KIN 507
Motor Control
Lecture notes
Fall 2012
Dr. Gordon Chalmers
Dept. of PEHR
Kinesiology & Physical Education Program
Western Washington University
 2012, Gordon Chalmers, Ph.D.
RESEARCH INVESTIGATION PAPER
You will select a motor control topic that interests you (see example topics later in
assignment description). Your investigation should start with a REVIEW of the critical
issues in your topic. This forms approximately 80% of your report. This is like the
literature review of your thesis proposal and final thesis. The viewpoints of multiple
investigators must be included. In this section it is important to address the strong
points and limitations of each study. A Summary - Consensus of conclusions or points
of disagreement between different investigations must be discussed. This is a critical
section that allows you to draw together the results from different studies in different
sections of your paper. Finally, from this review and understanding you have gained,
one key issue which you see that is not addressed (a question unanswered) must be
identified. It should follow logically from the summary you have done. You then
discuss this issue you have identified. Why is this key issue a critical and important
question, and how you would address it (i.e., how would you potentially
experimentally examined the unanswered question). There must be a clear explanation
of why you have selected a certain aspect of your topic for further investigation, and
how you would do it. The method described must be realistic.
Each of the topics underlined above corresponds to a section in the grading sheet for
evaluation of the paper. To help organize your paper it is required to have the
following three major sections identified using APA style headings: Review of the
literature, Summary - Consensus of conclusions or points of disagreement, A key issue:
Why and how to address it. The use of these three section headings within your paper
is required to help it be organized and more easily readable. For this research a major
emphasis is on your REVIEW of current knowledge on your topic. Note in the grading
sheet that the review is in three sections for grading because the review is heavily
weighted. The review of the literature section is to be broken into subtopics, these major
subtopics will have sections headings to allow for coherent organization of facts and
ideas (see APA style guide for instructions on levels of headings). Each subtopic section
is to start with a single powerful leading sentence that summarizes the findings of the
section. Individual research articles are then discussed under that subtopic heading.
Finally, a conclusion for that subtopic section should be made, in more detail than the
lead sentence. An example for a paper titled "Motor Unit Changes with Aging" follows.
Review of the Literature
Introduction
Put introductory paragraph in here
Review of the Pertinent Literature
Motor Neuron Death Powerful lead sentence. Study 1. Study 2. Study n
Conclusion for this subtopic
Muscle Fiber Biochemical Changes Powerful lead sentence. Study 1. Study 2. Study n
Conclusion for this subtopic
Muscle Fiber Distribution Changes Powerful lead sentence. Study 1. Study 2. Study n
Conclusion for this subtopic
Summary - Consensus of Conclusions or Points of Disagreement
Put in pargraph(s) here
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 2
updated 6/21/12
RESEARCH INVESTIGATION PAPER
A key issue: Why and how to address it
Put in pargraph(s) here
If you feel that using section headings as suggested do not apply to your topic, then talk
with Dr. Chalmers.
Your report must have a minimum of 15 references, cited in APA style. If you have
not used APA style before, then it will be necessary to learn it for this assignment
because you will also need it for your thesis. APA style extends beyond the reference
style. All aspects of the paper formatting are defined in the style guide. Use the
biomedical databases (& other sources) for your literature search. A list of web links for
research in our field is on the course web page. A maximum of three book sources may
be used. You can not use undergraduate or graduate text books as references. The use
of non peer reviewed sources is rare in scholarly research in our field, so use it
judiciously if at all. This includes the use of any internet sources that are not peer
reviewed. The only internet sources that are acceptable are ones that provide scholarly
information that is not available elsewhere. If you plan to use any internet sources it
would be best to check them with Dr. Chalmers before you use them. You must ensure
that you provide a reference for all statements you make in your paper which are not
your own original thought. Also, you must use the most up-to-date information
available as your sources. Biomedical information that is greater than 10-15 years old is
likely out-of-date (Would you want your doctor or teacher to use only information that
he/she learned 20 years ago and has not updated since? Staying current in your
profession is crucial!). Cite only sources that you obtain and read completely. Do not
use a reference that you only obtain the abstract for. You are not required to submit
copies of your references with this paper. During evaluation of your paper, however,
Dr. Chalmers may request that you provide your complete references within 24 hours,
so keep them handy after writing the paper. The report should be 8-12 pages of typed
double spaced text (this does not include the title page or the reference list pages). The
grading sheet is to be attached as the last page of the assignment. Reading the grading
sheet before, and during your writing, will help ensure proper organization and
completeness. It is also recommended that you read Dr. Chalmers' "TERM PAPER &
CLASS PROJECT SUBMISSION SUGGESTIONS" web page, which can be accessed via
Dr. Chalmers' home page. For references you provide for this assignment, citation of
the class lecture notes as a reference is not allowed.
Ensure that your paper is checked by a human before submission. A paper that is
only checked by a spelling checking program may contain grammatical errors, or errors
of disjointed thought or poor organization. Only human checking by a person other
than the original author can detect these sorts of errors.
Report topic due date: The due date is listed in the course outline. You are to list
your name, your topic, and a sentence or two explaining why you picked that topic.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 3
updated 6/21/12
RESEARCH INVESTIGATION PAPER
Written report due date: The due date is listed in the course outline. Papers
submitted after start of class on this date lose 10% of the maximum total marks per day,
including each weekend day.
Paper extensions and course incomplete grades: Extensions on the paper due date
and incomplete grades for the course will be allowed only for documented medical
reasons or very significant personal reasons.
Presentation: On the date listed in the course outline, you will make a presentation
to the class on the research you have done. The presentation will be graded on the
clarity and organization of your presentation, your ability to handle questions, your
comfort and poise in front of the audience, the ability to present without excessive
dependence on notes, eye contact with the audience, and your voice projection. All of
these aspects of your presentation can be improved by practicing your presentation.
Review the presentation grading sheet as you prepare for your presentation. In class
we will discuss further the features of a good presentation. Note that the conclusion for
each subtopic may form a nice single slide which you can project as a summary, while
you give the needed description of the underlying studies. Your presentation must
include references to key studies discussed, placed after a stated fact.
Below is a list of possible topics which Dr. Chalmers has thought up, or previous
students have written papers on. They are intended to stimulate your thoughts on
possible topics. The best topic for you will be one you have a personal interest in.
Feel free to create your own topic, but be sure to discuss it with Dr. Chalmers. If you
pick a topic listed below discuss it with Dr. Chalmers to ensure your cover it well, or to
narrow the focus of your research.
Locomotion control.
Posture control.
Balance control, and training for balance.
Vestibular contribution to motor control.
Vision contribution to motor control.
Reaching, upper limb control.
Paraplegia, neuromuscular problems and therapies.
Neuromuscular electrical stimulation (NMES) for strengthening of muscle.
Functional electrical stimulation (FES) of paralyzed muscles.
Maximum voluntary contraction (MVC). Can people voluntarily produce 100%
of the possible muscle force?
Stress management / relaxation treatment affect on neuromuscular function,
and/or assessment of treatments by neuromuscular measures.
Mental practice and motoneuron activity.
Proprioceptive training, of healthy athlete and/or rehabilitation following injury.
Is it effective? (Not just a discussion of exercises to do)
Force control & tremor, influence of training & aging (and other variables?).
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 4
updated 6/21/12
RESEARCH INVESTIGATION PAPER
Changes in muscular contractile properties and motor unit control during
muscular fatigue.
Proprioception & prophylactic knee bracing.
Velocity specificity of strength training.
Muscle fiber type changes with chronic changes in endurance or power training.
Motor control during neuromuscular fatigue (e.g., proprioception, coordination,
motor unit control). Could include discussion of injury implications.
Muscle coordination following anterior cruciate ligament injury.
Nervous system contribution to fatigue of muscle (Neural fatigue).
Can you recruit (activate) fast muscle fibers selectively to perform fast
movments?
Aging affects on some of the topics listed above.
e.g.,
Aging effect on motor unit control.
Posture control and aging.
Fine motor control in the elderly.
Training affects on some of the topics listed above.
Changes in motor control during locomotion when wearing different shoe
designs.
The affect of exercise on neural and cognitive function in the elderly.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 5
updated 6/21/12
Motor Control Paper Grading Sheet
Good
Some Improvement
Correct facts at
Needed
sufficient detail to
Facts & detail explain
explain issues, and
issues, but more detail,
written
easily possible, or some
presentation
explanation confusing.
without any
Written presentation with
significant errors
some significant errors
5
4
3
FACTUAL CONTENT OF REVIEW
5 4 3 2 1
Exceptional
Obvious extra
& outstanding
effort in
research &
reporting
Weak
Facts & detail do
not explain issues,
or some significant
errors. Written
presentation with
very significant
errors
2
Comments
Missing
TOPIC:
Needs to be
completely redone
NAME:
1
0
Accuracy, clarity and detail of the
review of critical issues in the topic.
Strong points and limitations of each study.
Accuracy, clarity and detail of the
review of critical issues in the topic.
Accuracy, clarity and detail of the
review of critical issues in the topic.
Summary: Consensus of conclusions or
points of disagreement.
IDENTIFICATION OF ONE RESEARCH QUESTION
Key issues yet to be resolved. Why is it
a critical and important question. How
you would address it
PREPARATION OF PAPER
Paper and paragraph organization of
material, use of headings to organize
material (required), flow of writing.
Spelling, punctuation, & sentence
structure
Minimum 15 references, 0-3 books &
few to no select scholarly internet
sources. No undergraduate or
graduate text books as references
APA style reference list, Correct use of
citations within paper
8- 12 pages _____
Grading sheet attached _______
General Comments:
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 6
updated 6/21/12
Motor Control Presentation Grading Sheet
Good
Well done work in
the category.
Sufficient for a
presentation at a
regional conference,
or a thesis defense.
4
Presentation of research
review & proposal
5
4
3
2
Adequate
Could be
improved with a
bit more effort or
time devoted to
the items in the
category.
3
Weak
Much more
practice or time
needs to be
spent on this
aspect of your
presentation.
2
Missing
Exceptional
Obvious extra &
outstanding effort in
the category
Sufficient for a
presentation at a
national conference.
5
TOPIC:
Needs Help!
NAME:
1
0
Comments
1
Key points clearly
identified and
communicated to audience,
no use of excessive detail
when it is not needed.
References included
Overall clarity and
organization of your
presentation
Use of visual aids
No excessive reading from
notes
Ability to handle questions,
comfort and poise in front
of the audience
Eye contact with the
audience, voice projection
TIME: Within  2 min of target
= 5; 2-3 min under or over time
= 3; >3 min under or over time =
1; cut off by instructor due to
excessive length = 0
General comments:
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 7
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
MOTOR UNIT = MOTOR NEURON AND ALL THE MUSCLE FIBERS IT INNERVATES
MOTOR POOL = THE GROUP OF MOTOR NEURONS THAT INNERVATE ONE
MUSCLE
Motor neurons vary in SOMA SIZE
The number of muscle fibers a motor neuron innervates is the INNERVATION RATIO
The average innervation ratio varies between muscles:
• one motor neuron innervates 15 muscle fibers (1:15) in the eye muscles
• one motor neuron innervates 340 muscle fibers (1:340) in the first dorsal interosseus
muscle (hand)
• one motor neuron innervates 1,900 muscle fibers (1:1,900) in the tibialis anterior and
medial gastrocnemius muscles
ALL THE MUSCLE FIBERS OF ONE MOTOR UNIT ARE SIMILAR
CATEGORIES OF MUSCLE FIBERS
The view, that exists in some “current” text books, such as…
Exercise Physiology for Health, Fitness, and Performance (2007)
By Sharon Plowman, Denise L Smith
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 8
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
The PROBLEM with above table is that the fiber size data does not match
with research literature data on the size of human (untrained) muscle
fibers. (samples shown below)
Source: Campos (Males)
Table 3 Mean fibre area (μm2) determined by myofibrilar ATPase histochemistry. Source: Kesidis (males)
I
Bodybuilders
IIC
IIA
IIAX
IIX
6,266 ± 1535 7,217 ± 1443 9,639 ± 1659* 7,976 ± 1231* 5,634 ± 1586
Physical education students 4,647 ± 1775 5,444 ± 2710 5,496±1408
4,673 ± 1089 4,323 ± 1113
Values are means ± SD. * Statistically significant between the groups, P < 0.05
Pretraining Female Mean fibre area (μm2). Source: Staron (1989)
I
IIA
4253 ± 949 3370 ± 1048*
IIAB + IIB
2697 ± 931
Why does this problem of mismatched information exist ?
Likely: ANIMAL data, in which FG, or IIB, fibers ARE the largest is reported in the tables
of HUMAN anatomy and physiology textbooks.
Myosin ATPase classification of fibers based on myosin enzymatic activity:
I, IC, IIC, IIAC, IIA, IIAB, IIB.
 MEASURE OF CONTRACTION SPEED.
 MOST COMMON SYSTEM FOR STUDY OF HUMAN MUSCLE
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 9
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
Biochemical classification of fibers based on fast versus slow myosin
ATPase activity and oxidative and glycolytic enzymatic activity: SO,
FOG, FG.
