excersice physiology

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Exercise Physiology

JOSEPH P WEIR

85

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Copyright copy by Holcomb Hathaway Publishers Reproduction is not permitted without permission from the publisher



86 C H A P T E R 5

DEFINITIONS IN EXERCISE PHYSIOLOGY

E xercise physiology is defined as ldquothe study of how the body from afunctional standpoint responds adjusts and adapts to exerciserdquo (FoxBowers amp Foss 1993) and the exercise physiologist as one who

ldquostudies the muscular activity and functional responses and adaptations duringexerciserdquo (ACSM 2010) As is evident from these definitions the two aspects ofexercise physiology that form the core of the discipline are the responses and theadaptations to exercise A response is distinguished from an adaptation in that aresponse is an acute or short-term change (adjustment) in the body that is associ-ated with exercise For example as one jogs the heart rate increases from theresting value In contrast an adaptation to exercise involves a long-term changein the body due to exercise training For example highly conditioned runnerstypically have lower resting heart rates than less-fit individuals This decrease inresting heart rate (bradycardia) occurs over time as a result of regular exercisetraining It is the study of these types of responses and adaptations that providesthe scientific basis for the field of exercise physiology

In addition exercise physiology has applied aspects with many peopletrained to work in a hands-on environment with both healthy and patient

populations The application of the knowledge base of exercise physiologyto clinics health clubs and athletic conditioning can significantly improvehuman performance and quality of life

PROFESSIONAL DUTIES OF AN EXERCISE PHYSIOLOGIST

E xercise physiologists in the broadest sense provide a variety of services

in various settings Clinical exercise physiologists design implement andmonitor exercise programs for individuals with cardiac pulmonary and

metabolic disorders (eg diabetes) Practitioners in the health and fitness indus-

try perform exercise tests and design exercise programs for the general populationin order to improve health decrease clientsrsquo risk for disease and improve well-being and self-esteem Researchers study the mechanisms of response andadaptation that occur with exercise as well as the practical aspects of exercisephysiology such as how to maximize the benefits of an exercise intervention

Most exercise physiologists work in an applied setting that is they workwith real people in a clinical athletic or fitness setting Nonetheless research-ers are continually adding to the body of knowledge in exercise physiologyBecause of this continual information turnover applied exercise physi-ologists have the responsibility of staying current with research Similarlyresearchers in exercise physiology have the responsibility of effectively dis-seminating new information to practitioners

HISTORY OF EXERCISE PHYSIOLOGY

A lthough the formal study of exercise physiology as a discipline is still

relatively new interest in the physiology of physical activity dates backto the ancient Greeks (Astrand 1991 Berryman 1995 Buskirk

1996 1992 Costill 1994 Dill 1980 Dill Arlie amp Bock 1985 Kroll 1971McArdle Katch amp Katch 2007 Tipton 1996) Students are strongly encour-aged to consult Chapter 1 to develop an appreciation for the rich history thatled to modern-day exercise physiology

response 983150

adaptation 983150





E X E R C I S E P H Y S I O L O G Y 87

PARENT DISCIPLINES OF EXERCISE PHYSIOLOGY

E xercise physiology has two primary parent disciplines physiology andphysical education Academic training in exercise physiology typicallycrosses the boundaries of both disciplines Physiology involves the study

of the function of the body That is physiology is concerned with how the bodyworks Physiology itself is based on other disciplines such as anatomy biochem-istry and cellular biology Most academic training in exercise physiologyfocuses on the function of the body from a systems approach that is how theorgan systems respond and adapt to exercise Increasing emphasis however isbeing placed on the study of the cellular molecular and genetic aspects of exer-cise (Brooks 1987 Hagberg et al 2011 Tipton 1996) To physiologistsexercise can serve as a stressor thereby serving as a useful tool to challenge anorganism and study its responses and adaptations to the stressor (Brooks1987) Indeed because exercise can provide a potent stimulus to a variety ofphysiological systems simultaneously (eg the muscular cardiovascular ther-moregulatory and endocrine systems) it can be a powerful tool to help furtherthe understanding of how the body functions (Brooks 1994)

The second parent discipline is physical education (Brooks 1987) To

physical educators the knowledge from the study of exercise physiology canbe used to improve health and enhance human performance during physicalactivity and athletic events Indeed as early as the 1890s exercise physiologywas a part of the curricula in some university physical education programs(Buskirk 1996) and a biological aspect has been a component of physi-cal education since the inception of the field (Kroll 1971) Currently mostacademic programs in exercise physiology are part of departments that areor were affiliated with the applied professional field of physical educationwhich now usually involves the preparation of teachers for public and privateschools However the scope of exercise physiology now extends beyond bothphysiology and physical education because exercise physiology influences

researchers and clinicians in other professions such as medicine physicaltherapy and gerontology Further discussion of these topics is included laterin this chapter

AREAS OF STUDY IN EXERCISE PHYSIOLOGY

T his section presents a brief overview of the different areas of study thatare a part of exercise physiology both basic and applied areas Forsimplicity the areas are covered separately it should be noted how-

ever that there is a great deal of overlap For example it is difficult toadequately study the control of respiration without considering the nervoussystem (which controls the respiratory muscles) and the processes of bioener-

getics and metabolism (which provide metabolites that influence respiratorycontrol) Similarly applied areas of study such as gerontology and diabetesinvolve all of the areas of basic study

Areas of Basic Study

Cardiovascular system

The cardiovascular system is responsible for the transport of blood and thereforeoxygen and nutrients to the tissues of the body Similarly the cardiovascular sys-tem facilitates removal of waste products such as carbon dioxide from the body





88 C H A P T E R 5

In addition the cardiovascular system is centrally involved in the dissipation ofheat which is critical during prolonged exercise The primary components of thecardiovascular system are the heart (see Exhibit 51) which pumps the bloodand the arteries and veins (see Exhibit 52) which carry the blood to and from

the tissues Clearly the cardiovascular systemrsquosfunctions are critical during exercise therefore alarge proportion of study and research in exercise

physiology focuses on the responses and adapta-tions of the cardiovascular system to exerciseExamples of areas of research regarding the car-diovascular system and exercise include the effect

of exercise on the structure and function of the blood vessels and the relationshipbetween exercise and the neurological control of the heart

The primary cardiovascular disease is coronary artery disease in whichcholesterol and other blood lipids (fats) build up in the walls of arteriesthat supply blood to the heart itself This process of atherosclerosis can lead toblockage of a coronary artery and ultimately to a heart attack Physical activ-ity habitual exercise and exercise capacity are associated with decreased risk

of morbidity and mortality from cardiovascular disease (Kokkinos amp Myers2010 Myers et al 2002 Thompson et al 2003) Important beneficial effectsof exercise on the cardiovascular system include a decrease in resting blood pres-sure (an important risk factor in cardiovascular disease) and a decrease in blood

From a health perspective the study of the relationships

between exercise and the cardiovascular system is critically

important because cardiovascular disease is the leading cause

of death in the United States (Hoyert et al 2006)

F O C U S

P O I N T

Basic anatomy of the heartexhibit 51

cholesterol 983150

atherosclerosis 983150






cholesterol levels (reducing the risk for developing atherosclerosis) Furthermore

exercise is an important component of the cardiac rehabilitation process follow-ing a cardiac event such as a heart attack (Leon et al 2005) Individuals withtraining in exercise physiology are playing important roles in the research andimplementation of exercise programs for the prevention of cardiovascular dis-ease and the rehabilitation of individuals with cardiovascular disease

Pulmonary system

The pulmonary system is important for the exchange of oxygen and car-bon dioxide between the air and the blood The primary component of thepulmonary system is the lungs Exercise places a great deal of stress on the

The one-way valves of the veins Contraction of the surrounding

skeletal muscle aids in the movement of blood toward the heart

and the valves prevent blood from moving away from the heart

exhibit 52





90 C H A P T E R 5

pulmonary system as oxygen consumption and carbon dioxide productionare increased during exercise thus increasing the pulmonary ventilation rateThe control and regulation of the pulmonary system during exercise are areasof much research As with the cardiovascular system the interplay of exer-cise and the neurological control of breathing is not completely understoodSurprisingly most evidence indicates that there are few if any adaptations toexercise in the pulmonary system itself in healthy individuals (McArdle et al

2007) However adaptations in the musculature that controls breathing areapparent (Housh Housh amp deVries 2012) In addition an interesting areaof inquiry is the study of training the inspiratory muscles of ventilation as anintervention to improve exercise performance (Bailey et al 2010)

From a clinical perspective exercise is an important component of pulmo-nary rehabilitation for individuals with diseases such as chronic obstructivepulmonary disease (COPD includes diseases such as emphysema and asthma)and exercise physiologists may work with physical therapists respiratorytherapists and pulmonologists as part of the pulmonary rehabilitation teamOn the other hand exercise can induce asthmatic events in some individuals(exercise-induced asthma) and the exact mechanisms of this phenomenon

are under study These events in which exercise can precipitate airway con-striction shortness of breath and wheezing can occur in both asthmatic andnonasthmatic people however the incidence is much higher in asthmaticsObviously these events can lead to submaximal performance in athletes andlikely reduce exercise adherence in nonathletes (Hough amp Dec 1994)

Nervous system

Motor or voluntary Among the many functions of the nervous system is the con-trol of movement by way of the skeletal muscles which are under voluntary(and reflex) control Most of the study of the neural control of movement isconsidered the domain of motor control and motor learning (see Chapter 10)

However certain areas of inquiry are also of interest to exercise physiologistsTwo notable areas are neuromuscular fatigue and neurological adaptations tostrength training

With respect to neuromuscular fatigue research suggests that under cer-tain conditions the central nervous system (CNS includes the brain and spinalcord) may play an important role in the development of fatigue (Weir et al2006) For example changes in brain levels of serotonin and dopamine mayinfluence fatigue (Blomstrand 2006 Davis Alderson amp Welsh 2000) Inaddition the firing rate of motor units can change during fatigue (Rubinsteinamp Kamen 2005) which may be due to an elegant interplay between periph-eral receptors and the CNS

Similarly strength training may influence the CNS control of muscleactivation by changing the number of motor units that the CNS will activateduring a contraction and the firing rate of the active muscle (Gabriel Kamenamp Frost 2006) Much of the data regarding neurological adaptations tostrength training are contradictory but this remains an important areaof study These areas of study are important to basic researchers in exercisephysiology and new information in these areas may also have implications inthe rehabilitation of individuals with neuromuscular disorders

Autonomic or involuntary The autonomic nervous system is involved in theinvoluntary control of body functions The autonomic nervous system has two

autonomic nervous

system 983150






divisions The sympathetic nervous system becomes active during situations ofincreased stress such as during exercise The parasympathetic nervous system is more active during resting conditions Most notable in exercise physiologyis the autonomic control of the cardiovascular system For example duringexercise an increase in sympathetic activity and a decrease in parasympatheticactivity result in an increase in activity of the heart and an increase in bloodpressure In addition the autonomic nervous system is involved in the redis-

tribution of blood flow away from inactive tissues such as the gastrointestinaltract and toward the active tissues during exercise

Adaptations also occur in the autonomic nervous system following exer-cise training For example the decrease in resting heart rate and heart rate ata submaximal exercise load in trained individuals is believed to be a resultat least in part of altered autonomic function that is elevated parasympa-thetic activity (Shi et al 1995 Smith et al 1989) These adaptations haveimportant clinical implications as a shift in the balance toward sympatheticand away from parasympathetic tone is associated with increased risk ofheart attack and sudden death (ChattipakornIncharoen Kanlop amp Chattipakorn 2007

Tsuji et al 1994) Therefore the adaptationsin autonomic balance following aerobic exercisetraining especially after a first heart attack maydecrease risk

Muscular system

Exercise is about movement and the muscular system is primarily respon-sible for creating movement Therefore the responses and adaptations ofthe muscular system to exercise are important parts of exercise physiologyDuring exercise many changes take place in skeletal muscle such as changesin temperature acidity and ion concentrations These changes affect muscle

performance and may lead to fatigue Indeed the mechanism(s) of musclefatigue is an important area of inquiry in exercise physiology (MacLaren et al1989 Weir et al 2006) In addition the adaptations of the muscular systemto exercise lead to long-term changes in exercise capability Depending on thetype of exercise changes in enzyme concentrations contractile protein con-tent and vascularization affect the ability of the muscle to perform work Forexample endurance exercise increases concentrations of enzymes in skeletalmuscle that are involved in the aerobic production of energy (Gollnick amp King1969 Holloszy 1967)

In contrast strength training is associated with increases in the size of themuscle due to increased synthesis of contractile proteins with little changein anaerobic enzyme content (Tesch Komi amp Hakkinen 1987) These types

of adaptations are appropriate for a certain typeof activity in that these adaptations will improvemuscle performance in the types of activities thatstimulated these adaptations The muscle biopsyprocedure has been and continues to be an impor-tant tool for studying these adaptations

Several neuromuscular conditions such asmultiple sclerosis postpolio syndrome and Guillain-Barreacute syndrome affectskeletal muscle The effect of exercise on individuals with these conditionsmay be important for improving quality of life Although much of the research

983150 sympathetic nervous

system

983150 parasympathetic

nervous system

Recent technological advances allow for the noninvasive

assessment of autonomic nervous system function andshould further our understanding of the effects of exercise

on the autonomic nervous system

F O C U S

P O I N T

Technology such as electromyography (EMG) nuclear

magnetic resonance spectroscopy (MRS) and magnetic

resonance imaging (MRI) are helping to further our

understanding of muscle function with exercise (discussed

further in other chapters)

F O C U S

P O I N T





92 C H A P T E R 5

is still in its infancy most studies suggest that appropriately designed exerciseprograms can benefit those with neuromuscular disorders (Curtis amp Weir1996 Malek York amp Weir 2007) Future research may create new roles forexercise physiologists in the rehabilitation of neuromuscular disease

