. R., Matthews, C. E., & Buring, J. E. (2019). Association of step
volume and intensity with all-cause mortality in older women. JAMA Internal Medicine, 179(8), 1105-1112.
doi.org/10.1001/jamainternmed.2019.0899
Levine J. A. (2002). Non-exercise activity thermogenesis (NEAT). Best Practice & Research: Clinical
Endocrinology & Metabolism, 16(4), 679–702. doi.org/10.1053/beem.2002.0227
Levine, J. A., Vander Weg, M. W., Hill, J. O., & Klesges, R. C. (2006). Non-exercise activity thermogenesis: the
crouching tiger hidden dragon of societal weight gain. Arteriosclerosis, Thrombosis, and Vascular Biology,
26(4), 729-736. doi.org/10.1161/01.ATV.0000205848.83210.73
Morris, J. N., Heady, J. A., Raffle, P. A. B., Roberts, C. G., & Parks, J. W. (1953). Coronary heart-disease and
physical activity of work. The Lancet, 262(6796), 1111-1120. doi.org/10.1016/s0140-6736(53)91495-0
Owen, N., Healy, G. N., Matthews, C. E., & Dunstan, D. W. (2010). Too much sitting: the population health science
of sedentary behavior. Exercise and Sport Sciences Reviews, 38(3), 105–113.
doi.org/10.1097/JES.0b013e3181e373a2
Paffenbarger, R. S., Jr., & Hale, W. E. (1975). Work activity and coronary heart mortality. New England Journal of
Medicine, 292(11), 545-550. doi.org/10.1056/nejm197503132921101
Panagiotou, M., Koulouris, N. G., & Rovina, N. (2020). Physical activity: a missing link in asthma care. Journal of
Clinical Medicine, 9(3), 706. doi.org/10.3390/jcm9030706
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Rowlands, A. V., & Eston, R. G. (2005). Comparison of accelerometer and pedometer measures of physical
activity in boys and girls, ages 8-10 years. Research Quarterly for Exercise and Sport, 76(3), 251–257.
doi.org/10.1080/02701367.2005.10599296
Silfee, V. J., Haughton, C. F., Jake-Schoffman, D. E., Lopez-Cepero, A., May, C. N., Sreedhara, M., Rosal, M. C., &
Lemon, S. C. (2018). Objective measurement of physical activity outcomes in lifestyle interventions among
adults: A systematic review. Preventive Medicine Reports, 11, 74–80. doi.org/10.1016/j.pmedr.2018.05.003
Streeter, J., Roche, M., & Friedlander, A. (2021). From bad to worse: the impact of work-from-home on sedentary
behaviors and exercising. Stanford Center on Longevity. longevity.stanford.edu/wpcontent/uploads/2021/05/Sedentary-Brief.pdf
Yegian, A. K., Heymsfield, S. B., & Lieberman, D. E. (2021). Historical body temperature records as a populationlevel ‘thermometer’of physical activity in the United States. Current Biology, 31(20), R1375-R1376.
doi.org/10.1016/j.cub.2021.09.014

TERMS TO KNOW
Exercise
A subcategory of physical activity that involves doing planned and structured activity with a fitness-based
objective.
Hypokinetic Diseases
Diseases associated with sedentary lifestyles.
Non-Exercise Activity Thermogenesis (NEAT)
Energy expended throughout the day from any activities besides planned exercise, sleeping, and eating.
Physical Activity
Any body movement that increases metabolism over resting energy expenditure, which can include daily
tasks like housework or occupational duties.
Physical Fitness
The ability and health of your body to work efficiently and perform activities of daily living with the least
effort possible.
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
Page 8
Benefits of Physical Activity
by Sophia

WHAT'S COVERED
In this lesson, you will learn about the major health benefits associated with physical activity, as well as
the risks of being sedentary. Specifically, this lesson will cover the following:
1. Health Benefits of Physical Activity
1a. Cardiorespiratory Health
1b. Reduced Cancer Risk
1c. Musculoskeletal Health
1d. Improved Body Composition and Weight
1e. Improved Functional Ability
1f. Mental and Psychological Health
2. Risks of a Sedentary Lifestyle
1. Health Benefits of Physical Activity
Regular physical activity is one of the most important things people can do to improve their health. Moving more
and sitting less have tremendous benefits for everyone, regardless of age, sex, race, ethnicity, or current fitness
level. The scientific evidence continues to build—physical activity is linked with even more positive health
outcomes than we previously thought. And, even better, benefits can start accumulating with small amounts of,
and immediately after doing, physical activity.
A single session of moderate to vigorous physical activity can reduce blood pressure, improve insulin
sensitivity, improve sleep, reduce anxiety symptoms, and improve some aspects of cognition on the day that it
is performed. Most of these improvements become even larger with the regular performance of moderate to
vigorous physical activity. Other benefits, such as disease risk reduction and improved physical function, accrue
within days to weeks after consistently being more physically active.
Bouts, or episodes, of moderate to vigorous physical activity of any duration may be included in the daily
accumulated total amount of physical activity. This means even a brief episode of physical activity like climbing
up a few flights of stairs counts towards your daily total and that even 10-minute walks or activities are just as
important to accumulate as longer workouts.
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1a. Cardiorespiratory Health
The benefits of physical activity on cardiorespiratory health are some of the most extensively documented of all
the health benefits. Cardiorespiratory health involves the health of the heart, lungs, and blood vessels. There
are multiple risk factors that increase the likelihood of cardiovascular diseases, including low cardiorespiratory
fitness.
People who do moderate- or vigorous-intensity aerobic physical activity have a significantly lower risk of
cardiovascular disease than inactive people. Regularly active adults have lower rates of heart disease and
stroke, lower blood pressure, and better blood lipid profiles. Significant reductions in risk of cardiovascular
disease occur at activity levels equivalent to 150 minutes a week of moderate-intensity physical activity. Even
greater benefits are seen with 200 minutes (3 hours and 20 minutes) a week. The evidence is strong that
greater amounts of physical activity result in even further reductions in the risk of cardiovascular disease.
1b. Reduced Cancer Risk
Physically active people have a significantly lower risk of some types of cancers than inactive people. Research
shows that a wide range of moderate-intensity physical activity—between 210 and 420 minutes a week (3 hours
and 30 minutes to 7 hours)—significantly reduces the risk of colon and breast cancer. It also appears that
greater amounts of physical activity lower the risks of these cancers even further, although exactly how much
lower is not clear. Finally, cancer survivors have a better quality of life and improved physical fitness if they are
physically active, compared to survivors who are inactive.
IN CONTEXT
Heart disease and cancer are two of the leading causes of death. Since physical activity reduces the
risks of these, living longer is another significant benefit of being physically active. There are few
other lifestyle choices that affect mortality as significantly as physical activity. It has been estimated
that people who are physically active for approximately 7 hours a week have a 40% lower risk of early
death than those who are active for less than 30 minutes a week. Reducing the risk of early death
does not require high amounts of activity or vigorous exercise—risk is substantially lowered by doing
150 minutes of at least moderate-intensity physical activity each week. In addition, reducing the risk of
premature death is a benefit available to everyone, regardless of age, ethnicity, body composition, or
other factors. For example, research shows that physically active people of all body weights (normal
weight, overweight, obese) have lower rates of early death than inactive people.
1c. Musculoskeletal Health
Bones, muscles, and joints support the body and help it move. Healthy bones, joints, and muscles are critical to
the ability to do daily activities without physical limitations.
Preserving bone, joint, and muscle health is essential with increasing age. Studies show that the frequent
decline in bone density that happens during aging can be slowed with regular physical activity. These effects
are seen in people who participate in aerobic, muscle-strengthening and bone-strengthening physical activity
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programs of moderate or vigorous intensity. The range of total physical activity for these benefits varies widely.
Important changes seem to begin at 90 minutes a week and continue up to 300 minutes a week.
Regular physical activity also helps people with arthritis or other rheumatic conditions affecting the joints.
Participation in 130 to 150 minutes (2 hours and 10 minutes to 2 hours and 30 minutes) a week of moderateintensity, low-impact physical activity improves pain management, function, and quality of life.
Progressive muscle-strengthening activities increase or preserve muscle mass, strength, and power. Higher
amounts (through greater frequency or higher weights) improve muscle function to a greater degree.
Individuals can attain improvement in muscle function regardless of their age or physical condition. Though it
doesn’t increase muscle mass in the same way that muscle-strengthening activities do, aerobic activity may also
help slow the loss of muscle with aging.
1d. Improved Body Composition and Weight
As you’ve learned, physical activity and caloric intake both must be considered in body weight and body
composition goals. Because of this role in energy balance, physical activity is a critical factor in determining
whether a person can maintain a healthy body weight, lose excess body weight, or maintain successful weight
loss. People vary a great deal in how much physical activity they need to achieve and maintain a healthy weight.
Some need more physical activity than others to maintain a healthy body weight, to lose weight, or to keep
weight off once it has been lost.
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Strong scientific evidence shows that physical activity helps people maintain a stable weight over time.
However, the optimal amount of physical activity needed to maintain weight is unclear. People vary greatly in
how much physical activity results in weight stability. Many people need more than the equivalent of 150 minutes
of moderate-intensity activity a week to maintain their weight.
Over short periods of time, such as a year, research shows that it is possible to achieve weight stability by doing
the equivalent of 150 to 300 minutes (5 hours) a week of moderate-intensity walking at about a 4-mile-an-hour
pace. Muscle-strengthening activities may help promote weight maintenance, although not to the same degree
as aerobic activity.
1e. Improved Functional Ability
Functional ability is the capacity of a person to perform tasks or behaviors that enable them to carry out
everyday activities, such as climbing stairs or walking on a sidewalk. Functional ability is key to a person’s ability
to fulfill basic life roles, such as personal care, grocery shopping, or playing with grandchildren. Loss of
functional ability is referred to as functional limitation. Middle-aged and older adults who are physically active
have lower risk of functional limitations than do inactive adults.
Older adults who already have functional limitations also benefit from regular physical activity. Typically, studies
of physical activity in adults with functional limitations tested a combination of aerobic and muscle-strengthening
activities, making it difficult to assess the relative importance of each type of activity. However, both types of
activity appear to provide benefits.
In older adults at risk of falls, strong evidence shows that regular physical activity is safe and reduces this risk.
Reduction in falls is seen for participants in programs that include balance and moderate-intensity musclestrengthening activities for 90 minutes a week plus moderate-intensity walking for about an hour a week.

TERM TO KNOW
Functional Ability
The capacity of a person to perform tasks or behaviors that enable them to carry out everyday
activities.
1f. Mental and Psychological Health
Physically active adults have a lower risk of depression and cognitive decline (declines with aging in thinking,
learning, and judgment skills). Other research has shown that physical activity is associated with improved sleep
quality (Wang & Boros, 2021).
Mental health benefits have been found in people who do aerobic or a combination of aerobic and musclestrengthening activities 3 to 5 days a week for 30 to 60 minutes at a time. Some research has shown that even
lower levels of physical activity also may provide some benefits. In fact, just a single bout of exercise can
provide a mood boost that helps mitigate depressive symptoms (Bourke et al., 2022).
2. Risks of a Sedentary Lifestyle
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The risks of a sedentary lifestyle, or being physically inactive, affect almost every body system and can pose
significant health risks.
Being sedentary can alter components of our metabolism and metabolic processes, such as increasing
levels of cholesterol in the blood, making our body less sensitive to insulin, and creating stress and
inflammation in body systems. Over time, these impacts increase the risk of heart disease and diabetes
(Park et al., 2020).
The function and integrity of the musculoskeletal system suffers with a sedentary lifestyle. Bone mineral
density is decreased, which increases the risk for osteoporosis and bone fractures. Sedentary individuals
report higher incidences of low back pain (Baradaran Mahdavi et al., 2021) and knee pain (Park et al., 2020).
Sedentary time has a strong association with certain types of cancers, such as breast cancer, colon cancer,
endometrial cancer, prostate cancer, and ovarian cancer (Park et al., 2020). Prolonged sedentary time can
add up where cancer risk is increased by up to 20% (Schmid & Leitzmann, 2014).
Individuals with sedentary lifestyles are much more likely to have increased levels of body fat and higher
waist circumference. Research has highlighted that one reason for this goes beyond the concept of energy
balance and eating more calories than are expended. Our appetite is partially influenced by our body’s
internal perception of how much it weighs compared to gravity. When we are sedentary for long periods,
this ‘internal scale’ has less accurate function (Ohlsson et al., 2020).
Sedentary behavior, particularly from screen time (like watching TV) is associated with a significantly higher
risk of depression (Wang et al., 2019).

DID YOU KNOW
Today, about half of all American adults—117 million people—have one or more preventable chronic
diseases. Seven of the ten most common chronic diseases are favorably influenced by regular physical
activity. Yet nearly 80 percent of adults are not meeting the key guidelines for both aerobic and musclestrengthening activity, while only about half meet the key guidelines for aerobic physical activity. This lack of
physical activity is linked to approximately $117 billion in annual healthcare costs and about 10 percent of
premature mortality. The impact of sedentary lifestyles is now significant enough where some researchers
refer to it as a pandemic (Xu et al., 2022).

SUMMARY
In this lesson, you learned about the health benefits of physical activity. Being physically active
improves cardiorespiratory health and reduces risk of heart diseases. Reduced cancer risk is
associated with physical activity for some types of cancer. Structures such as bones, joints, and muscles
benefit from musculoskeletal health improvements from physical activity. Improved body composition
and weight is another benefit of physical activity. Being able to carry out everyday activities, or
improved functional ability improves with physical activity. And mental and psychological health
benefits include lower risk of depression and improved mood and sleep. Conversely, there are many
risks of a sedentary lifestyle, from increasing disease risk, to increasing mortality, and others.
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
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Source: THIS TUTORIAL HAS BEEN ADAPTED FROM (1) “WELLNESS” BY EXTENDED LEARNING INSTITUTE
(ELI) AT NOVA. ACCESS FOR FREE AT oer commons. LICENSING: CREATIVE COMMONS ATTRIBUTION 4.0
INTERNATIONAL.
Disclaimer: The use of any CDC and United States government materials, including any links to the materials on
the CDC or government websites, does not imply endorsement by the CDC or the United States government of
us, our company, product, facility, service, or enterprise.
REFERENCES
Baradaran Mahdavi, S., Riahi, R., Vahdatpour, B., & Kelishadi, R. (2021). Association between sedentary behavior
and low back pain; A systematic review and meta-analysis. Health Promotion Perspectives, 11(4), 393–410.
doi.org/10.34172/hpp.2021.50
Bourke, M., Patten, R. K., Klamert, L., Klepac, B., Dash, S., & Pascoe, M. C. (2022). The acute affective response
to physical activity in people with depression: A meta-analysis. Journal of Affective Disorders, 311, 353–363.
doi.org/10.1016/j.jad.2022.05.089
Lindshield, B. L. Lumen Learning Kansas State University. Human Nutrition (FNDH 400) Flexbook. goo.gl/vOAnR.
ACCESS FOR FREE AT LUMEN LEARNING BOUNDLESS COURSES. LICENSED UNDER CREATIVE COMMONS
ATTRIBUTION-SHAREALIKE 4.0 INTERNATIONAL.
Ohlsson, C., Gidestrand, E., Bellman, J., Larsson, C., Palsdottir, V., Hägg, D., ... & Jansson, J. O. (2020). Increased
weight loading reduces body weight and body fat in obese subjects–a proof of concept randomized clinical
trial. EClinicalMedicine, 22. doi.org/10.1016/j.eclinm.2020.100338
Park, J. H., Moon, J. H., Kim, H. J., Kong, M. H., & Oh, Y. H. (2020). Sedentary lifestyle: Overview of updated
evidence of potential health risks. Korean Journal of Family Medicine, 41(6), 365–373.
doi.org/10.4082/kjfm.20.0165
Schmid, D., & Leitzmann, M. F. (2014). Television viewing and time spent sedentary in relation to cancer risk: a
meta-analysis. JNCI: Journal of the National Cancer Institute, 106(7), dju098. doi.org/10.1093/jnci/dju098
Wang, X., Li, Y., & Fan, H. (2019). The associations between screen time-based sedentary behavior and
depression: a systematic review and meta-analysis. BMC Public Health, 19, 1-9. doi.org/10.1186/s12889-0197904-9
Wang, F., & Boros, S. (2021). The effect of physical activity on sleep quality: a systematic review. European
Journal of Physiotherapy, 23(1), 11-18. doi.org/10.1080/21679169.2019.1623314
Xu, Y. Y., Xie, J., Yin, H., Yang, F. F., Ma, C. M., Yang, B. Y., Wan, R., Guo, B., Chen, L. D., & Li, S. L. (2022). The
Global Burden of Disease attributable to low physical activity and its trends from 1990 to 2019: An analysis of
the Global Burden of Disease study. Frontiers in Public Health, 10, 1018866.
doi.org/10.3389/fpubh.2022.1018866

TERMS TO KNOW
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Functional Ability
The capacity of a person to perform tasks or behaviors that enable them to carry out everyday activities.
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Physical Activity Guidelines
by Sophia

WHAT'S COVERED
In this lesson, you will learn about the basis and importance of Physical Activity Guidelines for
Americans. Specifically, this lesson will cover the following:
1. Physical Activity Guidelines
1a. Preschool Children
1b. Children and Adolescents
1c. Adults
1d. Older Adults
1e. Women During Pregnancy and the Postpartum Period
1f. Adults with Chronic Health Conditions and Disabilities
2. Levels of Physical Activity
3. Physical Activity to Improve Health
1. Physical Activity Guidelines
The foundation for our current Physical Activity Guidelines for Americans goes back to landmark studies done
from the 1950s to the 1980s. These studies investigated the relationship between physical activity and the risk
of early death or chronic disease. Results across studies and thousands of participants showed that staying
physically active helped prevent disease and early death.
Research from these studies paved the way for national and government organizations to promote the
importance of exercise. In 2008, the first edition of the Physical Activity Guidelines for Americans was released
by the U.S. Department of Health & Human Services. However, rather than primarily focusing on the prevention
of early death, the guidelines focused on improving physical activity for well-being and health-related quality of
life. The guidelines also established that physical activity provides health improvements across all populations,
including children, pregnant women, and individuals with an existing chronic disease.
These guidelines are necessary because of the importance of physical activity to the health of Americans,
whose current inactivity puts them at unnecessary risk. Healthy People 2030 has set objectives for increasing
the level of physical activity in Americans and reducing the proportion of Americans who are not physically
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Page 16
active. Unfortunately, the latest information shows that inactivity among American adults, adolescents, and
children remains relatively high and that little progress has been made toward meeting these objectives.
1a. Preschool Children
Preschool-aged children (ages 3 through 5 years) should be physically active throughout the day to enhance
growth and development. Adult caregivers of preschool-aged children should encourage active play that
includes a variety of activities.
1b. Children and Adolescents
It is important to provide young people with opportunities and encouragement to participate in physical
activities that are appropriate for their age, that are enjoyable, and that offer variety.
Children and adolescents ages 6 through 17 years should do 60 minutes or more of moderate to vigorous
physical activity daily. Most of this time should be either moderate- or vigorous-intensity aerobic physical activity
and should include vigorous-intensity physical activity at least 3 days a week. As part of their 60 minutes or
more of daily physical activity, children and adolescents should include muscle-strengthening and bonestrengthening physical activity at least 3 days a week.
1c. Adults
Adults should move more and sit less throughout the day. Some physical activity is better than none. Adults who
sit less and do any amount of moderate-to-vigorous physical activity gain some health benefits.
For substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5
hours) a week of moderate-intensity aerobic physical activity, 75 minutes (1 hour and 15 minutes) to 150 minutes
(2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of
moderate- and vigorous-intensity aerobic activity. Preferably, aerobic activity should be spread throughout the
week.

KEY CONCEPT
Additional health benefits are gained by engaging in physical activity beyond the equivalent of 300 minutes
(5 hours) of moderate-intensity physical activity a week. Adults should also do muscle-strengthening
activities of moderate or greater intensity that involve all major muscle groups on 2 or more days a week as
these activities provide additional health benefits.
1d. Older Adults
The key guidelines for adults also apply to older adults in addition to the following guidelines. As part of their
weekly physical activity, older adults should do multicomponent physical activity that includes balance training
as well as aerobic and muscle-strengthening activities. Older adults should determine their level of effort for
physical activity relative to their level of fitness. Older adults with chronic conditions should understand whether
and how their conditions affect their ability to do regular physical activity safely.

KEY CONCEPT
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When older adults cannot do 150 minutes of moderate-intensity aerobic activity a week because of chronic
conditions, they should be as physically active as their abilities and conditions allow.
1e. Women During Pregnancy and the Postpartum Period
Women should do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity a week
during pregnancy and the postpartum period. Preferably, aerobic activity should be spread throughout the
week. Women who habitually engaged in vigorous-intensity aerobic activity or who were physically active
before pregnancy can continue these activities during pregnancy and the postpartum period.

KEY CONCEPT
Pregnant women should be under the care of a health care provider who can monitor the progress of the
pregnancy. The health care provider should be consulted about whether or how to adjust physical activity
during pregnancy and after the baby is born.
1f. Adults with Chronic Health Conditions and Disabilities
Adults with chronic conditions or disabilities, who are able, should do at least 150 minutes (2 hours and 30
minutes) to 300 minutes (5 hours) a week of moderate-intensity aerobic physical activity, 75 minutes (1 hour and
15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or an
equivalent combination of moderate- and vigorous-intensity aerobic activity. Preferably, aerobic activity should
be spread throughout the week. Adults with chronic conditions or disabilities, who are able, should also do
muscle-strengthening activities of moderate or greater intensity that involve all major muscle groups on 2 or
more days a week as these activities provide additional health benefits.
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Page 18
When adults with chronic conditions or disabilities are not able to meet the above key guidelines, they should
engage in regular physical activity according to their abilities and should avoid inactivity.

KEY CONCEPT
Adults with chronic conditions or symptoms should be under the care of a health care provider. People with
chronic conditions can consult a health care professional or physical activity specialist about the types and
amounts of activity appropriate for their abilities and chronic conditions.
2. Levels of Physical Activity
The scientific reports that support the physical activity guidelines provide the basis for dividing the amount of
aerobic physical activity an adult gets every week into four categories: inactive, low, medium, and high. This
classification is useful because these categories provide a rule of thumb for how the total amount of physical
activity is related to health benefits. Low amounts of activity provide some benefits; medium amounts provide
substantial benefits; and high amounts provide even greater benefits.
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Page 19
Classification of Total Weekly Amounts of Physical Activity Into Four Categories
Level of Physical Range of Moderate-Intensity
Activity
Minutes Per Week
Summary of
Overall Health
Comment
Benefits
Inactive
No activity beyond baseline
None
Being inactive is unhealthy.
Low
Activity beyond baseline but
Some
Low levels of activity are clearly
fewer than 150 minutes a
preferable to an inactive lifestyle.
week
Medium
150 minutes to 300 minutes a Substantial
Activity at the high end of this range has
week
additional and more extensive health
benefits than activity at the low end.
High
More than 300 minutes a
week
Additional
Current science does not allow
researchers to identify an upper limit of
activity above which there are no
additional health benefits.
IN CONTEXT
Inactive is no activity beyond baseline activities of daily living.
Low activity is activity beyond baseline but fewer than 150 minutes (2 hours and 30 minutes) of
moderate-intensity physical activity a week or the equivalent amount (75 minutes, or 1 hour and 15
minutes) of vigorous-intensity activity.
Medium activity is 150 minutes to 300 (5 hours) minutes of moderate-intensity activity a week (or
75 to 150 minutes of vigorous-intensity physical activity a week).
High activity is more than the equivalent of 300 minutes of moderate-intensity physical activity a
week.

THINK ABOUT IT
Based on your typical weekly activity, where do you fall in the above chart?
3. Physical Activity to Improve Health
The guidelines focus on reducing the risk of chronic disease and promoting health-related fitness, particularly
cardiovascular and muscular fitness. You will learn more about the components of health-related fitness in the
next lesson. People can gain this kind of fitness by doing the amount and types of activities recommended in
the guidelines.
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Page 20

KEY CONCEPT
The guidelines do not address the types and amounts of activity necessary to improve performance-related
or skill-related fitness. Competitive or recreational athletes, or people with physical performance-related
goals, may need more specific activities than the guidelines outline. People who are interested in training
programs to increase performance-related fitness should seek advice from other sources, such as a
certified personal trainer or strength and conditioning specialist.
Within the overall parameters of the physical activity guidelines, individuals have many choices about
appropriate types and amounts of activity.
To make these choices, individuals need to set personal goals for physical activity. Setting these goals can
involve questions like, “How physically fit do I want to be?” “How important is it to me to reduce my risk of heart
disease and diabetes?” “How important is it to me to reduce my risk of falls and hip fracture?” “How much
weight do I want to lose and keep off?” People can meet the guidelines and their own personal goals through
different amounts and types of activity.
Although the guidelines focus on the health benefits of physical activity, these benefits are not the only reason
why people are active. Physical activity gives people a chance to have fun, be with friends and family, enjoy the
outdoors, improve their personal appearance, and improve their fitness so that they can participate in more
intensive physical activity or sporting events. Some people are active because they feel it gives them certain
health benefits (such as feeling more energetic) that aren’t yet conclusively proven for the general population.
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Page 21
The guidelines encourage people to be physically active for any and all reasons that are meaningful for them.
Nothing in the guidelines is intended to mean that health benefits are the only reason to do physical activity.

BIG IDEA
The main idea behind the guidelines is that regular physical activity over months and years can produce
long-term health benefits. Achieving these benefits requires physical activity each week.

