BTEC National Sport © Hodder Education 2010 Key Learning Points for Unit 2

BTEC National Sport © Hodder Education 2010 Exercise & the Body Systems 1 At the onset of exercise, the various systems respond to try to increase oxygen delivery, energy production and carbon dioxide removal. The Physiology of Fitness

BTEC National Sport © Hodder Education 2010 Exercise & the Body Systems 2 The short-term effects of exercise on the body systems are as follows: The Physiology of Fitness –Musculoskeletal system: increased joint range of movement; micro-tears in muscle fibres from resistance exercises –Energy system: ATP is produced by anaerobic energy systems – the phosphocreatine energy system, the lactic acid energy system and the aerobic energy system –Cardiovascular system: increase in heart rate; increase in blood pressure; redirection of blood flow to working skeletal muscles and skin surface –Respiratory system: increase in breathing rate; increase in tidal volume.

BTEC National Sport © Hodder Education 2010 Energy System Adaptations to Aerobic Exercise Adaptations to aerobic exercise are: The Physiology of Fitness –Cardiovascular system: cardiac hypertrophy; increased stroke volume; decreased resting heart rate; increased number of capillaries; increased number of red blood cells; decreased haematocrit. –Respiratory system: decreased resting breathing rate; increased lung volume; increased vital capacity; increased tidal volume (in maximal exercise); increased strength of respiratory muscles; increased capillarisation around alveoli. –Neuromuscular system: increased myoglobin content; increased number of capillaries; increased number of mitochondria; hypertrophy of slow-twitch muscle fibres; increased stores of glycogen; increased stores of fat. –Energy systems: increased number of aerobic enzymes; increased breakdown of fat.

BTEC National Sport © Hodder Education 2010 Energy System Adaptations to Anaerobic Exercise Adaptations to anaerobic exercise are: The Physiology of Fitness –Cardiovascular system: no significant adaptations. –Respiratory system: no significant adaptations. –Neuromuscular: hypertrophy of fast-twitch muscle fibres; increased content of ATP; increased content of PC; increased tolerance to lactic acid. –Energy systems: increased number of anaerobic enzymes. –Skeletal system: increased strength of bones; increased strength of tendons; increased stretch of ligaments.

BTEC National Sport © Hodder Education 2010 Reviewing the Effects of Exercise on the Body Systems Methods of investigation include comparison of pre-exercise, during-exercise and post-exercise physiological readings. Physiological readings include heart rate, blood pressure, flexibility tests, tidal volume rating of perceived exertion. Both acute and long-term adaptations to the body systems need to be examined. The Physiology of Fitness