Bioenergetics and metabolism

With respect to exercise the area of bioenergetics and metabolism involvesthe study of how the body generates energy for muscular work The energyfor exercise in the form of adenosine triphosphate (ATP) is derived from thebreakdown of food from the diet Originally in the form of protein fat andcarbohydrate the energy is made available by different enzymatic pathwaysthat break down food and ultimately lead to ATP formation The specificmetabolic pathway used and the associated food broken down for energy areaffected by the type of exercise that a person is performing and have implica-tions for the ability of the person to perform that exercise These are importantissues in exercise physiology because they affect decisions that exercise pro-fessionals make regarding the type intensity and duration of exercise to beprescribed to a client

Tools that are described later in the chapter such as indirect calorimetrymuscle biopsy and magnetic resonance spectroscopy are used in research tostudy these processes Exercise biochemists use muscle biopsy and nuclear

magnetic resonance spectroscopy to study thebiochemical changes that occur in skeletal muscleduring and after exercise Box 51 presents anabstract of a research study that utilized mag-netic resonance spectroscopy to examine musclemetabolism at differing intensities during legexercise The whole-body metabolic response to

exercise is studied with indirect calorimetry which involves the collection and

analysis of oxygen and carbon dioxide levels in expired air

Endocrine system

The endocrine system is the system of hormones which are chemicals releasedinto the blood by certain types of glands called endocrine glands Manyhormones are important during exercise and may affect performance Forexample during exercise the hormone called growth hormone increases inconcentration in the blood This hormone is important in regulating bloodglucose concentrations Similarly other hormones such as cortisol epine-phrine and testosterone increase during exercise Their effects may be shortterm in that they affect the body during the exercise bout Other effects are

prolonged and may be important in the long-term adaptation to regular exer-cise The effects of exercise training on hormonal responses and the effects ofthese hormones on the responses and adaptations to acute and chronic exer-cise are areas of intense study

Another aspect of exercise endocrinology is the study of exogenous (pro-duced outside the body) hormone supplementation on both short- andlong-term exercise For example supplemental testosterone and associatedanabolic steroids have been used by athletes for many years to enhance per-formance in athletic events that require strength and power This is a type ofergogenic aid (discussed later) Although the use of anabolic steroids is against

adenosine triphosphate 983150

indirect calorimetry 983150

hormone 983150

endocrine gland 983150

The study of whole-body metabolic responses and adaptations

to exercise has application to topics such as exercise and

obesity because this type of metabolic information can be

used to maximize the fat-burning effects of exercise

F O C U

S

P O I N T






the rules of most athletic governing bodies and may have detrimental healthconsequences the use of such substances may have significant therapeuticeffects for those with limited exercise capacity such as the frail elderly (Bhasinet al 1996 Sheffield-Moore et al 2006)

Immune system

The immune system fights off pathogens and infections The study of the effectof exercise on the immune system is a relatively new phenomenon Indeed thefirst exercise physiology textbook to include a specific chapter on exerciseand the immune system was published in 1994 (deVries amp Housh 1994)Currently the relationship between exercise and the immune system is under

intense study however much more research is needed to fully understandthe implications of exercise on the ability of the body to fight disease Someevidence indicates that exercise may have a deleterious effect on the immuneresponse under certain conditions whereas it may enhance the immuneresponse under other conditions (Housh et al 2012) depending on theimmune parameter being measured (Nieman 1996) Specifically very intenseor exhaustive exercise may result in short-term immunosuppression (deVriesamp Housh 1994 Gleeson 2006 Nieman 1996) For example marathon run-ning has been associated with increased incidence of upper respiratory tractinfection (Nieman et al 1990) In contrast submaximal exercise may result

Jones A M Wilkerson D P DiMenna F Fulford J amp Poole D C (2008) Muscle metabolic responses to exercise above

and below the ldquocritical powerrdquo assessed using 31P-MRS American Journal of Physiology Regulatory Integrative and

Comparative Physiology 294 R585ndashR593

Abstract of a research study that examined muscle metabolism

at differing intensities of exercise 51

box

We tested the hypothesis that the asymptote of the hyper-

bolic relationship between work rate and time to exhaustion

during muscular exercise the ldquocritical powerrdquo (CP) repre-

sents the highest constant work rate that can be sustained

without a progressive loss of homeostasis [as assessed using

31P magnetic resonance spectroscopy (MRS) measurements

of muscle metabolites] Six healthy male subjects initially

completed single-leg knee-extension exercise at three to

four different constant work rates to the limit of tolerance

(range 3ndash18 min) for estimation of the CP (mean plusmn SD 20

plusmn 2 W) Subsequently the subjects exercised at work rates

10 below CP (ltCP) for 20 min and 10 above CP (gtCP)

for as long as possible while the metabolic responses in

the contracting quadriceps muscle ie phosphorylcreatine

concentration ([PCr]) Pi concentration ([P

i]) and pH were

estimated using 31P-MRS All subjects completed 20 min of

ltCP exercise without duress whereas the limit of tolerance

during gtCP exercise was 147 plusmn 71 min During ltCP exer-

cise stable values for [PCr] [Pi] and pH were attained within

3 min after the onset of exercise and there were no further

significant changes in these variables (end-exercise values

= 68 plusmn 11 of baseline [PCr] 314 plusmn 216 of baseline [Pi]

and pH 701 plusmn 003) During gtCP exercise however [PCr]

continued to fall to the point of exhaustion and [Pi] and pH

changed precipitously to values that are typically observed

at the termination of high-intensity exhaustive exercise (end-

exercise values = 26 plusmn 16 of baseline [PCr] 564 plusmn 167

of baseline [Pi] and pH 687 plusmn 010 all P lt 005 vs ltCP

exercise) These data support the hypothesis that the CP

represents the highest constant work rate that can be sus-

tained without a progressive depletion of muscle high-energy

phosphates and a rapid accumulation of metabolites (ie H+

concentration and [Pi]) which have been associated with the

fatigue process

Reprinted with the permission of the American Physiological Society





94 C H A P T E R 5

in increases in immune system parameters (Housh et al 2012) Clearly moredetailed information must be obtained in order for applied exercise physiologiststo be able to optimally design exercise programs that enhance rather thansuppress immune function

Skeletal system

The skeletal system serves as a structural framework and provides the leversystem by which muscle contraction can lead to movement In addition theskeletal system acts as a depot of important minerals such as calcium Interest

in the skeletal system with respect to exercisehas largely focused on the effects of exercise orlack thereof on bone mass The importance ofthis area is reflected in the fact that there is arelationship between bone density and risk offracture and in the fact that bone mass decreases

with time in the elderly (Bailey Faulkner amp McKay 1996) In postmeno-pausal women the decrease in estrogen production that occurs followingmenopause is implicated in the development of osteoporosis Exercise may

help slow the process of osteoporosis but the effect may be rather modest(Howe et al 2011) In addition weight-bearing exercise prior to the onset ofmenopause may enhance the development of bone mass so that the effects ofmenopause on the skeletal system are diminished (Borer 2005) Individualswith training in exercise physiology may help to design exercise programsthat maximize the beneficial effects of exercise on the skeletal system andminimize the deleterious effects

Areas of Applied Study

Microgravity and spaceflight

Spaceflight and the associated microgravity cause a variety of changes inhumans including decreases in muscle and bone mass (Sulzman 1996)and orthostatic hypotension (low blood pressure upon standing) In addi-tion decrements in motor function also occur that compromise the abilityof astronauts to function effectively especially upon initial return to EarthWith the potential for more long-term exposure to microgravity (eg in aninternational space station) some of the deleterious effects of microgravitymay have significant health and performance implications (Adams Caiozzoamp Baldwin 2003) In the case of loss of bone mass one month of spaceflightresults in bone loss that is equal to 1 year of bone loss on Earth in postmeno-pausal women (Cavanagh Licata amp Rice 2005)

Exercise during spaceflight is one countermeasure used to combat theseeffects However under conditions of microgravity it is difficult to designeffective exercise programs because weight-bearing exercise is not possibleExercise devices designed specifically for spaceflight have been developed(Convertino 1996) and future research will need to be performed to takebest advantage of these devices In addition most early attempts at exercise inmicrogravity focused on endurance exercise However research into exercisecountermeasures has involved other types of exercise most notably resistanceexercise (Haus Carrithers Carroll Tesch amp Trappe 2007 Tesch EkbergLindquist amp Trieschmann 2004)

osteoporosis 983150

In younger women extreme exercise training and excessive

weight loss may lead to menstrual dysfunction hormonal

disturbances and possible deleterious effects on bone

mineral density (Arena et al 1995)

F O C U S

P O I

N T






Gerontology

Exercise has great potential to enhance the quality of life of individualswho are elderly and possibly to extend life Much research is under way tomore clearly understand the unique responses and adaptations to exercisein the elderly

Some of the consequences of the aging process are a decrease in restingmetabolic rate loss of muscle mass an increase in body fat percentage and adecline in aerobic capacity (Deschenes 2004 Evans 1995 Fleg et al 2005)These effects are associated with increased incidence of conditions such as car-diovascular disease Exercise may be a powerful tool to retard these processes(Tanaka amp Seals 2003)

A growing area of study is strength training for the elderly Although thestrength levels of the sedentary elderly have been reported to be quite lowresearch has shown that the elderly are capable of significantly increasingboth muscle size and strength with strength training (Macaluso amp De Vito2004 Rogers amp Evans 1993) Increased muscle strength makes the perfor-mance of the activities of daily living easier and increased muscle mass mayincrease metabolism and help in maintaining appropriate body composition

(Hunter McCarthy amp Bamman 2004) Furthermore resistance exercise inthe elderly appears to have beneficial effects on a variety of indices associatedwith chronic diseases such as glucose tolerance and triglyceride levels (HurleyHanson amp Sheaff 2011) Although more research is needed both aerobicand strength training are being utilized by exercise physiologists to improvethe quality of life of the elderly

Spinal cord injury

Every year in the United States approximately 10000 individuals experiencea spinal cord injury (SCI) (Jacobs amp Nash 2004) Depending on the severityand site of the lesion paralysis can result Paralysis of both the upper and

lower body results in quadriplegia (also called tetraplegia) paralysis of thelower body is referred to as paraplegia Among the many effects of paralysisthe decrease in physical activity can lead to increases in risk factors for cardio-vascular disease (Bauman et al 1999 Khan et al 2011)

Although strength training and range of motion exercises are commonin the rehabilitation of individuals with SCI there is great potential forthe inclusion of aerobic exercise in the rehabilitation following SCI Box52 presents an abstract from a research study that examined the effect ofexercise in subjects with paraplegia Individuals with paraplegia can exercisetheir upper bodies with the use of arm crank ergometers and wheelchairexercise In addition functional electrical stimulation (FES) can be used to

allow for lower-body aerobic exercise in individuals with SCI (Hettinga ampAndrews 2008 Kirshblum 2004) This type of intervention has the poten-tial to enable individuals with SCI to experience the beneficial effects ofaerobic exercise

Stroke

In the United States per year an estimated 785000 individuals experiencea stroke (Roger et al 2011) A stroke or cerebrovascular accident (CVA)occurs as a result of a disruption of blood flow to an area of the brain result-ing in death of the tissue supplied by the now-disrupted blood flow There are





96 C H A P T E R 5

a variety of effects of a CVA and the effects depend on the severity and loca-tion of the lesion Common motor consequences of CVA include hemiparesisand spasticity Hemiparesis is a loss of motor control (including strength)and sensation on one side of the body whereas spasticity is a condition ofexcessive muscle tone and resistance to stretch The effects of strength train-ing and aerobic exercise in stroke patients with hemiparesis and spasticityhave been studied (Engardt et al 1995 Macko et al 2005 Potempa et al1995) Indeed in the past strength training was avoided in many patientswith stroke because of a fear of making certain stroke complications such as

spasticity even worse Although much more research needs to be performedthe rehabilitation of patients with stroke may require increased participationby professionals with training in exercise physiology

Cardiac rehabilitation

The primary tasks of exercise physiologists in cardiac rehabilitation are design-ing implementing and monitoring exercise programs Functions related tothese activities include exercise testing and client education Exercise testing isuseful in diagnosing disease and measuring exercise capacity (Myers 2005)The diagnosis of cardiac disease is performed under physician supervision and

hemiparesis 983150

spasticity 983150

Wecht J M Marsico R Weir J P Spungen A Bauman W and De Meersman R E (2006) Autonomic recovery from

peak arm exercise in fit and unfit individuals with paraplegia Medicine and Science in Sports and Exercise 38 (7) 1223ndash1228