 BEST FOR UNDERSTANDING METABOLISM, CONTRACTION SPEED AND
FORCE.
 NOT WIDELY USED TO STUDY HUMAN MUSCLE.
Because current human research on fiber type changes with
training uses the I, IIA, IIB/X mATPase fiber type
classification system…
We need to start thinking in, and using, the mATPase fiber
type classification system (correctly) if we are to read and
understand the literature on human muscle fiber types and
their changes with training
PROPERTIES IN MYOSIN ATPase CLASSIFIED TYPES OF
MUSCLE FIBERS (in Untrained Humans)
MUSCLE FIBERS CALLED
Male MUSCLE FIBER SIZE
1,2,3,6
Female MUSCLE FIBER SIZE
7
I
(contains type I
myosin)
(contains
types I & IIa
myosin)
IIA
IIAB
IIB/X
(contains type IIa
myosin)
(contains types
IIa & IIx myosin)
(contains type IIx
myosin)
small
large
medium
large
Medium
small
CONTRACTION SPEED 4, 5
Male MAXIMUM FORCE
slowest
(based on fiber size and slightly
greater specific tension in fast
fibers)
low
OXIDATIVE CAPACITY 1,5,9
high
GLYCOLYTIC CAPACITY 9
low
low
POWER 2
IC, IIC,
IIAC
slow
intermediate
fast
fastest
high
medium
high
medium
medium
intermediate
medium
medium low
low
high
high
1) Staron RS et al., Human skeletal muscle fiber type adaptability to various workloads. J Histochem Cytochem. 1984
Feb;32(2):146-52.
2) Campos et al., Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum
training zones. European Journal of Applied Physiology. 88, 50-60, 2002.
3) Kesidis, et al., Myosin heavy chain isoform distribution in single fibres of bodybuilders. European Journal of Applied Physiology.
103, 579 – 583, 2008
4) D'Antona G. et al., Skeletal muscle hypertrophy and structure and function of skeletal muscle fibres in male body builders.J
Physiol. 2006 Feb 1;570(Pt 3):611-27.
5) Scott W. et al., Human skeletal muscle fiber type classifications. Phys Ther. 2001 Nov;81(11):1810-6
6) Hather, BM et al., (1991) Influence of eccentric actions on skeletal muscle adaptations to resistance training. Acta Physiologica
Scandinavica. 143:177-185
7) Staron RS et al., (1989) Muscle hypertrophy and fast fiber type conversions in heavy resistance-trained women. European
Journal of Applied Physiology and Occupational Physiology. 60(1), 71-9.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 10
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
8) Adams GR, Skeletal muscle myosin heavy chain composition and resistance training. J Appl Physiol. 1993 Feb;74(2):911-5.
9) Gregory CM, Vandenborne K, Dudley GA. 2001. Metabolic enzymes and phenotypic expression among human locomotor
muscles. Muscle Nerve 24:387-93
In untrained muscle: Type IIB fibers: produce the greatest POWER
(Power = Force x velocity of shortening) due to dramatically highest velocity
Bottinelli R. and Reggiani C. Human skeletal muscle fibres:
molecular and functional diversity. Progress in Biophysics
and Molecular Biology. 2000; 73(2-4):195-262.
BUT…
The above Force:Velocity:Power curve is for single muscle fibers or single isolated muscles.
The above Force:Velocity:Power curve has been used (see later in Motor Control Unit 8
discussion) to indicate that in humans produce PEAK POWER at approximately 30%
1RM when resistance training.
The above Force:Velocity:Power curve does not represent the relationship between these
variables when doing movements (including resistance training) due to: length:tension
relationships, biomechanical angle of tendon pull, and the concurrent integration of these
changing variables across the MULTIPLE muscles involved in a movement, even a single joint
movement.
The Force:Velocity:Power curve for a multi joint movement can be demonstrated
for the BENCH PRESS.
Cronin JB, et al. Force-velocity analysis of strength-training techniques and load:
implications for training strategy and research. J Strength Cond Res. 2003
Feb;17(1):148-55.
Note: F:V curve not hyperbolic, Power:force curve rather flat (i.e., maximal power output is
similar across a wide range of load and speed combinations).
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 11
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
ARE ALL 3 TYPES OF MUSCLE FIBERS FOUND IN ALL MUSCLES?
“Most mammalian muscles, including those of humans, contain fibers with diverse histochemical
characteristics and in this sense are “heterogeneous”. In fact, histochemically homogeneous
muscles such as the cat soleus are quite exceptional”
Cat Soleus: : 0-5% Type II (table 2 pg 370)
Reference: Burke, RE, (1981) Motor Units: Anatomy, physiology and functional organization. In:
Handbook of Physiology, Section I: Vol II. Motor Control Part 1. The nervous system. American
Physiological Society, Bethesda MD
Other mammalian muscles, including cat wrist flexors, are a mixture of fiber types.
See: Gonyea WJ, Marushia SA, Dixon JA. (1981). Morphological organization and contractile
properties of the wrist flexor muscles in the cat. Anat Rec. Mar;199(3):321-39
BUT proportions of fiber types within a muscle vary
Large limb muscles 40-60% type I, in typical people
IS EVERYBODY THE SAME?
CAN YOU CHANGE YOUR % FIBER TYPES?
Do genetics or training determine % fiber types?
Endurance Exercise: increases the oxidative capacity of the trained fibers1,2,6.
For low intensity aerobic training of typical people with approximately 50% type I fibers: very
little activation of type II fibers (see subsequent recruitment unit discussion)
For intense endurance training with activation of type II fibers: increases % IIA
&/or IIAB, and decreases % IIB fibers3,5,6 , as IIB fibers change to express IIA
myosin, and increase oxidative capacity greatly.
(1-Taylor & Bachman, Can J Appl Physiol, 1999; 2-Hoppeler, Sportverletz Sportschaden, 1987; 3- Abernethy et al., Sport Med, 1990; 4Saltin & Gollnick, Skeletal Muscle Adaptability. In Peachey (Ed.), Handbook of Physiol, Sec. 10: Skeletal Muscle. Am Physiol Soc. 1983; 5 Campos et al., Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training
zones. European Journal of Applied Physiology. 88, 50-60, 2002.; 6- Scott W. et al., Human skeletal muscle fiber type classifications. Phys
Ther. 2001 Nov;81(11):1810-6)
For intense endurance training: atrophy of type I1,2, , IIa4,5 or IIb5 fibers may occur3.
1.
2.
3.
4.
5.
Kraemer WJ, et al., Compatibility of high-intensity strength and endurance training on hormonal and skeletal muscle adaptations. J
Appl Physiol. 1995 Mar;78(3):976-89
Deschenes MR, Maresh CM, Crivello JF, Armstrong LE, Kraemer WJ, Covault J. The effects of exercise training of different
intensities on neuromuscular junction morphology. J Neurocytol. 1993 Aug;22(8):603-15.
Terrados N, Melichna J, Sylvén C, Jansson E. Decrease in skeletal muscle myoglobin with intensive training in man. Acta Physiol
Scand. 1986 Dec;128(4):651-2.
Schantz P, Henriksson J, Jansson E. Adaptation of human skeletal muscle to endurance training of long duration. Clin Physiol. 1983
Apr;3(2):141-51.
Staron RS et al., Human skeletal muscle fiber type adaptability to various workloads. J Histochem Cytochem. 1984 Feb;32(2):146-52
OR, the endurance training does not need to be really intense to produce atrophy…
Scott Trappe, et al., Single muscle fiber adaptations with marathon training J Appl Physiol September
1, 2006 101:721-727
13 weeks of run training in college students preparing for a marathon decreased muscle
type I and IIa fiber size by ~20% (too low # of other fiber types to be examined).
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 12
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
Strength/power Exercise: increases the size of the trained fibers, all fibers trained in proper
program.
All fiber types hypertrophy9,10,11,12, hypertrophy greater in fast fibers1,2,4,6,10,11,12
AND
Increases % IIA5,10,11,12 &/or IIAB6,8, and decreases, or complete loss of, % IIB
fibers
(1-Hakkinen, J Sport Med Physical Fit, 1989; 2-Tesch, Med Sci Sport Ex, 1988 Suppl; 4- Noble, Rice, Thayer, Taylor. Evolving Concepts of muscle
Fibers. In: Poortmans JR (ed) Principles of Exercise Biochemistry, 3rd ed. Med Sport Sci., Basel, Karger, 2004, Vol 46, pp 36-61.; 5 - D'Antona G. et
al., Skeletal muscle hypertrophy and structure and function of skeletal muscle fibres in male body builders.J Physiol. 2006 Feb 1;570(Pt 3):611-27; 6 Campos et al., Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training zones.
European Journal of Applied Physiology. 88, 50-60, 2002; 7 - Staron RS et al., Human skeletal muscle fiber type adaptability to various workloads. J
Histochem Cytochem. 1984 Feb;32(2):146-52; 8- Kesidis, et al., Myosin heavy chain isoform distribution in single fibres of bodybuilders. European
Journal of Applied Physiology. 103, 579 – 583, 2008; 9- Scott W. et al., Human skeletal muscle fiber type classifications. Phys Ther. 2001
Nov;81(11):1810-6; 10 - Hather, BM et al., (1991) Influence of eccentric actions on skeletal muscle adaptations to resistance training. Acta
Physiologica Scandinavica. 143:177-185. 11- Staron RS et al., (1990) Muscle hypertrophy and fast fiber type conversions in heavy resistance-trained
women. European Journal of Applied Physiology and Occupational Physiology. 60(1), 71-9. 12- Wang N. et al., (1993) Muscle fiber types of women
after resistance training — Quantitative ultrastructure and enzyme activity. Pflügers Archiv European Journal of Physiology. 424(5): 494-502)
E.G. Kramer, WJ, Strength Power Hour Radio Show Podcast, Show date: 4/28/08, Available at iTunes ,
also available: http://www.sphour.com
Discussing crew athletes: “The IIx fibers have disappeared if you have recruited them”.
IIX TO IIA fiber conversion occurs for either intense
endurance or resistance exercise
Most studies conclude:
Endurance1,2,3,4,5 and Strength/power2,3 Exercise does not change the % fast & slow
(1-Salmons, Int J Sport Med, 1994; 2- Abernethy et al., Sport Med, 1990; 3- Saltin & Gollnick, Skeletal Muscle Adaptability. In Peachey (Ed.),
Handbook of Physiol, Sec. 10: Skeletal Muscle. Am Physiol Soc. 1983, also see Andersen, Schjerling & Saltin, Scientific American, 2000; D Pette, J
Appl Physiol. 2001 Mar;90(3):1119-24.; 4- Noble, Rice, Thayer, Taylor. Evolving Concepts of muscle Fibers. In: Poortmans JR (ed) Principles of
Exercise Biochemistry, 3rd ed. Med Sport Sci., Basel, Karger, 2004, Vol 46, pp 36-61.; 5- Scott W. et al., Human skeletal muscle fiber type
classifications. Phys Ther. 2001 Nov;81(11):1810-6)
Noble et al., Evolving Concepts of Skeletal Muscle Fibers. In: Poortmans JR (ed): Principles
of Exercise Biochemistry, 3rd ed. Med Sport Sci. Basel, Karger, 2004, vol 46, pp 36-61
“…although it appears that transitions within fast fiber types may be relatively
common, there is little evidence that fast fibers can readily convert to slow fibers
with exercise training.”
Yan Z. et al., Regulation of exercise-induced fiber type transformation, mitochondrial
biogenesis, and angiogenesis in skeletal muscle. J Appl Physiol. 2010 Oct 28. [Epub ahead
of print]
“… Endurance exercise readily promotes transformation from a glycolytic to an
oxidative phenotype within the fast twitch fiber types (type IIb/x to IIa).”
“… Exercise-induced transformation [from type II] to type I fibers remains to be
experimentally confirmed.”
Why older studies may show fiber type changes not currently believed to be
valid based upon modern immunohistochemistry techniques. “…ATPase
histochemistry is vulnerable to subtle changes in pH… Caution should be
taken when interpreting the data, particularly in regard to changes in type I
fibers.”
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 13
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
What about a recent study showing increases in % slow twitch fibers with training???
Gehlert S, Weber S, Weidmann B, Gutsche K, Platen P, Graf C, Kappes-Horn K, Bloch W.
Cycling exercise-induced myofiber transitions in skeletal muscle depend on basal fiber
type distribution. Eur J Appl Physiol. 2011 Oct 29.




21 male cyclists with different performance levels and different initial % slow
twitch fibers
Trained with increased volume (3.3 hrs/d, 4 d/wk) and reduced power output for
3 months (early season training)
Used ATPase staining to determine % fiber types (weak, older technique, see
above caution)
Results:
o Group average data: Cyclists starting with a LOW proportion of slow fibers
REDUCED IIa (p=0.01) & INCREASED type I (not sig).
o Individual data: 4 Cyclists starting with a 50 – 83% slow fiber DECREASED
% type I (!!!!!!!!)
