Exercise and mental health. Beneficial and detrimental effects.

Physical exercise is increasingly being advocated as a means to maintain and enhance good mental health. In general, findings from research indicate that exercise is associated with improvements in mental health including mood state and self-esteem, although a causal link has not been established. Research on acute exercise indicates that 20 to 40 minutes of aerobic activity results in improvements in state anxiety and mood that persist for several hours. These transitory changes in mood occur in both individuals with normal or elevated levels of anxiety, but appear to be limited to aerobic forms of exercise. In the case of long term exercise programmes, improvements in the mental health of 'normal' individuals are either modest in magnitude or do not occur, whereas the changes for those with elevated anxiety or depression are more pronounced. Evidence from studies involving clinical samples indicates that the psychological benefits associated with exercise are comparable to gains found with standard forms of psychotherapy. Hence, for healthy individuals the principal psychological benefit of exercise may be that of prevention, whereas in those suffering from mild to moderate emotional illness exercise may function as a means of treatment. Exercise may also result in detrimental changes in mental health. Some individuals can become overly dependent on physical activity and exercise to an excessive degree. This abuse of exercise can result in disturbances in mood and worsened physical health. In the case of athletes the intense training, or overtraining, necessary for endurance sports consistently results in increased mood disturbance.(ABSTRACT TRUNCATED AT 250 WORDS)