Abstract of a research study that examined the effect

of exercise in subjects with paraplegia 52

box

INTRODUCTION Altered autonomic cardiovascular

control in persons with paraplegia may reflect peripheral

sympathetic denervation caused by the injury or decon-

ditioning due to skeletal muscle paralysis Parameters of

autonomic cardiovascular control may be improved in fit

persons with paraplegia similar to effects reported in the

noninjured population

PURPOSE To determine differences in resting and recovery

HR and cardiac autonomic control in fit and unfit individuals

with paraplegia

METHODS Eighteen healthy males with paraplegia below

T6 were studied nine participated in aerobic exercise con-

ditioning (fit ge 30 min bull dndash1 ge 3 d bull wk ndash1 ge 6 months) and

nine were sedentary (unfit) Analysis of heart rate variability

(HRV) was used to determine spectral power (ln transformed)

in the high- (lnHF) and low-frequency (lnLF) bandwidths and

the LFHF ratio was calculated Data were collected at base-

line (BL) and at 2 10 30 60 and 90 min of recovery from

peak arm cycle ergometry

RESULTS The relative intensity achieved on the peak exer-

cise test was comparable between the groups (ie 88 peak

predicted HR) However peak watts (P lt 0001) and oxygen

consumption (P lt 001) were higher in the fit compared

with the unfit group (56 and 51 respectively) Recovery

lnHF was increased (P lt 005) and recovery lnLF (P lt 001)

and LFHF (P lt 005) were reduced in the fit compared with

the unfit group Mean recovery autonomic activity was notdifferent from BL in the fit group In the unfit group mean

recovery lnHF was reduced and mean recovery lnLF and LF

HF remained elevated above BL

CONCLUSION These data suggest that fit individuals

with paraplegia have improved cardiac autonomic control

during the postexercise recovery period compared with their

unfit counterparts

Reproduced with permission of Lippincott Williams amp Wilkins via Copyright Clearance Center






focuses on electrocardiogram (ECG) monitoring which provides informa-tion about blockage in the arteries that supply blood to the heart Howeverexercise testing that also incorporates gas exchange measurements (indirectcalorimetry) can provide additional valuable clinical information (Balady et al2010 Myers 2005) Determination of exercise capacity is useful in designingexercise programs and monitoring progress Client education focuses on topicssuch as self-monitoring of exercise proper nutrition stress management and

weight managementTraditional cardiac rehabilitation programs are separated into three to

four phases Phase I is in-patient (hospital-based) rehabilitation and is usuallyconducted for patients who have recently experienced a heart attack (calleda myocardial infarction) had cardiac surgery or have been hospitalized foranother cardiac condition such as heart failure or peripheral vascular diseaseAlthough exercise physiologists may perform phase I cardiac rehabilitation itis more typically performed by the nursing staff or physical therapists PhasesII through IV are outpatient services and are more likely to be performed byclinical exercise physiologists than phase I Phase II occurs from just afterdischarge from the hospital for up to 12 weeks and involves close supervi-

sion with electrocardiogram monitoring of the patientsrsquo exercise sessionsThe transition from phase II to III involves less supervision and limited ECGmonitoring during exercise Phase IV is the transition to a commitment topermanent lifestyle changes including regular exercise and a healthful diet

Although many students think of cardiac rehabilitation as focusing onpatients who have had a myocardial infarction or bypass surgery other cardio-vascular conditions are also treated with cardiac rehabilitation In heart failurethe heart is unable to adequately pump blood through the circulatory system Thismay be secondary to a heart attack but it may also occur from conditions suchas damage to the heart valves The effects of exercise on damaged hearts per seare limited but exercise tolerance can be significantly increased in these patientspresumably because of adaptations in the skeletal muscle Peripheral artery dis-

ease (PAD) is analogous to atherosclerosis of the arteries supplying blood to thelocomotor muscles such as the calves A common symptom of PAD is pain andcramping in muscles during tasks such as walking or climbing stairs (Sontheimer2006) Exercise training improves exercise tolerance in these patients largely byincreasing local muscular endurance in the locomotor muscles

Pulmonary rehabilitation

The primary purposes of pulmonary rehabilitation are to decrease symptomsincrease function and reduce health care costs in individuals with respiratorydiseases (Nici et al 2006) Exercise is an important component in the processof pulmonary rehabilitation because one of the primary consequences of pul-monary disease is a decrease in functional abilities (Butcher amp Jones 2006)Exercise and pulmonary rehabilitation can significantly improve quality of lifeand enhance performance in the activities of daily living Indeed pulmonarypatients most often initially seek medical attention because of breathlessnessduring physical exertion Exercise physiologists perform clinical exercise testsand design and implement exercise programs for these patients

Exercise testing provides information that is more correlated with func-tional abilities than even lung-function testing (Bach amp Moldover 1996)The information from clinical exercise testing in the suspected pulmonarypatient can be used for diagnostic purposes to provide information for





98 C H A P T E R 5

decision making regarding therapeutic intervention and to monitor theprogress of the rehabilitation

The primary purpose of exercise training in pulmonary rehabilitation is toincrease functional capacity resulting in an increase in the ability to performactivities of daily living Of these increased endurance for walking is essen-tial Endurance strength and flexibility exercises are all components of therehabilitation process Endurance exercise training should increase the amount

of work that a person can perform without shortness of breath Becauselung disease often leads to weight loss and weakness strength training exer-cises increase the ability of patients to do work with less fatigue Similarlyalterations in posture and mobility that occur as a consequence of pulmonarydisease can be corrected or minimized with flexibility training (Barr 1994)An added benefit of exercise is the component of emotional support (providedby additional human contact) which may also contribute to improvement inpatient function (Siebens 1996)

Body composition and weight control

Obesity is defined as an excess amount of body fat The current estimate isthat approximately 34 percent of U S adults are obese and the incidence hasincreased over the last 20 years (Flegal et al 2010) Because obesity has impor-tant implications for health reducing the incidence of obesity is considered animportant national health goal Diseases that are associated with obesity includeheart disease type 2 diabetes and cancer (Pi-Sunyer 1993) Epidemiologicalevidence also indicates that obesity and ldquooverweightrdquo (and also underweight)can lead to an increased risk of illness andor death (Flegal et al 2005)

Exercise can facilitate fat loss in a comprehensive weight-managementprogram (Shaw Gennat OrsquoRourke amp Del Mar 2006 Stiegler amp Cunliffe2006) However important questions remain to be answered regardingthe most beneficial approach when using exercise in treating obesity One

important consideration is the type of exercise to be used Aerobic exercisehas traditionally been used to burn fat but the role and effectiveness of resis-tance exercise needs further study It has been shown that resistance traininghelps to maintain lean body weight during weight-loss diets (Ballor et al1988) and may increase resting metabolic rate (Ryan et al 1995) Questionsremain regarding the optimal mix of exercise intensity versus exercise dura-tion for facilitating fat loss Clearly long-term exercise adherence needs tobe a consideration Gender differences may play an important role in theinteraction between exercise and fat loss and need further study

The effectiveness of physical activity in the prevention of obesity is animportant area of inquiry There are ldquocritical periodsrdquo in childhood and adoles-

cence when excessive weight gain will likely influence adult obesity (Daniels etal 2005) Exercise may be important in preventing obesity during these yearsand after especially because obesity at these ages is a significant predictor ofobesity in later life Similarly as people get older their resting metabolic ratetends to decrease and percent body fat tends to increase Increasing physicalactivity may help prevent or slow this process As can be seen researchers inexercise physiology have many questions to answer regarding exercise and obe-sity Because new information is being reported applied exercise physiologistsin both clinical and health and fitness areas need to stay current in order toadequately serve their clients






Exercise and diabetes

Diabetes is a disorder of the endocrine system a system of ductless glands thatsecretes its products called hormones into the blood which carries them toldquotargetrdquo organs or systems where they have their effects In healthy individu-als the amount of hormones produced by each gland is carefully balancedToo much or too little of a certain hormone can have effects throughout thebody and cause various endocrine disorders In the case of diabetes blood glu-cose regulation is disrupted due to dysfunction of the bodyrsquos insulin systemInsulin is a hormone secreted from the pancreas and serves to facilitate glucosetransport from the blood to the cells Diabetes is classified as type 1 or type 2Individuals with type 1 diabetes usually develop the disease in childhood andalmost all require exogenous insulin to supplement pancreatic productionPersons with type 2 diabetes usually develop insulin resistance in later life andmost do not require exogenous insulin (Young 1995)

High fitness levels and high levels of physical activity have been shown todecrease the risk of developing diabetes (Gill amp Cooper 2008 LaMonte Blairamp Church 2005) thus exercise training may help individuals avoid develop-ing type 2 diabetes For those with diabetes exercise has been shown to have

a beneficial effect on glucose regulation This effect is in part due to the factthat exercise promotes glucose transport from theblood to muscle cells (Wasserman amp Zinman1994) Although this effect is largely beneficialexercise physiologists who work with individualswith insulin-dependent diabetes must be aware ofthe potential for the combined effects of exercise and exogenous insulin manip-ulation to result in hypoglycemia (low blood sugar) or hyperglycemia (highblood sugar) (Wasserman amp Zinman 1994) Beyond the effects of exercise onblood glucose regulation per se exercise can have a beneficial effect on risk fac-tors associated with diabetes such as obesity elevated blood cholesterol and

high blood pressure Because of the high incidence of diabetes applied exercisephysiologists should be aware of all current information regarding exercise anddiabetes The ACSM has specific recommendations for the design of exerciseprograms for individuals with type 2 diabetes (Colberg et al 2010)

Exercise and pregnancy

There is as yet no conclusive evidence indicating that exercise during preg-nancy facilitates the process of labor and delivery however a clear benefit ofmaternal exercise is maternal health and a more rapid return to prepregnancylevels of fitness Applied exercise physiologists may work with pregnant cli-ents and need to be aware of the exercise modifications necessary for safe and

effective exercise during pregnancyThe effect of exercise on both the mother and the infant has receivedincreased research attention since 1984 when the first guidelines regardingexercise and pregnancy were published by the American College of Obstetricsand Gynecology (ACOG) Two of the primary considerations were the effectof elevation in maternal core temperature on the unborn child and the effectsof maternal exercise on fetal blood flow Because there was relatively littlepublished research at that time the initial guidelines were conservative in thatit was recommended that exercise heart rate not exceed 140 beats per minuteand core temperature not exceed 38degC

There are over 19 million diabetics in the United States (Cowie

et al 2006) and complications from diabetes (eg heart

disease or stroke) are among the major causes of death

F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5

Since that time more research and clinical information has accumulatedand the ACOG guidelines were updated (ACOG 2002) These guidelinesencourage physical activity and exercise in pregnant women (includingstrengthening and flexibility exercises) but provide specific precautions andcontraindications for exercise It has also been noted that exercise may helpcontrol gestational diabetes and decrease the risk of preeclampsia (DammBreitowicz amp Hegaard 2007) ACSMrsquos Guidelines for Exercise Testing and

Prescription (ACSM 2010) has specific exercise prescription informationfor exercise during pregnancy

Muscle soreness and damage

The soreness that occurs 24 to 48 hours following strenuous exercise (espe-cially if it is a new type of exercise) is familiar to all who exercise This isoften referred to as delayed onset muscle soreness (DOMS) (Housh et al2012) The specific cause(s) of this soreness is (are) still being investigated butmuch evidence suggests that it is associated with muscle damage and is moresevere with eccentric contractions (contractions in which the muscle activelylengthens such as when lowering a weight or walking down a hill) than with

concentric contractions (contractions in which the muscle is shortening suchas when curling a barbell to the chest) Although muscle soreness may be onlya nuisance for healthy individuals for some it may affect exercise adherence Itmay also have important health implications for individuals with neuromuscu-lar disease who wish to exercise because some evidence suggests that muscledamage from overwork may exacerbate some diseases In addition musclesoreness is used as a model for the study of mechanisms of injury repair

Environmental exercise physiology

Environmental exercise physiology encompasses many aspects These includeissues such as exercise in cold environments and exercise and pollution Inthis section a brief overview of two frequently studied areas altitude andheatndashhumidity will be presented

Altitude As one moves from sea level to high altitudes barometric pressuredecreases which decreases the amount of oxygen that is driven into the bloodto bind to hemoglobin (hemoglobin is the protein in red blood cells that carriesoxygen and carbon dioxide) The decreased oxygen content leads to decreasedperformance in endurance exercise at the elevated altitude Prolonged exposureto high altitude however results in increased synthesis of hemoglobin andred blood cells These adaptations increase the oxygen-carrying capacity ofthe blood and theoretically may improve exercise performance at sea level

One model used in endurance sports is ldquoliving highmdashtraining lowrdquo (Levine ampStray-Gundersen 2005) In this model athletes live at high altitude to stimu-late red blood cell production while they train at low altitude so that trainingis not compromised by hypoxia (the deficiency of oxygen reaching body tis-sues) Whether the benefits of this model are actually due to increases in redblood cells is an open debate (Gore amp Hopkins 2005)

Altitude exposure also poses health risks and unique problems for thosewho exercise For example mountain climbers must perform work at altitudesthat may lead to mountain sickness and even death Therefore the studyof physiological adaptations to altitude and the consequences of associated

eccentric contraction 983150

concentric contraction 983150

hemoglobin 983150






exercise is an important area of research Projects such as Operation EverestII (Sutton Maher amp Houston 1983) in which a hypobaric chamber allowedfor the simulation of high altitude have made important contributions to ourunderstanding of these issues

Heat and humidity Thermal adjustments comprise a very important aspect ofexercise in a hot andor humid environment where exercise without adequate

thermal adjustments can lead to serious health consequences including deathIn general the most important heat-dissipating mechanism during exercise issweating The evaporation of sweat from the skin results in a transfer of heatfrom the skin to the environment resulting in cooling This process howevercan lead to a loss of body water and electrolytes (eg sodium) Thereforeboth the increase in body temperature and the effect of the water and elec-trolyte loss can affect performance and lead to medical problems such as heatstroke Humidity is an especially important problem because high humidityminimizes the amount of sweat that can evaporate thus sweat is wasted

Research by exercise physiologists led to important recommendations regard-ing exercise in the heat fluid replacement and prevention of heat illnesses with

exercise (Armstrong et al 2007 Sawka et al 2007) Current areas of researchfocus on issues such as the proper method of fluid replacement during exercisein the heat (ACSM 2010) Many sports drinks are commercially available andmany have been developed in part from research conducted by exercise physi-ologists More recently it was recognized that drinking too much fluid duringexercise can lead to hyponatremia (decreased concentration of sodium in theblood) a potentially life-threatening condition (Hsieh et al 2002)

Ergogenic aids

In athletic competition the difference between winning and losing can be smallBecause of this athletes and coaches will try many things in order to gain acompetitive advantage The term ergogenic aid refers to any substance deviceor treatment that can or is believed to improve athletic performance In contrastergolytic refers to practices that can impair performance Many nutritional prod-ucts and practices (eg carbohydrate loading) are used to gain a competitiveadvantage Some techniques can be beneficial but most donrsquot work Drugs suchas amphetamines and anabolic steroids are used illegally and may have dangerousside effects Other aids can be mechanical such as knee wraps in power lifting

