Exercise in prevention of disease.

Measures to increase individual participation in adequate amounts of physical exercise have a key place among the strategies to improve health and prevent disease. The scientific justification is based on a variety of evidence drawn from numerous epidemiological, clinical and physiological studies and is accepted as sound. The prevalence of physical disability is high. Disability attributable to age or chronic disease is helped by exercise. Inactivity compounds the effects of disability--an effect which deserves recognition because it is reversible and not inevitable. The association between a high level of habitual physical activity and a reduction in the individual risk for coronary vessel disease (CVD) is real and appears to be causal. Regular vigorous aerobic exercise is certainly effective in maintenance of health. Weight-bearing exercise has been shown to prevent osteoporosis at any age. The links between many of the functional adaptations which occur with exercise and improvements in health have been demonstrated. The exercise programmes which are effective have been defined.