SUMMARY
In this lesson, you learned about the physical activity guidelines, which take a lifespan approach in
providing recommendations for preschool children, children and adolescents, adults, older adults,
women during pregnancy and postpartum, and adults with chronic health conditions and disabilities.
The general recommendation for adults is to get at least 150 minutes of moderate-intensity aerobic
activity each week and at least 2 days per week of muscle-strengthening activity. Classifying the levels
of physical activity highlights what health benefits individuals receive or may receive by being more
active. The guidelines focus on physical activity to improve health, but there are many other reasons
that can motivate us to be active.
Source: THIS TUTORIAL HAS BEEN ADAPTED FROM (1) “WELLNESS” BY EXTENDED LEARNING INSTITUTE
(ELI) AT NOVA. ACCESS FOR FREE AT oer commons. LICENSING: CREATIVE COMMONS ATTRIBUTION 4.0
INTERNATIONAL.
Disclaimer: The use of any CDC and United States government materials, including any links to the materials on
the CDC or government websites, does not imply endorsement by the CDC or the United States government of
us, our company, product, facility, service, or enterprise.
REFERENCES
Lindshield, B. L. Lumen Learning Kansas State University. Human Nutrition (FNDH 400) Flexbook. goo.gl/vOAnR.
ACCESS FOR FREE AT LUMEN LEARNING BOUNDLESS COURSES. LICENSED UNDER CREATIVE COMMONS
ATTRIBUTION-SHAREALIKE 4.0 INTERNATIONAL.
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Page 22
Health-Related Fitness
by Sophia

WHAT'S COVERED
In this lesson, you will learn about the importance of the five health-related fitness components and
how to implement them as per the Physical Activity Guidelines. Specifically, this lesson will cover the
following:
1. Health-Related Fitness Components
1a. Cardiorespiratory Endurance
1b. Muscular Strength
1c. Muscular Endurance
1d. Flexibility
1e. Body Composition
2. The FITT Principle
1. Health-Related Fitness Components
The ultimate focus of the health-related components of physical fitness is to provide a framework for
components that are necessary for good health. There are five areas of health-related fitness: cardiorespiratory
endurance, muscular strength, muscular endurance, flexibility, and body composition.
1a. Cardiorespiratory Endurance
Cardiorespiratory endurance is the ability to carry out prolonged, large muscle, dynamic movements at a
moderate to high level of intensity. In cardiorespiratory endurance, the heart, lungs, and blood vessels work
together in three main ways: delivering oxygen to body tissues, delivering nutrients, and removing waste
products. Cardiovascular activity makes the heart beat more rapidly to meet the demands of the movement.
Both planned exercise and physical activity throughout the day can count toward meeting the Physical Activity
Guidelines. For example, physically active occupations can count toward meeting the guidelines, as well as
active transportation choices (walking or bicycling). All types of cardiovascular activities can count as long as
they are of sufficient intensity and duration. Over time, regular cardiovascular activity makes the cardiovascular
system more fit.
Examples of Different Aerobic Physical Activities and Intensities
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Moderate Intensity
Walking briskly
Vigorous Intensity
Racewalking, jogging, or running; hiking uphill or with
a heavy pack
Water aerobics
Swimming laps
Bicycling at less than 10 miles (6.2 km) per hour
Bicycling at more than 10 miles (6.2 km) per hour
Tennis (doubles)
Tennis (singles)
Ballroom dancing
Jumping rope
General gardening

Heavy gardening, such as continuous digging or
shoveling
TERM TO KNOW
Cardiorespiratory Endurance
The ability to carry out prolonged, large muscle, dynamic movements at a moderate to high level of
intensity.
1b. Muscular Strength
Muscular strength is the ability of the muscles to exert force over a single or maximal effort. Improving muscular
strength involves making the muscles do more work than they are accustomed to doing. That is, they overload
the muscles. Resistance training, including weight training, is a familiar example of muscle-strengthening activity.
Other examples include working with resistance bands, doing calisthenics that use body weight for resistance
(such as push-ups, pull-ups, and sit-ups), carrying heavy loads, and heavy gardening (such as digging or hoeing).
Muscle-strengthening activities provide additional benefits not found with aerobic activity. The benefits of
muscle-strengthening activity include increased bone strength and muscular fitness. Muscle-strengthening
activities can also help maintain muscle mass during a program of weight loss.
Muscle-strengthening activities count if they involve a moderate to high level of intensity or effort and work the
major muscle groups of the body: the legs, hips, back, chest, abdomen, shoulders, and arms. Musclestrengthening activities for all the major muscle groups should be done at least 2 days a week.
Muscle-strengthening exercises should be performed to the point at which it would be difficult to do another
repetition without help. When resistance training is used to enhance muscle strength, one set of 8 to 12
repetitions of each exercise is effective, although two or three sets may be more effective. Development of
muscle strength and endurance is progressive over time. Increases in the amount of weight or the days a week
of exercising will result in stronger muscles.

TERM TO KNOW
Muscular Strength
The ability of the muscles to exert force over a single or maximal effort.
1c. Muscular Endurance
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Muscular endurance is the ability to exert a force over a period of time or repetitions. You’ll learn more about
resistance training principles in a future lesson, but the same types of equipment in the form of external
resistance can be used for both muscular strength and muscular endurance. A person might use weights to
increase the amount they can lift over time (muscular strength) or else use weights in a circuit-training type
format to see how many repetitions they can get in a given time period (muscular endurance). Activities that
build muscular endurance can also overlap with activities that build cardiorespiratory endurance, such as
swimming, dancing, and circuit training.

TERM TO KNOW
Muscular Endurance
The ability to exert a force over a period of time or repetitions.
1d. Flexibility
Flexibility is the ability to move your joints through a full range of motion. Examples of activities where flexibility
is used are yoga, stretching, and tai chi. Some types of activity, such as dance or gymnastics, require more
flexibility than others. Stretching exercises can increase flexibility when done consistently over time.
Flexibility activities are an appropriate part of a physical activity program since they help people maintain painfree range of motion. However, the research on flexibility activities is not clear on specific health benefits or
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Page 25
injury reduction. In addition, time spent doing flexibility activities by themselves does not count toward meeting
the aerobic or muscle-strengthening Guidelines.

TERM TO KNOW
Flexibility
The ability to move your joints through a full range of motion.
1e. Body Composition
As you’ve learned, body composition refers to the proportion of fat mass and fat-free mass within the body.
Body composition is a unique component of health-related fitness because it is not an action we do (unlike
cardiovascular endurance activities, muscular strength and endurance activities, and flexibility activities).
Instead, it is an outcome of other healthy behaviors, where changes in body composition usually occur as a
result of other health-related fitness components, as well as changing eating habits. Body composition is
included as part of the five health-related fitness components because a balanced amount of fat and muscle is
vital for health and wellness.
The first step in achieving or maintaining a healthy body composition is to meet the minimum level of physical
activity in the Guidelines. People who are at a healthy body weight but slowly gaining weight can either
gradually increase the level of physical activity (toward the equivalent of 300 minutes a week of moderateintensity aerobic activity), or reduce caloric intake, or both, until their weight is stable. By regularly checking
body weight, people can find the amount of physical activity that works for them.
Many adults will need to do more than the recommended 150 minutes a week of moderate-intensity aerobic
physical activity as part of a program to lose weight or keep it off. These adults should do more physical activity
and/or further reduce their caloric intake. Some people will need to do the equivalent of 300 or more minutes
of moderate-intensity physical activity a week to meet their weight-control goals. Combined with restricting
caloric intake, these adults should gradually increase minutes or the intensity of aerobic physical activity per
week, to the point at which the physical activity is effective in achieving a healthy weight.
It is important to remember that all activities, both baseline and physical activity, “count” for energy balance.
Active choices, such as taking the stairs rather than the elevator or adding short episodes of walking to the day,
are examples of activities that can be helpful in weight control and improving body composition.
2. The FITT Principle
Using the FITT principle is a way to apply the Physical Activity Guidelines and implement improvements in your
own health-related physical fitness. FITT stands for:
Frequency: how often a person performs the activity
Intensity: how hard a person exercises during the activity, which can be measured in different ways
Time: also known as duration, refers to the amount of time or repetitions when performing an activity
Type: the kind of exercise or activity being performed
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The Physical Activity Guidelines use FITT to provide recommendations on 4 out of the 5 health-related fitness
components (but not body composition, since that is an outcome rather than a type of physical activity or
exercise).
Cardiorespiratory
Muscular Strength
Frequency 3–5 times per week or 2 or more days per
Muscular Endurance
Flexibility
Daily for some muscle
No specific
more, at least 3 days a
week using all major
groups; perform 3–4
recommended
week
muscle groups
times per week
frequency; useful to
include with warm-up
and cool-down for
other activities
Intensity
In moderate intensity, a Perform movements at Start with bodyweight,
Stretch all major
person can talk, but not 60–80% of the
then add resistance,
muscle groups and
sing, during the activity. maximal amount you
performing
associated joint areas,
In vigorous intensity, it
movements at less
hold to the point of
is difficult to say more
than 50% of the
mild tension
than a few words
maximal amount you
without pausing for
can lift (1 rep max).
can lift (1 rep max)
breath
Time
20–60 minutes of
15–60 minutes, 1–3
30–60 minutes, 1–3
Hold stretches for 15–
continuous activity
sets of 8–12 reps
sets of 15 or more reps 30 seconds, perform
1–3 repetitions of each
stretch
Type
Choose rhythmic
Done through
Done through
Can be improved
activities that use large resistance such as
resistance such as
through static
muscle groups, such as body weight, bands,
body weight, bands,
stretches, controlled
walking, cycling,
weighted implements
weighted implements
dynamic stretches, or
swimming, or dancing
like free weights,
like free weights,
other activities
machines, and others
machines, and others
involving flexibility,
such as yoga
Each component of the FITT principle can be used to guide you in starting a regular physical activity or
progressing to improve your fitness. Inactive adults should work gradually toward reaching the Physical Activity
Guidelines. The initial amount of activity should be at a light or moderate intensity, for short periods of time, with
the sessions spread throughout the week. Even 60 minutes a week of moderate-intensity physical activity can
provide some health benefits.
Gradual progression is important to reduce the risk of injury and reduce fatigue. In addition, a general rule of
thumb is to change only one component of FITT at a time as you progress. An inactive person might try to
gradually be active more frequently before increasing time or intensity. Or, muscle-strengthening activities
might be done just one day a week starting a light or moderate level of effort. Over time, the number of days a
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Page 27
week can be increased to 2, and then possibly to more than 2. After that, the level of effort (intensity) can be
increased slightly each week until it becomes moderate to high.
IN CONTEXT
Adults can meet the Physical Activity Guidelines in all sorts of ways and with many types of physical
activity through applying FITT. The choices of types and amounts of physical activity depend on
personal health and fitness goals. Here is one example:
Douglas is an active middle-aged man who was actively playing soccer when he was younger. His goal
is to get back into shape by running regularly. In addition to his job operating heavy equipment, he
walks 30 to 40 minutes a day on 5 days each week. He also lifts weights 2 days a week.
Starting out: Douglas starts a walk/jog program with a coworker and plans to gradually replace
walking with jogging and then running. The first week he goes out on 5 days, walking for 25 minutes
and jogging for 5 minutes.
Making good progress: Each week, Douglas gradually increases the time spent jogging (vigorousintensity activity) and reduces the time spent walking (moderate intensity activity). He also continues
his weight-lifting program.
Reaching his goal: Eventually, Douglas is running 30 to 45 minutes 4 days a week and lifting weights 2
days a week. He goes for a 1-hour bicycle ride on most weekends.
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Because Douglas was already active most days of the week, and because he wanted to progress from
walking to running, modifying Intensity in FITT made the most sense for his goals.

TERM TO KNOW
FITT Principle
A way to implement improvements and progression in fitness; FITT stands for frequency, intensity, time,
and type.

SUMMARY
In this lesson, you learned about the five health-related fitness components: cardiorespiratory
endurance, muscular strength, muscular endurance, flexibility and body composition. The Physical
Activity Guidelines for Americans provide recommendations on most of these, where the FITT principle
can be implemented to maintain or improve physical activity for health.
Source: THIS TUTORIAL HAS BEEN ADAPTED FROM (1) "WELLNESS" BY EXTENDED LEARNING INSTITUTE
(ELI)" AT NOVA. ACCESS FOR FREE AT: oer commons. (2) "HEALTH EDUCATION" BY COLLEGE OF THE
CANYONS. ACCESS FOR FREE AT: open.umn.edu. LICENSING (1 & 2): CREATIVE COMMONS ATTRIBUTION 4.0
INTERNATIONAL.
Disclaimer: The use of any CDC and United States government materials, including any links to the materials on
the CDC or government websites, does not imply endorsement by the CDC or the United States government of
us, our company, product, facility, service, or enterprise.

TERMS TO KNOW
Cardiorespiratory Endurance
The ability to carry out prolonged, large muscle, dynamic movements at a moderate to high level of
intensity.
FITT Principle
A way to implement improvements and progression in fitness; FITT stands for frequency, intensity, time,
and type.
Flexibility
The ability to move your joints through a full range of motion.
Muscular Endurance
The ability to exert a force over a period of time or repetitions.
Muscular Strength
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Page 29
The ability of the muscles to exert force over a single or maximal effort.
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Skill Related Fitness
by Sophia

WHAT'S COVERED
In this lesson, you will learn about the importance of the six skill-related fitness components and their
relevance to various populations. Specifically, this lesson will cover:
1. Skill-Related Fitness Components
1a. Power
1b. Speed
1c. Agility
1d. Balance
1e. Coordination
1f. Reaction Time
2. Importance of Skill-Related Fitness Components
1. Skill-Related Fitness Components
Skill-related fitness components are mainly related to physical performance, and are relevant to people who
want to compete, perform, or train at higher levels beyond everyday health-improving activities. There are six
areas of skill-related fitness: power, speed, agility, balance, coordination, and reaction time. However, as we’ll
see, some skill-related components overlap with health-related components.
1a. Power
Power is a product of both strength and speed and relates to the rate at which someone can perform physical
work or quickly exert muscle force (Corbin et al., 2000). Since speed is a component of power, power-based
movements typically are performed at high speeds. Plyometric movements are a type of power movement that
involve quick contraction of the muscles to generate high amounts of force, such as in a box jump or a medicine
ball slam. Movements that involve speed paired with lifting, throwing, jumping, or quick starts and stops are all
methods to improve power (Sipe, 2017).
IN CONTEXT
Research in recent years has made the case for power being considered a health-related component.
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Building power enhances bone mass, reduces bone fracture risk, and promotes healthy muscle
development (Corbin et al., 2017). Power relates to health, and not just skill, as it is associated with
higher quality of life as well as reduced risk of disease and early death (Corbin et al., 2022).
Since power is the product of strength (a health-related component) and speed (a skill-related
component), it is likely most accurate to consider power as a combined component with overlap into
both health-related fitness and skill-related fitness.

TERMS TO KNOW
Power
A product of both strength and speed; power relates to the rate at which someone can perform
physical work or quickly exert muscle force.
Plyometric
A type of power movement that involves quick contraction of the muscles to generate high amounts of
force.
1b. Speed
Speed is the ability to perform a movement in a short amount of time (Corbin et al., 2000). We might most
readily think of track and field athletes doing sprint events like the 100-meter dash, but sports like tennis or
baseball also require quick bursts of speed. Movements that focus on health-related fitness components – like
running or walking for cardiorespiratory endurance, and resistance training for muscular strength – can be
progressed to incorporate speed. A person might choose to start incorporating quick bursts of sprinting or
speedwalking in intervals, or they might lift a relatively light load at a higher speed.

TERM TO KNOW
Speed
The ability to perform a movement in a short amount of time.
1c. Agility
Agility relates to the ability to rapidly change body positions in space with speed and accuracy (Corbin et al.,
2000). An athlete playing team sports such as football or basketball must have agility to dodge other players or
move toward the ball; or surfers and snowboarders need to be responsive to the surface underneath them to
stay on the board (DeMet & Wahl-Alexander, 2019).
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
TERM TO KNOW
Agility
The ability to rapidly change body positions in space with speed and accuracy.
1d. Balance
Balance is the ability to maintain equilibrium, whether stationary, which is termed static balance, or moving,
termed dynamic balance (Corbin et al., 2000).
EXAMPLE Standing on one leg is an example of static balance. While this movement might be useful,
it’s typically more relevant to improve balance through dynamic training, which involves maintaining balance
while moving (McCall, 2015). Dynamic balance movements are more of what we perform in activities of
everyday life, like navigating a curb or walking up stairs. Improving balance can improve walking or running
gait, as well as improving your core muscle function, since the core muscles are responsible for helping
stabilize you during balance (McCall, 2015).

TERM TO KNOW
Balance
The ability to maintain equilibrium, whether stationary (static balance) or moving (dynamic balance).
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1e. Coordination
Coordination is the ability to use senses, like sight, along with the body to perform motor tasks smoothly and
accurately (Corbin et al., 2000). Coordination may be expressed as hand-eye coordination, like hitting a
volleyball, or foot-eye coordination, like dribbling a soccer ball. To execute coordinated movements, an
individual needs proprioception, or having a sense of how their body is positioned and moves in space.

TERMS TO KNOW
Coordination
The ability to use senses, like sight, along with the body to perform motor tasks smoothly and
accurately.
Proprioception
Having a sense of how the body is positioned and moves in space.
1f. Reaction Time
Reaction time entails the time elapsed between a stimulus and responding to that stimulus (Corbin et al., 2000).
Most contexts of sports require quick reaction, such as a swimmer diving into the pool as soon as they hear the
starting gun in a race.
IN CONTEXT
Many skill-related activities have overlap into improving more than one component of skill-related
fitness. For example, improving dynamic balance can also boost coordination and agility (McCall,
2015). The benefits of improving these are not just sports-specific but can promote injury prevention in
everyday life. For example, if your dynamic balance is good, you will likely also have the proper
coordination and agility to avoid falling if you step on an icy patch outside during winter.

TERM TO KNOW
Reaction Time
Entails the time elapsed between a stimulus and responding to that stimulus.
2. Importance of Skill-Related Fitness
Components
Even though the health-related fitness components are arguably more important overall for health than the skillrelated components, skill-related components still have importance for some populations and goals.
Children in particular benefit from physical activity that emphasizes both health-related components and skillrelated components. Building control of coordination and reaction time can promote confidence in movements,
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
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boosting the motivation to continue being active (American Council on Exercise, 2014). Improving skill-related
fitness also sets children up to be more successful in a variety of physical activities or sports and is an engaging
and fun way to be active (DeMet & Wahl-Alexander, 2019).
Training power and speed can benefit individuals that want to improve their body composition and already have
a good foundation of the health-related components of fitness. Movements that focus on speed and power are
higher intensity, where high intensity training can have a large calorie burn in a shorter amount of time than
slower-paced cardiovascular activity (McCall, 2014a). Speed training also signals the body to release musclebuilding hormones and recruits additional types of muscle fibers that can enhance muscle mass and definition
(McCall, 2014a).
Older adults can benefit from specific training for balance and coordination. These skills tend to decrease with
age, but are important for activities of daily living, like climbing stairs or doing household tasks (Kovar, 2016).
Agility, speed, and reaction time are also useful for older adults. Training these skills improves muscle force
production and reflexes, which typically reduce with the aging process (McCall, 2014b).
The following are some example movements for each of the skill-related components of fitness. Incorporating
skill-related movements should only be done after a thorough warm-up, since they can place more stress on
the body (McCall, 2014b). Consulting with a certified fitness professional, such as a personal trainer or strength
and conditioning specialist, is the best way to ensure that skill-related fitness training is safe and effective.
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
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Skill-Related Component
Power
Example Movements
Medicine ball slams, broad jumps, vertical jumps, plyometric
movements like squat jumps or pushups
Speed
Sprinting (including short interval bursts, such as on a bicycle, treadmill,
or rower), or faster tempo of resistance training
Agility
Agility ladder drills or cone drills
Balance
Walking on balance beams, using unstable surfaces such as stability
balls
Coordination
Juggling, jumping rope, dribbling basketballs
Reaction time
Catching, bouncing, and throwing movements with balls

WATCH
Skill-Related Exercises
IN CONTEXT
In 2022, the U.S. Army began implementing new fitness testing for the military, termed the Army
Combat Fitness Test (ACFT). This test requires soldiers to perform six tasks (Bigelman et al., 2019):
3 repetition maximum deadlift
Standing power throw of a 10 lb. medicine ball for distance
Maximum amount of hand release pushups in 2 minutes
Sprint-Drag-Carry using 5 x 50 meter runs and a weighted sled
Holding a plank for as long as possible
2 mile run as fast as possible
The updated ACFT was a significant change from the previous fitness testing, which had been in place
since 1980. The previous test, termed the Army Physical Fitness Test (APFT), required soldiers to
complete three tasks – a 2-mile run, 2 minutes of pushups, and 2 minutes of sit-ups (Heinrich et al.,
2022). Per the U.S. Army, a main reason for changing the test was because the three tasks in the APFT
were not enough to simulate the various real-world demands that a soldier could face in combat. In
comparing the two tests, you might observe that the APFT mainly covered only cardiorespiratory
endurance and muscular endurance. In contrast, the ACFT covers multiple components of both healthrelated fitness and skill-related fitness – highlighting the value of combining various components for
specific outcomes.

BIG IDEA
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Page 36
People can achieve good health without excelling in the skill-related components of fitness. However,
incorporating training to improve skill-related fitness can be relevant and beneficial for populations besides
athletes. Skill-related fitness movements also provide fun and variety when someone already has a solid
foundation of the health-related fitness components.

SUMMARY
In this lesson, you learned about the six skill-related fitness components: power, speed, agility, balance,
coordination, and reaction time. The importance of skill-related components of fitness extends to
various populations beyond athletes, such as children, older adults, people with body composition
goals, and people who benefit from fun and variety when they already have a solid foundation of
health-related fitness components.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE.
Disclaimer: The use of any CDC and United States government materials, including any links to the materials on
the CDC or government websites, does not imply endorsement by the CDC or the United States government of
us, our company, product, facility, service, or enterprise.
REFERENCES
American Council on Exercise (2014). Youth fitness: integrative fitness training. American Council on Exercise.
www.acefitness.org/resources/everyone/blog/5061/youth-fitness-integrative-fitness-training/
Bigelman, K. A., East, W. B., Thomas, D. M., Turner, D., & Hertling, M. (2019). The new Army Combat Fitness Test:
an opportunity to improve recruitment and retainment. Obesity, 27(11), 1772-1775. doi.org/10.1002/oby.22619
Corbin, C. B., Pangrazi, R. P., & Franks, B. D. (2000). Definitions: Health, fitness, and physical activity. President's
Council on Physical Fitness and Sports Research Digest, 3(9). files.eric.ed.gov/fulltext/ED470696.pdf
Corbin, C. B., Janz, K. F., & Baptista, F. (2017). Good health: The power of power. Journal of Physical Education,
Recreation & Dance, 88(9), 28-35. doi.org/10.1080/07303084.2017.1367742
Corbin, C.B., Castelli, D.M., Sibley, B.A., and Le Masurier, G.C. (2022). Fitness for Life (7th ed.). Human Kinetics.
ISBN: 9781718208704.
DeMet, T., & Wahl-Alexander, Z. (2019). Integrating skill-related components of fitness into physical education.
Strategies, 32(5), 10-17. doi.org/10.1080/08924562.2019.1637315
Heinrich, K. M., Streetman, A. E., Kukić, F., Fong, C., Hollerbach, B. S., Goodman, B. D., ... & Poston, W. S. (2022).
Baseline physical activity behaviors and relationships with fitness in the army training at high intensity study.
Journal of Functional Morphology and Kinesiology, 7(1), 27. doi.org/10.3390/jfmk7010027
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
Page 37
Kovar, E. (2016). Coordination exercises for active aging clients. American Council on Exercise.
www.acefitness.org/resources/pros/expert-articles/5984/coordination-exercises-for-active-aging-clients/
McCall, P. (2014a). The benefits of speed training for non-athletes. American Council on Exercise.
www.acefitness.org/resources/everyone/blog/5030/the-benefits-of-speed-training-for-non-athletes/
McCall, P. (2014b). Benefits of agility training for non-athletes. American Council on Exercise.
www.acefitness.org/resources/everyone/blog/5041/benefits-of-agility-training-for-non-athletes/
McCall, P. (2015). Dynamic balance: 5 benefits of training for dynamic balance. American Council on Exercise.
www.acefitness.org/resources/everyone/blog/5428/dynamic-balance-5-benefits-of-training-for-dynamicbalance/
Sipe, C. (2017). Stop loading and start exploding: power training for powerful aging. American Council on
Exercise. www.acefitness.org/resources/pros/expert-articles/6572/stop-loading-and-start-exploding-powertraining-for-powerful-aging/

TERMS TO KNOW
Agility
The ability to rapidly change body positions in space with speed and accuracy.
Balance
The ability to maintain equilibrium, whether stationary (static balance) or moving (dynamic balance).
Coordination
The ability to use senses, like sight, along with the body to perform motor tasks smoothly and accurately.
Plyometric
A type of power movement that involves quick contraction of the muscles to generate high amounts of
force.
Power
A product of both strength and speed; power relates to the rate at which someone can perform physical
work or quickly exert muscle force.
Proprioception
Having a sense of how the body is positioned and moves in space.
Reaction Time
Entails the time elapsed between a stimulus and responding to that stimulus.
Speed
The ability to perform a movement in a short amount of time.
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Cardiovascular Training Principles
by Sophia

WHAT'S COVERED
In this lesson, you will learn about how the body uses fuel sources in cardiovascular exercise and the
adaptations that occur from doing cardiovascular exercise. Specifically, this lesson will cover the
following:
1. Fuel for Cardiovascular Exercise
2. Adaptations to Cardiovascular Exercise
2a. Cardiovascular System
2b. Respiratory System
2c. Muscular System
2d. Metabolism
1. Fuel for Cardiovascular Exercise
Our bodies store carbohydrates, fats, and proteins from the food we eat to give us energy (or fuel) to be active.
This energy must be broken down to be used as fuel. ATP (adenosine triphosphate) is an energy-carrying
molecule found in all living things, capturing energy from the breakdown of food and releasing it to fuel other
body processes. None of your body cells would have the power to work without ATP.
As you learned in the lessons on nutrition, carbohydrates that you eat are broken down into glucose, which your
body uses for energy. Glucose is the body’s primary source of energy and can come from blood glucose or
muscle glycogen. Fatty acids (from dietary fat) are stored in muscles as triglycerides, and when you are
exercising at a low or moderate rate, the fatty acids can become the major source of energy. The primary
source of ATP is carbohydrates, but fats and protein can also be used. However, protein is not a good source of
energy even though a few amino acids can be used while you are active.
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ATP energy can be used in aerobic metabolism (a chemical process in which oxygen is used to make energy
from carbohydrates) or anaerobic metabolism (the release of energy by partially breaking down glucose and
glycogen but without combining oxygen). More specifically, there are three basic energy pathways to use or
make ATP during exercise, and the intensity of exercise determines what energy sources are used.
The phosphagen system is active immediately when we start to exercise, and during very short-duration,
high-intensity activities lasting about 1–30 seconds such as a 100-meter sprint (Gagliardi, 2019). This system
uses creatine phosphate as a stored source of energy that can ultimately be converted to ATP. However,
creatine phosphate is used quickly, which is why you cannot maintain all-out efforts for more than a short
time.
Anaerobic glycolysis is the primary system used in activities requiring high intensities over longer periods
of time—approximately 30 seconds to 3 minutes (Gagliardi, 2019).
Aerobic glycolysis requires oxygen and is most active in longer-duration, lower-intensity activities. This
energy system helps you maintain exercise for longer periods beyond just a few minutes because it
produces ATP at a slower, steady pace, and fat can be used as the energy source (Gagliardi, 2019).
IN CONTEXT
You might have heard recommendations about working at certain intensities as being in the “fatburning zone”, such as for a weight-loss goal or a body composition goal. It is true that your body
typically uses more fat than carbohydrates during lower-intensity exercise (about 60% of your
maximum heart rate). However, the total calories burned is what matters overall for weight loss.
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Exercising at higher intensities can burn more calories per minute and can keep metabolism elevated
for a longer post-exercise duration (Douglas, 2018). We’ll explore this concept further later in this
lesson. To make progress once you’re used to exercising consistently, it is beneficial to change up
your cardiovascular exercise to incorporate higher intensities, rather than always exercising at a
steady, lower-intensity state.
The transition between aerobic to anaerobic metabolism is marked by changes in the body. This transition goes
by multiple names, such as the anaerobic threshold, the lactate threshold, or the onset of blood lactate
accumulation (OBLA). Lactate is a byproduct of metabolic processes during exercise. At lower-intensity
exercise, your body can remove lactate as quickly as it is produced, but at higher intensities with anaerobic
activity, lactate builds up in the blood faster than the body can clear it. If you began to exercise at a steady pace,
for example, if you began running or biking, and then gradually increased the speed, the anaerobic threshold
would roughly correspond to the point where you are breathing heavily enough that you can only speak a word
or two (American Council on Exercise, 2020).