Can strength/power Exercise in humans cause HYPERPLASIA (an increase in the
number of muscle fibers)? Due to splitting of existing mucle fibers or new fiber
formation from satellite cells?
G Goldspink and S Harridge, Cellular and Molecular Aspects of Adaptation in Skeletal Muscle. In:
Strength and power in sport, 2nd ed. Paavo V. Komi (ed), Malden, MA: Blackwell Science, 2003,
pp 231-251.
“… animal experiments using normal
changes in the total number of fibres.”
types of exercise have not shown any
JD MacDougall, Cellular Hypertrophy and Hyperplasia. In: Strength and power in sport, 2nd ed.
Paavo V. Komi (ed), Malden, MA: Blackwell Science, 2003, pp 252-264
“Net increases in fibre numbers do not occur in health adult human muscle in response to
resistance exercise; or, if they do, that they are of little numerical significance.”
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 14
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
Effects Of Genes On Structure, Function, And Performance
CHARACTERISTIC
EFFECT OF
GENES
POTENTIAL EFFECT OF
TRAINING (i.e. typical
environmental influences)
Small
Small
Height, Length of Arms
Large
Muscle Fiber Composition
Large
(Fast- and Slow-Twitch)
Mitochondria/Gram of Muscle Small
Large
Muscle Size
Large
Small
Aerobic Endurance (e.g.,
Moderate to
Small to Moderate
distance running or cycling)#
Large
# Aerobic endurance is influenced by multiple organ systems, the function of
some of which are largely determined by genes. So a large training effect on
muscle enzymes does not mean a large effect of training on aerobic
endurance.
From: Skinner, J. S. (2001) Do genes determine champions? Gatorade Sports Science Institute,
Sports Science Exchange #83, Volume 14 Number 4, Retrieved January 17, 2002, from
http://www.gssiweb.com/reflib/refs/298/sse_83.cfm?btid=1
Effect of Endurance AND Strength/power exercise in the same
person:
Endurance training inhibits resistance adaptations1-3,5.
Resistance training does not impair endurance adaptation1,4.
a.
b.
c.
Kraemer WJ, Spiering BA. (2006) Skeletal muscle physiology: plasticity and responses to exercise. Horm Res., 66 Suppl
1:2-16
Hakkinen K, Neuromuscular adaptations during concurrent strength and endurance training versus strength training, Eur J
Appl Physiol. 2003 Mar;89(1):42-52
:
Noncompatibility of power and endurance training among college baseball players
Rhea MR et al., J Strength Cond Res. 2008 Jan;22(1):230-4.
Exercise professionals seeking to develop evidence-based training programs rely on several
training principles demonstrated through research and professional experience. In an effort to
further research examining these principles, an investigation was designed and completed to
evaluate the compatibility of cardiovascular endurance and neuromuscular power training. Sixteen
Division-I collegiate baseball players were divided into two training groups with lower body power
measured before and after their college playing season. The two groups differed in training in
that one group performed moderate- to high-intense cardiovascular endurance training 3-4
days per week throughout the season, while the other group participated in speed/speed
endurance training. A significant difference between groups (P < .05) was identified in the change
in lower body power during the baseball season. During the season, the endurance training
group decreased an average of 39.50 +/- 128.03 watts while the speed group improved an
average of 210.63 +/- 168.96 watts. These data demonstrate that moderate- to high-intense
cardiovascular endurance and neuromuscular power training do not appear to be
compatible when performed simultaneously. For baseball players, athletes who rely heavily
on power and speed, conventional baseball conditioning involving significant amounts of
cardiovascular endurance training should be altered to include more speed/power interval
training.
d. :
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 15
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
Støren O et al., Maximal strength training improves running economy in distance runners.
Med Sci Sports Exerc. 2008 Jun;40(6):1087-92.
PURPOSE: The present study investigated the effect of maximal strength training on
running economy (RE) at 70% of maximal oxygen consumption [formula: see text] and
time to exhaustion at maximal aerobic speed (MAS). Responses in one repetition maximum
(1RM) and rate of force development (RFD) in half-squats, maximal oxygen consumption, RE,
and time to exhaustion at MAS were examined. METHODS: Seventeen well-trained (nine male
and eight female) runners were randomly assigned into either an intervention or a control group.
The intervention group (four males and four females) performed half-squats, four sets of four
repetitions maximum, three times per week for 8 wk, as a supplement to their normal endurance
training. The control group continued their normal endurance training during the same period.
RESULTS: The intervention manifested significant improvements in 1RM (33.2%), RFD (26.0%),
RE (5.0%), and time to exhaustion at MAS (21.3%). No changes were found in [formula: see text]
or body weight. The control group exhibited no changes from pre to post values in any of the
parameters. CONCLUSION: Maximal strength training for 8 wk improved RE and increased
time to exhaustion at MAS among well-trained, long-distance runners, without change in
maximal oxygen uptake or body weight.
e.
Kraemer WJ, et al., Compatibility of high-intensity strength and endurance training on hormonal and skeletal muscle
adaptations. J Appl Physiol. 1995 Mar;78(3):976-89.
WHY is concurrent Endurance AND Strength/power exercise in the
same person incompatible for maximal gain in either of the two
modalities?
“Satellite cell response to resistance exercise is blunted when immediately
followed by aerobic exercise…the physiological environment evoked by aerobic
exercise might attenuate the eventual addition of myonuclei important for
maximum muscle fiber growth…”
L Babcock, et al., Concurrent Aerobic Exercise Interferes With the Satellite Cell Response to Acute Resistance Exercise. Am J
Physiol Regulatory Integrative Comp Physiol, April 4, 2012
“… Competition between signaling pathways for synthesis of myofibrillar proteins
and proteins associated with oxidative metabolism; i.e., increased mitochondrial
biogenesis via AMP-activated protein kinase attenuates the rate of protein
synthesis”
You cannot have fibers that are maximal in BOTH size and oxidative capacity,
you can maximize one OR the other only.
van Wessel T, de Haan A, van der Laarse WJ, Jaspers RT. 2010. The muscle fiber typefiber size paradox: hypertrophy or oxidative metabolism? Eur J Appl Physiol. DOI:
10.1007/s00421-010-1545-0
WHO needs to be concerned about the ability for Endurance training
to inhibit concurrent Strength/power exercise effects?
a) Generally…
Non-exercise stimulus (e.g., infant and elderly aging, immobilization, muscle or nerve
injury, spinal cord injury, polio, space flight) is required to change the % type I & II (i.e.,
give you more fast or slow twitch fibers) (Roy, Baldwin, Edgerton, Ex Sport Sci Rev, 1991)
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 16
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 4: Motor units
How to answer on a NSCA or other standardized certification test regarding fiber
types, sizes and properties?
Source: Essentials of Strength Training and Conditioning - 3rd Edition
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 17
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 5: Motor unit recruitment
TO TURN ON THE MOTOR UNITS OF A MUSCLE POOL THE BRAIN USES
ORDERLY RECRUITMENT TO INCREASE MUSCLE FORCE
MORE TENSION NEEDS MORE UNITS, BUT WHICH UNITS TO USE?
RECRUITMENT IS BASED ON MOTOR NEURON SIZE
Smallest motor neuron recruited first
Next biggest recruited next
....
Biggest recruited last
Size = size of the motor neuron soma
recruitment sequence
increasing force requirement
Input to a motor neuron pool goes equally to every motor neuron in the pool
decending
commands
biceps 1a
what fiber type is recruited first?
what fiber type is recruited last?
: Can you selectively recruit fast twitch motor units for ballistic contractions?
: No, recruitment order the same, but all can be recruited virtually simultaneously
(Zehr & Sale, Can. J Appl. Physiol., 1994, Enoka, R. M. and Fuglevand, A. J. Motor unit
physiology: some unresolved issues. Muscle Nerve. 2001; 24:4-17)
Force production by a muscle can be increased by:
1. Recruitment of additional motor units (discussed above) AND
2. Summation of twitch forces (rate coding of muscle force)
Summation (rate coding of muscle force)
Each stimulus of muscle (i.e. each muscle action potential) produces one muscle twitch.
When muscle action potentials and resultant twitches are widely spaced (A), then the
tension from one twitch decays to zero before the next stimulus and resultant twitch
occurs.
In (B) stimulus 3 (S3) occurs before the complete decay in tension from S2, hence, the
force for twitch 3 adds onto the remaining force from twitch 2, resulting in greater
maximum force in twitch 3, compared to a twitch in which there is no summation
(addition of force because: all the Ca++ from twitch 2 has not been removed before a
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 18
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 5: Motor unit recruitment
new release of Ca++ for twitch 3, greater
intramuscular Ca++ concentration and
greater force results).
In (C) stimulus 3 (S3) occurs immediately
after S2, hence, the force (and Ca++) for
twitch 3 adds onto the force (and Ca++)
from twitch 2, resulting in greater
maximum force in twitch 3, compared to a
twitch in which there is no, or more widely
spaced, summation.
Below in (c), summation process described above occurs to greater degree when many
stimuli are closely spaced.
S S S
S
S
S
S S
S
SS S
S
S
S
S S
Remember: As the frequency of stimulation of a motor unit increases (i.e., action
potentials arrive more frequently) the resulting muscle force increases due to
summation.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 19
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 5: Motor unit recruitment
WHAT ARE THE IMPLICATIONS OF SIZE ORDERED RECRUITMENT FOR MUSCLE
PERFORMANCE?
I
IIa
IIb
Cat MG motor units types: S:28%, FR: 28%, FF 41.5% (unclassified: 2.5%)
Burke RE, Levine DN, Tsairis P, Zajac FE, Physiological types and histochemical profiles in motor units of the cat
gastrocnemius. J Physiol. 1973 Nov;234(3):723-48
Human medial gastrocnemius : 50% type I, 50% type II
Saltin & Gollnick, Sleletal Muscle Adapatability. Handbook of Physiology, Section 10, Skeletal Muscle, APS, 1983.
walking
running
jumping
Power (low,
medium, high)
Recruitment level
(% of motor pool)
Muscle fibers
utilized (which
type(s))
Are the type I fibers used in the sprint?
Are the type I fibers contributing much force to the sprint? Assume 45% type I fibers.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 20
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 5: Motor unit recruitment
How do recruitment and summation work together as force produced
by a muscle increases?
MODERATE FORCE EXAMPLE
Legend
Motor unit not firing, producing no force
Motor unit firing at a low frequency, producing low force
Motor unit firing at a moderate frequency, producing
moderate force
Motor unit firing at a high frequency, producing high
force
Force level being produced
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 21
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 5: Motor unit recruitment
HIGH FORCE EXAMPLE
Force level being produced
Legend
Motor unit not firing, producing no force
Motor unit firing at a low frequency, producing low force
Motor unit firing at a moderate frequency, producing
moderate force
Motor unit firing at a high frequency, producing high
force
TRAINING IMPLICATIONS OF RECRUITMENT ORDER:
: When you go jogging, how much of your muscle is being activated & used and
so stimulated to adapt?
: What % recruitment does a sedentary person typically use?
1 - % Motor neuron recruitment?
2 - % Muscle mass activation?
: What is the consequence of this low recruitment for people when they need to exert
high forces?
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 22
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 5: Motor unit recruitment
Edgerton VR, Roy RR, Allen DL, Monti RJ. Adaptations in skeletal muscle disuse or
decreased-use atrophy Am J Phys Med Rehabil. 2002 Nov;81(11 Suppl):S127-47.
% of maximum leg press effort to perform task
22 year-olds (mean)
Stair ascent
Stair decent
Chair rise
54%
42%
42%
74 year-olds
(mean)
78%
88%
89%
: When does someone who runs regularly ever use > 30% muscle activation?
NOTE: IT IS POWER OUTPUT (in non-isometric task) LEVEL THAT DETERMINES % OF
MUSCLE RECRUITED (not load lifted)
: HOW CAN YOU TELL WHEN RECRUITMENT IS INTO LARGE FG MUSCLE
FIBERS?
Glass SC, Stanton DR. Self-selected resistance training intensity in novice weightlifters. J Strength
Cond Res. 2004 May;18(2):324-7
The purpose of this study was to determine the intensity of self-selected weightlifting exercise in
untrained men and women. Thirteen men (age = 19.5 +/- 1.9, height = 70.0 +/- 2.4 in., weight = 174 +/20.1 lb, % fat = 14.3 +/- 6.7) and 17 women (age =18.7 +/- 1.0, height = 64.9 +/- 2.3 in., weight = 135.4
+/- 22.8 lb, % fat= 23.4 +/- 4.7) who were novice lifters completed seated bench press, leg extension,
seated back row, military press, and biceps curl. Following self-selection trials, subjects' 1 repetition
maximum (1RM) was assessed for each lift. Results showed that for both genders, self-selected loads
were all below 60% 1RM. All lift intensities were similar for men and women (range = 42-57%
1RM). Repetitions completed and rating of perceived exertion responses were not different between
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 23
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Section 2: Muscles fibers types and their use
Unit 5: Motor unit recruitment
gender. Results show that subjects do not select a lifting intensity sufficient to induce
hypertrophic responses and subsequent strength increases.
