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Sports Physiology

Sports Physiology. Prof. dr. Zoran Vali ć Department of Physiology University of Split School of Medicine. heavy exercise is extreme stresses for body high fever  100%  in metabolism marathon race  2000%  in metabolism. Female and Male Athletes:.

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Sports Physiology

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  1. Sports Physiology Prof. dr. ZoranValić Department of Physiology University of Split School of Medicine

  2. heavy exercise is extreme stresses for body • high fever  100%  in metabolism • marathon race  2000%  in metabolism

  3. Female and Male Athletes: • muscle strength, pulmonary ventilation and CO  2/3-3/4 of values recorded in men • strength per cm2 equal (30-40 N/cm2) • marathon race  11% slower • two-way swim across English Channel • Testosterone (40% more muscle mass) • 27% & 15% percent body fat, respectively • aggressiveness

  4. Strength, Power, and Endurance of Muscles • What the muscles can do for you? • What strength they can give? • What power they can achieve? • How long they can continue their activity?

  5. Muscle force (strength): • determined mainly by muscle size (training) • maximal contractile force – 30-40 N/cm2 • quadriceps is 150 cm2 (F=4500-6000N) • rupture & avulsion of tendons, displaced cartilages, compression fractures and torn ligaments

  6. Holding strength (force) of muscles: • force that attempts to stretch out already contracted muscle • greater about 40% than contractile strength • Fquadriceps= 6300-8400N • internal tearing in the muscle

  7. Power of Muscular Contraction: • mechanical work (W) performed by muscle is amount of force applied by the muscle multiplied by the distance over which the force is applied • power (P) is total amount of work that muscle performs in a unit period of time (t)

  8. determined not only by the strength but also: distance of contraction and the number of times that it contracts each minute • power is generally measured in watts (W, or in kilogram meters (kg-m) per minute)

  9. Maximal power of all muscles:

  10. Athletic (muscle) efficiency: • power  efficiency • velocity of 100-meter dash is only 1.75 times as great as velocity of a 30-minute race • depends on muscle supply by nutrients (glycogen)

  11. Endurance (measured by time):

  12. Amounts of glycogen stored in the muscle:

  13. Muscle Metabolic Systems in Exercise: • phosphocreatine-creatine system • glycogen-lactic acid system • aerobic system

  14. Phosphagen system: • ATP (adenosine – PO3 PO3 PO3-) •  high-energy P bonds (7.3 Cal/mol ATP) • amount of ATP sufficient for only about 3 s • phosphocreatine(creatine phosphate, creatine PO3-) • 10.3 Cal/mol creatine, quick transfer • 2-4 x more phosphocreatinethan ATP • combined 8-10 s of maximal muscle power

  15. Glycogen-Lactic Acid System: • glycogen  glucose (glycolysis, anaerobic metabolism) • two pyruvic acid molecules – 4 ATP • without oxygen – lactic acid • 2.5 x more rapid than oxidative mechanism • provides additional 1.3 to 1.6 minutes of maximal muscle activity (200-800 m)

  16. Aerobic System: • glucose, fatty acids, and amino acids

  17. ATP generation per minute:

  18. System endurance:

  19. Reconstitution of the lactic acid system: • removal of the excess lactic acid (extreme fatigue): • small portion is converted back into pyruvic acid • remaining lactic acid is reconverted into glucose (in the liver)

  20. Recovery of the Aerobic System After Exercise: • Oxygen Debt • Recovery of Muscle Glycogen

  21. Oxygen debt: • body contains about 2 L of stored oxygen: • 0.5 L in the air of the lungs • 0.25 L dissolved in the body fluids • 1L combined with the hemoglobin • 0.3 L stored in muscle fibers (myoglobin) • all this stored oxygen is used within minute • 9 L more reconstituting both phosphagen system and lactic acid system • total  11.5 L O2 – oxygen debt

  22. Recovery of Muscle Glycogen: • complex matter, often requires days

  23. it is important for an athlete to have a high-carbohydrate diet before a grueling athletic event • not to participate in exhaustive exercise during the 48 hours preceding the event

  24. Effect of Athletic Training: • muscle strength is not increased without load • 6 nearly maximal contractions performed in three sets 3 days a week – approximately optimal increase in muscle strength, without producing chronic muscle fatigue • 30%  in strength during 6-8 weeks • simultaneously equal increase in muscle mass – muscle hypertrophy

  25. Muscle Hypertrophy: • heredity & testosterone secretion • 30-60 % increase with training • increased diameter of the muscle fibers • increased numbers of fibers?

  26. Changes that Occur Inside the Hypertrophied Muscle Fibers: •  numbers of myofibrils •  mitochondrial enzymes for120% •  ATP and phosphocreatine for60-80% •  stored glycogen for50% •  stored triglyceride (fat) for 75-100%

  27. Muscle Fibers Types: • fast-twitch muscle fibers – (gastrocnemius)– typeII (white, a &b) • slow-twitch muscle fibers– (soleus)– typeI (red)

  28. Basic differences between: • diameter of fast-twitch fibers  2x larger • enzymes for anaerobic metabolism  2-3x more active in fast-twitch fibers (power) • slow-twitch fibers are organized for endurance, generation of aerobic energy (more mitochondria and myoglobin) • slow-twitch fibers – more capillaries • genetic inheritance

  29. % of fiber types in quadriceps:

  30. Respiration in Exercise: • depends on sport discipline, duration of activity

  31. Oxygen Consumption Under Maximal Conditions: • oxygen consumption for • young man at rest is about 250 ml/min

  32. Pulmonary Ventilation (PV):

  33. Limits of Pulmonary Ventilation: • MBC 50% higher thanPV during maximal exercise • respiratory system is not normally the most limiting factor in delivery of oxygen • element of safety if: • exercise at high altitudes • exercise under very hot conditions • abnormalities in respiratory system

  34. Effect of Training on Vo2 Max: • Vo2 Max – rate of oxygen usage under maximal aerobic metabolism • Vo2 Max of a marathoner is about 45 percent greater than that of an untrained person (genetically determined, many years of training)

  35. Oxygen-Diffusing Capacity of Athletes: ME – maximal exercise

  36. 3x increase in DC (activation of the pulmonary capillaries) • training procedures increases DC • partial pressures (O2 & CO2) remain nearly normal during strenuous athletics • regulation of breathing • negative effects of smoking (acute and chronic)

  37. Cardiovascular System in Exercise: • delivering required oxygen and other nutrients to the exercising muscles • arterial blood pressure regulation • flow decrease during each muscle contraction • blood flow to muscles during exercise increases markedly (up to25x)

  38. Maksimalno povećanje protoka:

  39. Mechanisms of Blood Flow Increase: • vasodilation caused by the direct effects of increased muscle metabolism • moderate increase in arterial blood pressure (30%) • muscle pump • FMD • other theories

  40. CO During Exercise:

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