KEY CONCEPT
Your body’s energy systems are active during all types of physical activity—it is not like there is a specific
cutpoint or amount of time when one system completely shuts off and another system activates. However,
the extent of involvement of the energy systems depends on how intensely and for how long you are
exercising (Haff & Triplett, 2016).

TERMS TO KNOW
ATP (Adenosine Triphosphate)
An energy-carrying molecule found in all living things, capturing energy from the breakdown of food
and releasing it to fuel other body processes.
Aerobic Metabolism
A chemical process in which oxygen is used to make energy from carbohydrates.
Anaerobic Metabolism
The release of energy by partially breaking down glucose and glycogen but without combining oxygen.
Phosphagen System
One of the three energy pathways in the body, it is most active during very short-duration, high-intensity
activities lasting 1–30 seconds.
Anaerobic Glycolysis
One of the three energy pathways in the body, it is most active during higher intensities over longer
periods (30 seconds to 3 minutes).
Aerobic Glycolysis
One of the three energy pathways in the body, it is most active during longer-duration, lower-intensity
activities.
Anaerobic Threshold, Lactate Threshold, Onset of Blood Lactate Accumulation (OBLA)
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All terms used to describe the transition between aerobic to anaerobic metabolism, where lactate
accumulates in the blood faster than the body can clear it.
2. Adaptations to Cardiovascular Exercise
Our lungs and respiratory system deliver oxygen to the muscles in our body. When we inhale, oxygen moves
into the lungs, and then from the lungs, it is transported to our blood, where our cardiorespiratory system then
circulates the oxygen-rich blood throughout our body. When we are active, our muscles use oxygen from the
blood, and it is used to make ATP. When we are physically active, our muscles need more energy and more
oxygen. To provide more oxygen, our heart rate and breathing rate increase. Let’s look further at how the body
responds in the short-term to cardiovascular exercise, and what adaptations occur over the long-term of
consistent cardiovascular exercise.
2a. Cardiovascular System
When you begin a bout of cardiovascular exercise, your heart needs to work harder to keep up with the body’s
increased demand for energy. Your heart rate increases above its resting levels, where the higher intensity of
exercise, the higher the heart rate. Your stroke volume also increases, which is the amount of blood pumped
out of the heart during each beat.
The product of heart rate and stroke volume is termed cardiac output. Improved cardiac output is one longterm adaptation to cardiovascular exercise. This adaptation happens as the heart becomes more efficient at
pumping blood. If comparing a sedentary person to a person who has been doing cardiovascular exercise
consistently, the exerciser will have a lower heart rate but a higher stroke volume.

TERMS TO KNOW
Stroke Volume
The amount of blood pumped out of the heart during each beat.
Cardiac Output
The product of heart rate and stroke volume.
2b. Respiratory System
Just as your heart needs to work harder during cardiovascular exercise, your lungs also need to work harder so
that your body is supplied with enough oxygen. Your minute ventilation increases, which is the volume of air
breathed per minute. Additionally, your tidal volume increases, which is the amount of air inhaled and exhaled
with each breath.
Your respiratory system uses multiple muscles that assist both in inspiration (inhaling) and expiration (exhaling).
One long-term adaptation of these respiratory muscles is that they become stronger and more fatigue-resistant
(American Council on Exercise, 2020). The body’s tidal volume also improves, enhancing the ability to deliver
oxygen through deeper breathing during exercise (American Council on Exercise, 2020).
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
KEY CONCEPT
VO2 max is a measure of cardiorespiratory fitness and is the maximum capacity of the body to take in and
use oxygen during exercise. VO2 max is expressed in milliliters of oxygen per kilogram of body weight per
minute, or mL/kg/min.
An important long-term adaptation of cardiovascular training is that VO2 max improves. As the heart and
lungs become stronger and more efficient, the body can also take in and use oxygen more efficiently.
At rest, the body’s VO2 max is 3.5 mL/kg/min. VO2 max varies based on age, gender, fitness level, and
other factors, including weight. The kilograms, or kg in VO2 max takes weight into account.
The average inactive male has a VO2 max of 35–40 mL/kg/min, and the average inactive female’s VO2 max
is 27–30 mL/kg/min (Bacon et al., 2013). People who are very active in cardiovascular exercise, such as
athletes, can have VO2 maxes that are in the 70s or even higher. A sedentary person who starts consistent
exercise can have measurable improvements in their VO2 max in a few weeks (American Council on
Exercise, 2020).

TERMS TO KNOW
Minute Ventilation
The volume of air breathed per minute.
Tidal Volume
The amount of air inhaled and exhaled with each breath.
VO2 Max
A measure of cardiorespiratory fitness expressed as mL/kg/min; it is the maximum capacity of the body
to take in and use oxygen during exercise.
2c. Muscular System
In a basic sense, your body has two types of muscle fibers—type I and type II. Type I fibers are considered
aerobic or “slow twitch” as they use oxygen for energy and are most active during lower-intensity, longerduration activities like taking a hike or a long bike ride, running for miles, or swimming laps (McCall, 2015a).
Type II fibers are considered anaerobic or “fast twitch” because they do not use oxygen for energy. They have
only a limited supply of stored energy and function in short-duration, high-intensity activities such as sprinting
(McCall, 2015a). These muscles fatigue quickly since they do not store energy like type I fibers. This is part of
the reason why we cannot maintain high-intensity exercise for long durations.
The image below shows slow twitch muscle fibers, which are also called red fibers because they have a higher
blood supply due to using oxygen. Fast twitch muscle fibers are also called white fibers because they contain
less blood and therefore less oxygen.
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Page 43
IN CONTEXT
Research has identified that there are multiple subtypes of muscle fibers within these type I and type II
categories. For example, type IIa muscle fibers are still considered fast-twitch and anaerobic but
produce less force and are more fatigue resistant (McCall, 2015b). The proportions of type I and type II
fibers in your body are overall genetically determined and you cannot completely transform one type
to another with training (Haff & Triplett, 2016). However, the ‘intermediate’ types of muscle fibers can
make small shifts in adapting to training, so training at high intensities would improve the properties of
type IIa fibers, making them more effective at generating force and power.
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Your body’s adaptations to cardiovascular exercise in the muscular system will depend on the predominant
energy system that has been used. For a sprinter who primarily is training short, high-intensity bursts of energy,
the ability of type II fibers to produce anaerobic energy will be enhanced. A person like a marathon runner,
working mostly at lower intensities and longer durations, will improve their muscles’ ability to use oxygen.

TERMS TO KNOW
Type I Fibers
Muscle fibers that are aerobic; using oxygen for energy and most active during lower-intensity, longerduration activities.
Type II Fibers
Muscle fibers that are anaerobic; they do not use oxygen for energy and are most active during shortduration, high-intensity activities.
2d. Metabolism
An important concept in the body’s adaptation to exercise is how it affects metabolism. Recall from the lessons
on nutrition that metabolism encompasses the body’s caloric needs each day and is made up of your basal or
resting metabolism, the thermic effect of food, and physical activity.
When you exercise, you burn calories as part of the physical activity. However, once you finish your exercise,
your metabolism stays elevated, burning additional calories as your body works to help you recover and get
back to homeostasis. This is termed excess post-exercise oxygen consumption (EPOC), also called oxygen
debt. EPOC is most influenced by the intensity of exercise and can occur after cardiovascular exercise or
resistance exercise.
Even though high-intensity activity uses glucose as the primary fuel source rather than fat, high-intensity
exercise can have significant effects on calorie burning and weight loss due to EPOC. Research on EPOC and
metabolism demonstrated that after light to moderate exercise, EPOC lasted about 90 minutes, and then
metabolism returned to its normal resting rate. However, after high-intensity interval exercise, metabolism was
elevated for 24–72 hours due to EPOC (American Council on Exercise, 2020).
Another related implication for metabolic adaptations to cardiovascular exercise is improving the anaerobic
threshold. With higher-intensity training, a person’s anaerobic threshold can improve, where they can exercise
at higher intensities for a longer period. An average person will reach their anaerobic threshold at about 55% of
their VO2₂ max, but a well-trained person can be exercising at 80–85% of their VO2 max before reaching the
anaerobic threshold (American Council on Exercise, 2020).
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IN CONTEXT
In 2019, Eliud Kipchoge, a Kenyan long-distance runner, became the first person to run a marathon
(26.2 miles, or 42.195 km) in under 2 hours. To do this, he had to maintain a pace of 4 minutes and 35
seconds for each mile. In applying what you’ve learned in this lesson, Kipchoge not only had a high
VO₂ max, but a high anaerobic threshold since he was able to run at a high intensity for the entire
distance.

TERM TO KNOW
Excess Post-Exercise Oxygen Consumption (EPOC)
Also termed oxygen debt, it describes elevated metabolism that occurs after exercise as the body
works to regain homeostasis.

SUMMARY
In this lesson, you learned about fuel for cardiovascular exercise, where there are three main energy
systems that use ATP as fuel from the food we consume - the phosphagen system, anaerobic
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
Page 46
glycolysis, and aerobic glycolysis. These systems are active at all times, but one system predominates
based on the intensity and duration of the activity. You then learned about adaptations to
cardiovascular exercise across various body systems. The cardiovascular system becomes more
efficient with exercise as the heart’s stroke volume improves, and in the respiratory system, breathing
becomes more efficient, and respiratory muscles become more fatigue resistant. Improvements in
both these systems contribute to improved VO₂ max, allowing the body to use oxygen more effectively.
In the muscular system, adaptations will depend on the type of training - type I fibers will have
improved function with longer-duration, lower-intensity exercise, while type II fibers will have improved
function with short-duration, high-intensity exercise. Cardiovascular exercise affects metabolism by
enhancing EPOC, where a person can burn more post-exercise calories as the body works to regain
homeostasis.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING WITH CONTENT
ADAPTED FROM "NUTRITION" PROVIDED BY LUMEN LEARNING AT Lindshield, B. L. Kansas State University
Human Nutrition (FNDH 400) Flexbook. goo.gl/vOAnR. ACCESS FOR FREE AT LUMEN LEARNING BOUNDLESS
COURSES. LICENSED UNDER CREATIVE COMMONS ATTRIBUTION-SHAREALIKE 4.0 INTERNATIONAL.
The use of any CDC and United States Government materials, including any links to the materials on the CDC or
government websites, does not imply endorsement by the CDC or the United States Government of us, our
company, product, facility, service, or enterprise.
REFERENCES
American Council on Exercise (2020). The exercise professional’s guide to personal training: A client-centered
approach to inspire active lifestyles. Jo, S., Bryant, C.X., Dalleck, L.C., Gagliardi, C.S., and Green, D.J. (eds). ISBN:
9781890720766
Bacon, A. P., Carter, R. E., Ogle, E. A., & Joyner, M. J. (2013). VO2max trainability and high intensity interval
training in humans: a meta-analysis. PloS One, 8(9), e73182. doi.org/10.1371/journal.pone.0073182
Douglas, S. (2018). The fat-burning heart-rate zone is a myth: how exercise and weight loss really work.
Washington Post. www.washingtonpost.com/lifestyle/wellness/the-fat-burning-heart-rate-zone-is-a-myth-howexercise-and-weight-loss-really-work/2018/12/17/548ea93a-fc8e-11e8-83c0-b06139e540e5_story.html?
utm_term=.c5cc16a1f34c
Gagliardi, C. (2019). The three primary energy pathways explained. American Council on Exercise.
www.acefitness.org/fitness-certifications/ace-answers/exam-preparation-blog/3256/the-three-primary-energypathways-explained/
Haff, G., & Triplett, N. T. (2016). Essentials of strength training and conditioning (4th ed). National Strength and
Conditioning Association. Champaign, IL, Human Kinetics.
McCall, P. (2015a). 10 things to know about muscle fibers. American Council on Exercise.
www.acefitness.org/resources/pros/expert-articles/5411/10-things-to-know-about-muscle-fibers/
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
Page 47
McCall, P. (2015b). Muscle fiber types: fast-twitch vs. slow-twitch. American Council on Exercise.
www.acefitness.org/resources/pros/expert-articles/5714/muscle-fiber-types-fast-twitch-vs-slow-twitch/

TERMS TO KNOW
ATP (Adenosine Triphosphate)
An energy-carrying molecule found in all living things, capturing energy from the breakdown of food and
releasing it to fuel other body processes.
Aerobic Glycolysis
One of the three energy pathways in the body, it is most active during longer-duration, lower-intensity
activities.
Aerobic Metabolism
A chemical process in which oxygen is used to make energy from carbohydrates.
Anaerobic Glycolysis
One of the three energy pathways in the body, it is most active during higher intensities over longer
periods (30 seconds to 3 minutes).
Anaerobic Metabolism
The release of energy by partially breaking down glucose and glycogen but without combining oxygen.
Anaerobic Threshold, Lactate Threshold, Onset of Blood Lactate Accumulation (OBLA)
All terms used to describe the transition between aerobic to anaerobic metabolism, where lactate
accumulates in the blood faster than the body can clear it.
Cardiac Output
The product of heart rate and stroke volume.
Excess Post-Exercise Oxygen Consumption (EPOC)
Also termed oxygen debt, it describes elevated metabolism that occurs after exercise as the body works to
regain homeostasis.
Minute Ventilation
The volume of air breathed per minute.
Phosphagen System
One of the three energy pathways in the body, it is most active during very short-duration, high-intensity
activities lasting 1–30 seconds.
Stroke Volume
The amount of blood pumped out of the heart during each beat.
Tidal Volume
The amount of air inhaled and exhaled with each breath.
Type I Fibers
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Page 48
Muscle fibers that are aerobic; using oxygen for energy and most active during lower-intensity, longerduration activities.
Type II Fibers
Muscle fibers that are anaerobic; they do not use oxygen for energy and are most active during shortduration, high-intensity activities.
VO₂ Max
A measure of cardiorespiratory fitness expressed as mL/kg/min; it is the maximum capacity of the body to
take in and use oxygen during exercise.
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Cardiovascular Assessment
by Sophia

WHAT'S COVERED
In this lesson, you will compare methods of assessing the intensity of cardiovascular exercise as well as
methods of assessing cardiovascular fitness. Specifically, this lesson will cover the following:
1. Assessing Intensity Levels
1a. Talk Test
1b. Rating of Perceived Exertion (RPE) Scales
1c. Heart Rate Methods
2. Assessing Cardiovascular Fitness
2a. Field Tests
2b. VO2 Max Exercise Testing
1. Assessing Intensity Levels
As you’ve learned, the Physical Activity Guidelines provide the recommendation that adults do 150 minutes of
moderate-intensity exercise per week, 75 minutes of vigorous-intensity exercise per week, or an equivalent
combination of both moderate-intensity and vigorous-intensity exercise. Being able to assess your intensity
level of cardiovascular exercise can serve two purposes—it can ensure you are working hard enough to meet
the guidelines, and it can show improvements in your cardiovascular fitness over time.
1a. Talk Test
The talk test is a very simple way to assess cardiovascular exercise intensity and is based on the premise that
the more intense the exercise, the greater the increase in your heart rate and breathing rate. If you are
exercising at a moderate intensity, you can talk but not sing (Centers for Disease Control and Prevention,
2022a). If you are exercising at a vigorous intensity, you will not be able to talk in more than a few words without
needing to take a breath (Centers for Disease Control and Prevention, 2022a).
1b. Rating of Perceived Exertion (RPE) Scales
Rating of perceived exertion (RPE) scales are based on how hard you feel your body is working during exercise
based on heart rate, breathing rate, sweating, and muscle fatigue (Centers for Disease Control and Prevention,
2022b). There are two commonly used types of RPE scales—the Borg scale and the 0–10 scale.
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The Borg scale was developed by Swedish researcher Gunnar Borg and is a 6–20 scale. 6, the lowest number
on the scale, represents complete rest. 20, the highest number on the scale, represents the highest level of
maximal exertion. The numbers from 6 to 20 on the scale correlate with heart rate, where a general average
resting heart rate for an adult would be 60 beats per minute at rest, and 200 beats at the hardest they have
ever exercised (Williams, 2017). However, these heart rate correlations are only approximate, as heart rate can
depend on factors like age and cardiovascular fitness (Centers for Disease Control and Prevention, 2022b).
In general, moderate-intensity activity corresponds with 12 to 14 on the Borg scale, where it feels ‘somewhat
hard’ (Centers for Disease Control, 2022b). Vigorous-intensity activity corresponds with 14 to 16 on the Borg
scale, or ‘hard’.
Borg 6–20 RPE Scale
Score
6
Level of Exertion
No exertion (Rest)
7
8
9
Very light
10
11
Light
12
13
Somewhat hard
14
15
Hard
16
17
Very hard
18
19
Extremely hard
20
Maximal exertion
Another type of RPE scale was further developed by Gunnar Borg and ranges from 0 to 10 instead (Williams,
2017). Like the 6–20 scale, the 0 represents rest and the 10 represents maximal exertion. Moderate-intensity
exercise corresponds to an RPE of 3–4, and vigorous-intensity exercise corresponds with an RPE of 5–7 (Zuhl,
2020).
0–10 RPE Scale
Score
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Level of Exertion
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0
No exertion (Rest)
1
Very easy
2
Easy
3
Moderate
4
Somewhat hard
5
Hard
6
7
Very hard
8
9
Very, very hard
10
Maximal effort
People new to exercise may perceive that most cardiovascular activity feels hard, but accurately monitoring
how the body feels improves with practice. If a person wants to meet the Physical Activity Guidelines but only
describes their breathing and fatigue as “very light,” they will want to increase their intensity to reach moderate
levels (Centers for Disease Control and Prevention, 2022b). As a person’s cardiovascular fitness improves with
consistent exercise, they can expect that activities previously rated as “somewhat hard” might feel “moderate”
or even “easy.”

TERM TO KNOW
Rating of Perceived Exertion (RPE) Scales
A way of estimating cardiovascular exercise intensity based on self-assessment of how hard you are
working, including heart rate, breathing rate, sweating, and muscle fatigue.
1c. Heart Rate Methods
Heart rate methods are also based on the premise that heart rate increases with the intensity of cardiovascular
activity. There are two main heart rate methods—estimated maximum heart rate, and heart rate reserve (HRR),
also called the Karvonen method.
Estimated maximum heart rate takes an individual’s age and subtracts it from 220. In theory, this number is their
maximum heart rate. According to the Centers for Disease Control and Prevention (2022c), moderate-intensity
physical activity is between 64 to 76% of your maximum heart rate, and vigorous-intensity physical activity is
between 77 to 93% of your maximum heart rate.
EXAMPLE Elizabeth is a 50-year-old woman who wants to determine her heart rate ranges for
moderate-intensity activity.
Subtracting 50 from 220 equals 170 beats per minute. This is Elizabeth’s estimated maximum heart rate.
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She then multiplies 170 by the bottom and top numbers in the moderate intensity range.
170 x 0.64 = 109 beats per minute
170 x 0.76 = 120 beats per minute
So, exercising at a moderate intensity for Elizabeth will require that she stay between 109 and 120 beats per
minute.
Heart rate reserve (HRR), also called the Karvonen method for Dr. Martti Karvonen, a Finnish researcher, tends
to be a more accurate estimate of intensity than the estimated maximum heart rate. This is because it takes
resting heart rate into account. An individual who has a high level of cardiovascular fitness will typically have a
lower resting heart rate than a sedentary person (Ignaszewski et al., 2017).
The Karvonen method still starts with subtracting a person’s age from 220 as an estimate of maximum heart
rate. However, then the person’s resting heart rate is subtracted from the maximal heart rate. This is termed
heart rate reserve (HRR). To obtain an intensity range, multiply the bottom and top number of the desired range
by the HRR, and then add the resting heart rate back into each result. In the Karvonen method, 40–60% of HRR
is moderate-intensity activity, and 60–90% of HRR is vigorous-intensity activity (Ignaszewski et al., 2017).
EXAMPLE Using our above example with Elizabeth, a 50-year-old woman:
Elizabeth’s maximum heart rate = 220–50 = 170.
Elizabeth measures her resting heart rate at 70, so 170–70 = 100.
She can now multiply 100 by 40% and by 60% per the moderate-intensity range.
100 x 0.40 = 40
100 x 0.60 = 60
Now she needs to add her resting heart rate back to each of these numbers.
40 + 70 = 110
60 + 70 = 130
Exercising at a moderate intensity for Elizabeth will require that she stay between 110 and 130 beats per
minute.

TRY IT
Now it’s your turn to apply the calculations for the estimated maximum heart rate and heart rate reserve.
Mason is a 19-year-old male who plays in recreational college sports leagues with a resting heart rate of 58.
He wants to perform vigorous-intensity exercise (77–93% of maximum heart rate).
Calculate Mason’s heart rate range using estimated maximum heart rate.
+
220 − 19 = 201, which is Mason’s maximum heart rate.
Multiply this number by the bottom and top number of the intensity range:
201 x 0.77 = 154.77 (Round to 155)
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201 x 0.93 = 186.93 (Round to 187)
Exercising at a vigorous intensity for Mason using estimated maximum heart rate will require that he
stay between 155 and 187 beats per minute.
Calculate Mason’s heart rate range using heart rate reserve (HRR) or the Karvonen method.
+
220 − 19 = 201, which is Mason’s maximum heart rate.
Remember that in HRR, we now also need to subtract resting heart rate. 201 − 58 = 143
Multiply this number by the bottom and top number of the intensity range:
143 x 0.77 = 110.11 (Round to 110)
143 x 0.93 = 132.99 (Round to 133)
Now we need to add Mason’s resting heart rate back to each number.
110 + 58 = 168
133 + 58 = 191
Exercising at a vigorous intensity for Mason using heart rate reserve (HRR); or Karvonen, will require
that he stay between 168 and 191 beats per minute.

KEY CONCEPT
Many types of wearable fitness devices, like smartwatches, can measure your heart rate for you. However,
you can also measure your heart rate easily by taking your pulse. The radial pulse at the wrist is a common
site. You can feel the radial pulse on the artery of the wrist in line with the thumb. Place the tips of the index
and middle fingers over the artery and press lightly. Do not use your thumb as the thumb has its own pulse
and your measurement could be inaccurate. Take a full 60-second count of the heartbeats or take for 30
seconds and multiply by 2. Start the count on a beat, which is counted as “zero.” If you are measuring your
resting heart rate to use in the Karvonen method, it will be most accurate if you measure it first thing after
waking up.
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
TERMS TO KNOW
Estimated Maximum Heart Rate
A method of assessing cardiovascular exercise intensity; it requires subtracting the person’s age from
220 and using that number as the maximum heart rate.
Heart Rate Reserve (HRR); Karvonen Method
A method of assessing cardiovascular exercise intensity; it takes a person’s resting heart rate into
account along with their estimated maximum heart rate by subtracting their age from 220.
2. Assessing Cardiovascular Fitness
Assessing an individual’s cardiovascular fitness can be done in many ways. Most cardiovascular assessments
provide an estimate or a measurement of the individual’s VO₂ max. A higher VO₂ max is directly associated with
higher cardiovascular fitness.
2a. Field Tests
Field tests are suitable in almost any setting and only require a measured course where someone can walk or
run. While there are multiple kinds of cardiovascular field tests, the following are some of the most common
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examples.
Rockport Fitness Walking Test: Walking 1 mile as quickly as possible, where time to complete the mile is
measured and post-walk heart rate is measured. This test is good for older adults or people who are not
regularly exercising (Housh et al., 2009).
12-Minute Run Test: The person covers as much distance as possible in the 12 minutes. The total distance is
measured in meters, where more distance means a higher estimated VO₂ max (Housh et al., 2009). This
test is good for people who can comfortably run for most if not all of the 12 minutes.
1.5-Mile Run Test: The person covers the 1.5 miles as quickly as possible, where a faster pace means a
higher estimated VO₂ max, and the total time is measured in minutes. This test is also good for people who
can comfortably run for the entire distance.
The PACER (Progressive Aerobic Cardiovascular Endurance Run) test involves a series of shuttle runs,
typically 20 meters apart (Mahar et al., 2011). The person has a set amount of time to complete each shuttle
run where the time gradually decreases, so they must run faster and faster to keep up. This test is also
known as the multistage fitness test, or ‘beep test’ (named because the test typically uses audio with a
‘beep’ that signals turning around for the next shuttle run). This test is good for people who already have a
foundation of cardiovascular fitness and want to train their ability to increase speed even while fatigued. It
is often used in sports like soccer or rugby.