A large amount of research in exercise physiology has been conducted toevaluate the efficacy of different ergogenic aids The research into ergogenicaids is important not only for the immediate effect of the data on athletic prac-tices but also because examination of these issues

can provide insight into the limiting processes andmechanisms involved in human performance Inaddition because ergogenic aids are an impor-tant issue in athletic competition applied exercise physiologists need to beup to date on the efficacy safety and ethical issues surrounding ergogenicaids that may be used by clients Of special concern are the potential healthconsequences of some ergogenic aids A few of these aids are discussed next

Anabolic steroids are synthetically developed cholesterol-based drugs thatresemble naturally occurring hormones such as testosterone and have anabolic(growth-promoting) and androgenic (masculinizing) effects (ACSM 1984)

983150 ergogenic aid

983150 ergolytic

At the 2008 Olympics Michael Phelps beat Milorad ˇ Caviacute c

by 1100th of a second in the menrsquos 100 meter butterfly

F O C U S

P O I N T

983150 anabolic steroids





102 C H A P T E R 5

Because testosterone is involved in skeletal muscle development among otherfunctions anabolic steroids are used by athletes primarily to facilitate strengthand power development Therefore they are most frequently used in sports suchas weight lifting throwing events in track and field and football (Hoberman ampYesalis 1995 Yesalis amp Bahrke 1995) Although the research data are equivo-cal the general consensus is that anabolic steroids do seem to be effective inthis regard However illegal use of anabolic steroids can have significant legal

implications In addition as noted earlier their use is against the rules of almostall athletic governing bodies Moreover many health consequences are associ-ated with the use of these drugs

Caffeine is a drug commonly found in coffee tea chocolate and many carbon-ated soft drinks It also appears to be effective as an ergogenic aid (Tarnopolsky2010) Caffeine can affect arousal levels and alter metabolism The main benefi-cial effect is in endurance activities (Tarnopolsky 2010) The influence of caffeineon strength and power events seems to be minimal (Williams 1991)

An ergogenic aid receiving much attention since the mid-1990s is creatinesupplementation Creatine phosphate is involved in ATP restoration in skeletalmuscle and research shows that creatine supplementation can increase intramus-

cular concentrations of both free creatine and creatine phosphate (Tarnopolsky2010 Terjung et al 2000) Creatine supplementation has also been shown toenhance performance and recovery from high-intensity exercise which may alsolead to more productive training sessions Strength and power athletes are theprimary beneficiaries of creatine supplementation The effects of creatine mayalso occur via effects on gene expression (Willoughby amp Rosene 2001 2003)

Sodium bicarbonate an alkalizing substance (neutralizes acids) has beenstudied for use as an ergogenic aid because increased acidity is one possiblemechanism of muscle fatigue Sodium bicarbonate is used to buffer acidsduring exercise and delay fatigue Research suggests that this procedure maybe beneficial for high-intensity large muscle mass activities where a largeincrease in acidity would be expected (Requena et al 2005) However side

effects include gastrointestinal distressBlood doping refers to two techniques used to increase red blood cell con-

tent to enhance endurance performance One technique involves the infusionof red blood cells either from a sample taken at an earlier time from the samesubject or from another donor The second technique involves administra-tion of a drug called erythropoietin (EPO) which stimulates red blood cellproduction by the bone marrow Research generally shows that blood dopingmay enhance endurance performance but both techniques violate currentInternational Olympic Committee rules and can have negative health conse-quences (Joyner 2003) Use of EPO has led to scandals in sporting events suchas the Tour de France (Joyner 2003)

Pediatric exercise physiology

Pediatric exercise physiology is concerned with children and adolescentsClearly this area of exercise physiology has a direct bearing on the field ofphysical education This is especially true considering the relatively poor stateof physical fitness in American youth In addition the topic of pediatric exer-cise physiology has important clinical and health implications As with adultsclinical exercise testing in children is used in the diagnosis of cardiovascularand pulmonary disease (Tomassoni 1996) The growth of the area of pedi-atric exercise physiology is evidenced by the publication of Pediatric Exercise

creatine supplementation 983150

blood doping 983150






Science which was first published in 1989 Because most of the subdisciplinesaddressed previously have application to pediatric exercise physiology in thissection we address only a few select areas

The relationship between bone mineral density and physical activity inchildren has important implications for the prevention of the loss of bone massin later years Most bone mass is laid down during childhood and adolescencewith peak bone mass occurring at about 30 years of age (Bailey et al 1996)

Vigorous weight-bearing exercise appears to increase bone growth duringthese years which may be protective during adulthood In contrast poor dietmenstrual irregularities and lack of physical activity may minimize the devel-opment of bone tissue and result in increased risk of fracture in later life

Strength training for children and adolescents also may pose unique risksIn addition the question of whether children can increase their strength withresistance training has received considerable examination With respect to risksbecause the growth plates at the ends of long bones are fragile and damage tothese growth plates can affect growth safety is of paramount concern Althoughreports of growth plate injuries with strength training are rare conservativeguidelines were developed and can be found in the position paper by the National

Strength and Conditioning Association (Faigenbaum et al 2009) In generalchildren are to avoid ldquoweight liftingrdquo that is children should not attempt tolift as much as they can Rather strength training can be used to help improvestrength levels Research evaluating the use of strength training in children hasgenerally shown that children can increase strength levels with resistance train-ing but the amount of change in muscle mass is limited until after puberty atwhich time the endocrine system develops to the point that adequate hormoneconcentrations exist to support muscle mass development (Blimkie 1992)

The effect of exercise on the rate and amount of growth in children andadolescents has important implications for the prescription of exercise in chil-dren Exercise provides conflicting signals for growth in children On the onehand the increased metabolic demands of physical activity can potentially

divert nutrients away from growth processes On the other hand exercisestimulates endocrine responses that facilitate growth (Borer 1995) Comparinggrowth in active versus sedentary subjects is problematic due to selection biasthat is any differences in growth and development between active and less-active subjects may be due to a tendency for individuals with a specific bodytype to gravitate toward certain activities and athletic pursuits Malina (1994)in a review of growth and maturation data in young athletes concluded thatmost athletic training did not affect these processes in the long term Howeverinadequate nutritional support as may be associated with sports like wrestlingand gymnastics may have effects (Roemmich Richmond amp Rogol 2001)Clearly female gymnastics is associated with short stature and delayed men-

arche (time of first menstruation) but the factors driving these observations(eg selection bias stress nutrition training) are difficult to untangle (Thomiset al 2005) In wrestling where ldquomaking weightrdquo is common in young ath-letes the data indicate that growth patterns are similar between wrestlers andnonathletes (Housh et al 1993 Roemmich amp Sinning 1997)

Exercise and human immunodeficiency virus

Human immunodeficiency virus (HIV) is the virus that causes AIDS (acquiredimmune deficiency syndrome) It is believed that HIV attacks specific types ofimmune cells which ultimately leads to decreases in the ability of the body to





104 C H A P T E R 5

fight infection There is no cure but important strides are being made withrespect to increasing both the life span and quality of life for individuals whoare HIV positive

Of interest here is the relationship between exercise and HIV Exerciseappears to have beneficial effects for individuals with HIV (Hand Lyerly

Jaggers amp Dudgeon 2009 OrsquoBrien Nixon Tynan amp Glazier 2010) Forexample strength training may help maintain muscle mass which may help to

slow down the loss in lean body mass associated with AIDS wasting (Lawless Jackson amp Greenleaf 1995) Aerobic exercise will similarly improve cardiore-spiratory endurance and quality of life As noted previously regarding exerciseand immunology however exercise also has the potential to be immunosup-pressive Nonetheless to date the limited number of studies that examinedexercise and HIV showed that exercise is safe (Hand et al 2009)

TECHNOLOGY AND RESEARCH TOOLS

T he tools used by exercise physiologists for conducting research are

numerous and a comprehensive review is beyond the scope of this

chapter However this section presents a brief outline of some com-mon tools with emphasis placed on noninvasive techniques

Treadmills and Ergometers

The treadmill and cycle ergometer are the basic tools used by exercise physi-ologists to induce exercise in research subjects The treadmill is very commonin the United States (see Exhibit 53) where walking and jogging are familiar

Exercise test on a treadmillexhibit 53






forms of exercise In Europe where bicycling is more common the use ofcycle ergometers is more prevalent (see Exhibit 54) However both devicesare used frequently

With treadmills the intensity of exercise is controlled by manipulating thespeed of the treadmill belt and the grade of the treadmill (ie the steepness of theslope) The disadvantage of the treadmill is that it is difficult to precisely measurethe exact work output by a subject because of differences in mechanical efficiency

between people In contrast because cycle ergometers support the subjectrsquos bodyweight the work by the subject is just a function of the resistance of the machineMost cycle ergometers have resistance applied by a friction belt When the exer-cise intensity is to be increased the resistance by the belt is increased Howeverthe pedal rate affects the intensity of the exercise therefore subjects must main-tain a constant pedal rate More expensive electronically braked cycle ergometersuse an electromagnet to provide resistance These devices have the advantage ofallowing the power output of the subject to be manipulated independent of pedalrate so subjects can choose the pedal rate that is most comfortable for them

Although less common than either the treadmill or the cycle ergometer othertypes of ergometers such as those for arm cranking allow for exercise testing

with modes of exercise other than running or cycling The arm-crank ergometeris a modified cycle ergometer for which the arms are used to ldquopedalrdquo the deviceThese devices are important for exercise testing and training of individuals suchas those with paraplegia who are unable to use the lower body Sports physiol-ogy laboratories may have access to sport-specific ergometers such as rowingergometers cross-country skiing ergometers and swim flumes In the training andtesting of high-level athletes these devices provide information that is more spe-cific to the types of events in which the athletes will be competing (Thoden 1991)

Exercise test on a Monark cycle ergometer exhibit 54

135





106 C H A P T E R 5

Metabolic Measurements

Probably the most common physiologic measurement in exercise physiologyis the determination of oxygen consumption and carbon dioxide productionfor the purpose of measuring metabolic activity using indirect calorimetryThis is most often performed during exercise on a treadmill or cycle ergom-eter These measurements obtained by collecting and analyzing expired gasesfrom the lungs allow for the determination of a variety of factors includingthe amount of energy (calories) used during an activity the relative amountof fat versus carbohydrate burned and the fitness status of a given individualThe maximal rate of oxygen consumption or V

bull

O2 max is the primary stan-

dard for determining aerobic fitness Prior to the development of fast andinexpensive computers performance of these metabolic measurements waslabor intensive and time-consuming Currently however computerized andautomated metabolic carts (see Exhibit 55) allow metabolic exercise tests tobe performed quickly and with fewer technicians

V bull

O 2 max 983150

A metabolic (met) cartexhibit 55






Body Composition Assessment

Measurement of body composition is an important tool for studying theeffects of various exercise andor dietary interventions The most commonmodel of body composition is the two-component model which divides thebody into fat weight and fat-free weight components The fat-free weightcomponent includes tissues such as muscle bone and various organs The fatweight component is primarily adipose tissue (fat tissue) but also includes someneurological tissue Newer multicomponent models further delineate bodycomposition components into smaller subcom-ponents These approaches are likely to improvemeasurement of body composition especially fordifferent racial groups (Heyward 1996)

Hydrostatic weighing or underwater weigh-ing is the primary gold standard for assessingbody composition New technology such as dual-energy X-ray absorptiometry (DXA also used tostudy bone mineral content) is expanding the assessment of body compositionand may displace underwater weighing as the gold standard Other tech-

niques such as the use of skinfold calipers bioelectrical impedance analysis(BIA) and near infrared reactance (NIR) provide predictions of what a per-sonrsquos body composition would be if assessed with underwater weighing Theselatter techniques while less accurate than underwater weighing do allow formore convenient and therefore widespread use of body composition assess-ment (Heyward 1996) Air displacement plethysmography assesses bodycomposition using logic similar to that of hydrostatic weighing (calculation ofbody density by determining body volume and mass) The validity and reli-ability of the technique appear acceptable (Lee amp Gallagher 2008) Newerapproaches include techniques based on MRI and computerized tomography(CT) (Lee amp Gallagher 2008)

Muscle Biopsy

The muscle biopsy procedure has been in use since the 1960s and can betraced to Bergstrom (1962) In this procedure a needle is inserted into thebelly of a muscle and a small piece of tissue is removed From this procedurean exercise physiologist can make a variety of observations For examplecomparison of pre- versus post-exercise biopsy samples has been used to studysubstrate utilization and metabolite accumulation during exercise In addi-tion the muscle biopsy procedure is a technique by which muscle fiber typepercentages can be determined in humans The three primary fiber types inhuman skeletal muscle are slow-twitch oxidative (SO) fast-twitch oxidative

glycolytic (FOG) and fast-twitch glycolytic (FG) (Peter et al 1972) Thesefiber types have also been called type I type IIa and type IIb or Betaslowtype IIa and type IIx respectively The names SO FOG and FG howeverprovide descriptive information about the characteristics and functioning ofthe various fiber types while type I IIa and IIb do not For example from thenames we know that SO fibers are slow-twitch and favor oxidative (aerobicwith oxygen) energy production while FG fibers are fast-twitch and favorglycolytic anaerobic (anaerobic without oxygen) energy production

Research employing muscle biopsies has led to many advances in ourunderstanding of the physiology of exercise Because of its invasive nature

The practical utility of body composition assessment is that it

facilitates the design of exercise and dietary programs for fat

loss Body composition data are used to set fat-loss goals

for clients In addition continued measurement of body

composition allows for the monitoring of progress over time

F O C U S

P O I N T

983150 slow-twitch oxidative (SO

983150 fast-twitch oxidative

glycolytic (FOG)

983150 fast-twitch glycolytic (FG)





108 C H A P T E R 5

however use of the procedure requires extensive training which limits its useto a relatively small number of research laboratories