Self-selected resistance training intensity in healthy women: the influence of a personal trainer
Ratamess NA et al. J Strength Cond Res. 2008 Jan;22(1):103-11.
The purpose of the present investigation was to examine the influence of resistance training with a
personal trainer versus unsupervised resistance training on the self-selected intensities used by women
during resistance exercise. Forty-six resistance-trained women (age = 26.6 +/- 6.4 years; body mass =
64.2 +/- 10.9 kg) who either trained individually (n = 27; No PT) or with a personal trainer (n = 19; PT)
were carefully instructed to select a weight they used in their own resistance training workouts
that enabled the completion of 10 repetitions for the chest press (CP), leg press (LP), seated row
(SR), and leg extension (LE) exercises. Each participant was subsequently tested for one
repetition-maximum (1RM) strength on each exercise, and the self-selected intensity was
calculated based on a percent of each 1RM value. For self-selected relative intensity, the PT group
selected significantly greater intensities for LP (50% vs. 41%), CP (57.4% vs. 48%), and SR (56% vs.
42%) whereas a trend (p = 0.10) was observed for LE (43% vs. 38%) compared with No PT. Overall, the
average self-selected intensity for all exercises was approximately 51.4% in PT group and
approximately 42.3% in the No PT group. 1RM values for LP, LE, and SR were greater in the PT than
No PT group. Ratings of perceived exertion values were significantly greater in the PT compared with the
No PT group for CP, LE, and SR but not LP. These results indicate that resistance training under the
supervision of a personal trainer leads to greater initial 1RM strength values, self-selection of greater
workout intensities, and greater ratings of perceived exertion values during resistance exercise.
At what age do you need to start exercising to be as fit and functional for
as long as possible?
Aoyagi Y, Katsuta S. Relationship between the starting age of training and physical
fitness in old age. Can J Sport Sci. 1990 Mar;15(1):65-71.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 24
updated 6/21/12
Section 2: Muscles fibers types and their use
Unit 5: Motor unit recruitment
At what age do you need to start exercising to be as fit and functional for
as long as possible?
Answer: ???
Electrical stimulation of muscle:
For healthy people:
 electrical stim does not add to strength gains from a strength training program
 electrical stim which does not produce significant muscle force does not result
in strength gains due to low recruitment and lack of force generation (e.g.,
home muscle stimulation kits)
For injured people:
 electrical stim does add to strength gains from a strength training program
 electrical stim does maintain muscle mass when a voluntary training program
is not possible, if done correctly (i.e., sufficient recruitment & loading of
muscle)
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 25
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6a: Neuromuscular adaptations with resistance training
What changes when a person weight trains to make them stronger?
6 months heavy resistance training plus explosive jump training ( Hakkinen et al, (1998) J Appl Physiol, 84:pp
1341).
Isometric strength
 36%
 66%
 36%
 57%
Men 40
Women 40
Men 70
Women 70
CSA
 5%
 9%
 6%

Observe the changes seen in the following 4 strength training studies:
1) THE INCREASE IN STRENGTH THAT OCCURS IN THE FIRST FEW
WEEKS OF A STRENGTH TRAINING PROGRAM PRECEDES INCREASES IN
MUSCLE MASS



muscle mass typically takes up to 8 weeks to increase significantly
strength increases before this
increased EMG is observed during these early weeks, when strength is
increasing before muscle mass does (Komi 1986)
2) THE INCREASE IN STRENGTH THAT OCCURS IN A LONG TERM
STRENGTH TRAINING PROGRAM EXCEEDS INCREASES IN MUSCLE MASS
Study A: 60 days of training
Quad CSA  8.5%
MVC  21%
EMG  42%
(Narici et. al., 1989).
Study B: 8 weeks of training
biceps CSA  6.5
MVC  36%
EMG  11%
(Moritani & Devires, 1979)
In both studies, strength increased more than muscle size did. So muscle hypertrophy
alone does not explain all of the strength increase.
3) AN INCREASE IN STRENGTH COMMONLY OCCURS IN THE UNTRAINED
LIMB IN A UNILATERAL STRENGTH TRAINING PROGRAM (Munn J, Herbert RD,
Gandevia SC. Contralateral effects of unilateral resistance training: a meta-analysis. J Appl
Physiol. 2004 May;96(5):1861-6. Adamson M et al., Unilateral arm strength training improves
contralateral peak force and rate of force development. Eur J Appl Physiol. 2008 Jul;103(5):5539.)
Study A: 60 days, examination of untrained contralateral limb
Quad CSA NO CHANGE
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 26
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6a: Neuromuscular adaptations with resistance training
MVC  9%
iEMG  25%(Narici et. al., 1989)
Study B: 8 weeks isometric strength training, examination of untrained
contralateral limb
biceps CSA NO CHANGE
MVC  24%
EMG  21% (Moritani & Devires, 1979)
These results in the untrained limb are similar to those seen in the first weeks of a
strength training program, more force is exerted but with no hypertrophy.
THE MECHANISMS FOR ABOVE STRENGTH INCREASES THAT ARE NOT
PROPORTIONAL TO MUSCLE SIZE CHANGES MUST BE UNDERSTOOD, if we
want to understand force production and training (to be answered below)
4) From Sale (1988)
For the people who trained with a free squat: WHY is there less of an
increase in knee extensor force under the different testing conditions
using the same muscle?
But… what exactly are the…“Neural adaptations to resistance
training” that contribute to increased force production with training
Neural adaptations likely to occur (based on study quality & quantity) in bold ….
1. Increased maximum EMG level seen, SOME studies in which MVC strength
increases with training e.g. 3,4,9,12, due to increased motor unit firing frequency,
produces higher maximum force from muscle. Increases in neural drive are
observed to be greater for lengthening contractions compared to shortening
contractions1. See figures below
BUT:
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 27
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6a: Neuromuscular adaptations with resistance training
a. Not all training studies show increased EMG with strength increases e.g.,
9,13
b. Increase in motor unit firing frequency with training has been found in only
some studies 6, 9
c. Increase in maximal effort motor unit firing frequency with training has
been found to be much higher in elderly & moderately higher in young
adults 10, OR has been found to occur in young, but NOT in elderly 11.
d. The use of surface EMG to measure muscle activation level (neural drive)
has recently been questioned 4, 9.
85% MVC FORCE EFFORT BEFORE RESISTANCE TRAINING
HAS 100% RECRUIMENT (BUT LOW FIRING RATE IN LARGEST
MOTOR UNITS)
85% MVC Force level being produced
Legend
Motor unit not firing, producing no force
Motor unit firing at a low frequency, producing low force
Motor unit firing at a moderate frequency, producing
moderate force
Motor unit firing at a high frequency, producing high
force
MAXIMUM FORCE EFFORT BEFORE RESISTANCE TRAINING
Force level being produced
Legend
Motor unit not firing, producing no force
Motor unit firing at a low frequency, producing low force
Motor unit firing at a moderate frequency, producing
moderate force
Motor unit firing at a high frequency, producing high
force
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 28
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6a: Neuromuscular adaptations with resistance training
MAXIMUM FORCE EFFORT AFTER RESISTANCE TRAINING
Higher force level being produced
Legend
Motor unit not firing, producing no force
Motor unit firing at a low frequency, producing low force
Motor unit firing at a moderate frequency, producing
moderate force
Motor unit firing at a high frequency, producing high
force
2. Increased RATE of rise of EMG at start of force development 1,2,4,6 (increased
doublets in motor unit firing at start of contraction1,6,9, lower recruitment
threshold for motor units so they are recruited earlier as force is increasing 9),
produces increased maximum rate of force development.
3. Reduction in the antagonist coactivation allows prime mover torque to not be
counteracted by antagonsts. (remember: Coactivation of agonist and antagonists will
work against each other and reduce the net torque (force) output from a agonist
prime mover,) BUT:
a. Reduced coactivation is observed in the elderly 3, 12
b. Reduced coactivation was observed in an isometric contraction in young
subjects in which there was no increased EMG of the prime movers 14
c. Some studies find no decrease in antagonist activation with resistance
training 15
4. Multijoint/multimuscle coordination for posture and stabilization 4. e.g., hip,
knee, angle, trunk, contralateral leg, & arm muscle activation coordination for
leg extension during kick
5. Increased recruitment of more motor units that were previously inactive in a maximal
effort not likely, since limb muscle are likely fully recruited at 85% MVC force level 4,
9, 16
6. Increased synchronization of motor units firing, found in some studies, but not all 4.
But synchronization, when it occurs, has not been demonstrated to increase muscle
force 4,5
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 29
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6a: Neuromuscular adaptations with resistance training
Yao et al., J Neurophysiol. 83:441-52, 2000.
7. Enlargement of neuromuscular junction [“functional significance unknown”] 7
8. Reduction in GTO inhibition of muscle activation. Does not occur 8
“Neural adaptations to resistance training” for a
healthy young male
100 %
% of
improvement
is due to
which factor
0%
From: Physiology of Exercise and Sport, Wilmore & Costill, 1999
The understanding of the exact nature of neural adaptations
to resistance training is still in it’s early stages 9 (2005), 13 (2005)
1- Aagaard P. Training-induced changes in neural function. Exerc Sport Sci Rev. 2003, Apr;31(2):61-7
2- Aagaard P, et al. Increased rate of force development and neural drive of human skeletal muscle following resistance training. J
Appl Physiol. 2002 Oct;93(4):1318-263
3- Hakkinen K et al., Changes in agonist-antagonist EMG, muscle CSA, and force during strength training in middle-aged and older
people J Appl Physiol. 1998 Apr;84(4):1341-9
4- Duchateau et al. Training adaptations in the behavior of human motor units. J Appl Physiol. 2006 Dec;101(6):1766-75.
5- Holtermann et al., Changes in agonist EMG activation level during MVC cannot explain early strength improvement. Eur J Appl
Physiol. 2005:94, 593-601
6- Gabriel DA, Kamen G, Frost G. Neural adaptations to resistive exercise: mechanisms and recommendations for training
practices. Sports Med. 2006;36(2):133-49.
7- Gardiner et al., Effects of exercise training on alpha-motoneurons. J Appl Physiol. 2006, 101:1228-36
8- Chalmers, G. R. Do Golgi Tendon Organs Really Inhibit Muscle Activity at High Force Levels to Save Muscles From Injury, and
Adapt with Strength Training? Sport Biomechanics, 1:239-249, 2002.
9- Griffin L, Cafarelli E. Resistance training: cortical, spinal, and motor unit adaptations. Can J Appl Physiol. 2005 Jun;30(3):32840.
10Kamen G, Knight CA. Training-related adaptations in motor unit discharge rate in young and older adults. J Gerontol A
Biol Sci Med Sci. 2004 Dec;59(12):1334-8
11Patten C, Kamen G, Rowland DM. Adaptations in maximal motor unit discharge rate to strength training in young and
older adults. Muscle Nerve. 2001 Apr;24(4):542-50.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 30
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6a: Neuromuscular adaptations with resistance training
12Hakkinen K et al., Neuromuscular adaptation during prolonged strength training, detraining and re-strength-training in
middle-aged and elderly people. Eur J Appl Physiol. 2000 Sep;83(1):51-62.
13Holtermann et al. Changes in agonist EMG activation level during MVC cannot explain early strength improvement. Eur J
Appl Physiol. 2005 Aug;94(5-6):593-601.
14Carolan B, Cafarelli E. Adaptations in coactivation after isometric resistance training. J Appl Physiol. 1992 Sep;73(3):9117.
15Morse et al. Muscle strength, volume and activation following 12-month resistance training in 70-year-old males. Eur J
Appl Physiol. 2005 Oct;95(2-3):197-204.
16Beltman, J. G.; de Haan, A.; Haan, H.; Gerrits, H. L.; van Mechelen, W., and Sargeant, A. J. Metabolically assessed
muscle fibre recruitment in brief isometric contractions at different intensities. Eur J Appl Physiol. 2004 Aug; 92(4-5):485-92.
Now can we generate answers for?:
THE MECHANISMS FOR STRENGTH INCREASES THAT ARE GREATER THAN
MUSCLE SIZE INCREASES
WHY DOES AN UNTRAINED LIMB IMPROVE IN STRENGTH, WHEN
CONTRALATERAL LIMB IS TRAINED?
Study results:
There was a very weak to moderate correlation between strength of isolated single muscle
groups and functional performance (e.g., stair climbing, rising from a chair, balance, 6 min walk
time).
Question: Why is there little to no relationship between how strong individual
muscle groups are, and functional performance, in the elderly?
WHAT ALLOWS ANYONE WHO TRAINS TO PRODUCE MORE FORCE?
Which of these adaptations play a dominant role in:
 women
 elderly (males & females)
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 31
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
Part B: How should people weight strength resistance train?
