1. KIN 240 – Introduction to Kinesiology
Physiology of Physical Activity

2. What is Exercise Physiology?
Application of principles of biology and chemistry to understand how the body responds to physical activity
How does body respond to immediate demands of being physically active?
How does body adapt to repeat bouts of exercise?

3. What Do Exercise Physiologists Do?
Faculty members in colleges/universities
Teach courses and conduct research in exercise physiology, anatomy, exercise prescription, sport nutrition
Non-academic settings
Exercise instructors in commercial/corporate fitness centers
Personal trainers, strength & conditioning specialists
Cardiac and pulmonary rehabilitation
Military and NASA applications
Credentials
Certifications through ACSM, NSCA, ACE, etc. to enhance academic training

4. Goals of Exercise Physiology
Enhance sport performance and training
Application of physiological techniques to understand and improve human exercise performance
Impact of flexibility on performance, effects of dehydration in wrestlers
Fitness
Understanding physiological determinants of physical fitness and how training programs improve fitness
Development of recommendations of optimal intensity, frequency and duration of training program for various activities and populations

5. Goals of Exercise Physiology
Promote health
Understanding why exercise is beneficial in reducing risk of some diseases
Cardiovascular disease and other hypokinetic diseases (Type II diabetes, hypertension, obesity)
Understand anatomical and physiological changes from exercise
Examination of functional responses and structural adaptations of body systems to different types of physical activity
Skeletal muscle, cardiovascular, respiratory, endocrine systems

6. History of Sub-discipline
Early beginnings
Krogh (Denmark) developed first cycle ergometer to study physiological response to injury in 1920
Hill (London) studied energy metabolism in 1921
Laboratory settings
Karpovich (Springfield College) studied effects of ergogenic aids on physical performance starting in 1927 & founded ACSM
Cureton (University of Illinois) established lab in which has produced many of leading investigators in field

7. History of Sub-discipline
Since 1950
Morris (England) published study in 1953 on hearth disease and physical activity of bus drivers vs. conductors on double-decker buses
US government statements in 1990’s
Physical activity is major risk factor for cardiovascular disease and moderate levels of physical activity confer significant health benefits (1995)
Regular physical activity, in addition to reducing risk of heart disease, reduces risk of diabetes, hypertension and colon cancer and helps control weight (1996)

8. Research Methods Laboratory work
Affords greater opportunity to control factors that can affect response to exercise (temperature, humidity) and to utilize standardized techniques to compare results
Many different tools available to assess VO2 max
Cycle ergometers, treadmills, arm ergometers, rowing ergometers
Usually rely upon prediction equations with given variables vs. true assessment of maximal oxygen uptake
Body composition assessed via hydrostatic weighing, bioelectrical impedance, air displacement plethysmography and dual-energy x-ray absorptiometry

9. Research Methods Laboratory work Biochemical methods Animal models
Invasive techniques that require obtaining blood samples and muscle tissue biopsies before and after exercise bouts to study cellular and tissue changes
Animal models
Allows for study of brain, heart, other organ changes that can’t be studied in humans
Allows for study of experimental techniques (e.g. – radioactive isotopes) that can’t be studied on humans
Allows greater uniformity of subjects and environment

10. Research Methods Field work
Use of non-laboratory based assessments to gauge fitness elements – obvious limitations vs. lab settings
Walk-run tests done to estimate VO2 max
Heart rate monitors (POLAR units, devices on most fitness center cardiorespiratory exercise equipment
Pedometers and accelerometers used throughout day/week to assess physical activity intensity/duration
Skinfold calipers used to assess body composition

11. Overview of Knowledge Skeletal muscles Muscle fiber types
Fast-twitch vs. slow-twitch muscle fibers
Energy sources – knowledge allows for specificity of training
ATP-phosphocreatine system
High-intensity exercise bouts for short time periods (<15 seconds)
Anaerobic glycolytic system
Longer durations exercise bouts (1-2 minutes), lactic acid build up as byproduct of system
Aerobic system
Lower intensity exercise bouts for longer time periods

12. Overview of Knowledge Skeletal muscles Resistance training
Muscular strength – maximal force exerted by muscle/s
Muscular power – product of force x speed of movement
Muscular endurance – ability to repeatedly exert force over prolonged time period
Muscular hypertrophy – increase in size of muscle fibers
No human research evidence of increased number of muscle fibers (hyperplasia)
Types of exercise
Isometric (no movement), isotonic (muscle changes length – concentric & eccentric contractions) and isokinetic (muscle changes length at constant rate of velocity)

13. Overview of Knowledge Cardiovascular system
Cardiac output – amount of blood pumped out of heart each minute
Stroke volume – amount of blood pumped per heart beat
Blood flow distribution – to brain and internal organs at rest, shifts to skeletal muscles during exercise
Adaptations to training
Endurance training increases size and efficiency of contraction of heart muscle – leads to increased stroke volume and cardiac output
Grade exercise tests allow for assessment of baseline status and for evaluation of training program effectiveness

14. Overview of Knowledge Respiratory system
Regulates exchange of gases between external environment and internal environment (body/lungs)
Minute volume is amount of air exhaled per minute
Product of tidal volume (amount of air exhaled per breath) and number of breaths per minute
Maximal ventilation (amount of air entering and leaving lungs) increases with exercise

15. Overview of Knowledge Nutritional intake and exercise Carbohydrates
Stored as glycogen in muscles and liver + blood glucose – available as energy source
Low blood sugar associated with early fatigue
Muscle glycogen stores depleted within 90 minutes of continuous exercise
Diet with appropriate amount of carbohydrates will allow blood glucose to be optimized and maintained and for maintenance/replenishment of glycogen stores following exercise bouts

16. Overview of Knowledge Nutritional intake and exercise Fluid intake
Failure to adequately maintain and replace fluids lost via sweat during exercise can impair performance and increase risk of heat related injuries
Sweat loss decreases plasma volume and increases body temperature
Must pre-hydrate prior to exercise, consume adequate liquids during exercise and re-hydrate following exercise
Iron intake
Iron allows body to make hemoglobin which allows for transport of oxygen via circulatory system
Low iron intake can result in anemia – feeling fatigued

17. Overview of Knowledge Physical activity, fitness and health
Strenuous exercise programs not needed to gain health benefits
Recommended to accumulate 30 minutes of moderate intensity (brisk walk, moderate cycling, moderate swimming, etc.) physical activity most, if not all, days of the week – doesn’t have to be continuous
Greater volumes and intensity of exercise result in additional health and fitness benefits
To improve cardiorespiratory endurance, recommended to do minutes of physical activity 3-5 days/week at 70-94% maximal heart rate

18. Overview of Knowledge Physical activity, fitness and health
Effects of age
VO2 max decreases with age but decreases less for physically active individuals vs. sedentary individuals
Coronary artery disease
Individuals who are physically active/fit have less risk of cardiovascular disease and some cancers
Weight management
When caloric intake exceeds caloric expenditure, excess calories are converted to fat and stored in body