LEARN MORE
At Topend Sports Network, you can search for tests by name or browse other types of cardiovascular tests,
including the directions on how to conduct them accurately. The page for each type of test typically
provides an equation or ranking where you can estimate your VO₂ max from your test results, or compare
your values to norms to gauge your fitness level.
2b. VO2 Max Exercise Testing
The most accurate way to measure someone’s cardiovascular fitness is through directly measuring their VO2
max. This is considered the “gold standard” in cardiovascular testing, where field tests are only an estimate. In a
maximal VO2 test, the person exercises on a treadmill or a special stationary bike, called a cycle ergometer,
while the difficulty increases in stages. There are multiple types of protocols for how often or quickly the stages
increase. The increase in difficulty on a treadmill is either from increasing the incline, the speed, or both. The
increase in difficulty on a cycle ergometer is either from increasing the speed, the resistance that the person
must pedal against, or both. This type of test requires special lab equipment called a metabolic cart. The
person exercising wears a mask where the metabolic cart takes measurements like heart rate and breathing
rate during exercise.
For very fit people or well-trained athletes, a VO2 max test can push them to their true maximum, where the test
eventually reaches such a high intensity that they cannot continue. The point when they stop is the
measurement of their VO2 max. In other contexts, submaximal VO2 tests are done, where a metabolic cart is
still used, but the person is not pushed to their limit, and the resulting measurement is an estimate of what their
maximum VO2 would be.
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
SUMMARY
In this lesson, you learned various methods for assessing intensity levels of cardiovascular exercise. In
the talk test, moderate-intensity exercise means you can talk but not sing, and vigorous-intensity
exercise means you can only speak in a few words before needing a breath. Rating of perceived
exertion (RPE) scales provide a subjective ranking based on factors like heart rate and fatigue for how
hard you feel you’re working. The main heart rate methods are estimated maximum heart rate and
heart rate reserve (HRR), also known as the Karvonen method. Assessing cardiovascular fitness can be
done in two main ways—through field tests, which do not require special equipment besides a
measured distance, and graded exercise testing, which requires special equipment like a metabolic
cart and can provide a direct measurement of VO₂ max.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE. Markup: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING.
PLEASE SEE OUR TERMS OF USE.
REFERENCES
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
Page 57
Centers for Disease Control and Prevention (2022a). Measuring physical activity intensity.
www.cdc.gov/physicalactivity/basics/measuring/index.html
Centers for Disease Control and Prevention (2022b). Perceived exertion – Borg rating of perceived exertion
scale. www.cdc.gov/physicalactivity/basics/measuring/exertion.htm
Centers for Disease Control and Prevention (2022c). Target heart rate and estimated maximum heart rate.
www.cdc.gov/physicalactivity/basics/measuring/heartrate.htm
Housh, T. (2009). Physical fitness laboratories on a budget. Arizona: Holcomb Hathaway. ISBN: 9781890871901
Ignaszewski, M., Lau, B., Wong, S., & Isserow, S. (2017). The science of exercise prescription: Martti Karvonen
and his contributions. BC Med J, 59(1), 38-41. bcmj.org/articles/science-exercise-prescription-martti-karvonenand-his-contributions
Mahar, M. T., Guerieri, A. M., Hanna, M. S., & Kemble, C. D. (2011). Estimation of aerobic fitness from 20-m
multistage shuttle run test performance. American Journal of Preventive Medicine, 41(4), S117-S123.
doi.org/10.1016/j.amepre.2011.07.008
Robert Wood, "Topend Sports | The Sports Fitness, Nutrition and Science Resource." Topend Sports Website,
January 2001, www.topendsports.com/index.htm, Accessed 31 August 2023.
www.topendsports.com/testing/tests/index.htm
Williams, N. (2017). The Borg rating of perceived exertion (RPE) scale. Occupational Medicine, 67(5), 404-405.
doi.org/10.1093/occmed/kqx063
Zuhl, M. (2020). Tips for monitoring aerobic exercise intensity. American College of Sports Medicine.
www.acsm.org/docs/default-source/files-for-resource-library/exercise-intensity-infographic.pdf

TERMS TO KNOW
Estimated Maximum Heart Rate
A method of assessing cardiovascular exercise intensity; it requires subtracting the person’s age from 220
and using that number as the maximum heart rate.
Heart Rate Reserve (HRR); Karvonen Method
A method of assessing cardiovascular exercise intensity; it takes a person’s resting heart rate into account
along with their estimated maximum heart rate by subtracting their age from 220.
Rating of Perceived Exertion (RPE) Scales
A way of estimating cardiovascular exercise intensity based on self-assessment of how hard you are
working, including heart rate, breathing rate, sweating, and muscle fatigue.
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Resistance Training Principles
by Sophia

WHAT'S COVERED
In this lesson, you will learn about the main principles involved in resistance training. Specifically, this
lesson will cover:
1. Muscle Fiber Types and Resistance Training
2. Specificity
3. Overload
4. Reversibility
5. Progression
6. Individualization
1. Muscle Fiber Types and Resistance Training
In the lesson titled “Cardiovascular Training Principles”, you learned about type I, aerobic ‘slow twitch’ fibers,
and type II, anaerobic ‘fast twitch’ fibers. This concept is also relevant to resistance training. Recall that type I
fibers are suited for endurance-type activities by being more fatigue resistant and able to work at lower
intensities for long periods of time. Conversely, type II fibers are used in high-intensity activities of short
duration. Everyone has both type I and type II muscle fibers in their bodies, though the proportion can differ
based on genetics and training. Certain muscles in your body have higher densities of one type than the other.
EXAMPLE The muscles that support your posture all day, such as muscles along the spine, have higher
densities of type I fibers, since they need to work at low levels constantly to keep you upright. Two
examples of muscles with higher densities of type II fibers are the triceps and gastrocnemius. These are
recruited in activities with higher speed and power, such as throwing or jumping.
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The concept of fiber types is relevant to resistance training principles like specificity, as you will see shortly,
because the adaptations will depend on the primary fiber types and energy system used. Type II fibers are not
only responsible for producing large amounts of force, but they also have a greater cross-section than type I
fibers and are responsible for hypertrophy, or increased muscle size.

TERM TO KNOW
Hypertrophy
Increased muscle size.
2. Specificity
Remembering back to the lessons on stress, recall that the body can handle stress through adaptation, as long
as the stressor isn’t too severe or too chronic. Since exercise is a type of stress, the body can adapt to this
stress and change positively in becoming more fit. The principle of specificity means that the body’s
adaptations depend on what the exercise stress is and how it is applied (American Council on Exercise, 2020).
Specificity is often further described by the acronym SAID, or Specific Adaptations to Imposed Demands.
If a person wants to get stronger and build more muscle, they will need to do resistance training, not just
cardiovascular exercise. The specificity principle applies to any type of exercise, not just resistance training. If a
person wants to become faster at sprinting, they will need to regularly incorporate sprint training at high
intensities. This goal will not be achieved with something like long moderate-intensity running, because the
body will not adapt in the same way.
IN CONTEXT
Based on what we’ve learned about fiber types and specificity, if a person has a goal for hypertrophy,
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muscle definition, or building strength, they will need to do resistance training that mainly activates
type II fibers (McCall, 2015a). This may include lifting heavy weights or doing explosive power-based
movements (McCall, 2015b). In applying the principle of specificity to a goal for muscular endurance,
this is best achieved through lighter weights or bodyweight movements and higher repetitions, or
circuit training, where a person goes from one exercise to the next over multiple exercises with little
to no rest (McCall, 2015b).

TERMS TO KNOW
Specificity
A principle of resistance training where the body’s adaptations to exercise depend on the nature of the
stress and how it is applied.
Circuit Training
A form of training where a person goes from one exercise to another over multiple exercises with little
to no rest.
3. Overload
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Overload dictates that a person needs to continue implementing changes in their training if they want to
continue seeing fitness gains (Newell, 2015). A person who begins a resistance training program will often see
rapid gains in their first few weeks or months. These gains are mainly caused by improvements in muscular
coordination where the muscles learn to work together efficiently (Delavier & Gundill, 2011). However, gains will
decrease or hit a plateau if the resistance training program is not structured to continue overloading the
muscles, which is called diminishing returns. If a person always does the same exercise routine, they will not
see any results beyond what they’ve already achieved.
IN CONTEXT
The concept of diminishing returns also applies to people who already have a high level of fitness or
are elite athletes. If you consider a world-class sprinter or weightlifter, they are already at or near their
pinnacle with speed or strength. Therefore, it’s not feasible to continue making significant
improvements—any improvements will be relatively small.

TERMS TO KNOW
Overload
A principle of resistance training stating that changes need to continue in a training program for fitness
to improve.
Diminishing Returns
A principle of resistance training noting that fitness gains will decrease or plateau if overloading the
muscles does not continue.
4. Reversibility
Related to the body adapting to exercise stress and becoming more fit, the opposite is also true. If a person
stops exercising, their body will eventually lose the adaptations it has made. This principle is called reversibility,
which you can also think of as “use it or lose it”. The loss of adaptations due to the reversibility is described as
detraining. Detraining can occur across any type of exercise. A runner who gets injured and cannot run will
experience decreased VO₂ max, or a weightlifter who takes time away from their training program will lose
some strength and muscle mass. Flexibility can decrease in major joints of the body with a few weeks of
inactivity as well (Mujika & Padilla, 2000).
However, your body does not lose all adaptations after just a few days of not exercising, like a busy weekend or
going on vacation. Short-term detraining is considered anything 4 weeks or less, while long-term detraining is
anything longer than 4 weeks (Mujika & Padilla, 2000). Research generally shows that a week or two without
training does not typically result in significant fitness decreases (Mujika & Padilla, 2000). In fact, strength can be
maintained for up to 4 weeks (Haff & Triplett, 2016). Aerobic adaptations, like VO₂ max, seem to be more
sensitive to reversibility (Haff & Triplett, 2016).
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IN CONTEXT
A study sponsored by the American Council on Exercise put inactive adults through a 13-week exercise
program that included both cardiovascular training and resistance training. After the 13 weeks, one
group continued their exercise for 4 more weeks, and the other group stopped doing any structured
exercise for 4 weeks. The second group experienced their fitness decreasing back to where it was
before the study, essentially erasing their progress (Nolan et al., 2019).
One way to reduce the effects of reversibility and detraining is to continue doing at least some small
amount of physical activity. If you know that you will be taking extended time away from your exercise
routine due to travel, vacation, or busy life circumstances, see where you can fit in short bouts of
movement, like a brisk walk or a few minutes of bodyweight movements (Green, 2017). Some
movement is better than none!

TERMS TO KNOW
Reversibility
“Use it or lose it”, the principle of resistance training that states the body will lose exercise adaptations
if no stress is placed on it.
Detraining
A principle of resistance training that describes the loss of adaptations that occur due to reversibility.
5. Progression
Progression is how variables in a resistance training program are manipulated over time to reach training goals
and avoid overtraining (Kraemer & Ratamess, 2004). Progression and overload are directly related because
progression refers to the stepwise increases that occur over time to create overload (Newell, 2015). In a future
lesson, we’ll talk more about how you might implement progression for your own exercise program.
EXAMPLE Von can back squat 205 lbs (93 kg) for 6 repetitions. He wants to get stronger, so the next
time he trains, he increases the weight by 5%, which is 215 lbs (97.5 kg). This weight increase is how Von is
applying overload in his session. To apply progression over the long term, Von could continue to overload
by increasing his weight by 5% every other week for the next four weeks.
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IN CONTEXT
Based on information from the National Strength and Conditioning Association, there are multiple
ways to apply the principles of overload and progression to resistance training (Haff & Triplett, 2016).
Which ones to use depends on many factors, like an individual’s training experience or goals.
Increase load, such as using more weight on a weight machine, a barbell, or choosing heavier
dumbbells. Like the example with Von above, a general guideline is to increase the weight by 5%
once the person gets to the end of the repetition range for their goals. We’ll discuss resistance
training for specific goals in a future lesson.
Increasing the number of training sessions per week. While the Physical Activity Guidelines
recommend 2 days, this is the minimum for health. People training for specific goals of building
strength or increasing muscle mass will benefit from more frequent sessions to reach their goals.
Adding sets. A person new to resistance training might do a single set for their first few weeks,
and then progress to doing two sets.
Decreasing the length of the rest period between exercises. In some contexts of resistance
training, adequate rest is essential so that muscles can perform at their peak. However, in
resistance training with lighter weight and higher reps, or circuit training, gradually decreasing
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rest can help muscles adapt to being more fatigue resistant. A circuit might start with 30 seconds
of rest between exercises and progress over time to only 10 seconds.
Exercise selection. A person might choose a different exercise for the sake of variety in working
the same muscle group. Another person might choose a more complex or challenging exercise
once they have mastered good form on a simpler one. We’ll talk more about types of resistance
training exercises in a future lesson.

TERM TO KNOW
Progression
A principle of resistance training, it describes how variables in a resistance training program are
manipulated over time to reach training goals and avoid overtraining.
6. Individualization
The principle of individualization states that training should be modified to account for an individual’s unique
abilities, goals, and characteristics. Factors in individualization include current fitness, age, training history, and
even psychological factors like confidence (Kasper, 2019). Medical conditions or previous injuries also factor
into individualization since not all exercises are suitable for all people.
EXAMPLE The training program for a 75-year-old inactive woman with arthritis will likely look very
different from the training program for a 22-year-old female college student, even if both have the same
general goal like building endurance or building strength.
A closely related concept to individualization is individual differences, meaning that not everyone responds to
the same training stimulus in the same way. Since the proportion of muscle fiber types is based on genetics, a
person with more type II fibers has a greater potential for hypertrophy than a person with more type I (American
Council on Exercise, 2020). Males have a greater potential for muscle mass and overall strength than females,
in part because they have larger muscle fiber cross-sectional area and have higher levels of muscle-building
hormones, such as testosterone and growth hormone (Schoenfeld et al., 2010). Older people can still gain
muscle and strength with training but have less hypertrophy potential because these hormone levels decrease
with age (American Council on Exercise, 2020).

TERM TO KNOW
Individualization
A principle of resistance training, it explains that training should be modified to account for an
individual’s unique abilities, goals, and characteristics.

SUMMARY
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In this lesson, you first learned about muscle fiber types and resistance training. This knowledge
directly relates to principles of resistance training since type I and type II fibers have different functions
and therefore require different exercise stresses depending on a person’s goals. The principle of
specificity explains this further by stating that the body will adapt to the specific demands placed on it.
The principle of overload dictates that continued change is needed in a resistance training program for
these adaptations to occur. If a person stops exercising, they will experience reversibility, where the
fitness gains they have made decrease or disappear since the body no longer has stress placed on it
to adapt. Progression explains how variables in a resistance training program are manipulated to
provide overload and continue progress. The premise of individualization is that a training program
needs to take into account individual factors like fitness level or age and the fact that not everyone
responds to the same type of exercise in the exact same way.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE. Markup: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING.
PLEASE SEE OUR TERMS OF USE.
REFERENCES
American Council on Exercise (2020). The exercise professional’s guide to personal training: A client-centered
approach to inspire active lifestyles. Jo, S., Bryant, C.X., Dalleck, L.C., Gagliardi, C.S., and Green, D.J. (eds). ISBN:
9781890720766
Delavier, F., & Gundill, M. (2011). The strength training anatomy workout: starting strength with bodyweight
training and minimal equipment. Human Kinetics.
Green, D. (2017). Reversing reversibility: how to help clients get back on track. American Council on Exercise.
www.acefitness.org/continuing-education/certified/march-2017/6268/reversing-reversibility-how-to-helpclients-get-back-on-track/
Haff, G., & Triplett, N. T. (2016). Essentials of strength training and conditioning (4th ed). National Strength and
Conditioning Association. Champaign, IL, Human Kinetics.
Kasper, K. (2019). Sports training principles. Current Sports Medicine Reports, 18(4), 95-96.
doi.org/10.1249/JSR.0000000000000576
Kraemer, W. J., & Ratamess, N. A. (2004). Fundamentals of resistance training: progression and exercise
prescription. Medicine and Science in Sports and Exercise, 36(4), 674–688.
doi.org/10.1249/01.mss.0000121945.36635.61
McCall, P. (2015a). 10 things to know about muscle fibers. American Council on Exercise.
www.acefitness.org/resources/pros/expert-articles/5411/10-things-to-know-about-muscle-fibers/
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
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McCall, P. (2015b). Muscle fiber types: fast-twitch vs. slow-twitch. American Council on Exercise.
www.acefitness.org/resources/pros/expert-articles/5714/muscle-fiber-types-fast-twitch-vs-slow-twitch/
Mujika, I., & Padilla, S. (2000). Detraining: loss of training-induced physiological and performance adaptations.
Part I: short term insufficient training stimulus. Sports Medicine, 30, 79-87. doi.org/10.2165/00007256200030020-00002
Newell, J. (2015). The basics of exercise science (part 5). American Council on Exercise.
www.acefitness.org/fitness-certifications/ace-answers/exam-preparation-blog/5371/the-basics-of-exercisescience-part-5/
Nolan, P.B., Keeling, S.M., Robitaille, C.A., Buchanan, C.A., Dalleck, L.C., & Green, D.J. (2019). How fast does
fitness fade? American Council on Exercise.
acewebcontent.azureedge.net/March2019/ACE_FitnessFadeStudy.pdf
Schoenfeld, B. J. (2010). The mechanisms of muscle hypertrophy and their application to resistance training.
Journal of Strength and Conditioning Research, 24(10), 2857–2872. doi.org/10.1519/JSC.0b013e3181e840f3

ATTRIBUTIONS
Major muscles of the body. | Author: OpenStax | License: CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL
https://creativecommons.org/licenses/by/4.0/

TERMS TO KNOW
Circuit Training
A form of training where a person goes from one exercise to another over multiple exercises with little to
no rest.
Detraining
A principle of resistance training that describes the loss of adaptations that occur due to reversibility.
Diminishing Returns
A principle of resistance training noting that fitness gains will decrease or plateau if overloading the
muscles does not continue.
Hypertrophy
Increased muscle size.
Individualization
A principle of resistance training, it explains that training should be modified to account for an individual’s
unique abilities, goals, and characteristics.
Overload
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A principle of resistance training stating that changes need to continue in a training program for fitness to
improve.
Progression
A principle of resistance training, it describes how variables in a resistance training program are
manipulated over time to reach training goals and avoid overtraining.
Reversibility
“Use it or lose it”, the principle of resistance training that states the body will lose exercise adaptations if
no stress is placed on it.
Specificity
A principle of resistance training where the body’s adaptations to exercise depend on the nature of the
stress and how it is applied.
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Resistance Training Assessment
by Sophia

WHAT'S COVERED
In this lesson, you will compare methods of assessing the intensity of resistance training exercises, as
well as comparing methods of assessing muscular fitness. Specifically, this lesson will cover the
following:
1. Assessing Intensity Levels
1a. Percent of 1-RM
1b. Rating of Perceived Exertion (RPE) Scales
2. Assessing Muscular Fitness
2a. Muscular Endurance Tests
2b. Muscular Strength Tests
1. Assessing Intensity Levels
In the lesson titled “Cardiovascular Assessment,” we talked about different ways to assess intensity, which can
help provide a baseline of where your current fitness is and demonstrate fitness improvements over time.
Similarly, there are a few different ways to assess intensity levels for resistance training.
1a. Percent of 1-RM
A common method to assess intensity for resistance training is to use a percent of 1-repetition maximum, also
known as 1-RM. A 1-RM is the heaviest amount of weight that can be lifted for a single repetition in a given
movement. Testing 1-RM is typically done with either barbell movements, such as bench press, back squat, or
deadlift; or with weight machines, such as a leg press. With these methods, the weight can be gradually
increased until a person is at the maximum amount they can lift. (We’ll talk about the process for testing 1-RM
later in this lesson, but for now, understand that not everyone needs to undergo maximal testing to find their
exact 1-RM).
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Based on a person’s goal, there are percent ranges of 1-RM that are most suitable. As you can see from the
table below, working at a lower percentage of 1-RM allows more repetitions, while a higher percentage is more
intense and fewer reps can be completed.
Training Goal
Intensity
Repetitions
Muscular endurance
60–70% of 1-RM
12 or more
Muscular hypertrophy
70–80% of 1-RM
6–12
Muscular strength
80–90% of 1-RM
6 or less
Using the right percent ranges for a specific goal will best create adaptations in the body toward that goal. This
is an application of the principle of specificity that you learned about in the lesson titled “Resistance Training
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Principles”.

TERM TO KNOW
1-Repetition Maximum (1-RM)
The heaviest amount of weight that can be lifted for a single repetition in a given movement.
1b. Rating of Perceived Exertion (RPE) Scales
You previously learned about RPE scales in the lesson titled “Cardiovascular Assessment”, and they can also be
applied to resistance training. Just like using the 0–10 RPE scale for cardiovascular assessment, a person can
use this to subjectively assess how difficult or intense their resistance training is feeling that day. This method
can be good for beginners or people doing resistance training where there isn’t a clear numerical load, like
doing bodyweight movements or working with resistance bands.
EXAMPLE Shay does resistance training twice a week by doing a circuit of bodyweight movements.
After doing the circuit for 3 weeks, Shay notices that she is rating the circuit’s intensity as lower on the RPE
scale. It is feeling easier, indicating that Shay’s fitness is improving. Shay will eventually want to consider
using the FITT principle to keep progressing, such as choosing different exercises or reducing the rest
time.
One variation on RPE scales that is specific to resistance training is a 1–10 scale based on repetitions in reserve.
On this scale, 10 represents a person’s 1-RM where they could not do any more load or repetitions, and 1–4
represents extremely light intensity with little to no effort.
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IN CONTEXT
Resistance training doesn’t just require the work of your muscles, it also requires the input of your
central nervous system to coordinate movements and direct muscle fibers to fire appropriately.
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Therefore, if your central nervous system is not well-rested—like if you’re under a lot of stress, very
tired, or haven’t recovered well from your last exercise session—the weight you lift will seem heavier
than normal (Delavier & Gundill, 2011). Using RPE can be helpful in highlighting if this is the case. For
example, if 8 reps at a given weight normally feels like a 7 on the RPE scale, but today it feels like an
8, that may indicate that the body needs more recovery.
2. Assessing Muscular Fitness
There are various ways to assess muscular fitness, where the most appropriate choice depends on factors like
goals and resistance training experience. For some types of tests, like 1-RM, equipment access is also a factor
since this requires having access to barbells or weight machines.
In cardiovascular fitness assessment, doing one type of test is usually sufficient. However, in assessing muscular
fitness, choosing a single test has limitations because it is only assessing some of the body’s muscle groups.
Ideally, a well-rounded muscular fitness assessment will include multiple tests for most, if not all, major muscle
groups.
2a. Muscular Endurance Tests
Muscular endurance tests assess the ability of muscles to resist fatigue. There are many types of muscular
endurance tests, but some of the most common ones involve performing as many repetitions as possible in 1
minute, with common choices including squats, pushups, and sit-ups (Vaara et al., 2012). Testing these can be
done almost anywhere and only requires a way to time the 1 minute and a comfortable surface for the sit-ups
and pushups, such as a mat or large towel.

WATCH
If you want to assess the muscular endurance of your abdominal muscles, this video will walk you through a
1-minute test and provide guidelines for proper form.
Muscular endurance can also be assessed with isometric movements, where the body remains in a static,
motionless position, such as in holding a plank (Edwards, 2017). Many types of resistance training movements
involve concentric muscle action where the muscle shortens, and eccentric muscle action where the muscle
lengthens (Edwards, 2017).
EXAMPLE In a sit-up, your abdominals concentrically contract (shorten) as you perform the upward
portion, and then eccentrically contract (lengthen) as you lower your torso back down to the floor.
However, in isometric movements, there are no muscles shortening or lengthening, though work is still being
performed. Besides a plank, other isometric movements include side planks, wall sits, and hanging from a pullup bar. These test muscular endurance by assessing how long the isometric position can be held before
fatiguing.
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Another way to assess muscular endurance is to perform a weighted movement at a lower percent of 1-RM for a
set amount of time or a specific tempo. The YMCA bench press test is one example where males use 80
pounds (36.3 kg) and females use 35 pounds (15.9 kg). A metronome is set to 60 beats per minute, where the
person tested presses the weight up on one beat and lowers the weight on the next beat. They maintain this
cadence as long as they can, where the test stops when they can no longer perform the bench press at the
metronome’s tempo (Haff & Triplett, 2016).
IN CONTEXT
The National Football League (NFL) uses an event called a Combine to test the muscular fitness (and
other abilities) of college players. One event in the NFL Combine is the 225-pound bench press,
where prospective NFL athletes complete as many repetitions as possible until fatigue (National
Football League, 2016).