Electromyography

Electromyography involves the measurement of muscle electrical activityBecause the stimulus for a muscle to contract is electrical the measurement

of this electrical activity provides information regarding the activation of theskeletal muscles involved during exercise In general there are two types ofEMG measurement procedures Intramuscular EMG involves placing record-ing electrodes into the belly of the muscle itself most typically in the formof a needle electrode This common clinical tool is used for the diagnosis ofneuromuscular diseases but it also has some utility in studying exercise Morecommon however is the use of surface electrodes to record the EMG signalSurface EMG provides information about the relative strength of a musclecontraction because in general the larger the amount of muscle activatedthe larger the amount of electrical activity produced Changes in the amountof electrical activity recorded have been used to study the neurological effects

of strength training (Gabriel et al 2006 Moritani amp deVries 1979) In addi-tion as a muscle fatigues there occur changes in the EMG signal that provideinsight into the rate of fatigue of the muscle as well as the mechanisms offatigue (Dimitrova amp Dimitrov 2003)

Magnetic Resonance Imaging and Nuclear

Magnetic Resonance Spectroscopy

Magnetic resonance technology has been a tool used for studying musclesand exercise since the early 1980s Both magnetic resonance imaging andnuclear magnetic resonance spectroscopy (MRS) are based on the applica-tion of strong magnetic fields to the tissue of interest MRI has been used to

examine changes in muscle size following strength training because the MRIimages offer advantages over ultrasound and CT scans in visualizing muscletissue and other soft tissues (Housh Housh Johnson amp Chu 1992) Twoother applications involve the use of MRI to study body composition andactivation patterns of skeletal muscle during different tasks For body com-position a series of cross-sectional scans can be made from head to toe Thisallows for the assessment of not only the amount of fat versus lean tissue butalso the distribution of fat in different areas of the body most notably in theabdominal cavity versus under the skin (subcutaneous) This is importantbecause intra-abdominal fat appears to be more related to disease risk thandoes subcutaneous fat Although the use of MRI for this purpose is likely to

be limited to research data derived using these procedures may significantlyimprove our understanding of exercise diet and obesityWith respect to muscle activation changes in the contrast of MRI images

of skeletal muscle are indicative of activation of the muscle Future researchwith MRI may reveal important new information regarding muscle activationduring exercise

In contrast to MRI MRS does not involve imaging of the tissues understudy per se rather it allows for the noninvasive measurement of muscle sub-strates and metabolites so that changes that occur during an exercise bout canbe monitored This facilitates investigations of muscle fatigue and is being used

electromyography 983150






in research studies that previously would have required subjects to undergomuscle biopsy Another potential use is for the noninvasive determination ofmuscle fiber type The primary disadvantage of both MRI and MRS is the costassociated with their use Because of the expense the use of these technologiesto study exercise physiology will likely be limited to relatively few laboratories(Kent-Braun Miller amp Weiner 1995)

EDUCATIONAL PREPARATION

A cademic programs in exercise physiology vary to some degree in theirrequirements and course content (see Chapter 1) Another complica-tion is that there is no set standard for the amount of education

required to become an exercise physiologist that is an individual is notrequired to obtain a bachelorrsquos masterrsquos or doctoral degree in exercise phys-iology to call himself or herself an exercise physiologist Similarly there is noconsensus about what every exercise physiologist should know For examplesome academic programs heavily stress clinical aspects of exercise physiologyin which students are trained to work in clinical environments such as cardiac

rehabilitation and pulmonary rehabilitation Other academic programs pre-pare students for research careers In both cases undergraduate and graduateprograms are offered

Undergraduate

Courses in exercise physiology have long been a part of the curriculum forundergraduate physical education majors Intensive study of exercise physiologyat the undergraduate level is a more recent phenomenon Most undergradu-ate degrees related to exercise physiology are not exercise physiology degreesper se rather they are more likely to be degrees in exercise science This moregeneric title allows for a broad emphasis in which exercise physiology is inte-

grated with other areas of study such as biomechanics and motor learningAlthough an undergraduate degree may be sufficient for many purposes it isoften the case that these degrees are preparatory for more advanced training atthe graduate level or in professional school

As preparation for the core courses in the degree mathematics and basicscience courses such as chemistry physics and general physiology are helpfuland may be required In addition for those individuals who wish to pursuegraduate training or who will apply for professional school (eg medicine orphysical therapy) these courses are often requirements for application tothe various programs

Core courses in the degree program will typically include one or more

courses in exercise physiology itself with emphasis on the basic areas ofstudy outlined in this chapter Additional courses at the undergraduatelevel may include emphasis on nutrition cardiovascular exercise physiol-ogy exercise biochemistry exercise testing and exercise prescription Withrespect to exercise testing these courses often provide hands-on experi-ences in conducting exercise tests for both fitness evaluation and clinicalevaluation Similarly exercise prescription courses provide theoretical andpractical information regarding the design and implementation of indi-vidualized exercise programs for both healthy individuals and those withconditions such as cardiovascular disease





110 C H A P T E R 5

Graduate

Graduate programs in exercise physiology tend to be more specializedthan undergraduate programs Indeed differences between institutions forsimilarly titled programs can be quite large Outlined next are some char-acteristics of different types of graduate programs at both the masterrsquos anddoctoral levels For those interested in pursuing graduate training in exer-cise physiology it is advisable to research the specific programs of interestcarefully to ensure that the chosen program fits the studentrsquos specific needsand goals

Masterrsquos

At the masterrsquos level many programs emphasize training in clinical exer-cise physiology Courses in these programs tend to focus on advancedtraining in exercise testing and exercise prescription Specialized trainingoften includes in-depth analysis of exercise electrocardiograms study ofthe effect of cardiovascular medications on exercise study of the effect ofexercise on cardiovascular disease and designing of exercise programs for

those with cardiovascular disease Many clinical exercise physiology pro-grams do not require the completion of a thesis project At the other endof the spectrum some masterrsquos programs focus on preparation for doctoraltraining and place very little emphasis on clinical training These programstend to place an increased emphasis on basic science and perhaps statisticsand research design

Doctoral

Doctoral education provides advanced training with a focus on developingresearch skills The two most common degrees in exercise physiology arethe doctor of philosophy (PhD) and the doctor of education (EdD) In

general the PhD degree emphasizes training in research while the EdDdegree as the title suggests tends to place more emphasis on training ineducation Traditionally the EdD degree tends to require more formalcourse work than the PhD while the scientific rigor of the PhD disserta-tion is expected to be higher than that for the EdD degree It is often thecase however that there is little difference in the two degrees and manyfine educators hold PhD degrees while a number of outstanding research-ers have an EdD

During the training for the doctoral degree the course work typicallyincludes courses in exercise physiology but many courses are taken outside theprimary department For example training in statistical procedures often occursthrough statistics departments or other departments with statistical specialists

such as psychology or educational psychology Advanced basic science coursessuch as endocrinology immunology and neurophysiology are taught in biologydepartments or through affiliated allied health andor medical schools

The culminating step in the doctoral degree is the completion of a dis-sertation Traditionally the dissertation project is the first independentresearch project by the doctoral candidate The process involves develop-ing a dissertation proposal completing the data collection and analysiswriting the document and finally defending the dissertation before a fac-ulty committee






Exercise Physiology as Part of a

Preprofessional School Degree

Courses in exercise physiology can also be important in preparing for admis-sion to various professional programs such as physical therapy medicinechiropractic and others

Physical therapy Physical therapists are primarily involved in the rehabilitation of patientsfollowing injury and disease As part of the treatment process physicaltherapists are often involved in the design of exercise programs to increasecardiovascular fitness muscular strength and flexibility (American PhysicalTherapy Association 1995) Therefore expertise in exercise physiology canbe of great benefit to many physical therapists

Today all physical therapy academic programs are required to be at thepostbaccalaureate level that is upon completion the graduate will have atleast a masterrsquos degree and most programs now offer a clinical doctoratedegree in physical therapy (DPT) The academic programs do not typi-

cally require that an applicant receive his or her undergraduate degree in aspecific major for admission however most require broad training in thesciences (biology chemistry and physics) and have specific requirementsfor the humanities Many of these requirements overlap with requirementsfor exercise science and combined with the overlap in content area maketraining in exercise science an appealing choice in preparation for admissionto physical therapy school

Medicine

Admission to both allopathic (grants the medical doctor MD degree)and osteopathic (grants the doctor of osteopathy DO degree) medical

schools requires high-level performance in basic science courses at theundergraduate level As with physical therapy many of the courses requiredfor admission to medical school are also prerequisites for many courses inexercise physiology More important training in exercise physiology maybe very useful to practicing physicians Therefore an undergraduate degreewith emphasis in exercise science along with the appropriate premedicalrequirements is an attractive option for those seeking admission to medi-cal school

Chiropractic

In general the admission requirements for chiropractic schools are similar tothose of medical schools Therefore as with the MD and DO programsundergraduate training in exercise physiology is an appealing approach forthose who wish to pursue the DC degree

Other preprofessional opportunities

A strong background in the basic sciences as well as exercise physiology pro-vides a foundation for other professional schools such as dentistry physicianrsquosassistant and optometry





112 C H A P T E R 5

CERTIFICATIONS

U nlike physical therapists nurses physicians and other health profession-

als no license is required to practice exercise physiology Howeverprofessional organizations such as the ACSM and the NSCA offer

certifications in related areas

American College of Sports MedicineThe ACSM began certification in 1975 and thousands have received certifica-tions since then Currently the ACSM has two certification categories eachwith two levels

The Health Fitness Certifications include the ACSM Certified PersonalTrainer and the ACSM Certified Health Fitness Specialist Both certificationsare designed for individuals who will provide exercise services to apparentlyhealthy clients and low-risk individuals who are cleared to exercise

The second category of ACSM certifications includes the Clinical Cer-tifications As the name suggests these certifications are designed for thosewho will work in clinical environments such as cardiac and pulmonary

rehabilitation The first level the ACSM Certified Clinical Exercise Special-ist requires a minimum of a bachelorrsquos degree and a specified number ofhours of clinical experience in order to sit for the exam The highest levelof clinical certification is the ACSM Registered Clinical Exercise Physiolo-gist Among other requirements to take the exam one must have at least amasterrsquos degree in exercise physiology (or similar degree) and at least 600hours of clinical experience

Specific requirements and competencies are described in detail in variousACSM publications such as ACSMrsquos Guidelines for Exercise Testing andPrescription (ACSM 2010) and on its website Certification examinations inboth tracks are administered online

National Strength and Conditioning Association

The NSCA began a certification in 1985 called the Certified Strengthand Conditioning Specialist (CSCS) To sit for the CSCS examination aminimum of a bachelorrsquos degree (or senior-level standing at an accreditedinstitution) and CPR certification are required The focus of the examina-tion is on the design and implementation of strength training programs forapplication to sports conditioning The examination includes questions onboth the scientific and practicalndashapplied aspects of strength and condition-ing training

The NSCA has also instituted another certification track for those indi-viduals who are or will be personal fitness trainers This is called the NSCA

Certified Personal Trainer certification (NSCA CPT)Information on both of the NSCArsquos certifications is available on its website

EMPLOYMENT OPPORTUNITIES

Clinics

Exercise physiologists have been working in clinical settings for many yearsand the two most common areas of clinical exercise physiology cardiac andpulmonary rehabilitation were addressed previously in this chapter

ACSM Certifications

wwwacsmorgcertification

NSCA Certifications

wwwnsca-ccorg

www

www






The education required for expertise in clinical exercise physiology is notstandardized At the very minimum a bachelorrsquos degree in exercise science ora related discipline with specialized course work in clinical topics of exercisephysiology such as exercise testing and electrocardiography is important Amasterrsquos degree is often necessary Hands-on experience often gained froman internship as part of an academic program is very helpful as is one of theACSMrsquos clinical certifications The AACVPR website (see p 115) has infor-

mation about job openings in cardiac and pulmonary rehabilitationOne important task of a clinical exercise physiologist is to perform clinical

exercise testing Currently clinical exercise testing (stress testing) is used pri-marily for assessing individuals with suspected or diagnosed cardiovascular orpulmonary disease The general approach is to stress the client with a progressiveexercise test so that indications of disease severity of disease and exercise capac-ity can be determined progressive in this context means that the exercise intensitystarts at a low level and increases over time until the subject can no longer contin-ue or signs and symptoms develop such that stopping the test is warranted Unlessan orthopedic or neurological condition prevents lower-body exercise testing isusually performed with a treadmill or less often a cycle ergometer

Clinical exercise testing always includes electrocardiographic monitoringand may but does not always include metabolic measurements by indirectcalorimetry ECG monitoring is important for client safety but is also used asa diagnostic tool for assessing coronary artery disease The diagnostic utilitycomes from the fact that heart size and occlusion of coronary arteries dueto atherosclerosis result in specific alterations in ECG signals These effectsmay not show up at rest but because exercise places stress on the heartcoronary artery occlusion will become evident during exercise and result inthese changes in the ECG Similarly pulmonary dysfunction may not be fullyexhibited with resting pulmonary measurements whereas ventilatory andmetabolic changes during exercise testing can provide diagnostic informa-tion (Jones 1988) For both cardiac and pulmonary disease impairments in

peak workload attained during exercise low maximal oxygen consumptionabnormalities in blood pressure response and other information from theexercise test considered in context with other diagnostic information can beuseful in the diagnostic process

In addition the exercise testing data provide information regarding theseverity and progression of disease and can be used to monitor the effects ofinterventions such as exercise training With respect to exercise data suchas maximal oxygen consumption heart-rate response to different exerciseintensities and ventilatory responses to the exercise test are used to design theexercise program for the client Finally exercise test data are used to predictoutcomes and survival in patients

Health and Fitness Venues

For those with training in exercise physiology there appear to be two primarytypes of positions in the health and fitness industry one is to work in a privatehealth club YMCAYWCA or corporation-based center and the other is toserve as a personal trainer Employment in health clubs involves tasks suchas providing fitness evaluations designing exercise programs and educatingmembers about exercise nutrition and health Personal trainers are oftenemployed through a health club but many are entrepreneurs who contract





114 C H A P T E R 5

their services to clients on an individual basis Regardless of the route ofemployment personal trainers design exercise programs for their clients andthen supervise the clientsrsquo individual exercise sessions

