XII. Energy & performanceChapter 10.5 - 10.8A. Metabolism1. All reactions in body that involve energy transformations2. Categories:a. Catabolismi. Digestingii. Energy is releasedb. Anabolismi. Buildingii. Energy is storedB. ATP1. Adenosine Triphosphate2. Short term energy carrier3. Constantly re-madea. 4-6 second reservoir4. Used for:a. Endergonic Reactionsb. Active Transportc. Muscle contractionC. Making ATP 1. Direct Phosphorylationa. Creatine phosphate i. Only in muscle fibers ii. donates a phosphate to ADP iii. instantly forms ATPb. Reaction catalyzed by Creatine kinasec. Muscles have ATP and CP for ~15secd. CP is recharged during rest2. Anaerobic Cell Respirationa. Does not require oxygenb. 30-40+ Sec of energy c. 2 partsi. Glycolysis1) 2 ATPs made/glucoseii. Lactic acid Fermentation1) Waste is converted to lactic acid2) “cleaned up” during rest3. Aerobic Cell Respirationa. Requires oxygenb. Produces 95% of ATP during rest & moderate exercisec. Slower than anaerobic pathwayd. Uses many fuelsi. Fatty acids = main after 30 mine. Up to 32 ATPC6H12O6 + 6O2 6CO2 + 6H2O + ATPD. Determining Whole Muscle Force1. Type of fibersa. Type I: i. Lots of Myoglobin & mitochondriaii. High resistance to fatigueiii. Slow myosin = “slow-twitch”iv. Fewer myofibrils = Small diameterb. Type II:i. Low myoglobin & few mitochondria ii. More glycogeniii. Fatigue fasteriv. Fast myosinv. More myofibrils = Largest diametervi. Three types2. Number of fibers activateda. More motor units = more forceb. Motor units have the same number but not the same size of cells3. Frequency of stimulationa. More frequent stimuli = more forceb. Called summationi. More force is added before muscle relaxes completelyii. Tetanus = full contraction4. Muscle stretcha. Optimal = 80-120% of resting length5. Muscle Fatiguea. Physiological inability to contract despite continued stimulationb. Causesi. Waste accumulationii. Reduced ATP sourcesiii. Reduced O2 availabilityiv. ion imbalances from sweatingE. Effects of Physical training1. Endurancea. More mitochondriab. More enzymes to use lipids2. Resistancea. Hypertrophy = Number of myofibrils increasesb. Relatively fewer mitochondria3. Disusea. Atrophy = loss of myofibrilsb. Fewer enzymesF. Recovery1. Return to its pre-exercise conditiona. Heat dissipationb. Ion balance restorationc. Blood pH restoration2. All require ATP & oxygena. Excess Postexercise Oxygen Consumption
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