Sports Physiology

1. Sports Physiology Prof. Dr. Bayram Yılmaz Yeditepe University Faculty of Medicine Department of Physiology

2. Female and Male Athletes • Muscle strength • Pulmonary ventilation • Cardiac output • 11% difference in performance in women • Body fat distribution • Estrogen increases deposition of fat in female • 27% body fat in female, 15% in male • Anabolic effects of testosterone

3. Muscles in Exercise • Power of muscle • Strength • Holding strength is about 40% greater than contractile strength • Endurance • Supply of nutrients • Amount of glycogen stored

4. Muscles Metabolic Systems in Exercise • Phosphocreatine-creatine system • Glycogen-lactic acid system • Aerobic system

5. Muscles Metabolic Systems in Exercise • 1) ATP and Phosphocreatine-creatine system are also called phosphagen energy system • These together provide maximal muscle strength for 8 to 10 seconds • 2) Glycogen-lactic acid system: (1.3-1.6 min) • Initial stage is glycolysis, anaerobic metabolism • Glycose – pyruvic acid – mitochondria – ATP formation • When there is insufficient oxygen, pyruvic acid is converted to lactic acid – diffuses out of cell and enters blood

6. Muscles Metabolic Systems in Exercise • 3) Aerobic system:

7. Energy Systems in Various Sports

8. Recovery of Muscle After Exercise • Energy from glycogen-lactic acid system can be used to reconstitute both phosphocreatine and ATP • Reconstitution of lactic acid – removal of excess lactic acid • 1) A small portion is converted back to pyruvic acid and then metabolized oxidatively • 2) Remaining lactic acid is reconverted into glucose in the liver

9. Recovery of Aerobic System After Exercise • Oxygen debt: • The body contains about 2 lt of stored oxygen • 0.5 lt in the air of lungs • 0.25 lt dissolved in the body fluids • 1 lt combined with Hg • 0.3 lt in muscle fibers (myoglobin) In heavy exercise, the stored O2 is used in a minute or so for aerobic mechanism 3.5 + 8 = 11.5 lt O2 debt

10. Recovery of Aerobic System After Exercise

11. Recovery of Muscle Glycogen

12. Nutrients Used During Muscle Activity

13. Effect of Athletic Training on Muscles and Muscle Performance • Muscle hypertrophy

14. Fast Twitch and Slow-Twitch Muscle Fibers

15. Respiration in Exercise • Normal O2 consumption is 250 ml/min for men • Untrained average men: 3600 ml/min • Athletically trained men: 4000 ml/min • Men marathon runner: 5100 ml/min

16. Respiration in Exercise • Effect of training on VO2 Max: rate of oxygen usage under maximal aerobic metabolism is VO2 Max

17. Respiration in Exercise • Oxygen diffusion capacity of athletes • Blood oxygen gases during exercise • Effect of smoking on pulmonary ventilation in exercise • Nicotine constricts terminal bronchioles • Irritation causes fluid secretion • Nicotine paralyzes the cilia, failure of removal of excess fluid and foreign substances

18. Cardiovascular System in Exercise • Muscle blood flow

19. Cardiovascular System in Exercise • Cardiac output • Effect of training on heart hypertrophy and on cardiac output • Role of stroke volume and heart rate in increasing the cardiac output

20. Cardiovascular System in Exercise • Cardiac output

21. Cardiovascular System in Exercise • Relation of Cardiovascular Performance to VO2 Max

22. Body Heat in Exercise • Heatstroke

23. Body Fluids and Salt in Exercise • Body fluids and salt in exercise • Replacement of NaCl and K

24. Drugs and Athletes • Caffeine can increase athletic performance by about 7% • Androgens are powerful anabolic drugs • Amphetamines and cocaine have been claimed to increase athletic performance