Sports Conditioning Venues

The area of sports physiology a subdiscipline of exercise physiology empha-

sizes the study and application of exercise physiology to the improvementof athletic performance Most coaches have historically been involved in thedesign and implementation of exercise and conditioning programs to improvethe performance of their athletes A strong knowledge base in sports physiol-ogy is clearly helpful in this regard

More recently the emergence of the personal trainer has led to manyindividuals serving as one-on-one conditioning coaches for some athletesespecially for individual sports such as distance running and cycling As withmany personal trainer situations these types of positions are often entre-preneurial in that the trainers contract their services individually with theirclients At colleges universities and many large high schools full- or part-time strength and conditioning coaches develop the conditioning programs for

the athletes in many different sports These types of positions require knowl-edge in not only sports physiology but also in other areas of exercise science(eg biomechanics and sports nutrition)

PROFESSIONAL ASSOCIATIONS

American College of Sports Medicine (ACSM)

As mentioned previously the ACSM has grown to become the leading organi-zation in the world dedicated to the disciplines associated with exercise scienceand sports medicine Its membership has grown from an initial 11 foundingmembers to over 20000 today The ACSM has 12 regional chapters that hold

their own meetings and programs The annual national meeting grows almostevery year and attracts several thousand participants each year The nationalmeeting includes lectures tutorials colloquia and research presentationsaddressing all areas of exercise science and sports medicine

American Physiological Society (APS)

The APS is an organization of scientists who specialize in the physiologicalsciences Regular membership is restricted to those who conduct originalresearch in physiology however other membership categories such as stu-dent membership are available

American Alliance for Health Physical Education

Recreation and Dance (AAHPERD)

AAHPERD is the primary professional organization for individuals in physicaleducation and related disciplines Because of the ties between exercise physi-ology and physical education many exercise physiologists have AAHPERDmembership and are active in the organization However because ofAAHPERDrsquos primary focus on teaching at the kindergarten through 12th-grade levels the activity level of exercise physiologists in this organization isless than in the ACSM and APS

ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www







The NSCA was started in 1978 and was originally called the NationalStrength Coaches Association which reflects its roots as an organization forindividuals who work as strength and conditioning coaches often at the col-legiate or professional level Since that time the organization has grown in sizeand scope and attracts members from the health and fitness industry and fromcompetitive athletics

American Association of Cardiovascular

and Pulmonary Rehabilitation (AACVPR)

The AACVPR is an organization of physicians nurses exercise physiologistsand other health care professionals who specialize in cardiac and pulmonaryrehabilitation Student memberships are available

PROMINENT JOURNALS ANDRELATED PUBLICATIONS

T he American Journal of Physiology was an important venue for exer-cise physiology research in the first half of the 1900s Although this isstill an important source of exercise-physiology-related research the

publication of Journal of Applied Physiology in 1948 was a significant eventin that it became and remains a primary outlet for research in exercise physiol-ogy European researchers also made use of Internationale Zeitschrift fuumlrangewandte Physiologie einschlieslich Arbeitsphysiologie (currently European

Journal of Applied Physiology) and Acta Physiologica Scandinavia In 1969the ACSM began publishing Medicine and Science in Sports (currentlyMedicine and Science in Sports and Exercise) which has grown into anotherprimary journal for research in exercise physiology and is the official journalof the ACSM This journal publishes research in exercise physiology and otherareas of exercise science and sports medicine In addition the ACSM alsopublishes Exercise and Sport Sciences Reviews a quarterly publication thatcontains timely review articles by leading researchers

Other professional organizations also publish journals with articles ofinterest to exercise physiologists The APS publishes several different jour-nals one of which is Journal of Applied Physiology As mentioned this isa primary journal for original research in exercise physiology In additionAmerican Journal of Physiology regularly publishes original research inexercise physiology Other publications of the APS include Journal of Neuro-

physiology Physiological Reviews News in the Physiological Sciences ThePhysiologist and Advances in Physiology Education AAHPERDrsquos research

journal Research Quarterly for Exercise and Sport has historically publishedand continues to publish research in exercise physiology The NSCA pub-lishes two journals Strength and Conditioning and Journal of Strength andConditioning Research which as the name suggests is a research journal inwhich original investigations that have application to strength training andconditioning are published Strength and Conditioning publishes reviews andopinion articles with more direct application to the strength and conditioningprofessionals The official journal of the AACVPR is Journal of Cardio-

pulmonary Rehabilitation which publishes research articles addressing issuesof cardiac and pulmonary rehabilitation

AACVPR

wwwaacvprorg

www





116 C H A P T E R 5

As an indication of the growth of the field of exercise physiology morethan 25 scientific journals frequently publish research in exercise physiologyThese include

PRIMARY JOURNALS

Acta Physiologica Scandinavia

Applied Physiology Nutrition and MetabolismBritish Journal of Sports Medicine

European Journal of Applied Physiology

International Journal of Sports Medicine

Journal of Applied Physiology

Journal of Physiology

Journal of Sports Medicine and Physical Fitness

Journal of Strength and Conditioning Research

Medicine and Science in Sports and Exercise

Pediatric Exercise Science

Pfluumlgers Archives European Journal of Physiology

Sports Medicine

RELATED PUBLICATIONS

American Heart Journal

American Journal of Clinical Nutrition

American Journal of Physical Medicine and Rehabilitation

American Journal of Sports Medicine

Archives of Physical Medicine and Rehabilitation

CirculationErgonomics

International Journal of Sports Nutrition and Exercise Metabolism

Journal of the International Society of Sports Nutrition

Journal of Orthopaedic and Sports Physical Therapy

Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS

T wo trends in the population will likely significantly influence exercise

physiology and exercise physiologists (1) the dramatic increased inci-dence of obesity (and associated type 2 diabetes) and (2) the aging of

the baby boom generation Therefore it seems likely that obesity diabetesand gerontology will continue to grab a larger share of attention in exercisephysiology curricula and practice Applied exercise physiologists would bewell served by looking at these trends as opportunities to expand their practiceand sphere of influence

With respect to research cutting-edge exercise physiology research mustemploy one of two approaches to take advantage of technological innova-






tions The first approach is the melding of genetics and molecular biologyinto the study of integrative exercise physiology For example specific genesthat are associated with high-level exercise performance have been identifiedUnderstanding how these genes and their products affect exercise performanceat the organism level will be a key goal of future research Second advances innoninvasive measurement technology and sophisticated digital signal process-ing techniques will be increasingly employed by scientists to explore responses

and adaptations to exercise Therefore increased training in bioengineeringsoftware development and mathematics will be expected of future exercisephysiology researchers

Finally as the technical sophistication and medical importance of exercisephysiology increases it seems likely that academic exercise physiology willcontinue to drift away from its roots in physical education and move closer tophysiology biology and medicine

SUMMARY

E

xercise physiology is the study of how the body responds adjusts and

adapts to exercise The knowledge base of exercise physiology is appli-cable to many settings including clinics laboratories and health clubs Itis important for exercise science students to study the principles of exercisephysiology and to be able to utilize this knowledge base to improve human per-formance and quality of life For example a track coach may use the principlesof exercise physiology to design training programs for athletes that will enablethem to improve their running times whereas a fitness instructor may use theprinciples of exercise physiology to design exercise programs for the elderly thatwill make the performance of the activities of daily living easier The area ofexercise physiology has applications in a number of areas of exercise science

1 Distinguish between a response and an adaptation to exercise Provideexamples of each

2 Explain why the study of the cardiovascular system is of prime impor-tance in the study of exercise physiology

3 Define ergogenic aid and provide examples of different ergogenic aidsdescribing their potential uses and dangers

4 Explain the importance of the study of exercise and the skeletal system

5 Describe the phases of cardiac rehabilitation programs 6 Define obesity and outline current areas of study in exercise physiology

related to obesity

7 Outline the advantages and disadvantages of treadmill versus cycle ergom-eter exercise modes

8 Explain the difficulty in defining an exercise physiologist

9 Describe the process of clinical exercise testing and explain its uses

10 Explain the relationships among exercise physiology physiology andphysical education

study QUESTIONS

Visit the IES website to

study take notes and try

out the lab for this chapter





118 C H A P T E R 5

1 Go to the NSCA website (wwwnsca-liftorg ) Find information on theNSCA national conference and the NSCA Personal Trainersrsquo conferenceList the dates and locations of these conferences Choose two sessionsfrom each conference that relate to exercise physiology and write a two-

to three-sentence summary for each session 2 Go to the AAHPERD website (wwwaahperdorgindexcfm) Describe

the membership options and benefits as they relate to you

3 Visit the websites for the ACSM Certified Health Fitness Specialist certi-fication and the NSCA Certified Personal Trainer certification Comparethe requirements for the two certifications

Astrand P O Rodahl K Dahl H A amp Stromme S (2003) Textbook ofwork physiology Physiological bases of exercise (4th ed) ChampaignIL Human Kinetics

Brooks G A Fahey T D amp Baldwin K (2005) Exercise physiologyHuman bioenergetics and its applications (4th ed) Boston McGraw-Hill

Wilmore J H amp Costill D L (2004) Physiology of sport and exercise (3rd ed) Champaign IL Human Kinetics

learning ACTIVITIES

suggested READINGS

ACOG committee opinion (2002 January) Exercise duringpregnancy and the postpartum period International Journal of Gynecology and Obstetrics 77 (1) 79ndash81

Adams G R Caiozzo V J amp Baldwin K M (2003) Skel-etal muscle unweighting Spaceflight and ground-basedmodels Journal of Applied Physiology 95(6) 2185ndash2201

American College of Sports Medicine (2010) ACSMrsquos guidelines for exercise testing and prescription (8th ed)Baltimore MD Williams amp Wilkins

American College of Sports Medicine Position Stand (1984)The use of anabolic-androgenic steroids in sports SportsMedicine Bulletin 19 13ndash18

American Physical Therapy Association (1995) A guideto physical therapist practice volume l A description ofpatient management Physical Therapy 75 709ndash748

Arena B Maffulli N Maffulli F amp Morleo M A (1995)Reproductive hormones and menstrual changes with exer-cise in female athletes Sports Medicine 19 278ndash287

Armstrong L E Casa D J Millard-Stafford M MoranD S Pyne S W amp Roberts W O (2007) AmericanCollege of Sports Medicine position stand Exertionalheat illness during training and competition Medicineand Science in Sports and Exercise 39(3) 556ndash572

Astrand P-O (1991) Influence of Scandinavian scientistsin exercise physiology Scandinavian Journal of Medicineand Science in Sports 1 3ndash9

Bach J R amp Moldover J R (1996) Cardiovascularpulmonary and cancer rehabilitation 2 Pulmonaryrehabilitation Archives of Physical Medicine andRehabilitation 77 S45ndashS51

Bailey D A Faulkner R A amp McKay H A (1996)Growth physical activity and bone mineral acquisitionExercise Sport Science Review 24 233ndash266

Bailey S J Romer L M Kelly J Wilkerson D PDiMenna F J amp Jones A M (2010) Inspiratory mus-

cle training enhances pulmonary O2 uptake kinetics andhigh-intensity exercise tolerance in humans Journal ofApplied Physiology 109 457ndash468

Balady G J et al on behalf of the American Heart Asso-ciation Exercise Cardiac Rehabilitation and PreventionCommittee of the Council on Clinical Cardiology (2010)Clinicianrsquos guide to cardiopulmonary exercise testing inadults A scientific statement from the American HeartAssociation Circulation 122 191ndash225

Ballor D L Katch V L Becque M D amp Marks C R(1988) Resistance weight training during caloric restric-

references






tion enhances lean body weight maintenance American Journal of Clinical Nutrition 47 19ndash25

Barr R N (1994) Pulmonary rehabilitation In E A Hillegassamp H S Sadowsky (Eds) Essentials of cardiopulmonary physical therapy Philadelphia W B Saunders Company

Bauman W A Kahn N N Grimm D R amp SpungenA M (1999) Risk factors for atherogenesis and cardio-vascular autonomic function in persons with spinal cord

injury Spinal Cord 37 (9) 601ndash616Bergstrom J (1962) Muscle electrolytes in man Scandinavian

Journal of Clinical Lab Investigations 68(Suppl) 1ndash110

Berryman J W (1995) Out of many one A history of theAmerican College of Sports Medicine Champaign ILHuman Kinetics

Bhasin S Storer T W Berman N Callegari C Cleveng-er B Phillips J Bunell T J Tricker R Shirazi A ampCasaburi R (1996) The effects of supraphysiologic dosesof testosterone on muscle size and strength in normal menNew England Journal of Medicine 335 1ndash7

Blimkie C J R (1992) Resistance training during pre- andearly puberty Efficacy trainability mechanisms and persis-tence Canadian Journal of Sports Medicine 17 264ndash279

Blomstrand E (2006) A role for branched-chain aminoacids in reducing central fatigue Journal of Nutrition136(2) 544Sndash547S

Borer K T (1995) The effects of exercise on growth SportsMedicine 20 375ndash397

Borer K T (2005) Physical activity in the prevention andamelioration of osteoporosis in women Interaction ofmechanical hormonal and dietary factors Sports Medi-cine 35(9) 779ndash830

Brooks G A (1987) The exercise physiology paradigm incontemporary biology To molbiol or not to molbiolmdash

that is the question Quest 39 231ndash242Brooks G A (1994) 40 years of progress Basic exercise

physiology In 40th Anniversary Lectures IndianapolisIN American College of Sports Medicine

Buskirk E R (1992) From Harvard to Minnesota Keys toour history Exercise and Sport Sciences Review 20 1ndash26

Buskirk E R (1996) Exercise physiology Part I Early his-tory in the United States In J D Massengale amp R ASwanson (Eds) History of exercise and sport science pp 367ndash396 Champaign IL Human Kinetics

Butcher S J amp Jones R L (2006) The impact of exercisetraining intensity on change in physiological functionin patients with chronic obstructive pulmonary disease