Retrieved 11/14/05 from:
http://web.archive.org/web/20040118120739/www.coachesinfo.com/article/250/
Some Thoughts on Proper Terminology
Harvey Newton - Newton Sports, Ormand Beach, Florida, USA
…
Let's start simply with the term resistance training. This is the most correct, all-inclusive term to describe the various
methods of body weight or external resistance exercise for whatever athletic or cosmetic goal. In the U.S., nearly
everyone refers his or her use of resistance training as strength training. Certainly one syllable is easier than three
are and I suppose the shorter term implies a bit more importance. However, most of these individuals are far off
target in terms of actually training for improved strength. True strength training requires the use of an appropriately
high intensity and low repetitions to have a positive effect on one's strength.
Simply stated, while, those who use moderate or light resistances and perform many repetitions are engaged in
resistance training it is not typical strength training. Now, should they choose to use weights as their form of
resistance, we can then use the term weight training to describe their efforts. But, for example, if they employ body
weight, surgical tubing or water as resistance, then obviously resistance is not being created through the use of
weights. This is not weight or typical strength training.
…
Why do people
resistance train?
Goal in resistance training…..
To train the nervous system to maximize force production at a joint, it is not enough to
just do activities which maximize muscle size, and activities which are task specific
movements (to allow neural drive & multi joint coordination to develop), you must also
do movements at the correct VELOCITY
Review transfer in previously discussed:
o Sale, 1988
o Knutzen et al., 2002
AN INCREASE IN STRENGTH DOES NOT TRANSFER TO ALL SPEEDS AT WHICH
THE TRAINED MUSCLE MOVES
Study: (In Behm & Sale 1993)
 subjects trained at 1.05, 3.14, 5.24 rad/sec, 8 weeks
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 32
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Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training

slow speed training group showed greatest strength increases at slow speed
test
 fast speed training group showed greatest strength increases at fast speed
test
 middle speed training group showed similar strength increases at all speeds
Study: from Sale (1988)
MAX RFD = maximum rate of force development
PF = peak force
Comparison of “explosive” jump training (left column) and heavy resistance weight
training (right column) on rate of rapid increase in force (top plots) and EMG
(bottom plots) during maximal isometric contractions.
Explosive training caused the greatest increase in rate of force development and more
rapid EMG onset, while resistance training caused the greatest increase in peak
force.
THE PERSON WHO TRAINS AT A FAST SPEED, DEVELOPS THE ABILITY TO
RAPIDLY PRODUCE ISOMETRIC FORCE, & MAXIMIZES STRENGTH GAINS
AT FAST SPEEDS.
Velocity specificity of weight training for kayak sprint performance.
Liow DK, Hopkins WG.
Med Sci Sports Exerc. 2003 Jul;35(7):1232-7.
PURPOSE: Athletes often use weight training to prepare for sprint events, but
the effectiveness of different types of weight training for sprinting is unclear. We
have therefore investigated the effect of slow and explosive weight training
on kayak sprint performance. METHODS: Twenty-seven male and 11 female
experienced sprint kayakers were randomized to slow weight training,
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 33
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
explosive weight training, or control (usual training) groups. Weight training
consisted of two sessions per week for 6 wk; in each session the athletes
performed 3-4 sets of two sport-specific exercises with a load of 80% 1repetition-maximum. The two training programs differed only in the time taken to
complete the concentric phase of the exercises: slow, 1.7 s; explosive, <0.85 s.
To determine the effects of training on sprint acceleration and speed
maintenance, the athletes performed 15-m kayaking sprints pre- and
posttraining; an electronic timing system provided sprint times at 3.75-, 7.5-, and
15-m marks. RESULTS: Relative to control, both types of weight training
substantially improved strength and sprint performance. The improvements in
mean sprint time over 15 m in each group were: slow, 3.4%; explosive, 2.3%;
control, -0.2% (90% confidence limits for pairwise differences, approximately +/1.4%). Over the first 3.75 m, the improvements were: slow, 7.1%; explosive,
3.2%; control, 1.4% ( approximately +/-2.6%). Over the last 7.5 m, the
improvements were: slow, 2.1%; explosive, 3.0%; control, -0.8% (
approximately +/-1.9%). CONCLUSIONS: Slow weight training is
likely to be more effective than explosive training for improving
the acceleration phase of sprinting, when force is high
throughout the length of the stroke. Explosive weight training
may be more effective in speed maintenance, when forces are
developed rapidly over a short period at the start of the stroke.
What is the speed of performance of a javelin throw?
http://www.youtube.com/watch?v=svZ7DPi7rLI
SO.. What speed should you train at????
“Data… supports velocity specificity and demonstrate the importance of training
at fast, moderate, and slow velocities to improve isokinetic force production
across all testing velocities”
Fundamentals of resistance training: progression and exercise prescription. Kraemer
WJ, Ratamess NA. Med Sci Sports Exerc. 2004 Apr;36(4):674-88.
But: Velocity specificity of training may apply mainly to people who are trained, and not
for untrained people
Kraemer, WJ and RU Newton. (2000). Training for muscular power. Phys Med Rehab Clin North Amer.
11(2): 341-368.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 34
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
Kraemer, WJ and RU Newton. (2000). Training for muscular power. Phys Med Rehab
Clin North Amer. 11(2): 341-368.
Should we be training people for muscle strength or power?
What researchers in the physical training of athletes and the elderly are saying:
“In many sports activities, the ability to rapidly develop force is equally important or
even more important than the maximal force itself”.
Duchateau & Hainaut, Mechanism of muscle and motor unit adaptation to explosive power
training. In: Strength and power in sport, 2nd ed. Paavo V. Komi (ed), Malden, MA: Blackwell
Science, 2003, pp 315- 330.
“… in virtually all situations in sports and in daily activities an efficient means of
activating muscles quickly, or of producing high impulses within given time periods is
much more desirable [than basic MVC strength]…”
Albert Gollhofer, Proprioceptive Training: Considerations for Strength and Power Productions. In:
Strength and power in sport, 2nd ed. Paavo V. Komi (ed), Malden, MA: Blackwell Science, 2003,
pp 331-342.
“In normal human movement the time taken to produce a certain submaximal force
level may sometimes be as important as the absolute force level itself. Aging leads to
declines in … maximal strength … but it has been shown to lead to even greater
worsening in explosive force production.” “… modified power type of exercises could
also be useful as a part of an overall physical training for older people”.
K. Hakkinen, Ageing and neuromuscular adaptation to strength training. In: Strength and power in
sport, 2nd ed. Paavo V. Komi (ed), Malden, MA: Blackwell Science, 2003, pp 409-425.
“Muscle power recedes at a faster rate than strength with age and may also be a
stronger predictor of fall risk and functional decline. The optimal training paradigm for improving
muscle power in
older adults is not known, although some literature suggests high velocity, low
load training is optimal in young adults.”
de Vos NJ et al., Optimal load for increasing muscle power during explosive resistance training in
older adults. J Gerontol A Biol Sci Med Sci. 2005 May;60(5):638-47
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 35
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Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
“Power production, and not
just strength, may be the
relevant contributor to
performance in a functional
task.” (pg 638)
Effect of strength and power training on physical function in
community-dwelling older adults.
Miszko TA, Cress ME, Slade JM, Covey CJ, Agrawal SK, Doerr CE.
J Gerontol A Biol Sci Med Sci. 2003 Feb;58(2):171-5.
BACKGROUND: The performance of daily tasks, such as stair climbing or lifting an
object, requires both muscle strength and power. Age-associated reductions in strength
and power can affect an older adult's ability to complete daily tasks such as stair
climbing and lifting a child.
METHODS: The purposes of this study were to determine whether power training was
more efficacious than strength training for improving whole-body physical function in
older adults and to examine the relationship between changes in anaerobic power and muscle
strength and changes in physical function. Thirty-nine men and women (mean age +/- SD =
72.5 +/- 6.3 years) with below-average leg extensor power were randomly assigned to control
(C, n = 15), strength-training (ST, n = 13) or power-training (PT, n = 11) groups. The ST and PT
groups met 3 days per week for 16 weeks; the C group maintained usual activity and attended
three lectures during the course of the study. Primary outcome measures included the
Continuous Scale Physical Functional Performance test, maximal strength, and anaerobic
power.
RESULTS: After baseline was controlled for, the Continuous Scale Physical Functional
Performance test total score was significantly greater for the PT group than for the ST (p
=.033) and C (p =.016) groups. Maximal strength was significantly greater for the ST group than
for the C group (p =.015) after the intervention. There was no significant difference between
groups for peak anaerobic power.
CONCLUSIONS: Power training was more effective than strength training
for improving physical function in community-dwelling older adults.
Is power training or conventional resistance training better for
function in elderly persons?
Tschopp M, et al., A meta-analysis. Age Ageing (2011) doi: 10.1093/ageing/afr005
Objective: to determine the effects of power training with high movement velocity
compared with conventional resistance training with low movement velocity for older
community-dwelling people.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 36
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
Design: systematic review of randomised controlled trials.
Conclusion: power training is feasible for elderly persons and has a small advantage
over strength training for functional outcomes. No firm conclusion can be made for
safety.
Should we be training people for muscle strength or power?
Maximum power production involves speeds that are NOT slow
Power = force * (distance / time) = force * velocity
Bottinelli R. and
Reggiani C.
Human skeletal
muscle fibres:
molecular and
functional
diversity.
Progress in
Biophysics and
Molecular
Biology. 2000;
73(2-4):195262.
Maximum, mechanical power is produced at a resistance of 30% of maximum isometric
strength, which corresponds to a velocity of muscle shortening of approx. 30% of
maximum
Kraemer, WJ and RU Newton. (2000). Training for muscular power. Phys Med Rehab Clin North Amer.
11(2): 341-368.
Training increases in power output are specific to the velocity of the training
 train slow against heavy resistances = maximum power improvement at
slow speeds
 train with rapid movements at 30% of MVC, and power improvement is
greatest at this speed.
Kraemer, WJ and RU Newton. (2000). Training for muscular power. Phys Med Rehab Clin North Amer.
11(2): 341-368.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 37
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
If you need to pick one load to train at to maximize power adaptation:
Training against a “30% resistance produced the greatest increase in force and power
over the entire concentric velocity range”.
“If the coach or athlete had to choose a single resistance, then the resistance that
produces the greatest power output (30% of maximum voluntary contraction[MVC]) has
been shown to be optimal.
“.. it may be prudent to continuously adjust the resistance used in training to ensure
increased power output at slow and fast movement speeds. Also, the presentation of a
range of loads and resulting movment speeds may be more effective because of the
changing stimulus of the neuromuscular system eliciting grater adaptations. This
concept remains speculative, however, and should be investigated”
Kraemer, WJ and RU Newton. (2000). Training for muscular power. Phys Med Rehab Clin North Amer.
11(2): 341-368.
Thomas GA, Kramer, WJ et al.,
Maximal power at different
percentages of one repetition maximum: influence of
resistance and gender. J Strength Cond Res. 2007 May;21(2):336-42
“In order to optimize athletic performance, it is intuitive that athletes should train
using loads that will maximize power output.”
“30% of 1-RM was the standard resistance capable of being applied across
exercises and genders. Therefore from an exercise prescription perspective,
30% of the 1-RM for such power exercises appears to be a good stimuli or
resistance loading for enhancing maximal mechanical power development when
using these exercises.
If you need to pick one load to train at to maximize power adaptation: (“30% 1RM can’t be trained
with IF USING TYPICAL RESISTANCE TRAINING EQUIPMENT”)
Power Training for:
% 1RM
Reps
Single event effort (e.g., throw)
80-90
1-2(fast)
Multi-effort event (e.g., volleyball jumping)
75-85
3-5(fast)
Strength
>=85
<=6
Endurance
<=67
>=12
Hypertrophy
67-85
6-12
Baechle & Earle Essentials of Strength Training and Conditioning, 3 rd Ed. 2008, pg 400-404
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 38
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Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
Raoul F. Reiser et al., Between
the Beginning and End of a
Repetition: How Intrinsic and Extrinsic Factors Influence the
Intensity of a Biceps Curl. Strength and Conditioning Journal, 29(5) (October
2007) 64-76
How to train at speeds that are not slow?
“… performing traditional pressing movements rapidly with light loads does not create
the ideal loading conditions … with regard to maximal power production.” Due to
increased duration of the deceleration phase as the athlete must slow the bar to a
complete stop at the end of the range.
Kraemer, WJ and RU Newton. (2000). Training for muscular power. Phys Med Rehab Clin North Amer.
11(2): 341-368.
“Ballistic” Resistance training = athlete throws or jumps with the weight
“Being able to release the mass at the end of the range of motion is vital to promoting
power and acceleration”
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 39
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
Sample Ballistic Training Methods
 Plyometrics
Easy to Implement
 Medicine ball training
 Weighted jump squats, Pushups (weight
needed?)
 Speed up typical exercises (e.g., up stairs,
out of chair, do some typical machine or free
lifts faster)
 Add chains or elastics to some free lifts &
do them fast (e.g. Eric Tripp “dynamic”
training = 50% 1RM+10% in chain weight, lift it
fast, e.g., bench press, squat etc.)
