Summary

Exercise physiology studies how the body responds to exercise. Three physiological factors determine the components of physical fitness — the skeletal-muscle factor (the mix of slow-twitch Type I and fast-twitch Type II fibres), the energy-production factor (the ATP-CP, anaerobic and aerobic energy systems), and the cardiorespiratory factor — and together they shape strength, endurance, speed and flexibility.

Effects of exercise on the muscular system are short-term (increased blood supply, muscle temperature and flexibility, lactate accumulation, and micro-tears in muscle fibres) and long-term (hypertrophy, stronger ligaments and tendons, more and larger mitochondria, greater myoglobin and glycogen storage, higher oxidation/metabolism and better lactate tolerance).

Effects of exercise on the cardiorespiratory system cover the cardiovascular side (short-term: higher heart rate, blood circulation, blood pressure, stroke volume and cardiac output; long-term: a bigger, stronger heart, a lower resting heart rate, normal blood pressure and a denser capillary network) and the respiratory side (short-term: higher respiratory rate, tidal volume and rate of gas exchange; long-term: more efficient respiratory muscles and greater lung volume, pulmonary diffusion and residual volume).

Physiological changes due to ageing affect muscular strength, neural function, the endocrine system, pulmonary function, cardiovascular function, body composition and bone mass, with conditions such as osteoporosis becoming more common.

Sports injuries are physical damage to tissue, bone or organ during activity. They are classified by cause as direct, indirect, soft tissue, hard tissue and overuse injuries, and can also be described by their nature (microtrauma/macrotrauma, acute/chronic, minor/major, and so on). …