| Metabolism |
Anaerobic metabolism allows for intense and brief periods of exercise (100m sprint, speed skates). Lactic acid accumulates and limits its duration (fatigue). Anaerobic muscle fibres are white, fast twitch (type II).
Aerobic metabolism uses oxygen and provides for endurance events. It uses red, slow twitch (type I) muscle forces. The relative proportion of type I/II is genetically determined (endurance athletes = type I; sprinters = type II).
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| Muscle action |
Follows tension/length curve (Fig.1). Concentric contraction causes muscle shortening; eccentric lengthening (dampens joint reactive forces).
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| Training |
Endurance training is repetitive and increases the size/efficiency of type I fibres.
Sprint training concentrates on tension development and so selective hypertrophy of type II fibres.
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| Types of exercise | Exercise can be
Isometric - where tension develops but muscle length is unchanged (against a fixed object).
Isotonic - where muscle moves against a fixed resistance.
Isokinetic - performed at constant velocity with variable resistance (may cause patello-femoral problems).
Functional - dynamic exercises and allows rapid rehab (jump ropes).
Stretching
This improves isometric muscle function, prevents injury and enhances performance (Fig 2).
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| Exercise capacity |
Cardiovascular Function
Maximum exercise capacity is significantly determined by increased O2 delivery from increased stroke volume/cardiac output, vasodilation and to a lesser extent by increased mitochondrial volume (Fig 3).
Pulmonary Function
The pulmonary system may well determine the limits of athletic performance (the athletes full metabolic potential). Champions will need large vital capacities.
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| | Sports Psychology | |
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Looks at factors determining participation and performance. Areas include motivation (children who compete to beat others are more likely to drop out), stress/performance (competition); interpersonal relations (coach, athlete, parents); exercise psychology (exercise probably promotes mental health); and mental training (success requires a clear focus with certainty and no fear).
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