Sports Medicine 36(4) 307ndash325Cavanagh P R Licata A A amp Rice A J (2005) Exer-

cise and pharmacological countermeasures for bone lossduring long-duration space flight Gravity and SpaceBiology Bulletin 18(2) 39ndash58

Chattipakorn N Incharoen T Kanlop N amp Chat-tipakorn S (2007) Heart rate variability in myocardialinfarction and heart failure International Journal of Car-diology 120(3) 289ndash290

Colberg S R Albright A L Blissmer B J Braun BChasen-Tabor L Fernhall B Regensteiner J G

Rubin R R amp Sigal R J (2010) Exercise and type 2diabetes American College of Sports Medicine and theAmerican Diabetes Association Joint position statementExercise and type 2 diabetes Medicine and Science inSports and Exercise 42(12) 2282ndash2303

Convertino V A (1996) Exercise as a countermeasure forphysiological adaptation to prolonged spaceflight Medi-cine and Science in Sports and Exercise 28 999ndash1014

Costill D L (1994) 40 years of progress Applied exercisephysiology In 40th Anniversary Lectures IndianapolisIN American College of Sports Medicine

Cowie C C Rust K F Byrd-Holt D D EberhardtM S Flegal K M Engelgau M M et al (2006)Prevalence of diabetes and impaired fasting glucose inadults in the US population National health and nutri-tion examination survey 1999ndash2002 Diabetes Care29(6) 1263ndash1268

Curtis C L amp Weir J P (1996) Overview of exerciseresponses in healthy and impaired states NeurologyReport 20 13ndash19

Damm P Breitowicz B amp Hegaard H (2007) Exercise

pregnancy and insulin sensitivitymdashwhat is new AppliedPhysiology Nutrition and Metabolism 32 537ndash540

Daniels S R Arnett D K Eckel R H Gidding S SHayman L L Kumanyika S et al (2005) Overweightin children and adolescents Pathophysiology conse-quences prevention and treatment Circulation 111(15)1999ndash2012

Davis J M Alderson N L amp Welsh R S (2000) Sero-tonin and central nervous system fatigue Nutritionalconsiderations American Journal of Clinical Nutrition72(2 Suppl) 573Sndash578S

Deschenes M R (2004) Effects of aging on muscle fibretype and size Sports Medicine 34(12) 809ndash824

deVries H A amp Housh T J (1994) Physiology of exer-cise for physical education athletics and exercise science (5th ed) Dubuque IA W C Brown

Dill D Arlie B amp Bock V (1985) Pioneer in sportsmedicine Medicine and Science in Sports and Exercise17 401ndash404

Dill D B (1980) Historical review of exercise physiologyscience In W R Johnson amp E R Buskirk (Eds) Struc-tural and physiological aspects of exercise and sport pp37ndash41 Princeton NJ Princeton Book Company

Dimitrova N A amp Dimitrov G V (2003) Interpreta-tion of EMG changes with fatigue Facts pitfalls and

fallacies Journal of Electromyography and Kinesiology13(1) 13ndash36

Engardt M Knutsson E Jonsson M amp Sternhag M(1995) Dynamic muscle strength training in strokepatients Effects on knee extensor torque electro-myographic activity and motor function Archives ofPhysical Medicine and Rehabilitation 76 419ndash425

Evans W J (1995) What is sarcopenia Journal of Geron-tology 50A(Special Issue) 58

Faigenbaum A D Kraemer W J Blimkie C J JeffreysI Micheli L J Nitka M amp Rowland T W (2009)





120 C H A P T E R 5

Youth resistance training updated position statementpaper from the National Strength and ConditioningAssociation Journal of Strength and ConditioningResearch 23(5 Suppl) S60ndashS79

Fleg J L Morrell C H Bos A G Brant L J TalbotL A Wright J G et al (2005) Accelerated longitudi-nal decline of aerobic capacity in healthy older adultsCirculation 112(5) 674ndash682

Flegal K M Carroll M D Ogden C L amp Curtin LR (2010) Prevalence and trends in obesity among USadults 1999ndash2008 Journal of the American MedicalAssociation 303(3) 235ndash241

Flegal K M Graubard B I Williamson D F amp GailM H (2005) Excess deaths associated with under-weight overweight and obesity Journal of the AmericanMedical Association 293(15) 1861ndash1867

Fox E L Bowers R W amp Foss M L (1993) The physi-ological basis for exercise and sport (5th ed) DubuqueIA W C Brown

Gabriel D A Kamen G amp Frost G (2006) Neuraladaptations to resistive exercise Mechanisms and rec-ommendations for training practices Sports Medicine36(2) 133ndash149

Gill J M R amp Cooper A R (2008) Physical activity andprevention of type 2 diabetes mellitus Sports Medicine38(10) 807ndash824

Gleeson M (2006) Can nutrition limit exercise-inducedimmunodepression Nutrition Reviews 64(3) 119ndash131

Gollnick P D amp King D (1969) Effects of exercise andtraining on mitochondria of rat skeletal muscle Ameri-can Journal of Physiology 216 1502ndash1509

Gore C J amp Hopkins W G (2005) Counterpoint Posi-tive effects of intermittent hypoxia (live hightrain low)

on exercise performance are not mediated primarily byaugmented red cell volume Journal of Applied Physiol-ogy 99(5) 2055ndash2057 discussion 2057ndash2058

Hagberg J M Rankinen T Loos R J Perusse L RothS M Wolfarth B amp Bouchard C (2011) Advances inexercise fitness and performance genomics in 2010 Med-icine and Science in Sports and Exercise 43(5) 743ndash752

Hand G A Lyerly G W Jaggers J R amp Dudgeon WD (2009) Impact of aerobic and resistance exercise onthe health of HIV-infected persons American Journal ofLifestyle Medicine 3(6) 489-499

Haus J M Carrithers J A Carroll C C Tesch P A ampTrappe T A (2007) Contractile and connective tissue

protein content of human muscle Effects of 35 and 90 daysof simulated microgravity and exercise countermeasuresAmerican Journal of Physiology 293(4) R1722ndash1727

Hettinga D M amp Andrews B J (2008) Oxygen con-sumption during functional electrical stimulation-assistedexercise in persons with spinal cord injury Implicationsfor fitness and health Sports Medicine 38 825ndash838

Heyward V H (1996) Evaluation of body compositionCurrent issues Sports Medicine 22 146ndash156

Hoberman J M amp Yesalis C E (1995 February) The his-tory of synthetic testosterone Scientific American 76ndash81

Holloszy J (1967) Effects of exercise on mitochondrialoxygen uptake and respiratory enzyme activity in skeletalmuscle Journal of Biological Chemistry 242 2278ndash2282

Hough D O amp Dec K L (1994) Exercise-induced asthmaand anaphylaxis Sports Medicine 18 162ndash172

Housh D J Housh T J Johnson G O amp Chu W(1992) Hypertrophic response to unilateral concentricisokinetic resistance training Journal of Applied Physi-

ology 73 65ndash70

Housh T J Housh D J amp deVries H A (2012) Appliedexercise and sport physiology (3rd ed) Scottsdale AZHolcomb Hathaway

Housh T J Johnson G O Stout J amp Housh D J(1993) Anthropometric growth patterns of high schoolwrestlers Medicine and Science in Sports and Exercise25 1141ndash1150

Howe T E Shea B Dawson L J Downie F MurrayA Ross C Harbour R T Caldwell L M amp CreedG (2011) Exercise for preventing and treating osteopo-rosis in postmenopausal women Cochrane Database ofSystematic Reviews Jul 6(7) CD000333

Hoyert D L Heron M P Murphy S L amp Kung H C(2006) Deaths Final data for 2003 National Vital Statis-tics Reports 54(13) 1ndash120

Hsieh M Roth R Davis D L Larrabee H amp Calla-way C W (2002) Hyponatremia in runners requiringon-site medical treatment at a single marathon Medicineand Science in Sports and Exercise 34(2) 185ndash189

Hunter G R McCarthy J P amp Bamman M M (2004)Effects of resistance training on older adults SportsMedicine 34(5) 329ndash348

Hurley B F Hanson E D amp Sheaff A K (2011)Strength training as a countermeasure to aging muscle

and chronic disease Sports Medicine 41(4) 289ndash306 Jacobs P L amp Nash M S (2004) Exercise recommenda-

tions for individuals with spinal cord injury SportsMedicine 34(11) 727ndash751

Jones A M Wilkerson D P DiMenna F Fulford Jamp Poole D C (2008) Muscle metabolic responses toexercise above and below the ldquocritical powerrdquo assessedusing 31P-MRS American Journal of Physiology Regu-latory Integrative and Comparative Physiology 294R585-R593

Jones N L (1988) Clinical exercise testing (3rd ed)Philadelphia W B Saunders

Joyner M J (2003) VO2 max blood doping and erythropoi-

etin British Journal of Sports Medicine 37 (3) 190ndash191

Kearny J T (1996 June) Training the Olympic athleteScientific American 52ndash63

Kent-Braun J A Miller R G amp Weiner M W (1995)Human skeletal muscle metabolism in health and diseaseUtility of magnetic resonance spectroscopy Exercise andSport Sciences Review 23 305ndash347

Khan B Bauman W A Sinha A K amp Kahn N N(2011) Non-conventional hemostatic risk factors forcoronary heart disease in individuals with spinal cordinjury Spinal Cord 49(8) 858ndash866






Kirshblum S (2004) New rehabilitation interventions inspinal cord injury Journal of Spinal Cord Medicine27 (4) 342ndash350

Kokkinos P amp Myers J (2010) Exercise and physicalactivity Clinical outcomes and applications Circulation122 1637ndash1648

Kroll W P (1971) Perspectives in physical education NewYork Academic Press

LaMonte M J Blair S N amp Church T S (2005) Physi-cal activity and diabetes prevention Journal of AppliedPhysiology 99(3) 1205ndash1213

Lawless D Jackson C G R amp Greenleaf J E (1995)Exercise and human immunodeficiency virus (HIV-1)infection Sports Medicine 19 235ndash239

Lee S Y amp Gallagher D (2008) Assessment methods inhuman body composition Current Opinion in ClinicalNutrition and Metabolic Care 11(5) 566ndash572

Leon A S Franklin B A Costa F Balady G J BerraK A Stewart K J et al (2005) Cardiac rehabilitationand secondary prevention of coronary heart disease AnAmerican Heart Association scientific statement fromthe Council on Clinical Cardiology (subcommittee onexercise cardiac rehabilitation and prevention) and theCouncil on Nutrition Physical Activity and Metabolism(subcommittee on physical activity) in collaborationwith the American Association of Cardiovascular andPulmonary Rehabilitation Circulation 111(3) 369ndash376

Levine B D amp Stray-Gundersen J (2005) Point Positiveeffects of intermittent hypoxia (live hightrain low) onexercise performance are mediated primarily by augment-ed red cell volume Journal of Applied Physiology 99(5)2053ndash2055

Macaluso A amp De Vito G (2004) Muscle strength powerand adaptations to resistance training in older people

European Journal of Applied Physiology 91(4) 450ndash472

Macko R F Ivey F M Forrester L W Hanley DSorkin J D Katzel L I et al (2005) Treadmill exer-cise rehabilitation improves ambulatory function andcardiovascular fitness in patients with chronic stroke Arandomized controlled trial Stroke 36(10) 2206ndash2211

MacLaren D P M Gibson H Parry-Billings M ampEdwards R H T (1989) A review of metabolic andphysiological factors in fatigue Exercise and Sport Sci-ences Review 17 29ndash66

Malek M H York A M amp Weir J P (2007) Resistancetraining for special populations In T J Chandler amp L EBrown (Eds) Conditioning for strength and human per-

formance Philadelphia Lippincott Williams amp Wilkins

Malina R M (1994) Physical growth and biological matu-ration of young athletes Exercise and Sport SciencesReview 22 389ndash433

McArdle W D Katch F L amp Katch V L (2007) Exer-cise physiology Energy nutrition and human performance (5th ed) Philadelphia Lippincott Williams amp Wilkins

Moritani T amp deVries H A (1979) Neural factors ver-sus hypertrophy in the time course of muscle strengthgain American Journal of Physical Medicine 58 115ndash130

Myers J (2005) Applications of cardiopulmonary exercisetesting in the management of cardiovascular and pulmo-nary disease International Journal of Sports Medicine26(Suppl 1) S49ndash55

Myers J Prakash M Froelicher V Do D PartingtonS amp Atwood J E (2002) Exercise capacity and mor-tality among men referred for exercise testing NewEngland Journal of Medicine 346(11) 793ndash801

Nici L Donner C Wouters E Zuwallack RAmbrosino N Bourbeau J et al (2006) AmericanThoracic SocietyEuropean Respiratory Society state-ment on pulmonary rehabilitation American Journalof Respiratory and Critical Care Medicine 173(12)1390ndash1413

Nieman D C (1996) The immune response to prolongedcardiorespiratory exercise American Journal of SportsMedicine 24 S-98ndash103

Nieman D C Johanssen L M Lee J W et al (1990)Infectious episodes in runners before and after the LosAngeles Marathon Journal of Sports Medicine and Physi-cal Fitness 30 316ndash328

OrsquoBrien K Nixon S Tynan A M amp Glazier R (2010)Aerobic exercise interventions for adults living with HIV AIDS Cochrane Database of Systematic Reviews Aug4 (8) CD001796

Peter J B Barnard R J Edgerton V R Gillespie CA amp Stempel K E (1972) Metabolic profiles of threefiber types of skeletal muscle in guinea pigs and rabbits

Biochemistry 11 2627ndash2633

Pi-Sunyer F X (1993) Medical hazards of obesity Annalsof Internal Medicine 119 655ndash660

Potempa K Lopez M Braun L T Szidon J P FoggL amp Tincknell T (1995) Physiological outcomes ofaerobic exercise training in hemiparetic stroke patients

Stroke 26 101ndash105

Requena B Zabala M Padial P amp Feriche B (2005)Sodium bicarbonate and sodium citrate Ergogenic aids

