FW275 Exercise Physiology

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Chapter 2Exercise Physiology


Introduction to Exercise Physiology Physiology

The study of human function Molecular level or whole organism level

Exercise Form of physical exertion that can be carefully

quantified Exercise duration, intensity, type/mode, frequency


Exercise Physiology

Definition: the study of how the body functions during physical exertion that is carefully quantified

Exercise science curriculum incorporates exercise physiology as an upper level course (junior or senior) in addition to the study of biology, chemistry, anatomy & physiology,


History—Exercise Physiology Field has evolved through findings of several

different scientists 1700’s Antonie Lavoisier

Discovery that oxygen uptake increased with physical exertion

Mid to late 1800’s Fernand LaGrange—1st textbook The Physiology of Bodily Exercise

1879 Dudley Sargent Developed a physical fitness program at Harvard

University based on individual prescription


History—Exercise Physiology 1891 George Fitz

Exercise physiology laboratory created at Harvard. Courses in exercise physiology and laboratory research were instructed. This combination is continues today.

20th Century Finding that muscle activity is powered by carbohydrate not

heat (previously believed) 1900’s prominent researchers traced to Europe

Founded 1954 1920 August Krogh, Danish physiologist

Studied muscle activity and blood flow, Noble Prize


History—Exercise Physiology

1920’s Archibald Vivian Hill, British physiologist

Nobel Prize, studied muscle force and movement speeds Pioneer in studying VO2 responses pre and post running

John Haldane, European physiologist Influential development of respiratory gas analyzer Studied carbon dioxide on breathing regulation

Otto Meyerhof, German physiologist Shared Noble Prize with Hill Conducted studies on energy metabolism



1927 David B. Dill, biochemist from Stanford Harvard Fatigue Laboratory, legendary

accomplishments in exercise physiology. Studied the physiological, psychological, sociological

factors with manual work. Research in metabolic responses to exercise,

environmental stress, aging induced changes, blood-gas and acid-base chemistry

Remained open for 20 years Fundamental in the spread of the field along with many

European researchers



Same timeline as Harvard Fatigue Laboratory European researchers: Erik Howhu-Christensen

One of 1st researchers to study fuel patterns during exercise Became faculty at Gymnastik-och Idrottshogskolan in Stockholm and

mentor to many great researchers Per-Olof Astrand,

The Textbook of Work Physiology Astrand-Rhyming Submaximal Exercise Test

Ehrling Asmussen and Marius Nielsen Joined faculty University of Copenhagen Asmussen focus was exercise and muscle function Nielsen studied temperature regulation with exercise in hot and cold

environments Bengt Saltin

Leading contemporary exercise physiologists



1950’s American College of Sports Medicine

1954 held first scientific meeting Goal was to expand the knowledge of exercise

responses in humans Atherosclerosis

Evidence from the Korean War that young male casualties showed evidence of coronary artery disease

CVD problems were thought linked to aging, findings revealed that disease develops early in life


General Course Content Energy Nervous Endocrine Skeletal muscle Cardiovascular Respiratory


The Energy Systems Energy for exercise is derived from the

breakdown of stored resources

Fat and carbohydrate (protein not primary source) Chemical reactions transfer potential to ATP ATP—adenosine triphosphate ATP is the body’s usable form of energy


The Energy Systems

ATP is degraded to adenosine diphosphate (ADP) and inorganic phosphate (Pi)

Muscles can use three different pathways to make ATP Phosphagen Glycolytic Oxidative


The Energy Systems 3 energy pathways

Anaerobic pathways: phosphagen and glycolytic Do not require oxygen Occurs in cell’s cytoplasm Phosphagen pathway

Phosphate molecule is transferred to ADP to make ATP Glycolytic pathway

Requires more steps, involves the breakdown of a glucose to produce ATP.

Results in formation of ATP and pyruvate Not useful for prolonged exercise


The Energy Systems 3 energy pathways

Aerobic pathway: oxidative pathway Oxidation occurs in mitochondria Requires oxygen Glycolysis and Kreb’s cycle oxidizes glucose (from

carbohydrate) or fatty acid (breakdown of stored fat) and is completed with the electron transport chain to produce ATP

Provides energy for endurance activities


The Energy Systems Exercise Training

Specific energy pathways in the muscle can be enhance with training

Anaerobic (sprint) training increase cell’s ability to produce energy from the phosphagen and glycolytic pathways