TERMS TO KNOW
Isometric
A type of muscular work where the body remains in a static, motionless position.
Concentric
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A type of muscular work where the working muscle shortens.
Eccentric
A type of muscular work where the working muscle lengthens.
2b. Muscular Strength Tests
Muscular strength tests assess the ability of muscles to produce their maximal force. The most direct way of
assessing muscular strength is through testing 1-RM. However, another testing option allows an estimation of 1RM from a submaximal weight that is lifted for multiple repetitions.
1-RM testing is most appropriate for individuals who are experienced with weightlifting and have a general idea
of what their approximate 1-RM might be. It is not suitable for beginners and should not be done if someone is
unfamiliar with the proper form and technique for the lift. A true 1-RM test involves pushing your muscles to the
limit on the maximum load they can lift, so proper safety procedures must be followed, and many types of lifts
require having another person act as a spotter, assisting in lifting the weight if it becomes too heavy.
IN CONTEXT
The following describes the procedure for testing 1-RM, according to information from the American
Council on Exercise (Jimenez, 2018) and the National Strength and Conditioning Association (Haff &
Triplett, 2016):
The person being tested should do some type of light, dynamic, movement-specific warm-up for
at least 3–5 minutes.
Perform a warm-up set of 5–10 repetitions at about 50% of the estimated 1-RM, then rest for 1
minute.
Increase the weight to 70–75% of the estimated 1-RM and perform 3–5 repetitions, then rest for 2
minutes.
Increase the weight to 85–90% of the estimated 1-RM and perform 2–3 repetitions, then rest for 2
minutes.
Continue with increments of loading and single repetitions, resting for at least 2 minutes after
each attempt.
The amount of weight increase will depend on the nature of the lift, but ideally the individual
should reach their 1-RM in 3 to 5 attempts. Taking more attempts than this may fatigue the muscles
before they are truly at their maximum force generation.
An estimate of 1-RM can be derived from submaximal testing of completing 10 repetitions or less. This
information can then be used in a prediction equation to estimate 1-RM. An estimated 1-RM type of test is good
for someone who has built experience with weightlifting but may not need or want to test their true 1-RM.
Individuals with general fitness goals or muscular endurance goals do not typically need to directly test their 1RM. However, recall from the chart earlier in this lesson that the recommended intensity in training for muscular
endurance is 60-70% of 1-RM. Therefore, having an estimate of 1-RM is helpful even if someone is not
specifically training for strength.
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
WATCH
The leg press is a commonly used method to test lower-body muscular strength. It can be a safer option
than a movement like a barbell back squat since it does not require a spotter and most leg press machines
have a mechanism to adjust the range of motion so it’s right for your body proportions.
The general warm-up for an estimated 1-RM test starts in the same way as a maximal 1-RM test by doing a light,
dynamic, movement-specific warm-up for 3–5 minutes. The person then completes a warm-up set of 5–10
repetitions at a light weight. They will rest for 1 minute and then increase the weight, resting 2 minutes after
each attempt. The number of repetitions performed at each increase is somewhat subjective but should not be
more than 10 repetitions, otherwise, the prediction equation to estimate 1-RM will not work. Once the person
reaches a point where they have performed 2–10 repetitions to fatigue at the highest weight they can, this
information can be input into a prediction equation to provide a 1-RM estimate.

LEARN MORE
Four main prediction equations can be accessed at BrianMac Sports Coach, where you can input the weight
lifted and repetitions to obtain your own estimate of 1-RM.
The National Strength and Conditioning Association also provides a training load chart for you to calculate
1-RM or to select training intensity as a percent of 1-RM based on your goals.
Strength Level allows you to compare your muscular strength performance across different lifts against
other individuals per your sex, age, and bodyweight.

SUMMARY
In this lesson, you learned various methods for assessing intensity levels of resistance training
exercises. Using percent of 1-RM means you are basing your intensity off a percentage of the maximal
amount you can lift a single time for a given movement, and different percentage ranges are suitable
for different fitness goals.
Rating of perceived exertion (RPE) scales provide a subjective ranking based on how difficult the weight
or movement feels, and can be used for weighted movements to estimate repetitions in reserve.
Assessing muscular fitness can be done in two main ways. Muscular endurance tests can involve
holding an isometric movement as long as possible, or completing as many repetitions as possible in a
given time period, such as 1 minute. Muscular strength tests are most commonly done as assessing a
person’s 1-RM or doing a submaximal test that allows estimation of 1-RM.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE. Markup: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING.
PLEASE SEE OUR TERMS OF USE.
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REFERENCES
Delavier, F., & Gundill, M. (2011). The strength training anatomy workout: starting strength with bodyweight
training and minimal equipment. Human Kinetics.
Edwards, M. (2017). Muscles in motion. American Council on Exercise. www.acefitness.org/fitnesscertifications/ace-answers/exam-preparation-blog/3580/muscles-in-motion/
Haff, G., & Triplett, N. T. (2016). Essentials of strength training and conditioning (4th ed). National Strength and
Conditioning Association. Champaign, IL, Human Kinetics.
Jimenez, C. (2018). Understanding 1-RM and predicted 1-RM assessments. American Council on Exercise.
www.acefitness.org/fitness-certifications/ace-answers/exam-preparation-blog/2894/understanding-1-rm-andpredicted-1-rm-assessments/
National Football League (2016). Training for the NFL combine bench press test. www.nfl.com/news/trainingfor-the-nfl-combine-bench-press-test-0ap3000000637311
Vaara, J. P., Kyröläinen, H., Niemi, J., Ohrankämmen, O., Häkkinen, A., Kocay, S., & Häkkinen, K. (2012).
Associations of maximal strength and muscular endurance test scores with cardiorespiratory fitness and body
composition. The Journal of Strength & Conditioning Research, 26(8), 2078-2086.
doi.org/10.1519/JSC.0b013e31823b06ff

TERMS TO KNOW
1-Repetition Maximum (1-RM)
The heaviest amount of weight that can be lifted for a single repetition in a given movement.
Concentric
A type of muscular work where the working muscle shortens.
Eccentric
A type of muscular work where the working muscle lengthens.
Isometric
A type of muscular work where the body remains in a static, motionless position.
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Principles of Flexibility and Mobility
by Sophia

WHAT'S COVERED
In this lesson, you will learn about the importance of flexibility and mobility, along with what affects
them, their role in low back health, and their benefits. Specifically, this lesson will cover the following:
1. Definitions of Flexibility and Mobility
2. Factors Affecting Flexibility and Mobility
3. Back Health
4. Benefits of Improving Flexibility
1. Definitions of Flexibility and Mobility
Flexibility is the ability of a joint to move through its full range of motion. We use flexibility throughout our
everyday activities, such as reaching for an item on a high shelf, bending down to put on our shoes, or standing
up to get out of a chair. If joints are restricted in their full range of motion, these activities can become difficult if
not impossible.
EXAMPLE The normal range of motion at the shoulder joint is 180 degrees. If muscles surrounding the
shoulder are tight and inflexible, the range will be restricted. A lower range of motion can inhibit normal
movements, like being able to reach overhead.
One way to define mobility is the ability to move freely in changing and controlling body position (Ernstmeyer &
Christman, 2021). Mobility requires not just flexibility, but also strength, coordination, and body awareness
(Starrett & Cordoza, 2015). When we consider the common body positions of everyday life activities, such as
pushing, pulling, stepping, and squatting, mobility can give us a greater picture of a person’s overall movement
function.
EXAMPLE The sit-and-reach test is a common test to assess flexibility of the hamstrings and lower
back. (You’ll learn more about this test in the next lesson). However, scoring well on the sit-and-reach does
not necessarily mean that a person has good total body mobility.
IN CONTEXT
In the human body, about half of our major joints favor mobility with being able to move freely and
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uninhibited. The other half of the joints favor stability, the ability to maintain or control joint movement
or position (American Council on Exercise, 2020). In fact, your body is essentially a stability-mobility
sandwich, designed in a way that a more mobile joint can receive support from the stable joints above
and below it.
To imagine this “stability-mobility sandwich” in action, think about performing any type of squatting
movement, such as rising out of a chair, bending to pick up an object, or squatting with weights at the
gym. Your hip joints favor mobility, and that mobility partially dictates how deeply you can squat while
keeping an upright posture. Meanwhile, your knee joints favor stability, helping you keep your body
balanced over your feet. Your ankle joints favor mobility, so ankle mobility allows you to squat deeply
while keeping both feet fully on the floor.
Stability does not mean that the joint shouldn’t move at all. Rather, it means that the most effective
movement depends on the joint providing more support than a large range of mobility. Consider the
knees in our squatting example. Your knees need to bend and straighten to do movements of
everyday life. However, they can only bend and straighten primarily, rather than moving side to side or
rotating freely. If all the joints in the lower body favored mobility, squatting would likely feel quite
wobbly and imbalanced since some joints would lack support from stability.
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
TERMS TO KNOW
Flexibility
The ability of a joint to move through its full range of motion.
Mobility
The ability to move freely in changing and controlling body position.
Stability
The ability to maintain or control joint position.
2. Factors Affecting Flexibility and Mobility
The squatting example above illustrates one factor that affects flexibility and mobility, which is the type of joint
structure. The major joints in your body can be divided into three types based on their axis of motion and the
type of movement they allow (Haff & Triplett, 2016):
Uniaxial joints have one axis, such as your knees and elbows. These are also known as hinge joints. The
only movement they allow is flexion and extension, such as when you bend your knees to squat and then
straighten them to rise.
Biaxial joints have two axes, such as your wrists and ankles. They can not only flex and extend but also
move away from the body and back toward the body, which is termed abduction and adduction,
respectively.
Triaxial joints have three axes. These joints are also known as ball-and-socket joints because the head of
the bone (the ball) that fits into the joint capsule (the socket) allows the greatest range of motion of any joint
types in the body. Your hip joints and shoulder joints are examples, and this type of joint can flex and
extend, abduct and adduct, as well as rotate around its axis.
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Another factor affecting flexibility and mobility is soft tissue restriction. Soft tissue can include muscles, body fat,
and tendons.
EXAMPLE A person with a very muscular upper body may have trouble scratching their back because
their muscle mass gets in the way. Or, a pregnant woman or a person with a high amount of abdominal fat
mass may have trouble touching their toes because their stomach gets in the way.
Muscles and tendons can also develop restrictions from injuries. If a person has strained a hamstring
muscle, their body may build up scar tissue at the site to help the injury heal, but this may mean that the
hamstrings now have less range of motion.
Age and sex also play a role in flexibility and mobility. In general, females tend to be more flexible than males,
partly because females typically have greater muscle elasticity (Yu et al., 2022). Older adults tend to be less
flexible than younger adults; some reasons for this include lower physical activity (Yu et al., 2022) and agerelated diseases or conditions that can make full ranges of motion painful or fatiguing, such as arthritis
(Ernstmeyer & Christman, 2021).
Lastly, your activity and lifestyle can affect flexibility and mobility, whether for better or worse. You’ve learned
that the body adapts to the demands placed upon it. Putting the body in repetitive positions, such as sitting for
long periods with a sedentary lifestyle, can cause muscles to contract and shorten since they are not being used
(Hayward & Gibson, 2014). Conversely, staying active in a variety of ways can help the body maintain full ranges
of motion at all major joints.
IN CONTEXT
Genetic conditions can also affect flexibility and mobility by causing hypermobility in the body, where
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joints easily move beyond normal ranges of motion. Hypermobility becomes problematic when it
causes the joints to lack proper stability and control, which can then cause pain and increased risk of
injury (Clapp et al., 2021).

TERM TO KNOW
Hypermobility
When joints can move beyond normal ranges of motion.
3. Back Health
In our conversation about flexibility, mobility, and stability over this lesson, back health is an important
component, especially since back pain is a common issue in the population. When the normal “stability-mobility
sandwich” of the body is disrupted, compensation can occur which leads to pain or stiffness. Sitting for long
periods, being inactive, moving with poor posture, and other factors can tilt the pelvis out of alignment, whether
forward or backward. As a result, the stability-mobility sandwich of the muscles that act on the pelvis can
become altered.
Low back pain can have many other causes, such as muscle strains, damage to the discs, or arthritis, just to
name a few. If you are experiencing low back pain, seeking help from a health professional should be your first
step. However, exercises that promote stability and mobility of the spine can help restore the balance of the
stability-mobility sandwich of the body.
When considering the spine as part of the body’s stability-mobility sandwich, the lumbar spine, or lower back,
favors stability, and the thoracic spine, or mid-back, favors mobility. Spinal stability exercises help to reinforce
good movement patterns without putting extra load on the spine (McGill, 2006).
EXAMPLE The bird dog, or quadruped, is a spinal stability exercise. The body position for the bird dog
starts on all fours, with hands under the shoulders and knees under the hips. A person can start by
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extending and raising one leg, holding the leg parallel to the floor without any motion in the spine and
without the pelvis tilting to one side (McGill, 2006). If this feels stable, the movement can progress to
extending and raising the opposite arm and holding this body position for 6–8 seconds before switching
sides. This exercise can also be done while standing and using a chair or wall for balance if being on all
fours is painful or uncomfortable.
The bird-dog exercise.
Spinal mobility exercises take the spine slowly through full ranges of motion, such as flexing and extending the
spine (McGill, 2006).
EXAMPLE The cat-camel, which is sometimes called cat-cow, is a spinal mobility exercise. This
movement takes all regions of the spine through flexion and extension (McGill, 2006). The body position for
the cat-camel also starts on all fours, with hands under the shoulders and knees under the hips. In the
upward (cat) phase, exhale to gently round the spine upwards toward the ceiling, with the head falling
toward the chest. Inhale to slowly let the back drop into an arch with the stomach toward the floor and the
shoulder blades drawing together. This exercise can also be done while seated in a chair if being on all
fours is painful or uncomfortable.
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The cat-camel exercise.

WATCH
In addition to performing intentional movements that enhance mobility and stability, understanding and
using good posture in your everyday activities is another key to back health and has many benefits.
4. Benefits of Improving Flexibility
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Doing flexibility exercises regularly is recommended by national health and exercise organizations. The
American College of Sports Medicine provides the following guidelines per the FITT principle (Liguori, 2021):
Frequency: Perform flexibility exercises 2–3 days a week or more; stretching daily is most effective.
Intensity: Stretches should be performed only to the point of slight discomfort or tightness, never pain.
Time: Hold each stretch for 10–30 seconds; holding for 30–60 seconds may provide even more flexibility
benefits.
Type: Perform a series of flexibility exercises for all major muscle groups.
Doing flexibility exercises 2–3 times a week for 3–4 weeks can improve the range of motion, along with
improving postural stability and balance (Garber et al., 2011). Flexibility can also promote a sense of physical and
mental relaxation (American Council on Exercise, 2022).
However, research is mixed on the benefits of improving flexibility. While flexibility is one of the five
components of health-related fitness, it is the only component that is not associated with living longer or aging
better (Nuzzo, 2020). Some research indicates that performing flexibility exercises provides benefits like
preventing injuries, reducing pain, and improving performance (Matthews, 2017).
IN CONTEXT
One way that improving flexibility can impact performance is by improving the ability to apply force
through a greater range of motion (Haff & Triplett, 2016). For example, picture a tennis player about to
serve the ball. A tennis player with a full range of motion at the shoulder can apply force over a longer
time period than a tennis player with a limited range of motion.
However, other research reflects that doing regular flexibility exercises does not have any association with
reducing injuries, preventing pain, or performing better in sports (Nuzzo, 2020). Stretching is difficult to study on
an individual level, so it is still a valid part of an exercise program if it makes you feel good and seems to have
benefits.

SUMMARY
In this lesson, you first learned about the definitions of flexibility and mobility, specifically that having
good flexibility allows joints to move through their full range of motion, while mobility is the body’s
ability to move freely in changing and controlling positions. There are various factors affecting flexibility
and mobility, such as joint structure, soft tissue, age, sex, activity, and lifestyle. Back health is relevant
to the concept of flexibility and mobility since having the balance (or lack thereof) of mobility and
stability in the body can impact posture and movement. The benefits of improving flexibility and
mobility are somewhat unclear from research but may improve posture, balance, and stability, along
with reducing pain, and national exercise organizations provide guidelines per the FITT (frequency,
intensity, time, and type) principle on incorporating flexibility into a regular exercise routine.
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Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE. Markup: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING.
PLEASE SEE OUR TERMS OF USE.
REFERENCES
American Council on Exercise (2020). The exercise professional’s guide to personal training: A client-centered
approach to inspire active lifestyles. Jo, S., Bryant, C.X., Dalleck, L.C., Gagliardi, C.S., and Green, D.J. (eds). ISBN:
9781890720766
American Council on Exercise (2022). Benefits of flexibility. American Council on Exercise.
www.acefitness.org/resources/everyone/blog/6646/benefits-of-flexibility/
Clapp, I. M., Paul, K. M., Beck, E. C., & Nho, S. J. (2021). Hypermobile disorders and their effects on the hip joint.
Frontiers in Surgery, 8, 596971. doi.org/10.3389/fsurg.2021.596971
Ernstmeyer, K., Christman, E., eds. (2021). Nursing Fundamentals: Chapter 13, Mobility. Open Resources for
Nursing (Open RN). Eau Claire (WI): Chippewa Valley Technical College.
www.ncbi.nlm.nih.gov/books/NBK591828/
Garber, C. E., Blissmer, B., Deschenes, M. R., Franklin, B. A., Lamonte, M. J., Lee, I. M., ... & Swain, D. P. (2011).
Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and
neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Medicine & Science in
Sports & Exercise, 43(7), 1334-1359. doi.org/10.1249/MSS.0b013e318213fefb
Haff, G., & Triplett, N. T. (2016). Essentials of strength training and conditioning (4th ed). National Strength and
Conditioning Association. Champaign, IL, Human Kinetics.
Hayward, V.H., & Gibson, A.L. (2014). Advanced Fitness Assessment and Exercise Prescription. Illinois: Human
Kinetics. ISBN: 9781450466004
Liguori, G. (2021). ACSM’s guidelines for exercise testing and prescription. American College of Sports
Medicine. ISBN: 9781975150181
Matthews, J. (2017). 10 reasons why you should be stretching. American Council on Exercise.
www.acefitness.org/resources/pros/expert-articles/6387/10-reasons-why-you-should-be-stretching/
McGill, S. (2006). Ultimate back fitness and performance, 3rd ed. Backfitpro, Inc., Waterloo, Ontario, Canada.
ISBN: 0973501804.
Nuzzo J. L. (2020). The case for retiring flexibility as a major component of physical fitness. Sports Medicine,
50(5), 853–870. doi.org/10.1007/s40279-019-01248-w
Starrett, K., & Cordoza, G. (2015). Becoming a supple leopard: the ultimate guide to resolving pain, preventing
injury, and optimizing athletic performance, 2nd ed. Las Vegas, Victory Belt Publishing Inc.
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Yu, S., Lin, L., Liang, H., Lin, M., Deng, W., Zhan, X., Fu, X., & Liu, C. (2022). Gender difference in effects of
proprioceptive neuromuscular facilitation stretching on flexibility and stiffness of hamstring muscle. Frontiers in
physiology, 13, 918176. doi.org/10.3389/fphys.2022.918176

TERMS TO KNOW
Flexibility
The ability of a joint to move through its full range of motion.
Hypermobility
When joints can move beyond normal ranges of motion.
Mobility
The ability to move freely in changing and controlling body position.
Stability
The ability to maintain or control joint position.
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Flexibility and Mobility Assessment
by Sophia

WHAT'S COVERED
In this lesson, you will learn about some common methods to assess flexibility, mobility, and stability in
the body. Specifically, this lesson will cover the following:
1. Direct Methods of Testing Flexibility
2. Indirect Methods of Testing Flexibility
3. Evaluating Mobility and Stability
4. Evaluating Back Health
1. Direct Methods of Testing Flexibility
From what you’ve learned in the previous lesson, flexibility and mobility have some overlap, in that flexibility is
just one part of mobility. Many established tests from research just measure the flexibility of a given joint or
muscle group. The ‘gold standard’ for direct flexibility testing involves tools that evaluate the exact range of
motion. One example of this type of tool is called a goniometer, which resembles a protractor to precisely
measure joint angles with one stationary arm and one moving arm (Pate et al., 2012). A goniometer measures
joint angles in degrees. A half circle is 180 degrees, and a full circle is 360 degrees. Goniometers are typically
used in clinical settings by healthcare providers, such as orthopedic surgeons or physical therapists.
EXAMPLE Every joint in the body has a normal range of motion. A surgeon might use a goniometer to
assess if a person has regained enough normal range of motion post-surgery to effectively do everyday
activities, like walking, stepping, or bending (Hancock et al., 2018).
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The angle of knee flexion is being measured with the center of the goniometer over the knee joint and the moving
arm of the goniometer in line with the lower leg.
2. Indirect Methods of Testing Flexibility
There are multiple indirect methods of testing flexibility. Some of the most common indirect methods include
the sit-and-reach test for the lower body and the back scratch test for the upper body.
The sit-and-reach test, as shown in the below image, assesses the flexibility of the lower back and hamstring
muscles (Pate et al., 2012). In the standard sit-and-reach test, a measurement box is used. A person places their
feet against the box and uses their fingertips to push a measurement marker forward as they stretch as far as
they can. There are other variations such as using a yardstick on the floor, having one knee bent, or stretching
while seated in a chair (Hayward & Gibson, 2014).
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You can assess your own flexibility with the sit-and-reach test if you have a yardstick or long tape measure
(Morrow et al., 2015).

STEP BY STEP
1. First, perform a light 3–5-minute warmup of low- to moderate-intensity cardiovascular exercise, like
brisk walking or jogging so that you are not stretching cold muscles.
2. Next, place your yardstick or long tape measure vertically on the floor. Sit in a straddle position with
your legs straight. Your feet should be 12 inches apart (30.5 cm), and your heels should line up with the
15-inch mark (38.1 cm) on the yardstick or tape measure.
3. Reach forward along the yardstick or tape measure in a slow, controlled manner with the palms down
and fingertips of each hand evenly aligned over each other. Your middle fingers will reach the furthest.
Hold your stretch for 1–2 seconds. You will measure to the nearest 0.25 inch (0.64 cm) where your
overlapped middle fingers have reached. Perform 3 total attempts with 30 seconds rest in between.
The following provides the ranking for this flexibility test based on sex and age (Morrow et al., 2015). The higher
number is listed first. These are in inches, so you would need to perform a conversion if you measured your test
in centimeters. How do your results compare?
Male rating
Age 18–25
Age 26–35
Age 36–45
Age 46–55
Age 56–65
Age 66+
Excellent
28–22
28–21
28–21
26–19
24–17
24–17
Good
21–20
19
19–18
18–16
16–15
16–14
Above Average
19–18
17
17–16
15–14
13
13–12
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Average
17–16
16–15
15
13–12
11
11–10
Below Average
15–14
14–13
13
11–10
9
9–8
Poor
13–12
12–11
11–9
9–8
8–6
7–6
Very Poor
11–2
9–2
7–1
6–1
5–1
4–0
Age 18–25
Age 26–35
Age 36–45
Age 46–55
Age 56–65
Age 66+
Excellent
29–24
28–23
28–22
27–21
26–20
26–20
Good
22
22–21
21–20
20–19
19–18
19–18
Above Average
21–20
20
19–18
18–17
17–16
17
Average
19
19–18
17
16
15
16–15
Below Average
18–17
17–16
16–15
14
14–13
14–13
Poor
16
15–14
14–13
13–12
12–10
12–10
Very Poor
14–7
13–5
12–4
10–3
9–2
9–1
Female rating
The back scratch test shown in the image below, sometimes called the shoulder stretch test or zipper test,
assesses the flexibility of the muscles around the shoulder joint. In this test, the person raises one arm
overhead, then bends at the elbow to reach down the back. With the other arm, they reach behind the back and
upward (Pate et al., 2012). The person may be able to touch their hands together or even have them overlap, or
there may be a significant amount of distance between the hands. Being unable to reach very far with one or
both hands indicates that the muscles around the shoulder joint may lack flexibility.
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You can also assess your own flexibility with the back scratch test, though you may need a friend or family
member to be able to observe and measure how close or how far your hands are behind your back.

STEP BY STEP
1. If you are not already warmed up from the previous test, perform a light 3–5-minute warmup of low to
moderate-intensity cardiovascular exercise.
2. Reach one arm overhead and bend at the elbow to reach down your back, then reach the other arm
behind the back and up to meet your first arm. Move with control rather than trying to jerk the arms into
position.
3. Have your friend or family member observe and measure the distance between the tips of your middle
fingers. If the fingertips touch, the score is zero. If the fingertips cannot touch, the distance between
them is measured as a negative number. If the fingertips can overlap, the distance of their overlap is
measured as a positive number (Rikli & Jones, 2013).
The most common comparison charts for scoring exact values of the back scratch test are based only on data
from older adults, so they are not included here. However, being unable to have the fingertips touching may
indicate a lack of flexibility in the muscles of the upper body.
3. Evaluating Mobility and Stability
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One of the most common ways to evaluate mobility and stability is through some type of squatting movement.
Many national exercise organizations use a variation of the squat as an assessment tool. While a
comprehensive explanation of improving mobility and stability in the squat is outside of the scope of this lesson,
there are some general observations that can be made.
In a squat with good mobility and stability, the following aspects are observed (Clark et al., 2014):
The feet remain flat on the floor and pointed forward or slightly out
The knees are in line with the toes
The spine is straight or maintains a small natural arch
The hips are in line (parallel) with the bend of the knees, or below
Observing any of the following in a squat may indicate an area that would benefit from additional mobility or
stability (Clark et al., 2014):
Feet collapsing in or turning out
Heels rising off the floor
Knees collapsing in or moving excessively outside the line of the toes
Rounding of the spine
Excessive forward lean of the spine
Inability to squat below parallel where the hips are in line or below the bend of the knees
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4. Evaluating Back Health
You’ve learned that the muscles that support posture are primarily type I fibers, firing at low levels consistently
and being fatigue resistant. These muscles of our posture and core musculature can be tested for function
through isometric assessments or holding a position motionless. A simple test to assess the stability of the
spine and endurance of the core muscles is through testing a plank and a side plank on each side. However,
these tests may not be appropriate if a person has shoulder pain or back pain.
In the plank position, as shown in the below image, the forearms are in contact with the floor, the elbows are
under the shoulders, and the body forms one long straight line from the shoulders to the heels. There are
different versions of the plank test, and one variation from the American Council on Exercise is to hold the plank
for up to 30 seconds with proper form.
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Common errors in form when doing a plank include having the hips too high or having the hips too low. The test
is stopped if the person has one of these errors in form. If a person is unable to hold a plank with proper
alignment for 30 seconds, or if they feel the plank mostly in their lower back rather than their abdominal
muscles, this may indicate that the stability of their spine and core musculature needs improvement (American
Council on Exercise, 2012).
In the side plank position, shown below, the elbow is under the shoulder and the forearm is flat. The feet are
stacked on top of each other, and the body should form a straight line from the feet to the shoulders. The side
of the body closer to the ground is the side being tested, so if the right elbow is on the floor, this is a right-side
plank.
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Common errors in form for the side plank include the hips sinking down, when the body no longer forms a
straight line, or the torso rotating forward or back, in which case the hips and shoulders are no longer stacked
on top of each other. The test is stopped if the person has one of these errors in form before the 30 seconds is
up. If a person is unable to hold each side plank for 30 seconds, this may indicate that the stability of their spine
and core musculature needs improvement (American Council on Exercise, 2012).