Journal of Strength and Conditioning Research 19(1)213ndash224

Roemmich J N Richmond R J amp Rogol A D (2001)Consequences of sport training during puberty Journalof Endocrinological Investigation 24(9) 708ndash715

Roemmich J N amp Sinning W E (1997) Weight loss andwrestling training Effects on nutrition growth matura-tion body composition and strength Journal of AppliedPhysiology 82(6) 1751ndash1759

Rogers M A amp Evans W J (1993) Changes in skeletalmuscle with aging Effects of exercise training Exerciseand Sport Sciences Review 21 65ndash102

Roger V L et al on behalf of the American Heart AssociationStatistics Committee and Stroke Statistics Subcommittee(2011) Heart disease and stroke statistics ndash 2011 update Areport from the American Heart Association Circulation123 e18ndashe209

Rubinstein S amp Kamen G (2005) Decreases in motor unitfiring rate during sustained maximal-effort contractions inyoung and older adults Journal of Electromyography andKinesiology 15(6) 536ndash543





122 C H A P T E R 5

Ryan A S Pratley R E Elahi D amp Goldberg A P(1995) Resistive training increases fat-free mass andmaintains RMR despite weight loss in postmenopausalwomen Journal of Applied Physiology 79 818ndash823

Sawka M N Burke L M Eichner E R Manghan R J Montain S J amp Stachenfeld N S (2007) AmericanCollege of Sports Medicine position stand Exercise andfluid replacement 39(2) 377ndash390

Shaw K Gennat H OrsquoRourke P amp Del Mar C (2006)Exercise for overweight or obesity Cochrane Databaseof Systematic Reviews 4 CD003817

Sheffield-Moore M Paddon-Jones D Casperson S LGilkison C Volpi E Wolf S E et al (2006) Andro-gen therapy induces muscle protein anabolism in olderwomen Journal of Clinical Endocrinology and Metabo-lism 91(10) 3844ndash3849

Shi X Stevens G H J Foresman B H Stern S A ampRaven P B (1995) Autonomic nervous system controlof the heart Endurance exercise training Medicine andScience in Sports and Exercise 27 1406ndash1413

Siebens H (1996) The role of exercise in the rehabilitation

of patients with chronic obstructive pulmonary diseasePhysical Medicine Rehabilitation Clinics of North Amer-ica 7 299ndash313

Smith H L Hudson D L Graitzer H M amp RavenP B (1989) Exercise training bradycardia The role ofautonomic balance Medicine and Science in Sports andExercise 21 40ndash44

Sontheimer D L (2006) Peripheral vascular diseaseDiagnosis and treatment American Family Physician73(11) 1971ndash1976

Stiegler P amp Cunliffe A (2006) The role of diet and exercisefor the maintenance of fat-free mass and resting metabolicrate during weight loss Sports Medicine 36(3) 239ndash262

Sulzman F M (1996) Overview Journal of AppliedPhysiology 81 3ndash6

Sutton J R Maher J T amp Houston C S (1983) Opera-tion Everest II Progress in Clinical and Biological Research136 221ndash233

Tanaka H amp Seals D R (2003) Invited review Dynam-ic exercise performance in masters athletes Insight intothe effects of primary human aging on physiologicalfunctional capacity Journal of Applied Physiology95(5) 2152ndash2162

Tarnopolsky M A (2010) Caffeine and creatine use in sportAnnals of Nutrition and Metabolism 57 (Suppl 2) 1ndash8

Terjung R L Clarkson P Eichner E R GreenhaffP L Hespel P J Israel R G et al (2000) AmericanCollege of Sports Medicine roundtable The physiologi-cal and health effects of oral creatine supplementation

Medicine and Science in Sports and Exercise 32(3)706ndash717

Tesch P A Komi P V amp Hakkinen K (1987) Enzymaticadaptations consequent to long-term strength trainingInternational Journal of Sports Medicine 8 66ndash69

Thoden J S (1991) Testing aerobic power In J DMacDougall H A Wenger amp H J Green (Eds)Physiological testing of the high-performance athlete Champaign IL Human Kinetics

Thomis M Claessens A L Lefevre J Philippaerts RBeunen G P amp Malina R M (2005) Adolescentgrowth spurts in female gymnasts Journal of Pediatrics146(2) 239ndash244

Thompson P D Buchner D Pina I L Balady G J Wil-liams M A Marcus B H et al (2003) Exercise andphysical activity in the prevention and treatment of ath-erosclerotic cardiovascular disease A statement from theCouncil on Clinical Cardiology (subcommittee on exer-cise rehabilitation and prevention) and the Council onNutrition Physical Activity and Metabolism (subcommit-tee on physical activity) Circulation 107 (24) 3109ndash3116

Tipton C M (1996) Exercise physiology Part II A con-temporary historical perspective In J D Massengale ampR A Swanson (Eds) History of exercise and sport sci-ence Champaign IL Human Kinetics

Tomassoni T L (1996) Introduction The role of exercise

in the diagnosis and management of chronic disease inchildren and youth Medicine and Science in Sports andExercise 28 403ndash405

Tsuji H Venditti F J Manders E S Evans J C LarsonM G Feldman C L amp Levy D (1994) Reduced heartrate variability and mortality risk in an elderly cohort TheFramingham Heart Study Circulation 90 878ndash883

Wasserman D H amp Zinman B (1994) Exercise in indi-viduals with IDDM Diabetes Care 17 924ndash937

Wecht J M Marsico R Weir J P Spungen A M Bau-man W A amp De Meersman R E (2006) Autonomicrecovery from peak arm exercise in fit and unfit individ-uals with paraplegia Medicine and Science in Sports and

Exercise 38(7) 1223ndash1228

Weir J P Beck T W Cramer J T amp Housh T J (2006)Is fatigue all in your head A critical review of the centralgovernor model British Journal of Sports Medicine 40(7)573ndash586 discussion 586

Williams J H (1991) Caffeine neuromuscular function andhigh-intensity exercise performance Journal of Sports Med-icine and Physical Fitness 31 481ndash489

Willoughby D S amp Rosene J (2001) Effects of oral creatineand resistance training on myosin heavy chain expres-sion Medicine and Science in Sports and Exercise 33(10)1674ndash1681

Willoughby D S amp Rosene J M (2003) Effects of oralcreatine and resistance training on myogenic regulatoryfactor expression Medicine and Science in Sports andExercise 35(6) 923ndash929

Yesalis C E amp Bahrke M S (1995) Anabolicndashandro-genic steroids Current issues Sports Medicine 19 326ndash340

Young J C (1995) Exercise prescription for individualswith metabolic disorders Practical considerations Sports




86 C H A P T E R 5

DEFINITIONS IN EXERCISE PHYSIOLOGY

E xercise physiology is defined as ldquothe study of how the body from afunctional standpoint responds adjusts and adapts to exerciserdquo (FoxBowers amp Foss 1993) and the exercise physiologist as one who

ldquostudies the muscular activity and functional responses and adaptations duringexerciserdquo (ACSM 2010) As is evident from these definitions the two aspects ofexercise physiology that form the core of the discipline are the responses and theadaptations to exercise A response is distinguished from an adaptation in that aresponse is an acute or short-term change (adjustment) in the body that is associ-ated with exercise For example as one jogs the heart rate increases from theresting value In contrast an adaptation to exercise involves a long-term changein the body due to exercise training For example highly conditioned runnerstypically have lower resting heart rates than less-fit individuals This decrease inresting heart rate (bradycardia) occurs over time as a result of regular exercisetraining It is the study of these types of responses and adaptations that providesthe scientific basis for the field of exercise physiology

In addition exercise physiology has applied aspects with many peopletrained to work in a hands-on environment with both healthy and patient

populations The application of the knowledge base of exercise physiologyto clinics health clubs and athletic conditioning can significantly improvehuman performance and quality of life

PROFESSIONAL DUTIES OF AN EXERCISE PHYSIOLOGIST

E xercise physiologists in the broadest sense provide a variety of services

in various settings Clinical exercise physiologists design implement andmonitor exercise programs for individuals with cardiac pulmonary and

metabolic disorders (eg diabetes) Practitioners in the health and fitness indus-

try perform exercise tests and design exercise programs for the general populationin order to improve health decrease clientsrsquo risk for disease and improve well-being and self-esteem Researchers study the mechanisms of response andadaptation that occur with exercise as well as the practical aspects of exercisephysiology such as how to maximize the benefits of an exercise intervention

Most exercise physiologists work in an applied setting that is they workwith real people in a clinical athletic or fitness setting Nonetheless research-ers are continually adding to the body of knowledge in exercise physiologyBecause of this continual information turnover applied exercise physi-ologists have the responsibility of staying current with research Similarlyresearchers in exercise physiology have the responsibility of effectively dis-seminating new information to practitioners

HISTORY OF EXERCISE PHYSIOLOGY

A lthough the formal study of exercise physiology as a discipline is still

relatively new interest in the physiology of physical activity dates backto the ancient Greeks (Astrand 1991 Berryman 1995 Buskirk

1996 1992 Costill 1994 Dill 1980 Dill Arlie amp Bock 1985 Kroll 1971McArdle Katch amp Katch 2007 Tipton 1996) Students are strongly encour-aged to consult Chapter 1 to develop an appreciation for the rich history thatled to modern-day exercise physiology

response 983150

adaptation 983150























88 C H A P T E R 5











F O C U S

P O I N T


cholesterol 983150









Pulmonary system





exhibit 52





90 C H A P T E R 5





Nervous system






autonomic nervous

system 983150










Muscular system







system


nervous system




F O C U S

P O I N T






F O C U S

P O I N T





92 C H A P T E R 5








Endocrine system






hormone 983150






F O C U

S

P O I N T







Immune system








box
















i]) and pH were



















fatigue process






94 C H A P T E R 5


Skeletal system









osteoporosis 983150





F O C U S

P O I

N T






Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5























































88 C H A P T E R 5











F O C U S

P O I N T


cholesterol 983150









Pulmonary system





exhibit 52





90 C H A P T E R 5





Nervous system






autonomic nervous

system 983150










Muscular system







system


nervous system




F O C U S

P O I N T






F O C U S

P O I N T





92 C H A P T E R 5








Endocrine system






hormone 983150






F O C U

S

P O I N T







Immune system








box
















i]) and pH were



















fatigue process






94 C H A P T E R 5


Skeletal system









osteoporosis 983150





F O C U S

P O I

N T






Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5








































Pulmonary system





exhibit 52





90 C H A P T E R 5





Nervous system






autonomic nervous

system 983150










Muscular system







system


nervous system




F O C U S

P O I N T






F O C U S

P O I N T





92 C H A P T E R 5








Endocrine system






hormone 983150






F O C U

S

P O I N T







Immune system








box
















i]) and pH were



















fatigue process






94 C H A P T E R 5


Skeletal system









osteoporosis 983150





F O C U S

P O I

N T






Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































90 C H A P T E R 5





Nervous system






autonomic nervous

system 983150










Muscular system







system


nervous system




F O C U S

P O I N T






F O C U S

P O I N T





92 C H A P T E R 5








Endocrine system






hormone 983150






F O C U

S

P O I N T







Immune system








box
















i]) and pH were



















fatigue process






94 C H A P T E R 5


Skeletal system









osteoporosis 983150





F O C U S

P O I

N T






Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5










































Muscular system







system


nervous system




F O C U S

P O I N T






F O C U S

P O I N T





92 C H A P T E R 5








Endocrine system






hormone 983150






F O C U

S

P O I N T







Immune system








box
















i]) and pH were



















fatigue process






94 C H A P T E R 5


Skeletal system









osteoporosis 983150





F O C U S

P O I

N T






Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































92 C H A P T E R 5








Endocrine system






hormone 983150






F O C U

S

P O I N T







Immune system








box
















i]) and pH were



















fatigue process






94 C H A P T E R 5


Skeletal system









osteoporosis 983150





F O C U S

P O I

N T






Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5







































Immune system








box
















i]) and pH were



















fatigue process






94 C H A P T E R 5


Skeletal system









osteoporosis 983150





F O C U S

P O I

N T






Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































94 C H A P T E R 5


Skeletal system









osteoporosis 983150





F O C U S

P O I

N T






Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5






































Gerontology





Spinal cord injury





Stroke






96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































96 C H A P T E R 5





hemiparesis 983150

spasticity 983150





box










with paraplegia























unfit counterparts




















98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5



















































98 C H A P T E R 5


























F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5

















































F O C U S

P O I N

T

983150 diabetes

983150 insulin





100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































100 C H A P T E R 5













hemoglobin 983150











Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5











































Ergogenic aids






983150 ergolytic



F O C U S

P O I N T






102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































102 C H A P T E R 5












blood doping 983150




















104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5




















































104 C H A P T E R 5























135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5












































135





106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































106 C H A P T E R 5



bull



V bull

O 2 max 983150











Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5










































Muscle Biopsy









F O C U S

P O I N T



glycolytic (FOG)






108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































108 C H A P T E R 5


Electromyography






















Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5











































Undergraduate










110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































110 C H A P T E R 5

Graduate


Masterrsquos



Doctoral

















Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5












































Medicine



Chiropractic








112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































112 C H A P T E R 5

CERTIFICATIONS














Clinics


ACSM Certifications


NSCA Certifications

wwwnsca-ccorg

www

www


















114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5


















































114 C H A P T E R 5
















ACSM

wwwacsmorg

APS

wwwthe-apsorg

AAHPERD

wwwaahperdorg

www

www

www



















AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5



















































AACVPR

wwwaacvprorg

www





116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































116 C H A P T E R 5


PRIMARY JOURNALS












Sports Medicine











Muscle and Nerve

Physical Therapy

FUTURE DIRECTIONS













SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5









































SUMMARY

E








related to obesity





study QUESTIONS








118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5





































118 C H A P T E R 5








learning ACTIVITIES

suggested READINGS















references

















































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5

















































































120 C H A P T E R 5






















ology 73 65ndash70





























































122 C H A P T E R 5













































































122 C H A P T E R 5



































excersice physiology

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