Aerobic (endurance) training will increase the ability to synthesize ATP via oxidation Will increase muscle glycogen concentration Enhance ability of muscle to resist fatigue during prolonged

exercise


The Nervous System Primary control system for physiological

function Brain, spinal cord, all peripheral nerves

Central Nervous System Brain and spinal cord

Peripheral Nervous System All neurons that transmit information to (sensory

branch) and from (motor branch) the spinal cord


The Nervous System Peripheral Nervous System

Somatic nerves Sensory information (consciously sensed) light, taste,

touch, sound Voluntary motor transmission Skeletal muscles

Autonomic nerves Not consciously controlled: pressure, chemical

changes, heart, lungs, blood vessels, organs of digestion

Sub-divided: parasympathetic and sympathetic


The Nervous System Autonomic Nerves

Parasympathetic Autonomic regulation at rest

Sympathetic Activated during stress such as exercise

Example of autonomic function:One goes from resting position to increasing exercise intensities.


The Nervous System Exercise training can alter nervous system function

Strength training Adaptations in skeletal muscle to increase strength and recruitment

of muscle fibers through the nervous system

Endurance training Can reduce the amount of sympathetic activation during submax

exercise since endurance training reduces the overall stress on the body during exercise

Exercise can alter both somatic and autonomic nerves


The Endocrine System Glands secrete hormones into the blood Works with the nervous system to regulate

physiological function through hormones and glands.

Hormones travel through circulation to their target organ

Hormones bind to receptors and initiate cell activity


The Endocrine System Hormones and exercise

Pituitary gland With exercise secretes growth hormone which influences fuel use

with exercise And antidiuretic hormone will increase water conservation during

exercise Adrenal gland

Cortex secretes cortisol and alodosterone Medulla secretes epinephrine (adrenaline) and norepinephrine

(noradrenaline) Pancreas

Secretes insulin hormone in response to increase blood glucose levels Exercise causes insulin levels to decline

Secretes glucagon hormone when there is a decrease blood glucose levels Glucagon increases the amount of glucose formed and released by the liver


The Endocrine System Exercise training response to the endocrine

system

Endurance training Reduce the release of epinephrine & norepinephrine

Resistance training May influence the body’s response to the hormones

testosterone, insulin-like growth factor-I, and cortisol Due to increase muscle mass


The Skeletal Muscle System Comprises 40% of total body mass Together with nervous system, provides movement Functional unit of muscle is the muscle fiber Single muscle fiber is comprised of sacromeres Sacromeres contain the contractile elements actin

and myosin Once activated by neural stimulation, myosin and

actin filaments attach and pull toward the sacromere

Then, muscle fiber shortens and force is generated


The Skeletal Muscle System Human skeletal muscle is comprised of 3

different types of fibers Slow twitch (Type I)

Good endurance Reliance on oxidative metabolism to produce ATP

Fast twitch (Type IIa) Combination of good endurance and power

Fast twitch b (Type IIb) Most powerful fibers, poor endurance


Skeletal Muscle Fiber Type Classification SchemesTwitch Term Energetic

TermColor Term Generic

Term

Slow twitch (ST) Slow, oxidative (SO)

Red Type I

Fast twitch a (FTa) Fast, oxidative, glycolytic (FOG)

Intermediate Type IIa

Fast twitch b (FTb) Fast glycolytic (FG)

White Type IIb


The Skeletal Muscle System Exercise training response can impact

system Aerobic training

Will increase endurance capacity of all three fiber types

Strength training Will not change muscle fiber but will result in increase

in strength due to increase in muscle mass


The Cardiovascular System Delivers oxygen and nutrients and removes

carbon dioxide Consists of heart, blood vessels and blood Exercise will affect each component HR x SV = Q

Exercise increases Q Increase in Q and HR directly proportional to

exercise intensity Increase in Q increase BP


The Cardiovascular System HR—heart rate SV—stroke volume

Amount of blood pumped out of heart with each beat Q—cardiac output Vasoconstriction occurs in arterial blood vessels in

viscera Vasodilation occurs in blood vessels of working

skeletal muscles This causes changes in blood flow patterns,

shunting more blood to working skeletal muscles


The Cardiovascular System Exercise training response

Aerobic training Heart pumps stronger Blood volume expands Increase in capillaries Submaximal exercise: HR decreases and SV increases Maximal exercise: HR unchanged or decreases, SV

increases, Q increases


The Respiratory System Lungs responsible for ventilation and

diffusion Comprised of lungs and airways that conduct

air flow into the lungs Ventilation—process of drawing air into the

lungs Diffusion—process of oxygen and carbon

dioxide are exchanged between blood and alveoli (inner most region of lung)