BIG IDEA
There are multiple ways to assess flexibility, mobility, and stability, as well as assessing back health. This
lesson has provided some of the most common assessments that can be easy to do on your own. However,
people’s needs for flexibility, mobility, and stability will vary based on their activity level, age, lifestyle, goals,
and other factors, and there are many other types of flexibility, mobility, and stability tests that exist.
Consulting with a certified fitness professional can provide more insight into your own unique needs.

SUMMARY
In this lesson, you first learned about direct methods of testing flexibility, specifically about a
goniometer, which is a tool measuring the angle of movement at a joint. Indirect methods of testing
flexibility include the sit-and-reach, which tests lower body flexibility, and the back scratch test, which
tests upper body flexibility. Squatting movements are a common way for evaluating mobility and
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stability and seeing if errors in proper form are present. Evaluating back health can be done, in part,
through isometric testing such as the plank and side plank, which provide an idea of one’s core stability.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE. Markup: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING.
PLEASE SEE OUR TERMS OF USE.
REFERENCES
American Council on Exercise (2012). Task performance and health improvement recommendations for
emergency medical service practitioners. American Council on Exercise. www.naemt.org/docs/defaultsource/ems-health-and-safety-documents/Recommended_EMS_Fitness_Guidelines.pdf?sfvrsn=6
Clark, M.A., Lucett, S.C., & Sutton, B.G., eds. (2014). NASM Essentials of Corrective Exercise Training, 1st ed.,
revised. Jones & Bartlett Learning. ISBN: 9781284050257
Hancock, G. E., Hepworth, T., & Wembridge, K. (2018). Accuracy and reliability of knee goniometry methods.
Journal of Experimental Orthopaedics, 5(1), 46. doi.org/10.1186/s40634-018-0161-5
Hayward, V.H., & Gibson, A.L. (2014). Advanced Fitness Assessment and Exercise Prescription. Illinois: Human
Kinetics. ISBN: 9781450466004
Morrow Jr, J. R., Mood, D., Disch, J., & Kang, M. (2015). Measurement and evaluation in human performance, 5th
ed. Human Kinetics. ISBN: 9781450470438
Pate, R., Oria, M., & Pillsbury, L., eds. (2012). Fitness measures and health outcomes in youth. Health-Related
Fitness Measures for Youth: Flexibility. Washington DC: National Academies Press.
www.ncbi.nlm.nih.gov/books/NBK241323/
Rikli, R. E., & Jones, C. J. (2013). Development and validation of criterion-referenced clinically relevant fitness
standards for maintaining physical independence in later years. The Gerontologist, 53(2), 255-267.
doi.org/10.1093/geront/gns071
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Cardiovascular Training Exercises
by Sophia

WHAT'S COVERED
In this lesson, you will learn about different types of cardiovascular exercises. Understanding these
types can help you identify which types might be right for you. Specifically, this lesson will cover the
following:
1. Steady-State Cardiovascular Exercise
2. Rhythm-Based Cardiovascular Exercise
3. High-Intensity Interval Training
1. Steady-State Cardiovascular Exercise
So far, you’ve learned about cardiovascular training principles and the benefits of staying active, including using
the FITT (frequency, intensity, time, and type) principle and understanding the Physical Activity Guidelines. A
person can choose from many types of cardiovascular exercise to reach or exceed the recommendations of 150
minutes of moderate-intensity activity, 75 minutes of vigorous-intensity activity, or an equivalent combination.
Steady-state cardiovascular exercises are ones that can be done at a consistent intensity, such as walking,
hiking, jogging, running, bicycling, swimming, or using cardiovascular machines like an elliptical. Being able to
maintain movement at a moderate intensity for 20–30 minutes at a time is a good general goal for someone
who is starting to become physically active (American Council on Exercise, 2020). Working up to this goal can
begin with shorter bouts of exercise, like 10 minutes at a time.
Out of the FITT principles, frequency is the most important for those who are just beginning to make exercise
part of their regular habits (American Council on Exercise, 2020). Steady-state cardiovascular exercise is useful
because an individual can work at their own preferred intensity and choose a sustainable pace.
In addition, many steady-state cardiovascular exercises are low-impact exercises, meaning that they do not
place a lot of force or stress on the body’s joints (Smith, 2014). Swimming is a low-impact exercise since being in
water minimizes the effects of gravity on the body. Bicycling, whether on a stationary cycle or outdoors, or using
a cardiovascular machine, such as an elliptical, is also typically low impact. This is because these types of
exercise tend not to involve repetitive pounding, unlike running or jumping, which are high-impact exercises as
there are periods when both feet leave the ground. Walking and hiking are also low impact since at least one
foot is always in contact with the ground, minimizing the amount of stress on the joints.
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Just because a type of cardiovascular exercise is low in impact, it doesn’t mean that it must also be low in
intensity. A person can use the FITT principle to increase the intensity of a low-impact workout.
EXAMPLE A person can increase the incline of a treadmill or choose a steeper hiking path.
Incorporating brief bursts of speed as interval training in swimming or cycling workouts also increases
intensity. Overall, any cardiovascular exercise that can be performed at a steady state can also be
performed at intervals. We’ll talk more about the nature of interval training later in this lesson.

TERMS TO KNOW
Low-Impact Exercise
Exercise that does not place a lot of force or stress on the body’s joints, such as swimming or walking.
High-Impact Exercise
Exercise that involves repetitive impact since both feet leave the ground, such as running or jumping.
2. Rhythm-Based Cardiovascular Exercise
Cardiovascular exercise is inherently rhythmic because it involves the repeated motion of large muscle groups.
However, many types of cardiovascular exercise are done in a group fitness setting where an instructor leads
the movement patterns, or to music with a specific beat and cadence. Examples include aerobic classes, such
as step aerobics, dance-based classes like Zumba® or Jazzercise®, and fitness kickboxing classes. For this
lesson’s purposes, we will term these types of exercises “rhythm-based” since the tempo at which they are
performed typically depends on a specific rhythm.
You’ve learned that the word “aerobic” refers to energy metabolism in the presence of oxygen, as opposed to
anaerobic metabolism which does not use oxygen. While any cardiovascular exercise done for longer durations
at lower intensities is aerobic, the word “aerobic” became popular through the work of Dr. Kenneth Cooper, a
physician and exercise physiologist. Some of Dr. Cooper’s first research was on astronauts and military
personnel, where he confirmed the value of aerobic exercise for living longer and healthier lives (Cooper, 2018).
As the understanding of aerobic exercise’s value grew based on Dr. Cooper’s research, aerobic workouts done
in group class settings began to become popular (Bryant, 2021). Classes involving dance movements, rhythmic
stepping, and other movements set to music started to become mainstream. Some types of classes began
using planned choreography, creating repeated patterns and drills as part of the exercise.
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Today, there is a wide variety of rhythm-based cardiovascular exercise types that can be found in traditional gym
group fitness studios, online, or through phone apps. These can range from low intensity to very high intensity
depending on the format.
For some people, rhythm-based cardiovascular exercise can be more enjoyable than steady-state exercise.
Dance steps and repeating patterns create a sense of novelty that keeps exercise from feeling too boring or
repetitive. While all types of cardiovascular exercise benefit brain health, research has found that the
combination of music and dance stimulates the brain’s reward centers, helps develop new brain connections,
and improves the control of movement and coordination (Edwards, 2015).
Not all types of rhythm-based cardiovascular exercise may be suitable for all people. People with arthritis,
excess weight, or joint injuries should use caution, as should older adults (American Council on Exercise, 2016).
For any of these populations, some classes may be too high-impact, leading to overuse injuries from repetitive
high-impact motion. Also, a person’s body and abilities may not be ready for classes that require high levels of
skill, like balance and coordination.

DID YOU KNOW
Teaching group fitness classes, like rhythm-based cardiovascular exercise and others, typically requires a
group fitness instructor certification from a nationally accredited organization. The instructor should have
the knowledge and skill to provide a class that meets participants across multiple fitness levels. If you are
trying a new type of rhythm-based exercise for the first time, it’s a good idea to take a class led by an
instructor. The instructor can provide cues for intensity, such as working at a given RPE, or give
modifications that make the movements lower impact or less complex if needed.
3. High-Intensity Interval Training
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You’ve already learned about some of the benefits of incorporating higher intensities into cardiovascular
exercise, such as the elevated metabolism that results from excess post-exercise oxygen consumption, or
EPOC. Interval training allows someone to get the benefits of higher intensity exercise without needing to
sustain that intensity for their entire workout. High-intensity interval training (HIIT) is defined as bouts of highintensity effort alternating with lower-intensity recovery times, where the high-intensity effort is typically at 80–
95% of estimated maximum heart rate, and the recovery periods are often at 40–50% of estimated maximum
heart rate (Kravitz, 2014).
However, there are different variations on HIIT that manipulate aspects like the intensity of the work intervals, or
the timing of the work intervals relative to the recovery intervals.
Sprint interval training (SIT) is done at a nearly all-out intensity (think 9 on the 0–10 RPE scale). These
maximal efforts are done for 30 seconds or less with longer recovery times, such as 4 minutes (Gibala,
2006). SIT is sometimes called anaerobic HIIT, since the very short intense periods only use anaerobic
metabolism (Ito, 2019). Since this type of training is extremely demanding, it is only suitable for people with
a high level of fitness and motivation to push themselves this hard.
Tabata interval training is a type of HIIT that uses 8 bouts of 20 seconds of work followed by 10 seconds of
rest (Tabata, 2019). Originally, Tabata was developed for use with a stationary bike and was intended to
have a constant, high intensity through each of the 8 bouts (Tabata, 2019).
IN CONTEXT
The relationship between the work intervals and the recovery intervals in HIIT depends on the
principle of specificity, or what the desired adaptations to the cardiovascular system should be. For
example, a person who is new to HIIT can acclimate to a 1:4 ratio or a rest period that is 4 times as long
as the work period (Schoenfeld & Dawes, 2009). This allows a lot of time for recovery so that the
higher intensity exercise is sustainable. For individuals with high levels of fitness or athletes, a 1:1 ratio,
or equal work to equal rest, would be more appropriate for building endurance at higher intensities
(Schoenfeld & Dawes, 2009).
High-intensity interval training can be adapted to an individual’s abilities and exercise tolerance. A person who
has built consistent habits with steady-state, low-intensity exercise like walking might try incorporating brief
bouts of walking faster, jogging, or increasing the incline of their walk (if they are using a treadmill). According to
the American College of Sports Medicine, a person should not do HIIT if they have not built the foundational
level of cardiovascular fitness of doing consistent aerobic exercise 3–5 times a week, for 20–60 minutes, at a
somewhat hard intensity (a 4 on a 0–10 RPE scale).

WATCH
Learn more about the benefits and styles of high-intensity interval training to determine if, and what type,
could be the best fit for you.
Interval training can be a more time-efficient way to increase fitness than longer duration, steady-state exercise.
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However, a caution with high-intensity interval training (besides having a foundational level of cardiovascular
fitness) is that the more intense the exercise, the more thorough the warmup should be. You’ll learn more about
properly warming up to prevent injuries later in this Challenge.
IN CONTEXT
Since high-intensity interval training can be demanding on the body, it also warrants some special
considerations for recovery. Moderate-intensity exercise like walking can be done daily with low risk
of injury. However, HIIT training should not be done every day. Allowing 2–3 days for recovery
between HIIT sessions is a good general guideline, so performing HIIT no more than two to three
times a week (American Council on Exercise, 2020).

BIG IDEA
Besides FITT, enjoyment is an essential principle for exercise. Keeping exercise fun and engaging creates
motivation to stick with it. Understanding the characteristics of different types of cardiovascular training can
help you consider what activities are right for you or be inspired to try out a new type of exercise.

TERMS TO KNOW
High-Intensity Interval Training (HIIT)
Bouts of high-intensity effort alternating with lower intensity recovery times, where the high-intensity
effort is typically at 80–95% of the estimated maximum heart rate, and the recovery periods are often at
40–50% of the estimated maximum heart rate.
Sprint Interval Training (SIT)
Interval training done at a nearly all-out intensity, where maximal efforts are done for 30 seconds or less
with longer recovery times, such as 4 minutes.
Tabata
A form of HIIT that uses 8 bouts of 20 seconds of work followed by 10 seconds of rest.

SUMMARY
In this lesson, you learned about the characteristics of different types of cardiovascular exercise.
Steady-state cardiovascular exercises can be done at a consistent intensity and can be low-impact, such
as swimming or walking, or high-impact, such as running. Rhythm-based cardiovascular exercises
typically involve planned movement patterns and music with a specific beat, such as dance-based
classes, step aerobics, or kickboxing. High-intensity interval training (HIIT) alternates higher intensity
work periods with lower intensity recovery periods, and is a time-efficient way to get cardiovascular
exercise, as well as having different types of variations.
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Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE. Markup: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING.
PLEASE SEE OUR TERMS OF USE.
REFERENCES
American Council on Exercise (2016). ACE group fitness instructor handbook: The professional’s guide to
creating memorable movement experiences. ISBN: 9781890720599
American Council on Exercise (2020). The exercise professional’s guide to personal training: A client-centered
approach to inspire active lifestyles. Jo, S., Bryant, C.X., Dalleck, L.C., Gagliardi, C.S., and Green, D.J. (eds). ISBN:
9781890720766
Bryant, C.X. (2021). The evolution of fitness trends. American Council on Exercise. www.acefitness.org/aboutace/our-efforts/blog/7765/the-evolution-of-fitness-trends/
Cooper, K. H. (2018). The history of aerobics (50 years and still counting). Research Quarterly for Exercise and
Sport, 89(2), 129-134. pubmed.ncbi.nlm.nih.gov/29723136
Edwards, S. (2015). Dancing and the brain. Harvard Mahoney Neuroscience Institute – Harvard Medical School.
hms.harvard.edu/news-events/publications-archive/brain/dancing-brain
Gibala, M. J., Little, J. P., van Essen, M., Wilkin, G. P., Burgomaster, K. A., Safdar, A., Raha, S., & Tarnopolsky, M. A.
(2006). Short-term sprint interval versus traditional endurance training: similar initial adaptations in human
skeletal muscle and exercise performance. The Journal of Physiology, 575(Pt 3), 901–911.
doi.org/10.1113/jphysiol.2006.112094
Ito S. (2019). High-intensity interval training for health benefits and care of cardiac diseases - The key to an
efficient exercise protocol. World Journal of Cardiology, 11(7), 171–188. doi.org/10.4330/wjc.v11.i7.171
Kravitz, L. (2014). ACSM information on high-intensity interval training. American College of Sports Medicine.
www.acsm.org/docs/default-source/files-for-resource-library/high-intensity-interval-training.pdf
Schoenfeld, B., & Dawes, J. (2009). High-intensity interval training: Applications for general fitness training.
Strength & Conditioning Journal, 31(6), 44-46. doi.org/10.1519/ssc.0b013e3181c2a844
Smith, L. (2014). Low impact exercises. The Playbook: the official blog of HSS – strategies to keep you in the
game of life. Hospital for Special Surgery. www.hss.edu/playbook/low-impact-exercises/
Tabata, I. (2019). Tabata training: one of the most energetically effective high-intensity intermittent training
methods. The Journal of Physiological Sciences, 69(4), 559-572. doi.org/10.1007/s12576-019-00676-7

TERMS TO KNOW
High-Impact Exercise
Exercise that involves repetitive impact since both feet leave the ground, such as running or jumping.
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High-Intensity Interval Training (HIIT)
Bouts of high-intensity effort alternating with lower intensity recovery times, where the high-intensity
effort is typically at 80–95% of the estimated maximum heart rate, and the recovery periods are often at
40–50% of the estimated maximum heart rate.
Low-Impact Exercise
Exercise that does not place a lot of force or stress on the body’s joints, such as swimming or walking.
Sprint Interval Training (SIT)
Interval training done at a nearly all-out intensity, where maximal efforts are done for 30 seconds or less
with longer recovery times, such as 4 minutes.
Tabata
A form of HIIT that uses 8 bouts of 20 seconds of work followed by 10 seconds of rest.
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Resistance Training Exercises
by Sophia

WHAT'S COVERED
In this lesson, you will learn about different resistance training movements, types, and equipment to
help you consider which choices might be right for you. Specifically, this lesson will cover the following:
1. Exercises by Muscle Group
2. Exercises by Movement Type
3. Core Exercises
4. Considerations for Resistance Training Equipment
1. Exercises by Muscle Group
The Physical Activity Guidelines for Americans provide the recommendation that resistance training exercises
should be done 2 or more days a week for all major muscle groups. Therefore, it is helpful to further
understand what the major muscle groups are, as well as some examples of exercises for each group.
According to the Centers for Disease Control and Prevention, the major muscle groups of the body are the
legs, hips, back, abdomen, chest, shoulders, and arms. The following table provides some example exercise
movements for each major muscle group.
Muscle
Example Exercise Movements
Group
Legs
Any type of squat, lunge, or stepping movement
Hips
Any type of glute bridge, any type of lateral lower-body movement such as side-lying leg raises
or seated abduction/adduction
Back
Most types of pulling movements, such as any type of row, pulldown, or pull-up
Back muscles are also involved when the spine extends, like the camel portion of a cat-camel, or
as stabilizers for abdominal exercises, such as the bird-dog.
Abdomen
Movements where the spine flexes, rotates, or laterally bends, as well as isometric movements
like planks.
The abdominal muscles are also more involved in movements requiring balance and stability,
such as carrying a heavy load on one side or stepping with one leg.
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Chest
Any type of pressing or pushing movement, such as a push-up or a chest press
Shoulders
Overhead pushing movements, such as a shoulder press
Shoulders are also involved in moving the arms away from the body, such as in a lateral raise.
Depending on the movement, shoulders are also involved in other pushing and pulling
movements.
Arms
Arm muscles can be further divided into biceps and triceps. Biceps are involved in any movement
with elbow flexion, such as a bicep curl. Triceps are involved in any movement with elbow
extension, such as a tricep extension. In addition, the biceps assist in pulling exercises, and the
triceps assist in pushing exercises.
Working all major muscle groups in your exercise routine is important for the sake of muscle balance, ensuring
that the muscles surrounding each major joint in the body generate the appropriate amounts of opposing force
(McCall, 2016). Your muscles work together in pairs called agonists and antagonists, where the agonist is the
main muscle group doing the movement, and the antagonist moves in opposition to the agonist. Typically, as
the agonist contracts, it shortens, and the antagonist lengthens.
EXAMPLE Let’s say you are doing a bicep curl, like the illustration below demonstrates. As your elbow
flexes to move the weight closer to you, the biceps contract and act as the agonist. The triceps act as the
antagonist and lengthen in opposition to the biceps shortening. As you lower the weight and your elbow
extends, these muscle groups exchange roles—the triceps contracts as the agonist for elbow extension,
and the biceps lengths as the antagonist.
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IN CONTEXT
The amount of opposing force is not necessarily equal between agonist and antagonist muscle
groups. For example, a general premise is that the hamstring muscles should be about two third as
strong as the quadriceps (Ruas et al., 2019). When the hamstring muscles are less than two third as
strong as the quadriceps, the proper ratio for muscle balance is altered, and the risk of injuries
increases, such as injuries to the ligaments of the knee (Rosene et al., 2001). This is because the
hamstrings cannot stabilize the knee as well during movement.

TERMS TO KNOW
Muscle Balance
The principle that the muscles surrounding each major joint in the body generate the appropriate
amounts of opposing force.
Agonist
The main muscle group doing a given movement; typically contracting and shortening.
Antagonist
The muscle group that is working in opposition to the agonist; typically lengthening as the agonist
contracts.
2. Exercises by Movement Type
An alternate way to consider resistance training exercises for a well-balanced fitness program is by movement
type. Beyond agonists and antagonists, muscle groups have additional roles in working together for efficient
movement. Synergists assist the agonist muscle in the movement. In the table above, you read that the biceps
assist in pulling exercises, and the triceps assist in pushing exercises. In an exercise like a chest press, the chest
muscles (pectorals) are the agonist, but the triceps also provide assistance even though they are not the main
muscle group executing the movement. Stabilizers help to maintain alignment and proper movement as the
agonists work. In the table above, you read that the abdominal muscles provide stability during movements on
one side, like carrying a heavy load. In this action, stabilizers allow you to keep a relatively level upright posture
despite only one side of your body bearing a load.
From all this information, it’s evident that muscles in the body don’t typically work in isolation but work together
in groups. This is especially the case during any movement that is functional in mimicking activities of everyday
life. When you bend down to pick up a heavy package that’s been delivered to your door, multiple muscle
groups are at work in their various roles to help you move efficiently.
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National organizations have some slight differences in how they describe movements by type. The National
Strength and Conditioning Association (2015) describes the main movements as squat, hinge, lunge, push,
horizontal pull, vertical pull, and press. The American Council on Exercise (2020) describes five primary
movement patterns: bend-and-lift, single leg, push, pull, and rotation. Other organizations or fitness resources
have variations on these movements, such as including general “core” movements, or having gait-related
movements, like stepping and walking, in a separate category.
For our purposes in this part of the lesson, we’ll discuss movements in the categories of
squatting/bending/hinging, single leg movements including walking or stepping, pushing movements, and
pulling movements.
Movement Type
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Example Exercise Movements
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Squatting, bending, or
Glute bridge or hip thrust
hinging
Wall sit
Any type of deadlift movement (such as using dumbbells or barbells)
Any type of squat movement, from bodyweight to squats with load (such as using
a hack squat or leg press machine or squatting with a barbell)
Single leg movements,
Any type of stepping up or down (including stepping or walking while carrying
including walking or
weight)
stepping
Any type of lunge
Any type of single-sided lower body movement, such as a side-lying leg raise
Pushing movements
Any type of movement where weight is pressed away from the body (such as a
chest press or shoulder press) or where the body is pressed away from a
surface, such as any type of push-up
Pulling movements
Any type of movement where weight is pulled toward the body (such as a lat
pulldown or bent-over row), or where the body is pulled toward a surface, such
as a pull-up

WATCH
In applying the FITT principle to exercise selection for resistance training, choosing a different exercise from a
given movement category changes the Type. (In a basic sense, choosing a different exercise can also change
the Intensity if it adds more load or is done at a higher speed). Changing up the type of exercise for a given
movement type is important so that the body can keep progressing and so that muscles are worked at different
angles and directions.
EXAMPLE If a beginner to resistance training has been doing glute bridges with good form, they will
likely benefit from moving on to a squat to further challenge their body’s stability and mobility. Eventually,
they may move on to squatting with some type of load (such as holding a medicine ball or dumbbell) to
continue gradually overloading the muscles.
Movements that involve multiple joints and muscle groups are called compound movements. This is in
comparison to movements that involve a single joint, which are termed isolation movements. A leg extension
on a machine only works the muscles that extend the knee, making it an isolation movement. However, a squat
involves flexion and extension at the hip and the knee, making it a compound movement.

TERMS TO KNOW
Synergist
A muscle that assists the agonist muscles in their movement.
Stabilizer
A muscle that helps maintain alignment and proper movement as the agonist muscles work.
Compound Movement
A movement that involves multiple joints and muscle groups.
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Isolation Movement
A movement that involves a single joint.
3. Core Exercises
Your core muscles are not just the muscles of the abdominals, or the “six-pack” muscles that come to mind
when we think about a very athletic physique. Your core includes many deep muscles and surface muscles that
contribute to breathing, posture, and stable movements. In addition to the superficial six-pack muscles, which
are called the rectus abdominus, you have two pairs of oblique muscles and the deepest sheath of core muscle,
called the transverse abdominis. Together with other muscles of your core, like the ones that support your
spine, these muscles work together to help maintain the body’s stability and transmit force. In fact, this group of
muscles functions as the body’s natural weight belt. When your transverse abdominis contracts, it increases
stability of the lumbar spine, along with the coordination of other core muscles (Willardson, 2008).
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Considering what movements to select for core exercises can start with considering the movements at the
spine, since the core musculature supports the spine. In general, our spine can extend, flex, bend laterally
(termed lateral flexion), and rotate. However, it can be common for spinal flexion exercises to get priority, such
as sit-ups or crunches. Using a variety of movements and directions will help contribute to muscle balance and
help movements transfer better into everyday activities or sports.