 Lift & throw sandbags (weightlifting or other
movements)
 Weightlifting movements (cleans, hang
cleans from the knees)*
Difficult to Implement
 Lift and throw and drop weigh into sand pit
(e.,g weightlifting movements without the
catch)
 Air resistance (e.g., Keiser brand)
 Computerized weight equipment that allows
the release of the mass

Kraemer & Newton. (2000). Training for muscular power.
Phys Med Rehab Clin North Amer. 11(2): 341-368.
*Hang clean: start standing with bar at waist, snach to shoulder/chin level support
(power) clean: start with bar on ground, up to thigh, up to shoulder/ chin
power snatch: ground to arms overhead
But…. Previous strength training should be completed (i.e., able to squat 1.5x body
weight) BEFORE initiating a gradual increase in ballistic resistance training, due to
theorized protective role in terms of injury prevention.
Kraemer & Newton. (2000). Training for muscular power. Phys Med Rehab Clin North Amer. 11(2): 341-368.
BUT See also:Ed McNeely, (2007) Introduction to Plyometrics: Converting
Strength to Power, NSCA Performance Training Journal, 6(5), 19-22.
“Having a good strength base is essential for performing plyometrics safely and
effectively. Without good lower body and core strength, the amortization phase
becomes too long and much of the benefit of the plyometric is lost. Over the years, the
need to squat one to two times body weight has been suggested as a requirement for
plyometrics. While this is a good guideline for some of the higher intensity drills,
simple jumps in place and hops over very low barriers can be used with most
athletes as long as they have demonstrated the ability to land properly.”
See One Arm Throw video on KIN 410 web page
Discuss Bilateral Deficit and unilateral training
barbell vs 2 dumbbells vs one dumbbell
Oilers training video
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 40
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Section 3: Motor control aspects of resistance training
Unit 6b: Resistance training
= machine
weights
12
12
= Traditional
free lifts
(Squat,
bench press,
barbell bicep
curl)
2
2
Single
plane of 3
major
planes
Not single
plane of 3
major
planes
* Bilateral movement
* 2 hands or feet NOT fixed
together
Single
plane of 3
major
planes
Not single
plane of 3
major
planes
* Bilateral movement
* 2 hands or feet fixed
together
Highest
degree of
freedom
* Unilateral hand or foot
movement
Not single
plane of 3
major
planes
Increasing challenge and complexity for nervous system
Increasingly realistic movement
Single
plane of 3
major
planes
lowest
degree of
freedom
* Bilateral
movement
* 2 hands or
feet fixed
together
* load & often
body
stabilized for
you
4
19
8
3
17
11
Not used by
Oilers
Data for Oilers Exercise Video
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 41
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
Part C: Views from many people on resistance training
Source #1:
Steven Plisk, Director of Sport Conditioning, Yale University.
Plisk, S (2000) Resistance Training - Part I: Considerations in Maximizing Sport
Performance. Retrieved December 22, 2000 from the International Society of
Biomechanics in Sport - Coaches Information Service, Available:
http://www.sportscoach-sci.com/
In general, structural movements (e.g. multi-joint, weight-bearing exercises) have a
systemic effect which reaches far beyond the muscle fibers used in their execution.
Muscles act - and must be targeted - in functional task groups rather than in
isolation. This is one reason why athletes are well advised to emphasize powerlifting
and weightlifting-style movements, and compound exercises in general, in their training.
Furthermore, such movements are also a potent means by which the neuromuscular
and neuroendocrine systems are activated, in turn up-regulating every system in the
body. Thus, there are several reasons why strength training programs
should be based on free-weight movements rather than isolated
muscles:
POWER The greater the effort - and acceleration - with a given weight, the greater
the power development and subsequent training effect. Peak power output during
weightlifting movements (snatch and clean & jerk) is the highest ever documented, and
is comparable to the maximum theoretically possible for a human. For example, the
explosive "jump and pull" or "dip and drive" actions of these movements are executed in
0.2 - 0.3sec; and peak power production is:
• 4-5 times that of the deadlift or squat
• 11-15 times that of the bench press
MOTOR COORDINATION Skillful movements have a motor control / learning
effect which carries over to the athlete's "coordinative abilities":
• orientation
• differentiation
• reactive ability
• rhythm
• balance
• combinatory ability
• adaptive ability
EXERCISE PRIORITIZATION
In terms of specificity, training tasks should be selected and prioritized according
to their dynamic correspondence with the demands of the activity (also referred
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 42
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
to as specificity or transfer of training effect): Their basic biomechanics - but not
necessarily outward appearance - should be specific to those occurring in competition.
The rate of force development and time of force production (impulse) and
dynamics of effort (power) are especially important criteria in explosive athletic
movements. Other practical considerations include amplitude and direction of
movement, accentuated region of force application, and regime of muscular work.
This concept is analogous to the motor learning principle of practice specificity
with respect to sensorimotor, processing and contextual effects on acquisition,
retention and transfer. While these may appear to be statements of common
sense, it is difficult to overstate their importance because failure to address
them in training can result in limited transfer to competitive performance.
Source #2: Stone, M, Plisk, S. and Collins, D., Training Principles: Evaluation of Modes and
Methods of Resistance Training - A Coaching Perspective, Sport Biomechanics, 1:79103, 2002.
Source #3: Stone, M., Stone, M., Lamont, H. (2003) Explosive Exercise Retrieved
December 16, 2003, from http://www.coachesinfo.com/article/242/
“Because of these alterations in activation patterns, selection of exercises for
strength/power training should be viewed as movement specific rather than
simply training a muscle(s). Improvement in the efficiency of intra and especially
inter muscular activation implies an enhanced coordinative ability and is an important
mechanism contributing to improved strength expression (Semmler and Enoka 2001).”
Source #4: Mike Bahn, MS, CSCS, Arizona Diamondbacks. (2004) Personal
Communication
"Train movements, not muscles. And I agree that there is a place for isolation
movements in early stages of rehab, but other than that, not much use from a practical
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 43
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
standpoint. Our programs don't even include isolation movements like bicep curls or
tricep extensions, as those muscles are used quite a bit in more functional exercises
(some guys do them at the end of our workouts for the "beach muscles", but that is their
choice).
Source #5:
Pgs 29, 30, 42, 64. – published 2006
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 44
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 45
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 46
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
Source 5b:
Vern Gambetta, Athletic Development: Art & Science of Functional Sports
Conditioning, Human Kinetics, 2007
Isolation (pg 24):
Machines (pg 25):
Machine safety & body position (pg 193):
Source #6:
Functional-task exercise versus resistance strength exercise to improve daily
function in older women: a randomized, controlled trial.
de Vreede PL, et al. J Am Geriatr Soc. 2005 Jan;53(1):2-10.
Functional tasks exercise versus resistance exercise to improve daily function in
older women: a feasibility study.
de Vreede PL, et al. Arch Phys Med Rehabil. 2004 Dec;85(12):1952-61.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 47
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
Objectives: To determine whether a functional-task exercise program and a
resistance exercise program have different effects on the ability of communityliving older people to perform daily tasks. Design: A randomized, controlled, single-blind trial.
Setting: Community leisure center in Utrecht, the Netherlands. Participants: Ninety-eight healthy women aged 70 and
older were randomly assigned to the functional-task exercise program (function group, n=33), a resistance exercise
program (resistance group, n=34), or a control group (n=31). Participants attended exercise classes three times a
week for 12 weeks. INTERVENTIONS: Exercises were given 3 times weekly for 12
weeks. The functional tasks exercise program aimed to improve daily tasks in the
domains first affected in older adults, whereas the resistance exercise program
focused on strengthening the muscle groups that are important for functional
performance. Measurements: Functional task performance (Assessment of Daily Activity Performance
(ADAP)), isometric knee extensor strength (IKES), handgrip strength, isometric elbow flexor strength (IEFS), and leg
extension power were measured at baseline, at the end of training (at 3 months), and 6 months after the end of
training (at 9 months). Results: The ADAP total score of the function group (mean change 6.8, 95% confidence
interval (CI)=5.2-8.4) increased significantly more than that of the resistance group (3.2, 95% CI=1.3-5.0; P=.007) or
the control group (0.3, 95% CI=-1.3-1.9; P<.001). Moreover, the ADAP total score of the resistance group did not
change significantly compared with that of the control group. In contrast, IKES and IEFS increased significantly in the
resistance group (12.5%, 95% CI=3.8-21.3 and 8.6%, 95% CI=3.1-14.1, respectively) compared with the function
group (-2.1%, 95% CI=-5.4-1.3; P=.003 and 0.3%, 95% CI=-3.6-4.2; P=.03, respectively) and the control group (2.7%, 95% CI=-8.6-3.2, P=.003 and 0.6%, 95% CI=-3.4-4.6; P=.04, respectively). Six months after the end of training,
the increase in ADAP scores was sustained in the function group (P=.002).
Conclusion: Functional-task exercises are more effective than resistance
exercises at improving functional task performance in healthy elderly women and
may have an important role in helping them maintain an independent lifestyle.
The functional exercise tasks used follow… (NOT “intimidating” free weights)
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 48
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 49
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
Source #7:
Fri May 20, 2005
Gym Ditches High-Tech for Basic Workouts By MARK JOHNSON
At this gym, there are no Cybex, Universal or Nautilus machines. ….
Jeff Taylor, 11, of Clifton Park, N.Y., drags tugboat chains as part of
his workout at Cutting Edge Sport Sciences in Albany, N.Y. Monday,
May 9, 2005. Against the wall are concrete stones used for weight
lifting. (AP Photo/Tim Roske)
Instead of trendy elliptical trainers, there's a 117-pound cement ball to lift. In
place of indoor rowers, there are 68-pound tug boat chains to drag across the
floor. And instead of Stairmasters, there's a 200-pound truck tire to lift and push.
"We're pretty anti-machine here," said Naughton, 41.
Clients go through a series of basic, "multi-joint" exercises aimed at
strengthening the entire body, not just a single muscle group.
… We're talking about functional strength.
Source #8:
Accomodating Resistance. Joseph M. Warpeha, MA, CSCS, NSCA-CPT
NSCA's Performance Training Journal | www.nsca-lift.org/perform
Vol. 4 No. 2 | Page 22-23
We are all aware of the benefits that resistance training offers in terms of strength. If
you have ever attempted a maximal lift, you are also aware that a "weakest point" exists
in any range of motion that ultimately will limit your ability to complete the lift if the
weight is heavy enough. Traditional free weights offer one set resistance through any
given range of motion. Due to joint angles, biomechanics, and the involved musculature,
the body has different strength capabilities at different positions throughout a lift. For
example, most people can "lock out" the final few inches of a bench press with a weight
substantially greater than that which they can fully press. The idea of accommodating
resistance is based around the need to "accommodate" the strong and weak
points of any given motion by using such tools such as elastic bands or chains
that alter the resistance throughout the movement. Let's take the squat for example.
The weakest point is generally somewhere in the bottom half. We must recall at this
time that power is a function of mass moved per unit of time The greatest power
athletes typically spend a good deal of time training with loads of 40 70% of a 1-repetition maximum and concentrate on moving the weight
as fast as possible, thus increasing the rate of force development and
producing the greatest power. If your best squat is 300 pounds, training with
270 for singles, doubles, or triples all of the time probably would not be optimal (if you
have not been supplementing your routine with power/speed training) since that weight
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 50
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Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
will not be moved with a lot of speed and your sticking point will come into play more
times than not because you were not able to produce enough momentum to push
through it. Perhaps you would be better off reducing the load on the bar and
incorporating accommodating resistance . This can be accomplished by attaching a
large rubber band around each end of the bar (2 bands total) with the other ends of the
bands fixed to the ground directly beneath the bar's vertical plane of movement. Let's
say at the bottom of the squat the bands are totally relaxed but at the top they add 100
pounds of extra resistance due to the elastic energy exerted by the bands. Now put 200
pounds on the bar with these bands. At the bottom, you are essentially dealing with 200
pounds (which a 300-lb squatter should be able to accelerate quite rapidly). As you
ascend, the resistance gets greater and greater up to 300 pounds at the very top (200
lbs + 100 lbs), but you are able to keep accelerating the bar because of the momentum
you were able to produce at the beginning of the concentric phase due to the light load.
Additionally, in general, most people are stronger at the end of extension-type
movements due to more favorable biomechanical position (leverage) so the bands in
this case accommodate the increased strength potential near the completion of
the movement If you move the 200-lb bar fast enough, you are producing far greater
power (even at the bottom where you are truly only moving 200 pounds) than you were
with 270 pounds on the slower moving bar. Chains hung from a bar have a similar effect
to that of bands and both serve the purpose of training the neuromuscular system to
recruit more motor units, thus increasing the rate of force development. According to
Cal Dietz, Head Olympic Strength Coach at the University of Minnesota, "More and
more of my athletes are seeing maximal weights increase as well as enhanced
performance on the field because they incorporated workouts into their program
where they reduced the weight on the bar and concentrated on speed and
accommodating their strength curves. It might not seem obvious right away that
using lighter weights will make you more powerful. However, if speed/power
training is performed properly, the heavier weights will become easier because
now you have taught your body how to fire a greater number of muscle fibers and
to increase the rate of force development. These things are much more easily
accomplished with lighter loads and greater speeds.