The Respiratory System Airways that conduct air in and out of lungs

dilate, this reduces resistance to air flow. Additional airways open and increases

ventilation Diffusion of oxygen and carbon dioxide

between alveoli and capillaries occurs due to pressure differences


The Respiratory System Exercise training responses

Aerobic training Increase maximal capacity of lungs to increase tidal

volume and respiratory rate Training will enhance the rate of oxygen diffusion out

of the lungs and into the blood Respiratory system and cardiovascular system both

increase capacity with increasing exercise intensities


Additional topics studied Nutrition for health and

performance Body composition

techniques Physiological response

to environmental stress Exercise testing

protocols Exercise prescription

models

Exercise responses in special populations

Exercise and aging Pediatric exercise

responses Exercise effects gravity Sports training &

performance Metabolic disorders Bone health


Professional Organizations and Certifications Students should investigate possible

organizations that fit the need for their future direction

Certifications can be important for many job descriptions

Many employers in the clinical, education, health promotion fields are looking for candidates with both strong academic standing with certifications


Professional Organizations and Certifications American College of Sports Medicine

(ACSM) Various specialties: medical doctors, allied

health professionals, fitness professionals, exercise physiologists, biomechanists, sport psychologists, athletic trainers

Journals Medicine and Science in Sports and Exercise Exercise and Sport Sciences Reviews Health & Fitness Journal


Professional Organizations and Certifications ACSM certifications

ACSM Certified Personal Trainer ACSM Certified Health Fitness Specialist ACSM Certified Clinical Exercise Specialist ACSM Registered Clinical Exercise Physiologist


Professional Organizations and Certifications

National Strength and Conditioning Association (NSCA)

Various specialties: strength coaches, sport coaches, sport scientists, researchers, educators, sport medicine professionals, allied health professionals, students, business owners, exercise instructors

Journals Strength and Conditioning Journal Journal of Strength and Conditioning Research NSCA Bulletin NSCA’s Performance Training Journal


Professional Organizations and Certifications NSCA’s certifications

Certified Strength and Conditioning Specialist (CSCS)

NSCA-Certified Personal Trainer (NSCA-CC)



American Society for Exercise Physiology (ASEP) Founded 1997 Journals

Journal of Exercise Physiology-online The Professionalization of Exercise Physiology-online ASEP Newsletter

One certification Exercise Physiologist Certified (EPC)



American Alliance of Health, Physical Education, Recreation and Dance (AAHPER)

Founded 1885 Six associations:

National Association for Sport and Physical Education (NASPE) American Association for Health Education (AAHE) National Dance Association (NDA) American Association for Physical Activity and Recreation

(AAPAR) National Association for Girls and Women in Sports (NAGWS) Research Consortium (RC)


Professional Organizations and Certifications American Association of Cardiovascular and

Pulmonary Rehabilitation (AACVPR) Cardiopulmonary rehab, clinical exercise

physiology No certifications, AACVPR works closely with

ACSM guidelines and certifications Journal

Journal of Cardiopulmonary Rehabilitation


Professional Organizations and Certifications American Physiological Society (APS) Founded 1887 Journals

16 different journals Journal of Applied Physiology American Journal of Physiology



North American Society for Pediatric Exercise Medicine (NASPEM)

Physicians and allied health professionals who apply testing & therapy in children with cardiopulmonary disorders

Focus on acute responses and chronic adaptations with diseases and disorders

No Certification Journal

Pediatric Exercise Science


Fitness Related Organizations and Certifications American Council on Exercise (ACE) Certifications

ACE Personal Trainer ACE Group Fitness Instructor Lifestyle and Weight Management Consultant Advanced Health and Fitness Specialist


Fitness Related Organizations and Certifications Aerobics and Fitness Association of America

(AFAA) Certifications

Several certifications Personal Trainer Certification Primary Group Exercise Certification


Careers in Exercise Physiology

Many career options for different levels of study (select examples):

Personal trainer Bachelors

Fitness instructor Bachelors, Masters

Sports consultant Bachelors, Masters, Doctorate

Exercise physiologist Masters, Doctorate

Clinical exercise physiologist Bachelors, Masters, Doctorate

Exercise technologistor stress testing technician

Bachelors, Masters

Exercise specialist Bachelors, Masters

Wellness counselor Bachelors, Masters

Professor Doctorate

Physical therapist/Occupational therapist Bachelors, Masters, Doctorate in Physical or Occupational Therapy

Medical doctor Bachelors & Medical School

Chiropractor Chiropractic School

Nursing Bachelors plus degree in nursing

FW275 Exercise Physiology

Education

Transcript of FW275 Exercise Physiology