WATCH
This video provides a short beginner abdominal workout you can try that includes spinal flexion, lateral
flexion, and rotation, as well as an isometric movement.
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4. Considerations for Resistance Training
Equipment
People who are just starting off with resistance training typically benefit from focusing first on bodyweight
movements, or movements with light resistance, such as using resistance bands. This allows the body to adapt
and learn the correct form before adding more resistance (such as through machines, dumbbells, or barbells).
However, a disadvantage of using primarily bodyweight movements is that the resistance is limited to whatever
an individual weighs, so someone with a goal to build strength may eventually reach a plateau (Haff & Triplett,
2016).
Performing a bent-over row with a resistance band.
Weight machines are a common choice for adding load to resistance training exercises but have both
advantages and disadvantages. One advantage is that weight machines tend to be safer than using free
weights, such as dumbbells or barbells. Weight machines have selector pins and safety mechanisms that
prevent the weight from being dropped. In addition, most weight machines only allow movement in a straight
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line, so the range of movement is controlled. Because of this, weight machines can also be useful for someone
with joint conditions or past injuries. Weight machines can also be an advantage for someone who wants to
isolate specific muscle groups. If someone is trying to improve their hamstring strength relative to their
quadriceps strength, they can isolate the hamstrings on a machine. Someone who wants to build hypertrophy
may also use machines to ensure they are isolating all major muscle groups.
However, weight machines are typically less relevant to functional movements of everyday life, or sports. Many
weight machines have the person in a seated position, and the controlled movement in one straight line means
that the body has far less opportunity for core stability.
Performing a chest press on a weight machine.
Free weights, such as dumbbells, barbells, and kettlebells tend to be the most relevant choice for transferring
into actual movements. This is because they require multiple groups of muscles to work together for stability
and coordination (McCall, 2014). In the image below, the individual is not only using her leg muscles for
squatting, but the muscles of her core to maintain good posture and body alignment. Free weights also offer
more variety in changing up the exercise type to keep progressing per the FITT principle. In the image below,
the individual could use the barbell for other movement variations involving squatting, bending or hinging, such
as holding the barbell overhead to squat, or performing a deadlift with the barbell.
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A disadvantage of free weights is that these movements can be complex and require extra attention to safety.
Some free-weight movements require either a spotter or enough space to drop the weight when the person
cannot complete the movement. A person also needs to be well-versed in the proper form and technique for
free-weight movements. Otherwise, they are at risk of moving without control and coordination, increasing the
risk of injury.
Performing a back squat with a barbell.

BIG IDEA
There are a variety of considerations in selecting the right movements and equipment for resistance
training in your exercise program. While everyone benefits from working the major muscle groups, the
methods and movements used can be very individualized depending on goals, needs, and equipment
available.

SUMMARY
In this lesson, you first learned about the value of understanding resistance training exercises by muscle
group. Working all major muscle groups is not only a recommendation by the Physical Activity
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Guidelines but also promotes muscle balance. You then learned about exercises by movement type,
which can be another way of choosing what exercises to do based on the primary movements of
squatting/bending/hinging, single leg movements, pushing, or pulling. Core exercises ideally do not just
focus on sit-ups or crunches, but involve all ranges of motion at the spine—flexion, extension, lateral
flexion, and rotation. Lastly, you learned about considerations for resistance training equipment, such
as the benefits and drawbacks of body weight, resistance bands, machines, and free weights.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE. Markup: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING.
PLEASE SEE OUR TERMS OF USE.
REFERENCES
American Council on Exercise (2020). The exercise professional’s guide to personal training: A client-centered
approach to inspire active lifestyles. Jo, S., Bryant, C.X., Dalleck, L.C., Gagliardi, C.S., and Green, D.J. (eds). ISBN:
9781890720766
Centers for Disease Control and Prevention (2009). Fact sheet for health professionals on physical activity
guidelines for older adults. U.S. Department of Health and Human Services.
www.cdc.gov/physicalactivity/downloads/pa_fact_sheet_olderadults.pdf
Haff, G., & Triplett, N. T. (2016). Essentials of strength training and conditioning (4th ed). National Strength and
Conditioning Association. Champaign, IL, Human Kinetics.
McCall, P. (2014). How to select the right exercises for your clients. American Council on Exercise.
www.acefitness.org/resources/pros/expert-articles/4921/how-to-select-the-right-exercises-for-your-clients/
McCall, P. (2016). Muscle imbalance: 6 things to know about muscle imbalances. American Council on Exercise.
www.acefitness.org/resources/everyone/blog/5930/muscle-imbalance-6-things-to-know-about-muscleimbalances/
National Strength and Conditioning Association (2015). Foundations of fitness programming. National Strength
and Conditioning Association.
www.nsca.com/contentassets/8323553f698a466a98220b21d9eb9a65/foundationsoffitnessprogramming_20
1508.pdf
Rosene, J. M., Fogarty, T. D., & Mahaffey, B. L. (2001). Isokinetic hamstrings: quadriceps ratios in intercollegiate
athletes. Journal of Athletic Training, 36(4), 378. www.ncbi.nlm.nih.gov/pmc/articles/PMC155432/
Ruas, C. V., Pinto, R. S., Haff, G. G., Lima, C. D., Pinto, M. D., & Brown, L. E. (2019). Alternative methods of
determining hamstrings-to-quadriceps ratios: a comprehensive review. Sports Medicine-Open, 5, 1-14.
doi.org/10.1186/s40798-019-0185-0
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Willardson, J. M. (2008). A periodized approach for core training. ACSM's Health & Fitness Journal, 12(1), 7-13.
doi.org/10.1249/01.fit.0000298458.22383.bd

TERMS TO KNOW
Agonist
The main muscle group doing a given movement; typically contracting and shortening.
Antagonist
The muscle group that is working in opposition to the agonist; typically lengthening as the agonist
contracts.
Compound Movement
A movement that involves multiple joints and muscle groups.
Isolation Movement
A movement that involves a single joint.
Muscle Balance
The principle that the muscles surrounding each major joint in the body generate the appropriate amounts
of opposing force.
Stabilizer
A muscle that helps maintain alignment and proper movement as the agonist muscles work.
Synergist
A muscle that assists the agonist muscles in their movement.
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Flexibility and Mobility Exercises
by Sophia

WHAT'S COVERED
In this lesson, you will learn about different types of stretching and other modalities or techniques that
can improve flexibility and mobility. Specifically, this lesson will cover the following:
1. Types of Stretching
1a. Static Stretching
1b. Dynamic Stretching
1c. Proprioceptive Neuromuscular Facilitation (PNF)
2. Considerations for Stretching
3. Modalities to Enhance Flexibility and Mobility
3a. Self-Myofascial Release (SMR)
3b. Yoga
3c. Pilates
1. Types of Stretching
As you read about in the lesson titled “Principles of Flexibility and Mobility,” flexibility is included in the Physical
Activity Guidelines for Americans, though research is mixed on the role and benefits of improving flexibility. To
make choices on what type of flexibility movements are best for you, it’s important to understand the basic
types of stretching, as well as other types of movement that can enhance flexibility and mobility.
1a. Static Stretching
Static stretching places slow and constant tension on the muscle by lengthening it to the point of mild tension
and holding the stretch (Peck et al., 2014). Static stretching is the type of stretching described in the Physical
Activity Guidelines with the recommendation to stretch all major muscle groups and to hold the stretch for 10–
30 seconds. You learned about the sit-and-reach test as a flexibility assessment, where holding that reach at
mild tension for a duration of time would be an example of a static stretch.
The reason that static stretching can increase your flexibility comes down to the Golgi tendon organ, which is a
type of stretch receptor found in tendons and joint capsules (Feher, 2012). Golgi tendon organs are part of the
nervous system and sense the amount of tension in a muscle (Martin, 2017). When a muscle is lengthened, such
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as in a static stretch, the Golgi tendon organ signals the muscle to relax. If not for the Golgi tendon organ, your
muscles would stay tight and contracted during stretching, making stretches less effective.
Types of static stretches

TERMS TO KNOW
Static Stretching
A type of stretching that places slow and constant tension on the muscle by lengthening it to the point of
mild tension and holding the stretch.
Golgi Tendon Organ
A type of stretch receptor found in tendons and joint capsules; it senses the amount of tension in a
muscle.
1b. Dynamic Stretching
The stretches in dynamic stretching are not held motionless but instead involve active movements to create
length in muscles (Peck et al., 2014). Arm circles, leg swings, and even bodyweight movements such as squats
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or lunges are all types of dynamic stretches. Dynamic stretches are typically done before physical activity, rather
than after, and use movements that will mimic the exercises that will be performed (Edwards, 2012).
EXAMPLE In sports, dynamic stretches are often part of the warmup to help athletes take their muscles
through the ranges of motion and movement patterns they will use. A golfer may do dynamic stretches that
include rotation at the spine, like a lunge with a twist, since a golf swing requires rotation. A sprinter might
include walking knee hugs, alternating hugging one knee to chest while walking, since the hips will need
the full range of motion to generate the most force.
Types of dynamic stretches

TERM TO KNOW
Dynamic Stretching
A type of stretching where the stretches involve active movements to create length in muscles, rather
than being held motionless.
1c. Proprioceptive Neuromuscular Facilitation (PNF)
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A third type of stretching is called proprioceptive muscular facilitation (PNF), which involves cycles of active
contractions of muscles, then relaxation of those muscles during the stretch. While both PNF stretching and
static stretching are held relatively motionless, static stretching is passive and does not use active muscle
contraction. Some research shows that PNF improves the range of motion more effectively than static stretching
but is reported as more uncomfortable (Hayward & Gibson, 2014).

STEP BY STEP
Because PNF requires active muscle contraction, it works most effectively if the muscles being stretched
can push against something, such as a wall, stretching band, or using another person’s assistance. In the
image below, a man is performing a lying hamstring stretch using a band. A static stretch would involve just
holding the leg at the point of mild tension. However, a PNF stretch would have the following steps
(Edwards, 2012):
1. Perform a passive stretch to the point of mild tension for 10 seconds ( just like a static stretch).
2. Then, isometrically contract the muscle group being stretched—in this case, the hamstrings—for 6
seconds. The man using the band in the image below would resist the opposing force of the
hamstrings by keeping the band pulled tight.
3. Next, relax the muscle group into a passive stretch again and hold for 30 seconds, where a greater
range of motion should now occur.
The type of PNF described here only involves contracting the agonist, or the muscle to be stretched.
However, there are multiple subtypes of PNF stretching, where another type involves contracting the
antagonist muscle as well. For that type, the man pictured in the image would contract the hamstring
antagonist (the quadriceps) during the 30-second final stretch. You’ve learned that muscles work in
agonist/antagonist pairs, so contracting the opposing group (the antagonist) allows the agonist to further
lengthen.
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
TERM TO KNOW
Proprioceptive Neuromuscular Facilitation (PNF)
A type of stretching that involves cycles of active contractions of muscles and then relaxation of the
muscles during the stretch.
2. Considerations for Stretching
Not all types of stretches are ideal for all exercise situations. In general, dynamic stretching is most effective
before a workout or sport, and it’s better to do static stretching or PNF stretching after activity. This is because
muscles that have been held in lengthened positions tend to generate less power and force. Therefore, static
stretching—especially in activities requiring speed, strength, and power—can negatively affect performance
when done before the activity (Garber et al., 2011).
IN CONTEXT
An analysis of over 62 articles on stretching’s effect on performance found that dynamic stretching
done before exercise improved activities requiring agility, speed, strength, and power. Static
stretching done before these types of exercise tended to have no effect, or negative effects, such as
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slower sprint times, reduced golf accuracy, and less weight lifted in 1-rep max efforts (Peck et al.,
2014).
Another consideration for stretching effectively and safely is to avoid ballistic stretching, which uses repeated
bouncing movements (Edwards, 2012).
EXAMPLE A ballistic hamstring stretch could involve someone bending down and bouncing repeatedly
to try and reach further down toward their toes.
Earlier in this lesson, you learned about the Golgi tendon organ, which senses the amount of tension in a muscle
and signals the muscle to relax when slowly stretched. The muscle spindle reflex is also a type of stretch
receptor but is most responsive to the speed of movement (Hayward & Gibson, 2014). When you stretch a
muscle in a quick, bouncing manner, the muscle spindle reflex causes the muscle to contract further, becoming
more resistant to stretching (Hayward & Gibson, 2014). This muscle contraction can increase the risk of injury,
such as muscle strains or muscle tears. While ballistic stretching can be safe and useful in some contexts, such
as athletes who require extreme ranges of motion, this type of stretching is not typically the first choice in an
exercise program.
A third consideration for stretching is that muscles should be warm before they are stretched. If you picture a
ball of clay that has sat outside in the cold, immediately trying to stretch it would probably cause it to break or
snap. Instead, warming the clay would give you the best chance of stretching it. Your muscles can be compared
to this analogy where stretching them cold, without warming up, puts you at higher risk for injuries like muscle
strains. You’ll learn further about the components of a warm-up in the next lesson, but overall, muscles need to
be warm with adequate blood flow before stretching. Even if the temperature around you is warm and your
muscles are not physically cold, your stretches will be more effective if you first do some continuous movement
that elevates your heart rate slightly. Depending on the nature of your workout or sport, this can typically be
accomplished with a few minutes of dynamic movements or cardiovascular activity.

WATCH

TERMS TO KNOW
Ballistic Stretching
A type of stretch that uses repeated bouncing movements.
Muscle Spindle Reflex
A type of stretch receptor found in tendons and joint capsules, it is most responsive to the speed of
movement.
3. Modalities to Enhance Flexibility and Mobility
Besides types of stretching, there are some specific forms of exercise or movements that can also enhance
flexibility and mobility. It’s important to incorporate different stretching positions for the same muscle groups, as
this stretches the muscle in different planes of motion and different tension lengths (Hayward & Gibson, 2014).
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No muscle group has a single best stretch that is most effective, so incorporating other modalities can all
provide variety. This also promotes progression per the FITT principle (with the T for Type) by choosing
different types of flexibility and mobility movements.
3a. Self-Myofascial Release (SMR)
Self-myofascial release (SMR) is a type of technique that typically uses a tool (such as a foam roller or small ball)
to apply pressure to muscle and fascia (Beardsley & Škarabot, 2015). Fascia is a structural component that holds
your muscles together and is mostly made of collagen (Parisi & Allen, 2019). If you think about peeling open a
citrus fruit, the white membrane that holds the slices together is like the fascia holding your muscle fibers
together. Fascia can get matted and bunched up over time, whether through repetitive movement patterns,
sedentary lifestyles, injuries, or other factors. Self-myofascial release helps to align the fascia and release
muscle tension. Your fascia provides compression and elasticity for your muscles to produce force, so the
premise with SMR is that it can facilitate more effective movement over time (Parisi & Allen, 2019). Research is
mixed on the benefits of self-myofascial release, but reviews of multiple studies found that SMR does tend to
improve flexibility (Beardsley & Škarabot, 2015) and enhance recovery by reducing fatigue after workouts
(Healey et al., 2011).
Using a foam roller for self-myofascial release of the calf muscles.
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
TERM TO KNOW
Self-Myofascial Release (SMR)
A type of technique to enhance flexibility and mobility that typically uses a tool to apply pressure to
muscles and fascia.
3b. Yoga
There are many types of yoga ranging from very slow-moving and therapeutic, to faster-paced and athletic.
Regardless of the type, yoga poses promote movement through full ranges of motion, which enhances
flexibility (Sharma et al., 2015). One study on previously sedentary adults found that doing a 55-minute yoga
class, 3 days a week, for 8 weeks resulted in overall average flexibility increasing by 35% (Boehde et al., 2005).
Another study on college athletes found that 10 weeks of yoga twice a week provided significant gains in
flexibility and balance compared to a group of college athletes who did not perform yoga (Polsgrove et al.,
2016).
3c. Pilates
Pilates is a modality where every movement has both a stretching and a strengthening component. In addition,
Pilates movements have a particular focus on proper body alignment and initiating movements from the core
musculature (termed “the Powerhouse” in Pilates). Pilates can be done with just bodyweight movements on a
mat or with props like small balls, or with movements on specialized machines led by a Pilates instructor. Like
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yoga, Pilates can also range from gentle and rehabilitative to more challenging and highly skilled. However,
unlike yoga, Pilates movements are typically more dynamic and are not held for extended lengths of time. One
study used two groups to compare Pilates to static stretching, where each group did 60 minutes of exercise
twice a week for 3 months. The group that did Pilates had more flexibility improvements in some muscle groups
(de Oliviera et al., 2016).
IN CONTEXT
Both yoga and Pilates are considered forms of mind-body exercise, which is characterized by
movement paired with breath and focused attention (Zhang et al., 2021). Besides yoga and Pilates,
other types of mind-body exercise include tai chi and qigong, which both focus on pairing breath
practices with slow, graceful movements (Wang et al., 2017).
Mind-body exercise is different from cardiovascular exercise or resistance training as it is slower in
pace and lower in intensity (Zhang et al., 2021). However, mind-body exercise still has a variety of
health benefits. For instance, doing mind-body exercises can lower the body’s stress response,
benefiting the nervous system and bolstering the immune system (Eichenberger-Archer, 2008).
Research also has found that mind-body exercise improves cognitive functions of the brain (such as
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memory and attention) to a greater extent than cardiovascular or resistance training exercise
(Blomstrand et al., 2023).

TERM TO KNOW
Mind-Body Exercise
A form of exercise that is characterized by movement paired with breath and focused attention, such as
yoga, Pilates, tai chi, or qigong.

SUMMARY
In this lesson, you first learned about different types of stretching. Static stretching involves holding a
stretch at the point of mild tension, while dynamic stretching uses active movements to promote
muscle length. Proprioceptive neuromuscular facilitation (PNF) uses cycles of contracting and relaxing
the muscle. Some considerations for stretching include doing dynamic stretching before working out
and saving static stretching or PNF for afterward, avoiding ballistic stretches, and not stretching cold
muscles. Lastly, you learned about other modalities to enhance flexibility and mobility. Self-myofascial
release uses an external tool like a foam roller to align the fascia of the muscle. Yoga and Pilates are
both types of mind-body modalities that can improve flexibility and provide other health benefits by
pairing breath with movement and focused attention.
Source: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING. PLEASE SEE OUR
TERMS OF USE. Markup: THIS TUTORIAL WAS AUTHORED BY Anna Caggiano FOR SOPHIA LEARNING.
PLEASE SEE OUR TERMS OF USE.
REFERENCES
Beardsley, C., & Škarabot, J. (2015). Effects of self-myofascial release: a systematic review. Journal of Bodywork
and Movement Therapies, 19(4), 747-758. doi.org/10.1016/j.jbmt.2015.08.007
Boehde, D. D., Porcari, J. P., Greany, J., Udermann, B., Johanson, D., & Foster, C. (2005). The physiological
effects of 8 weeks of yoga training. Journal of Cardiopulmonary Rehabilitation and Prevention, 25(5), 290.
doi.org/10.1097/00008483-200509000-00016
Blomstrand, P., Tesan, D., Nylander, E. M., & Ramstrand, N. (2023). Mind body exercise improves cognitive
function more than aerobic-and resistance exercise in healthy adults aged 55 years and older–an umbrella
review. European Review of Aging and Physical Activity, 20(1), 15. doi.org/10.1186/s11556-023-00325-4
de Oliveira, L. C., de Oliveira, R. G., & de Almeida Pires-Oliveira, D. A. (2016). Comparison between static
stretching and the Pilates method on the flexibility of older women. Journal of Bodywork and Movement
Therapies, 20(4), 800-806. doi.org/10.1016/j.jbmt.2016.01.008
© 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC.
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Edwards, M. (2012). Types of stretching. American Council on Exercise. www.acefitness.org/fitnesscertifications/ace-answers/exam-preparation-blog/2966/types-of-stretching/
Eichenberger-Archer, S. (2008). What is mind-body exercise? IDEA Health & Fitness Association.
www.ideafit.com/personal-training/what-is-mind-body-exercise/
Feher, J. (2012). Quantitative human physiology: an introduction. Elsevier: Academic Press. ISBN:
9780123821638
Garber, C. E., Blissmer, B., Deschenes, M. R., Franklin, B. A., Lamonte, M. J., Lee, I. M., ... & Swain, D. P. (2011).
Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and
neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Medicine & Science in
Sports & Exercise, 43(7), 1334-1359. doi.org/10.1249/MSS.0b013e318213fefb
Hayward, V.H., & Gibson, A.L. (2014). Advanced Fitness Assessment and Exercise Prescription. Illinois: Human
Kinetics. ISBN: 9781450466004
Healey, K., Dorfman, L., Riebe, D., Blanpied, P., & Hatfield, D. (2011). The effects of foam rolling on myofascial
release and performance. The Journal of Strength & Conditioning Research, 25, S30-S31.
doi.org/10.1097/01.jsc.0000395625.08079.28
Kloubec, J. A. (2010). Pilates for improvement of muscle endurance, flexibility, balance, and posture. The Journal
of Strength & Conditioning Research, 24(3), 661-667. doi.org/10.1519/jsc.0b013e3181c277a6
Parisi, B. & Allen, J. (2019). Fascia training: a whole-system approach. [Independently]. ISBN: 9781794564657
Peck, E., Chomko, G., Gaz, D. V., & Farrell, A. M. (2014). The effects of stretching on performance. Current Sports
Medicine Reports, 13(3), 179-185. doi.org/10.1249/JSR.0000000000000052
Polsgrove, M. J., Eggleston, B. M., & Lockyer, R. J. (2016). Impact of 10-weeks of yoga practice on flexibility and
balance of college athletes. International Journal of Yoga, 9(1), 27–34. doi.org/10.4103/0973-6131.171710
Sharma, L. (2015). Benefits of yoga in sports–A study. Int J Phys Educ Sports Health, 1(3), 30-32.
www.kheljournal.com/archives/2015/vol1issue3/PartA/29.1.pdf
Wang, Y. T., Huang, G., Duke, G., & Yang, Y. (2017). Tai Chi, yoga, and qigong as mind-body exercises. Evidencebased complementary and alternative medicine, 2017. doi.org/10.1155/2017/8763915
Zhang, X., Zong, B., Zhao, W., & Li, L. (2021). Effects of mind-body exercise on brain structure and function: A
systematic review on MRI studies. Brain Sciences, 11(2), 205. doi.org/10.3390/brainsci11020205

TERMS TO KNOW
Ballistic Stretching
A type of stretch that uses repeated bouncing movements.
Dynamic Stretching
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A type of stretching where the stretches involve active movements to create length in muscles, rather
than being held motionless.
Golgi Tendon Organ
A type of stretch receptor found in tendons and joint capsules, it senses the amount of tension in a
muscle.
Mind-Body Exercise
A form of exercise that is characterized by movement paired with breath and focused attention, such as
yoga, Pilates, tai chi, or qigong.
Muscle Spindle Reflex
A type of stretch receptor found in tendons and joint capsules, it is most responsive to the speed of
movement.
Proprioceptive Neuromuscular Facilitation (PNF)
A type of stretching that involves cycles of active contractions of muscles and then relaxation of the
muscles during the stretch.
Self-Myofascial Release (SMR)
A type of technique to enhance flexibility and mobility that typically uses a tool to apply pressure to
muscles and fascia.
Static Stretching
A type of stretching that places slow and constant tension on the muscle by lengthening it to the point of
mild tension and holding the stretch.
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Injury Prevention, Safety, and Recovery
by Sophia

WHAT'S COVERED
In this lesson, you will learn about ways to stay safe and injury-free during exercise. Specifically, this
lesson will cover the following:
1. PAR-Q and Health Conditions
2. Individualizing Safety Factors
3. Warming Up and Cooling Down
4. Other Safety Considerations
1. PAR-Q and Health Conditions
Most people are not likely to be injured when doing moderate-intensity activities in amounts that meet the
Physical Activity Guidelines. However, injuries and other adverse events do sometimes happen. The first step in
doing physical activity safely is to consider any preexisting conditions or symptoms that could affect exercise.
The PAR-Q+ (Physical Activity Readiness Questionnaire for Everyone) is a commonly used screening tool that
will tell you if it’s necessary to seek advice from a medical professional regarding your physical activity.
You may remember from the lesson “Physical Activity Guidelines” that the guidelines include people with
chronic health conditions, and that the overall recommendations are the same—150 minutes of moderateintensity cardiovascular activity and at least 2 days a week of muscle-strengthening activity. Therefore, people
with chronic health conditions can still stay active and should avoid sedentary time, though different conditions
may have specific considerations advised by a medical professional.
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IN CONTEXT
People with heart conditions may receive advice from their medical professional to keep their
heart rates within a certain range to avoid putting extra stress on the heart.
People with diabetes may need to monitor their blood glucose levels before and after exercise
and pay special attention to proper footwear.
People with joint issues or musculoskeletal pain, such as arthritis or back pain, may need to avoid
certain types of movements.
Women who are pregnant and those who’ve recently had a baby should be under the regular care
of a health care provider. Moderate-intensity physical activity is generally safe for women with
uncomplicated pregnancies, but women should talk with their health care providers about how to
adjust the amounts and types of activity while they are pregnant and right after the baby’s birth.

LEARN MORE
You can take the PAR-Q online for yourself by answering a series of questions, where the results will
generate a recommendation if you may need to seek medical guidance before becoming physically active
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or increasing your activity.