Note: Only elastic bands that are specifically designed for strength training
or powerlifting should be used (Jump Stretch, Flex Bands ® , etc.) as other
types of rubber bands are not made to handle high tension loads and pose
a serious risk of injury or bodily harm if the bands break.
Source #9:
Functional vs. strength training in disabled elderly outpatients.
Krebs DE, Scarborough DM, McGibbon CA.
Am J Phys Med Rehabil. 2007 Feb;86(2):93-103.
OBJECTIVE: To determine whether high-intensity functional training (FT) or strength
training (ST) better enables impairment, disability, and functional gains among disabled
community-dwelling elders.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 51
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
DESIGN: Randomized, blinded, prospective clinical trial in a large, tertiary care outpatient
rehabilitation department. Fifteen elders (62-85 yrs old) referred for physical therapy with
one or more impairments, including lower-limb arthritis, participated in 6 wks of FT
(weekly outpatient and three to five times per week of home practice in rapid and correct
execution of locomotor activities of daily living, including gait, stepping, and sit to stand)
or progressive resistive ST using elastic bands with intensity, therapist contact, and
home practice similar to those of FT.
RESULTS: Both groups significantly improved their combined lower-extremity strength
(hip abduction, ankle dorsiflexion, knee flexion, ankle plantarflexion, and knee extension) (P =
0.003), but no statistical difference between the ST and FT group gains (P = 0.203) was found.
Subjects in both interventions improved their gait speed, but the FT group improved
more than the ST group (P = 0.001). During chair rise, the FT group improved their
maximum knee torque more than the ST group (P = 0.033), indicating that they employed a
more controlled and efficient movement strategy.
CONCLUSIONS: These data suggest that an intensive FT intervention results in strength
improvements of comparable magnitude as those attained from ST and that FT also
confers greater improvements in dynamic balance control and coordination while
performing daily life tasks.
The functional exercise tasks used follow… (NOT “intimidating” free weights)
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 52
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
Source #10:
Ultimate Regimen
Lisa Altobelli, Sports Illustrated. New York: Apr 9, 2007. Vol. 106, Iss. 15; pg. 28
Hackleman, a 10th-degree black belt and former Army boxing champion, leads Liddell through twice-daily
workouts with 14 other mixed-martial-arts fighters. "A lot of guys don't last because they hate
these medieval workouts," says Hackleman, 47. "But there is no New Age exercise or
machine that's better for you than pushing a wheelbarrow up a hill."
Source #11:
“The first radio podcast where experts explore the
science and real-world application of strength &
conditioning.”
CO-HOST, WILLIAM J. KRAEMER, PH.D.
Dr. William J. Kraemer is a professor in the Department of Kinesiology at the University
of Connecticut…(see web site below for description of his accomplishments)
http://www.sphour.com OR
Search “strength power hour” in podcasts at iTunes
SHOW DATE: 7/2/07
Dr. Kramer speaks on Fixed versus Free Weights:
Show date: 5/29/07 JERRY MARTIN, CSCS*D, UNIVERSITY OF CONNECTICUT
Mr. Martin, then Dr. Kramer speak on Power, & No deceleration when training:
Show date: 6/18/07
GUEST INTERVIEWS WITH MIKE CLARK (SEATTLE SEAHAWKS)
Mike Clark speaks on Advice for coaches - To train for activities on your feet, train
on your feet, not laying down:
Show release date: 2/18/08
Interviews with Juan Carlos Santana & Bill Kraemer.
Stability versus balance training, and muscle activation levels:
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 53
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
Source #12:
Keith C Spennewyn Strength Outcomes in Fixed Versus Free-Form Resistance
Equipment. Journal of Strength & Conditioning Research. 22(1):75-81, January 2008
The purpose of this study was to compare
measures of strength and balance
between subjects using fixed form or freeform resistance training equipment to
determine whether there is a difference in
strength or balance outcomes.
FX group increased strength 57% from
baseline while the FF group increased
strength 115% from baseline.
Balance improved 49% in the FX versus
245% in the FF groups.
Results of this study indicate a greater
improvement in FF over FX in strength (58%), and balance (196%).
Source #13:
http://www.sphour.com. Show Release Date: 4/28/08
Dr. Kramer speaks on Machine versus free weights for older adults
Source #14:
Lorne Goldenberg, owner of The Athletic Conditioning
Center, Ottawa, Canada www.ACCOttawa.com
Source: StrengthCoach.com
episode #15
Topics:



The body functions as a unit
Feet must be in contact with the ground
Big shiny machines do not correlate with function and how the body works
Topic:

The bench press
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 54
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
Source #15:
NSCA Tactical Strength and Conditioning Report, April 2009.
Source #16:
Erik Helland is Head Strength & Conditioning
Coach in his 22nd season with the Bulls.
Source: StrengthCoach.com 0906-28 episode
Topics:
 Symmetrical lifts & functional training
 “Functional training”, train on your feet, no machines.
Discuss:
1. Why are some exercise facilities still using isolating machines?
2. Examples of exercise facilities moving beyond isolating machines.
Discuss:
Summary of training principles: What does good training involve?
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 55
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
Top Ten Training Tips for (Athletic) Conditioning
Success
Retrieved 6/3/09 from: http://www.thestretchinghandbook.com/archives/athleticconditioning.php, Underlined sections identified by Dr. Chalmers
The IRON-ic rule of strength training for sport: The objective is not to get stronger per se
but to improve athletic performance to build better athletes. If your sport is power lifting,
then that means improving your total. If your sport is mixed martial arts, that means you
must improve your ability in the ring. It's important for the coach and the trainee to focus
on improving sports performance. I've seen several football teams over the years that
have the 405 Bench Press Club featured on the wall but are 0-20 for the season!
Here are my top ten tips to ensure athletic success.
1. Bodyweight before external resistance
Since when has the term strength and conditioning coach been confused with weight
room coach? I don't know but I'm still surprised at the eagerness of most coaches to get
their athletes under the bar. Many coaches and athletes make the mistake of beginning
a strength routine and going straight for the heavy weights. This usually ends up
causing an injury. An athlete has no business using load if he/she cannot stabilize,
control and move efficiently with only their bodyweight. If you can't stabilize your
shoulder girdle and core doing push-ups then there is no way I'm going to put you under
a bench press bar.
Can you sit in a full squat? What about a full range single leg bodyweight squat? Until
you have mastered these exercises you can forget doing dynamic effort work with a box
squat.
So your strength program in the beginning stages may actually include no weights
whatsoever. And it will work better and faster than a typical program that relies primarily
on weights and machines in the beginning stages. In fact in my experience I'd suggest
that some athletes cannot even work with their bodyweight so we may need to modify
certain exercises. Do not rush to lift heavy loads; muscle recruitment and control are far
more important than maximal strength for any athlete. Without control the strength is
useless.
2. Train to the 5th Power
I. Train in a standing position - GROUND BASED.
The majority of athletic training should take place ON YOUR FEET (standing) as
the majority of sport takes place in that position. Of course there are exceptions to
this rule, but in general, we always lose something when we go from a standing position
to a seated or lying position.
II. Train with free weights.
I almost feel stupid bringing this up. But I still see programs out there that include leg
extensions and leg curls. Any machine limits the range of motion and controls the
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 56
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
movement. This is fine for beginners, but athletes need to be able to stabilize and
control their bodies in all three planes of motion simultaneously.
III. Use Multiple Joints
Single joint strength (e.g. leg extension machine, bicep curls) develops useless
strength. A study was undertaken at Ohio State involving a knee extension test. The
participants included: 3 World ranked squatters and 1 World Record holder in the squat.
The test results of the above subjects averaged 180lbs of force on the Cybex leg
extension machine. However a local power lifter (ranked 15th in the state) broke the
machine. He wasn't even number one in his state but he was stronger on this machine
than the World ranked lifters. If there is a better example of the inability of single joint
machine training to translate to real world strength then I'd like to see it. A guy who was
only ranked 15th in the state can apply more single leg strength than a World Record
holder. Nice; pretty; but pretty useless. If that strength doesn't transfer to athletic
success then what's the point of having it? Basically, despite the strength that individual
exhibited on the machine, he was unable to apply it in a real world situation like
squatting. And the elite squatters weren't that strong on the leg extension showing it's
not even a factor. So leg extension machines are a waste of time. Unless of course you
compete in seated ass kicking leg extension contests.
"How can anyone expect to possess co-ordination in active work when his muscles
have never worked together in groups?" Earle Liederman, 1924. Nearly 80 years ago
and we are still having this argument today. Isolation machines have no place in the
preparation of a competitive athlete.
IV. Train with explosiveness.
Explosiveness, as I see it, can be defined as; "as fast as possible with control."
Some people seem to feel that explosiveness is somewhat dangerous. Sloppy
training; uncontrolled movements? Now that's dangerous. Training explosively
more closely mirrors what happens in sport and/or life.
V. Train movements not muscle groups.
Again, isolated muscle group training, outside of rehabilitation has no place in
athletic training. An athlete should focus on strengthening specific movements. True
muscle isolation is impossible anyway, so let's focus on using that body to work in an
integrated fashion.
3. Train unilaterally and multi-planar
The majority of strength training programs take place in the sagittal plane with bilateral
movements. However the majority of sport takes place in all 3 planes simultaneously
with primarily unilateral movements. EVERY single sports conditioning program should
include split squats, step ups and lunge variations. 85% of the gait cycle (walking,
running) is spent on one leg. Over 70% of the muscles of the core run in a rotational
plane. Does your training program reflect that?
4. Use all primary methods to develop strength
This should be of no surprise to readers of this website so I won't spend a whole lot of
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 57
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
time on this. Suffice to say you need to focus on all three. Max Strength method heavy loads Repeated Efforts Method - multiple sets and reps Dynamic Effort Method using relatively lighter weights and moving them at max speed (this is STILL the
least used method in most strength coaching programs). Traditional strength
training programs have focused overwhelmingly on max strength or force development.
More important for the competitive athlete is a focus on RATE OF force development. In
the world of sport speed is still the king.
5. Variation
Everybody seems to understand that training load should be progressively increased.
Few understand that the training stimulus must also be progressively and periodically
varied. All programs have positive and negative aspects no matter how well designed or
specific - too much time on one program and you'll habituate to the positive aspects and
accumulate the negative aspects. Even the most perfectly balanced program has to
have one exercise performed first and another performed last. Not being aware of the
potential negatives of this (i.e. one exercise is never trained when you are fresh) can
create an injury situation.
6. Avoid mimicking skills
This is a big one. Throwing weighted baseballs etc will do little to improve your
strength and a lot to screw up your technique. Make sure the roles of strength and
conditioning and skill training are separate. I HATE the term sport specific. I much prefer
NON-specific training. If I'm working with a freestyle swimmer, sport specificity means
that I'll do a ton of loaded internal rotation work. My approach? To do no internal rotation
work. In fact I'd spend most of our conditioning time on EXTERNAL rotation as an injury
prevention mechanism. The role of conditioning training is NOT skill training. Loading a
technique tends to affect the mechanics of the technique negatively.
7. Train with Balance
Make sure you address pushing and pulling on both horizontal and vertical planes and
attempt to balance the loading. If you are bench pressing 400lbs but can only do a chest
supported row with 50lbs your shoulder girdle is going to suffer. If you can't handle the
same loads for two opposing movements then increase the volume of the weaker
movement (e.g. by doing an extra exercise or an extra set or two) to compensate. Trust
me this might not seem that important now but I'm not just interested in athletic
performance, I'm interested in the long term health of my athletes.
8. Get out of the Weight Room
Try some strongman training: sled dragging; uphill sprints; or stadium stairs. I'm sick of
hearing coaches telling me that they think outside of the box, yet they never leave the
confines of their own little box - the weight room.
9. Train the antagonists
This ties in with the swimming example above. The speed of a throw or a kick or punch
is determined largely by the ability of the antagonist to eccentrically decelerate the joint
action efficiently and prevent joint injury. If your body cannot safely and effectively brake
the motion, then it will not allow you to achieve full acceleration. If you are not training
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 58
updated 6/21/12
Section 3: Motor control aspects of resistance training
Unit 6c: Expert views on resistance training
the antagonists eccentrically - you are not training deceleration. And if you are not
training deceleration you cannot be training acceleration.
10. Full Front Squats
This exercise may be the single most athletic exercise. You'll get core strength, wrist,
knee, hip, shoulder, and ankle flexibility in a single exercise.
Ok- as usual I can't shut up so I'll add one more.
10.5 Extension!
I'm not going to get into an article on the pros and cons of Olympic lifting, suffice to say
that explosive triple extension (ankle, knee and hip) is a valuable component when
training athletes. Remember though - we are training ATHLETIC PERFORMANCE. We
are not training weightlifters. It is not necessary to do the complete lifts; the power and
hang variations are fine. If you're not comfortable with the Olympic lifts then add jump
training or medicine ball overhead throws or at the very least deadlifts (double
extension) as a core lift.