TERM TO KNOW
PAR-Q
Abbreviation for Physical Activity Readiness Questionnaire for Everyone; it is a commonly used
screening tool to determine if it’s necessary to seek advice from a medical professional before starting
or increasing physical activity.
2. Individualizing Safety Factors
Although physical activity has many health benefits, injuries and other adverse events do sometimes happen.
The most common injuries affect the musculoskeletal system (the bones, joints, muscles, ligaments, and
tendons). Even so, studies show that only one such injury occurs for every 1,000 hours of walking for exercise,
and fewer than four injuries occur for every 1,000 hours of running.
First off, choose the appropriate type and amount of activity. The safest types of activities are moderate
intensity and low impact, such as walking, bicycling, dancing, and swimming. Competitive contact sports like
soccer, hockey, and basketball have a higher risk of injury. Also, competitive activities tend to have higher injury
rates than noncompetitive activities, likely due to different degrees of intensity of participation. This doesn’t
mean that sports or competitive activities should be avoided, as they can be fun and motivating. However,
someone who is inactive or inconsistent with exercise should build experience with safer activities before
choosing these.
Scientific studies indicate that the risk of injury to bones, muscles, and joints is directly related to the gap
between a person’s usual level of activity and a new level of activity. Creating a small overload and waiting for
the body to adapt and recover reduces the risk of injury. When amounts of physical activity need to be
increased to meet the Guidelines or personal goals, physical activity should be increased gradually over time,
no matter what the person’s current level of physical activity.
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Scientists have not established a standard for how to gradually increase physical activity over time. The
following recommendations give general guidance for inactive people and those with low levels of physical
activity on how to increase physical activity:
Use relative intensity (intensity of the activity relative to a person’s fitness) to guide the level of effort for
cardiovascular activity. The 0–10 RPE scale that you learned about is a good choice.
Generally, start with relatively moderate-intensity aerobic activity. Avoid relatively vigorous-intensity activity,
such as shoveling snow or running. Adults with a low level of fitness may need to start with light activity, or a
mix of light- to moderate-intensity activity.
First, increase the number of minutes per session (duration), and the number of days per week (frequency)
of moderate-intensity activity. Later, if desired, increase the intensity.
Pay attention to the relative size of the increase in physical activity each week, as this is related to injury
risk. In general, time or distance should not be increased by more than 10% each week.
EXAMPLE A 20-minute increase each week is safer for a person who does 200 minutes a week of
walking (a 10 percent increase), than for a person who does 40 minutes a week (a 50 percent increase).
The available scientific evidence suggests that adding a small and comfortable amount of light- to moderateintensity activity, such as 5 to 15 minutes of walking per session, two to three times a week, to one’s usual
activities has a low risk of musculoskeletal injury and no known risk of severe cardiac events. Because this
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range is rather wide, people should consider three factors in individualizing their rate of increase: age, level of
fitness, and prior experience.
Age likely affects the amount of time required to adapt to a new level of activity. Youth and young adults can
likely increase activity safely by small amounts every week, or every other week. Older adults appear to
require 2–4 weeks or more to adapt to a new level of activity.
With level of fitness, less fit adults, or those with excess body fat, are at higher risk of injury when doing a
given amount of activity compared to fitter adults at a normal weight. Slower rates of increase over time
may reduce injury risk.
Regarding prior experience, people can use their experience to learn to increase physical activity over time
in ways that minimizes the risk of overuse injury. Generally, if an overuse injury occurred in the past with a
certain rate of progression, a person should increase activity more slowly the next time.
3. Warming Up and Cooling Down
Warm-up and cool-down activities are an important part of a person’s physical activity plan. Commonly, the
warm-up and cool-down involve doing an activity at a slower speed or lower intensity. A warm-up before
moderate- or vigorous-intensity aerobic activity allows a gradual increase in heart rate and breathing at the start
of the episode of activity. According to the American Heart Association (2014), the warmup dilates your blood
vessels to supply your muscles with oxygen, raises your muscle temperature for efficient movement, and raises
your heart rate to minimize extra stress on your heart.
In general, a good warmup is at least a few minutes long and serves as a rehearsal with lighter or slower
movements than would be done in the workout. However, the more intense or complex the activity is, the more
intensive and detailed the warm-up should be. A person taking a moderate-intensity walk can start just walking
at a slower pace for the first few minutes, but a person doing sprint intervals or lifting heavy weights will need a
more extensive warmup. For intense or complex activities, the warmup also serves as psychological
preparation to reinforce being mentally ready for the challenge.
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IN CONTEXT
A common way to structure a warm-up is through using the acronym RAMP, which moves from more
general to more specific (Racianis et al., 2017).
The R stands for Raise. Choose a low-to-moderate intensity activity that will raise your body
temperature and get your heart rate up. Any general cardiovascular movement typically works
well, such as walking, jogging, biking, or rowing.
The A stands for Activate. Think about the main muscle groups you’ll use in your workout and do
similar movements. Body weight movements such as squats, pushups, or lunges are all examples.
The M stands for Mobilize. Think about what ranges of motion your joints will need for the activity.
Self-myofascial release and/or dynamic stretches fit well here to move through any areas that
could be stiff or tight. Someone going out for a run might foam roll their quads and calves, and do
leg swings, for example.
The P stands for Potentiate, which refers to selecting specific activities that will improve the
effectiveness of the workout (Jeffreys, 2006). This last part of RAMP is where the rehearsal
movements go that are specific to the activity but done at a slower pace, lower intensity, or lighter
weight.
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A cool-down after activity allows your body processes to gradually return to normal. Your heart rate, blood
pressure, and body temperature all elevate with exercise, and if you stop suddenly, you risk passing out or
feeling sick (American Heart Association, 2014). Similar to warm-up principles, the more intense the workout,
the more extensive the cool-down should be. Someone who has taken a moderate-intensity walk can likely take
a few minutes to walk more slowly and then perform static stretching. However, someone who has just been
exercising at an 8 to 9 on the 0–10 RPE scale may need a longer cool-down for their body to acclimate. Postworkout is a good time to perform static stretching, PNF stretching, and/or self-myofascial release as part of
your cool-down. This may help reduce muscle stiffness, and the slow movements of stretching can help you
slow your breathing rate back to normal.
4. Other Safety Considerations
Keeping a few other considerations in mind can help you have safe, injury-free workouts. Shoes are an
important part of any activity where your feet are in contact with the ground. Activities involving jumping or
running can put up to six times as much pressure on your joints (Insel et al., 2022). The same type of shoe
doesn’t work for everyone’s feet or every activity, so it can be a good idea to consult a fitness professional or
go to a shoe store that specializes in athletic shoes. In addition, shoes should be replaced approximately every
6 months if you are regularly active because the cushioning will wear out gradually (Harvard Health Publishing,
2010).
The environment that you exercise in can be a safety hazard if you are unprepared. Exercising in a hot, humid
environment increases the risk of dehydration and heat-related illness, since the body can’t cool itself as
efficiently (Thompson, 2017). In a regular environment, a good practice is to drink at least 16 ounces of fluid 2–4
hours before exercise, and then drink enough fluid to replace what you have lost in sweat during and after
exercise (Insel et al., 2022). However, you may need more fluid than this if you are working out in heat and
humidity. In addition, reducing your speed or intensity may be necessary so that your body does not have to
work as hard to cool itself.
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Working out in the cold can also warrant special considerations. Hypothermia is a medical emergency that
occurs when your body has a dangerously low temperature (Mayo Clinic, 2022). When you are sweating, your
body can become chilled more quickly since it is wet (Thompson, 2017). Wearing layers of clothing will allow you
to adjust accordingly as your body temperature rises. Choose workout apparel made of synthetic materials or
nylon rather than cotton, as these are best at absorbing sweat and blocking windchill (Thompson, 2017).
Lastly, listen to your body. If you are not feeling well or are very fatigued, cut back on your exercise session or
choose a lower-intensity option. Exercise is a good thing, but too much of a good thing can occur with
inadequate recovery. Delayed-onset muscle soreness (DOMS) is a normal muscle response that occurs 12–24
hours after a workout, though low-intensity activity like walking and flexibility exercise can help by promoting
blood flow to the recovering muscles. However, if you experience intense or persistent pain, soreness, or
stiffness during or after a workout, you should seek attention from a health professional rather than working
through the pain (Harvard Health Publishing, 2010).

TERMS TO KNOW
Hypothermia
A medical emergency that occurs when your body has a dangerously low temperature.
Delayed-Onset Muscle Soreness (DOMS)
A normal muscle response that occurs 12–24 hours after a workout.
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
SUMMARY
In this lesson, you learned about ways to stay safe and injury-free during exercise. The PAR-Q and
health conditions are ways to determine if you might need guidance from a medical professional
before starting or increasing exercise. There are multiple ways of individualizing safety factors in an
exercise program, such as considering your current fitness level and gradually increasing appropriately.
Warming up and cooling down are vital parts of staying safe by helping your body gradually acclimate
to and from the demands of a workout. Lastly, other safety considerations include proper footwear,
considering the temperature of your exercise environment, and listening to your body for proper
recovery.
Source: THIS TUTORIAL WAS CURATED AND/OR AUTHORED BY Anna Caggiano WITH CONTENT ADAPTED
FROM “WELLNESS” BY EXTENDED LEARNING INSTITUTE (ELI) AT NOVA. ACCESS FOR FREE AT oer commons.
LICENSING: CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL.

TERMS TO KNOW
Delayed-Onset Muscle Soreness (DOMS)
A normal muscle response that occurs 12–24 hours after a workout.
Hypothermia
A medical emergency that occurs when your body has a dangerously low temperature.
PAR-Q
Abbreviation for Physical Activity Readiness Questionnaire for Everyone; it is a commonly used screening
tool to determine if it’s necessary to seek advice from a medical professional before starting or increasing
physical activity.
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Your Exercise Program
by Sophia

WHAT'S COVERED
In this lesson, you will consider how to personalize your exercise plan to your own lifestyle,
circumstances, and goals. Specifically, this lesson will cover the following:
1. Personalizing Your Exercise Plan
1a. Goals
1b. Resources Available
1c. Time Available
1d. Existing Fitness Level and Experience
2. Overcoming Barriers
1. Personalizing Your Exercise Plan
Over these lessons on physical activity, you’ve learned there are a variety of ways to get moving and many
options for meeting the Physical Activity Guidelines and achieving fitness-related goals. While everyone
benefits from minimizing sedentary time and making physical activity a regular part of each day, this can look
quite different from person to person. The following factors are ones to consider in having an exercise plan that
is well-suited for you.
1a. Goals
Considering what you want to achieve or maintain through physical activity ensures that you have an exercise
plan that is personally meaningful to what you value. In the lesson titled “Wellness Assessment,” you learned
about setting goals with the SMART framework. Consider if your main goal is something like weight loss or
muscle gain, reaching a milestone like a certain amount of weight lifted or a certain distance run, or a goal of
progression or consistency like working up to the Physical Activity Guideline recommendations.
While people can exercise consistently and successfully without a defined goal, goals are motivating in the
following ways (American Council on Exercise, 2019):
Goals direct our attention toward daily behavior and actions. If you set a goal for being able to run a 5kilometer race without stopping, your actions should use the principle of specificity by training regularly in
running and doing fitness activities that support building muscular endurance.
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Goals help us put forth more effort and persistence. Although ideally, the types of exercise you choose are
overall enjoyable, exercise can be difficult and challenging. In using the 5k race example again, visualizing
the end goal of crossing the finish line can help you stick to your plan when you’re not feeling as motivated.
Having a goal promotes the use and exploration of strategies to reach that goal. If your goal is to ramp up
toward getting the recommended 150 minutes per week of moderate-intensity activity, you might
experiment with different ways to get there, such as taking a daily short walk, attending a group exercise
class, or trying an online video or app.
1b. Resources Available
It’s important to consider what resources you currently have available to you in personalizing your exercise plan
and setting SMART goals. First, consider what equipment and environment are available to you. If you have a
goal to build maximal strength and hypertrophy but do not have access to a fitness facility or any type of
resistance equipment, your goal will be less achievable and realistic since you have only your body weight to
work with. You may need to revise your goal based on what you have available, such as being able to complete
a certain number of repetitions of a bodyweight movement.
Also, consider what resources are available to track your progress toward your goal. If you have a goal to lose a
certain percentage of body fat, but don’t have a way to measure your body composition, you may start to lose
motivation since you can’t accurately assess your progress. It may be more helpful to set a process goal (which
you learned about in the lesson titled “Wellness Assessment”), such as accumulating a certain amount of
exercise on a weekly basis.
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1c. Time Available
Consider what time you have available to devote to exercise and how it will fit into your existing schedule. It may
not be realistic for someone with a full-time job, schoolwork, and a family to dedicate hours each day to
exercise. The types of time-efficient workouts you’ve learned about, like circuit training or high-intensity interval
training, maybe a better fit for someone with a packed schedule. Those who are time-crunched may also need
to consider how to fit short, portable exercise bouts into their routine throughout the day, rather than taking
travel time to go to and from a gym or other fitness facility.
1d. Existing Fitness Level and Experience
There is no single “best” exercise or way to organize and choose exercises. However, every exercise in a
person’s program, and the progression of that program, should logically be based on their current fitness level,
experience, and skill (McCall, 2014). People who are new to exercise and those with health conditions can
especially benefit from seeking the guidance of a certified fitness professional (Garber et al., 2011).
The American College of Sports Medicine provides some example guidelines for progressing both
cardiovascular exercise and resistance training exercises based on a person’s experience and using the FITT
principles (Bushman, 2018). With the terms below, a beginner is someone with no prior experience or who has
been sedentary for several years. Intermediate refers to someone who has approximately 6 months of
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consistent activity, and established or advanced refers to someone who has been training for years (American
College of Sports Medicine, 2009).
Cardiovascular Exercise – Walking Program Example
Beginner
Begin by walking a total of 20 minutes each day (which can be 10 minutes twice a day) at an
RPE of 3–4 to accumulate a weekly total of 60 minutes.
Once this is reached, add 10 minutes to the weekly total until 100 minutes is reached.
Maintain the duration and increase intensity over the next weeks to an RPE of 5–6. Maintain
this time and intensity and continue to add 10–15 minutes each week until consistently doing
150 minutes weekly.
Intermediate
Accumulate a weekly total of 150 minutes by walking at an RPE of 5–6 for 30–60 minutes, 3–
5 days a week. Progress either by continuing to increase exercise duration beyond 150
minutes or start to introduce bouts of vigorous-intensity exercise (RPE of 7–8), such as walkjog intervals.
Established
Walk at an RPE of 5–6 for a weekly total of 200–300 minutes or increase to vigorous intensity
(RPE of 7–8) for a weekly total of 100–150 minutes; or combine moderate and vigorous
intensities over the week.
Resistance Training Exercise Program Example
Beginner
Perform a total of 6 exercises for 1–2 sets, for 8–12 reps, 2–3 days a week.
Intermediate
Perform a total of 10 exercises for 2 sets, for 8–12 reps, for 2–3 days a week.
Advanced
Perform 10 exercises 2–3 times a week for larger muscle groups (hips, legs, chest, back), and
5 exercises twice a week for smaller muscle groups (abdominals, shoulders, biceps, triceps)
for 8–12 reps. Different exercises can be performed on different days and a given muscle
group should receive at least 48 hours of rest before working it again.
IN CONTEXT
The information in the table above provides general guidelines based on improving general fitness.
As you learned in the lessons “Cardiovascular Training Principles” and “Resistance Training
Principles”, someone with a specific goal—such as running a faster mile or improving the weight they
can lift for a 1-rep max—would need to use the FITT principle in a more targeted way. For example,
someone with a goal of maximal strength would do 6 repetitions or less because their intensity is
higher, rather than the 8–12 repetitions listed in the table.
2. Overcoming Barriers
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Given the health benefits of regular physical activity, we might have to ask why many Americans are not active at
recommended levels. Many technological advances and conveniences have made our lives easier and more
sedentary. In addition, many personal variables, including physiological, behavioral, and psychological factors,
may affect our plans to become more physically active. Understanding common barriers to physical activity and
creating strategies to overcome them can help with regular consistency.
Barrier
Lack of time
Strategies
Monitor your daily activities for one week. Identify at least three 30-minute potential time
slots. For example, perhaps there are times you spend watching TV or using your phone that
could be pared down to accommodate exercise.
Add physical activity to your daily routine, such as walking or biking to work or errands,
walking the dog if you have one, exercising while watching TV, and others.
Choose activities that require minimal time. Walking can be done almost anywhere and does
not need an extensive warm-up.
Lack of
Invite friends and family members to exercise with you.
motivation
Plan social activities involving physical activity, such as hikes or recreational games.
Develop new friendships with physically active people through joining groups or clubs
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centered around activity.
Join an exercise group or class at a fitness center or in your community.
Lack of energy Schedule physical activity ahead of time for times of day that you typically feel most
energetic.
Convince yourself that if you give it a chance, physical activity will increase your energy level
—then try it.
Fear of injury
Learn how to exercise appropriately considering your age, fitness level, skill level, and health
or lack of skill
status.
Consider seeking guidance from a certified fitness professional, such as a personal trainer.
Select activities that do not require skill and are low risk, such as walking.
Attend group fitness classes to develop new skills and learn proper form and technique to
prevent injury.
Weather
Have a set of enjoyable activities that are always available regardless of weather or being
conditions or
away from home, such as a bodyweight circuit you can do inside, stair climbing, mall walking,
travel
or routines online or through an app.
Lack of
Identify inexpensive, convenient resources available in your community. Examples include
resources
park and recreation programs, walking trails, local fitness events, and more.
Family
Exercise with your family if possible—walk together, play active games, or use an online
obligations
resource or app.
For those with children and obligations in caring for them, consider fitting in exercise when
kids are not around or awake yet, such as in the early morning hours or when kids are at
school.

THINK ABOUT IT
What is one of your own biggest barriers to physical activity? Even if you’re regularly active, there can be
days when you feel like you lack motivation or time, or encounter other barriers. Consider how you might
implement one of the above ideas into your own life.

SUMMARY
In this lesson, you learned about ways of personalizing your exercise plan. Accounting for your goals,
resources available, time available, and existing fitness level and experience can all ensure that your
exercise plan is right for your abilities and is overall enjoyable and set up for long-term success.
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Overcoming barriers is a necessary aspect to consider in an exercise program, where there are
multiple ways to encounter common barriers like lack of time or feeling unmotivated.
Source: THIS TUTORIAL WAS CURATED AND/OR AUTHORED BY Anna Caggiano WITH CONTENT ADAPTED
FROM “WELLNESS” BY EXTENDED LEARNING INSTITUTE (ELI) AT NOVA. ACCESS FOR FREE AT oer commons.
LICENSING: CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL.
REFERENCES
American College of Sports Medicine (2009). American College of Sports Medicine position stand. Progression
models in resistance training for healthy adults. Medicine and Science in Sports and Exercise, 41(3), 687–708.
doi.org/10.1249/MSS.0b013e3181915670
American Council on Exercise (2019). The professional’s guide to health and wellness coaching. ACE. ISBN: 9781-890720-71-1
Bushman, B. A. (2018). Developing the P (for Progression) in a FITT-VP Exercise Prescription. ACSM's Health &
Fitness Journal, 22(3), 6-9. doi.org/10.1249/FIT.0000000000000378
Garber, C. E., Blissmer, B., Deschenes, M. R., Franklin, B. A., Lamonte, M. J., Lee, I. M., ... & Swain, D. P. (2011).
Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and
neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Medicine & Science in
Sports & Exercise, 43(7), 1334-1359. doi.org/10.1249/MSS.0b013e318213fefb
McCall, P. (2014). How to select the right exercises for your clients. American Council on Exercise.
www.acefitness.org/resources/pros/expert-articles/4921/how-to-select-the-right-exercises-for-your-clients/
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Terms to Know
1-Repetition Maximum (1-RM)
The heaviest amount of weight that can be lifted for a single repetition in a given movement.
ATP (Adenosine Triphosphate)
An energy-carrying molecule found in all living things, capturing energy from the breakdown
of food and releasing it to fuel other body processes.
Aerobic Glycolysis
One of the three energy pathways in the body, it is most active during longer-duration, lowerintensity activities.
Aerobic Metabolism
A chemical process in which oxygen is used to make energy from carbohydrates.
Agility
The ability to rapidly change body positions in space with speed and accuracy.
Agonist
The main muscle group doing a given movement; typically contracting and shortening.
Anaerobic Glycolysis
One of the three energy pathways in the body, it is most active during higher intensities over
longer periods (30 seconds to 3 minutes).
Anaerobic Metabolism
The release of energy by partially breaking down glucose and glycogen but without
combining oxygen.
Anaerobic Threshold, Lactate Threshold, Onset of Blood Lactate Accumulation (OBLA)
All terms used to describe the transition between aerobic to anaerobic metabolism, where
lactate accumulates in the blood faster than the body can clear it.
Antagonist
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The muscle group that is working in opposition to the agonist; typically lengthening as the
agonist contracts.
Balance
The ability to maintain equilibrium, whether stationary (static balance) or moving (dynamic
balance).
Ballistic Stretching
A type of stretch that uses repeated bouncing movements.
Cardiac Output
The product of heart rate and stroke volume.
Cardiorespiratory Endurance
The ability to carry out prolonged, large muscle, dynamic movements at a moderate to high
level of intensity.
Circuit Training
A form of training where a person goes from one exercise to another over multiple exercises
with little to no rest.
Compound Movement
A movement that involves multiple joints and muscle groups.
Concentric
A type of muscular work where the working muscle shortens.
Coordination
The ability to use senses, like sight, along with the body to perform motor tasks smoothly and
accurately.
Delayed-Onset Muscle Soreness (DOMS)
A normal muscle response that occurs 12–24 hours after a workout.
Detraining
A principle of resistance training that describes the loss of adaptations that occur due to
reversibility.
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Diminishing Returns
A principle of resistance training noting that fitness gains will decrease or plateau if
overloading the muscles does not continue.
Dynamic Stretching
A type of stretching where the stretches involve active movements to create length in
muscles, rather than being held motionless.
Eccentric
A type of muscular work where the working muscle lengthens.
Estimated Maximum Heart Rate
A method of assessing cardiovascular exercise intensity; it requires subtracting the person’s
age from 220 and using that number as the maximum heart rate.
Excess Post-Exercise Oxygen Consumption (EPOC)
Also termed oxygen debt, it describes elevated metabolism that occurs after exercise as the
body works to regain homeostasis.
Exercise
A subcategory of physical activity that involves doing planned and structured activity with a
fitness-based objective.
FITT Principle
A way to implement improvements and progression in fitness; FITT stands for frequency,
intensity, time, and type.
Flexibility
The ability to move your joints through a full range of motion.
Functional Ability
The capacity of a person to perform tasks or behaviors that enable them to carry out
everyday activities.
Golgi Tendon Organ
A type of stretch receptor found in tendons and joint capsules, it senses the amount of
tension in a muscle.
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Heart Rate Reserve (HRR); Karvonen Method
A method of assessing cardiovascular exercise intensity; it takes a person’s resting heart rate
into account along with their estimated maximum heart rate by subtracting their age from
220.
High-Impact Exercise
Exercise that involves repetitive impact since both feet leave the ground, such as running or
jumping.
High-Intensity Interval Training (HIIT)
Bouts of high-intensity effort alternating with lower intensity recovery times, where the highintensity effort is typically at 80–95% of the estimated maximum heart rate, and the recovery
periods are often at 40–50% of the estimated maximum heart rate.
Hypermobility
When joints can move beyond normal ranges of motion.
Hypertrophy
Increased muscle size.
Hypokinetic Diseases
Diseases associated with sedentary lifestyles.
Hypothermia
A medical emergency that occurs when your body has a dangerously low temperature.
Individualization
A principle of resistance training, it explains that training should be modified to account for
an individual’s unique abilities, goals, and characteristics.
Isolation Movement
A movement that involves a single joint.
Isometric
A type of muscular work where the body remains in a static, motionless position.
Low-Impact Exercise
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Exercise that does not place a lot of force or stress on the body’s joints, such as swimming or
walking.
Mind-Body Exercise
A form of exercise that is characterized by movement paired with breath and focused
attention, such as yoga, Pilates, tai chi, or qigong.
Minute Ventilation
The volume of air breathed per minute.
Mobility
The ability to move freely in changing and controlling body position.
Muscle Balance
The principle that the muscles surrounding each major joint in the body generate the
appropriate amounts of opposing force.
Muscle Spindle Reflex
A type of stretch receptor found in tendons and joint capsules, it is most responsive to the
speed of movement.
Muscular Endurance
The ability to exert a force over a period of time or repetitions.
Muscular Strength
The ability of the muscles to exert force over a single or maximal effort.
Non-Exercise Activity Thermogenesis (NEAT)
Energy expended throughout the day from any activities besides planned exercise, sleeping,
and eating.
Overload
A principle of resistance training stating that changes need to continue in a training program
for fitness to improve.
PAR-Q
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Abbreviation for Physical Activity Readiness Questionnaire for Everyone; it is a commonly
used screening tool to determine if it’s necessary to seek advice from a medical professional
before starting or increasing physical activity.
Phosphagen System
One of the three energy pathways in the body, it is most active during very short-duration,
high-intensity activities lasting 1–30 seconds.
Physical Activity
Any body movement that increases metabolism over resting energy expenditure, which can
include daily tasks like housework or occupational duties.
Physical Fitness
The ability and health of your body to work efficiently and perform activities of daily living
with the least effort possible.
Plyometric
A type of power movement that involves quick contraction of the muscles to generate high
amounts of force.
Power
A product of both strength and speed; power relates to the rate at which someone can
perform physical work or quickly exert muscle force.
Progression
A principle of resistance training, it describes how variables in a resistance training program
are manipulated over time to reach training goals and avoid overtraining.
Proprioception
Having a sense of how the body is positioned and moves in space.
Proprioceptive Neuromuscular Facilitation (PNF)
A type of stretching that involves cycles of active contractions of muscles and then relaxation
of the muscles during the stretch.
Rating of Perceived Exertion (RPE) Scales
A way of estimating cardiovascular exercise intensity based on self-assessment of how hard
you are working, including heart rate, breathing rate, sweating, and muscle fatigue.
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Reaction Time
Entails the time elapsed between a stimulus and responding to that stimulus.
Reversibility
“Use it or lose it”, the principle of resistance training that states the body will lose exercise
adaptations if no stress is placed on it.
Self-Myofascial Release (SMR)
A type of technique to enhance flexibility and mobility that typically uses a tool to apply
pressure to muscles and fascia.
Specificity
A principle of resistance training where the body’s adaptations to exercise depend on the
nature of the stress and how it is applied.
Speed
The ability to perform a movement in a short amount of time.
Sprint Interval Training (SIT)
Interval training done at a nearly all-out intensity, where maximal efforts are done for 30
seconds or less with longer recovery times, such as 4 minutes.
Stability
The ability to maintain or control joint position.
Stabilizer
A muscle that helps maintain alignment and proper movement as the agonist muscles work.
Static Stretching
A type of stretching that places slow and constant tension on the muscle by lengthening it to
the point of mild tension and holding the stretch.
Stroke Volume
The amount of blood pumped out of the heart during each beat.
Synergist
A muscle that assists the agonist muscles in their movement.
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Tabata
A form of HIIT that uses 8 bouts of 20 seconds of work followed by 10 seconds of rest.
Tidal Volume
The amount of air inhaled and exhaled with each breath.
Type I Fibers
Muscle fibers that are aerobic; using oxygen for energy and most active during lowerintensity, longer-duration activities.
Type II Fibers
Muscle fibers that are anaerobic; they do not use oxygen for energy and are most active
during short-duration, high-intensity activities.
VO₂ Max
A measure of cardiorespiratory fitness expressed as mL/kg/min; it is the maximum capacity of
the body to take in and use oxygen during exercise.
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