Do not get caught up in the numbers game and do not confuse gym improvements with
real world or sports world improvements. The greatest athletes in the world do not
necessarily have the greatest bench presses in the world. The greatest athletes in the
world have an ability to produce useable force on their field of play.
Usable force is force that propels athletes towards the ball, knocks another athlete back
or down, helps you move at full speed, or throws the winning touchdown pass. Usable
force is force properly directed in an unstable real world,
unpredictable environment. The weight room, in general, is a stable environment
whereas a field of play or the competition ring is a constantly changing place. A good
strength and conditioning coach looks to improve athletic performances, not just gym lift
numbers.
***********************************************
About the author: For the past sixteen years Alwyn Cosgrove
has been committed to achieving excellence in the field of
fitness training and athletic preparation. Specializing in
performance enhancement, Alwyn has helped countless
individuals and athletes reach their goals through sound
scientific training.
Alwyn is also recognized and certified by the National Academy
of Sports Medicine, the American College of Sports Medicine,
the British Association of Sports And Exercise Sciences,
Kingsports International Australia, the Society for Weight
Training Injury Specialists, USA Weightlifting and the Chek
Insitute of Corrective High Performance Exercise Kinesiology.
Visit Alwyns site at... http://www.alwyngosgrove.com
***********************************************
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 59
updated 6/21/12
Section 4: Movement Control Systems
Unit 7: Additional effects of afferent signals
The SSC and fatigue
If you maximally jump up & down 20X, why do you progressively jump lower?
What is the physiological basis of the muscle fatigue?
Review: The combined contribution of decending
voluntary drive and reflex activation of motoneurons
Exhaustive SSC fatigue (e.g., 100 jumps) can dramatically reduce the reflex contribution
to force production through deterioration in the sensitivity of the reflex after fatigue
because of decreased pH:
 direct inhibition of muscle spindle firing
 activating other chemical sensitive afferent nerve endings, to act through
inhibitory interneuron, to inhibit homonymous motoneuron
INHIBITORY (-) = DECREASE THE PROBABILITY THAT THE POSTSYNAPTIC CELL
WILL FIRE AN ACTION POTENTIAL
hyperpolarize the cell away from threshold for firing an AP
threshold
+
+
+
+
+
+
-

Muscle fiber contractile activity inhibition
What is the physiological basis of a reduction in force production with repeated
SSC movements (e.g., jumping, hitting etc.)?
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 60
updated 6/21/12
Section 4: Movement Control Systems
Unit 7: Additional effects of afferent signals
Where are GOLGI TENDON ORGANS? What do GOLGI TENDON ORGANS
detect?
Type Ib afferent carries information from tendon organ
What happens when Golgi tendon organs (GTOs) are firing action
potentials?
OR “What is the GTO reflex?”
1.
GTOs serve as "safety devices" that
help prevent excessive force during
muscle contraction
2.
Inhibitory influences of the GTO could
be gradually reduced in response to
strength training (Exercise Physiology, Powers
& Howley, 4th ed, 2001)
Similar statements in:
Exercise Physiology, Brooks, Fahey, White & Baldwin, 3rd ed, 2000
Biomechanics, Kreighbaum & Barthels, 4th ed, 1996
Fleck and Kraemer, Designing resistance training programs, 1997
Baechle & Earle (eds), Essentials of Strength Training and Conditioning, 2 nd ed, 2000
What do GTOs really do when they are activated by muscle tension?
From neurophysiology research articles
1) GTOs do not always inhibit the homonymous muscle.
Ib afferents rarely inhibit ankle flexor motor neurons and inhibit only some
extensor motor neurons (Eccles et al., J Physiol, 138:227,1957)
2) GTOs can excite the homonymous and heteronymous muscles
Sample experimental results:
“during walking Ib activity(force feedback) of (ankle) extensors can reinforce the
ongoing extensor activity and prevent initiation of flexor activity.” (1,7,8,9)
WHILE WALKING: in stance phase of locomotion when ankle extensor contracts, Ib
firing excite extensors and inhibit flexors of leg to help hold you up (3,6,7),
contributing up to 50% of the ankle extensor force (5)
A system of positive force feedback across joints is enabled during locomotion (2)
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 61
updated 6/21/12
Section 4: Movement Control Systems
Unit 7: Additional effects of afferent signals
WHILE STANDING: When an extensor muscle contracts, Ib afferents from GTOs in
contracting muscle excite homonymous and other (heteronymous) leg extensors
(4,7)
“reinforcing force feedback is not a constant feature but is task dependent. It
appears only in situation where it is appropriate, such as gait. In other conditions
such as in the immobile resting animal, such pathways are closed…“(1)
1.
2.
3.
4.
5.
Duysens et al. Load Regulating Mechanisms in Gait and Posture, Physiological Reviews, 2000
Nichols et al., Rapid Spinal Mechanisms of Motor Control, Exercise & Sport Sci. Reviews, 1999.
Pearson et al, Exp Brain Res, 90:557, 1992
Pratt, J Neurophysiol, 1995 73: 2578
Donelan JM, Pearson KG. Contribution of force feedback to ankle extensor activity in decerebrate walking cats. J
Neurophysiol. 2004 Oct;92(4):2093-104.
6. Grey MJ, Nielsen JB, Mazzaro N, Sinkjaer T. Positive force feedback in human walking. J Physiol. 2007 May 15;581(Pt 1):99105.
7. Windhorst U. Muscle proprioceptive feedback and spinal networks. Brain Res Bull. 2007, 73(4-6):155-202
8. Richard af Klint, et al., Load rather than length sensitive feedback contribute to soleus muscle activity during human treadmill
walking. J Neurophysiol. 17 March 2010, 10.1152/jn.00547.2009
9. af Klint R, Cronin NJ, Ishikawa M, Sinkjaer T, Grey MJ. Afferent contribution to locomotor muscle activity during unconstrained
overground human walking: an analysis of triceps surae muscle fascicles. J Neurophysiol. 2010 Mar;103(3):1262-74. Epub
2009 Dec 23
See also: Do Golgi Tendon Organs Really Inhibit Muscle Activity at High Force Levels to Save Muscles From Injury, and Adapt with
Strength Training? By: G. Chalmers, Sport Biomechanics, 1:239-249, 2002
Bottom line:
Research evidence indicates when a GTO Ib fires due to muscle tension:
 May act on other muscles - not just on homonymous muscle
 May excite, or inhibit, the target muscles, depending on the motor task
This proprioceptive reflex facilitates movement (it is not “protective”)
Do GTOs adapt with strength training to allow you to produce higher forces?
b) The concept that GTO inhibit tension production is flawed (see: above)
c) There is no evidence that GTO reflex function adapts with resistance training.
(See: Do Golgi Tendon Organs Really Inhibit Muscle Activity at High Force Levels to Save
Muscles From Injury, and Adapt with Strength Training? By: G. Chalmers, Sport Biomechanics,
1:239-249, 2002)
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 62
updated 6/21/12
Section 4: Movement Control Systems
Unit 8: Higher centers for motor control
STEP 1: STRATEGIES FOR THE UPCOMING MOVEMENT MUST BE DEVISED
STEP 2: TACTICS FOR THE UPCOMING MOVEMENT MUST BE DECIDED UPON
STEP 3: EXECUTION OF THE MOVEMENT
LEVEL
High
Middle
Low
FUNCTION
Goal & strategy of movement
(what to do)
Tactics of movement
sequence of muscle contractions to produce
movement (how to do it)
Execution of movement
activation of specific muscles (do it)
STRUCTURE
Association areas of cortex (prefrontal & posterior
parietal), basal ganglia
Motor Cortex & cerebellum
Spinal cord & brain stem
see fig. 7.22 pg 339
Brain stem is at top of spinal cord. Cerebellum is posterior to brain stem.
Cerebral cortex is above brain stem.
see fig 7.18 pg 334
directly anterior to central sulcus (central lateral groove) is PRIMARY MOTOR CORTEX anterior is
the SUPPLEMENTARY MOTOR AREA (SMA) (top) and the PREMOTOR CORTEX
(below the SMA)
Primary Motor Cortex + Supplementary Motor Area + Premotor Cortex = MOTOR CORTEX
further in front is PREFRONTAL CORTEX
behind the central sulcus is PRIMARY SENSORY CORTEX
behind that (up high) is the POSTERIOR PARIETAL CORTEX
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 63
updated 6/21/12
Section 4: Movement Control Systems
Unit 8: Higher centers for motor control
THE POSTERIOR PARIETAL AND PREFRONTAL CORTEX TAKE THE FIRST STEP IN
PLANNING A MOVEMENT = step 1 strategies
You (the pitcher) need information about your body position and the position of things around you to
plan a movement.
The posterior parietal cortex receives sensory information (from sensory cortex) and visual
information
The prefrontal cortex in humans is thought to be important for abstract thought, decision
making, anticipation of consequences.
THESE TWO AREAS, TOGETHER, FORM THE HIGHEST LEVEL OF DECISION MAKING
FOR A MOVEMENT
“WHAT SHOULD I DO, WHAT IS LIKELY TO HAPPEN”
The posterior parietal cortex & the prefrontal cortex are extensively interconnected by neurons, so
they can communicate with each other
NEXT: WHERE IS THE MOVEMENT DECISION SENT?
posterior parietal and prefrontal cortex send the decision to supplemental motor area (SMA) and
premotor cortex
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 64
updated 6/21/12
Section 4: Movement Control Systems
Unit 8: Higher centers for motor control
SMA & PRE-MOTOR AREA START THE JOB OF PLANNING HOW TO DO THE MOVEMENT
DECIDED UPON = step 2 tactics
e.g., a subject decides direction to move the hand, but must wait for a command to move.
if the subject is to pitch overhand, one group of neurons in SMA fire, until the command to go
but
if the subject is to pitch underhand, another group of neurons in SMA fire, until the command
to go
NEURONS IN SMA FIRE FROM WHEN YOU FINISH YOUR DECISION MAKING TO
WHEN YOU START THE MOVEMENT
I.E., THEY ARE HOLD THE INSTRUCTION OF WHAT TO DO, UNTIL IT IS TIME TO
DO IT.
THE BASAL GANGLIA IS ALSO INVOLVED IN SELECTING AND INITIATING
MOVEMENTS (telling SMA what to do and when to start movement)
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 65
updated 6/21/12
Section 4: Movement Control Systems
Unit 8: Higher centers for motor control
Parkinson’s disease (1% of people over age 50) is due to a loss of neurons in the basal ganglia
result is difficulty in initiating movements, slowness of movement, increased muscle tone
because the SMA is not activated by the basal ganglia
MOVEMENT “TACTICS” ARE RELEASED FROM SMA & PRE-MOTOR CORTEX BY “GO”
SIGNAL, TO ACTIVATE BODY SPECIFIC NEURONS IN PRIMARY MOTOR CORTEX = step 3
THE PRIMARY MOTOR CORTEX NEURONS FORM A MAP OF THE BODY (SOMATOTOPIC
MAP)
see fig 7.18 pg 334
see fig 7.19 pg 335
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 66
updated 6/21/12
Section 4: Movement Control Systems
Unit 8: Higher centers for motor control
THE ROLE OF THE PRIMARY MOTOR CORTEX CELLS CAN CHANGE:
 if stroke kills the primary motor cortex cells which control the hand muscles, other neighboring
cells can slowly take over control of the hand
 if you practice find hand movements, the hand area of the primary cortex enlarges for even more
precise control.
PRIMARY MOTOR CORTEX ACTIVATES SPINAL CORD MOTOR NEURON POOLS, to
activate muscles
THE CEREBELLUM IS ALSO CRITICAL FOR DETERMINING THE DETAILED SEQUENCE
OF MUSCLE CONTRACTION before & during the movement
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 67
updated 6/21/12
Section 4: Movement Control Systems
Unit 8: Higher centers for motor control
To help PLAN movement cerebellum:
 receives movement idea (from posterior parietal & prefrontal) and tactics (from primary
motor cortex)
 sends contribution of muscle coordination to primary motor cortex
Characteristic of person early in learning stages with respect to coordination of muscles?
Characteristic of person with well learned skill with respect to coordination of muscles?
To help DURING movement cerebellum:
 compares desired planed movement to ACTUAL sensory feedback
 if desired and actual movement don’t match, then correction is made
CEREBELLUM IS AN IMPORTANT SITE WHERE MOTOR LEARNING OCCURS
FOLLOWING CEREBELLUM DAMAGE:
• the joints move independently (first shoulder, then elbow, then wrist) instead of coordinated
simultaneous movement of joints
• movement will fall short, or go past, the intended target position
ALCOHOL produces similar effects by inhibiting cerebellar neurons
THE CATCHER SIGNALS THE PITCHER FOR A FAST BALL
DESCRIBE THE SEQUENCE OF EVENTS THAT FOLLOW TO RESULT IN THE PITCH.
KIN 507 Lecture notes  2012, Gordon Chalmers, Ph.D.
Pg. 68
updated 6/21/12