Physical activity and hypertension.

Cross-sectional comparisons of athletes and nonathletes and of active and inactive occupations do not support the hypothesis that habitual physical activity protects against hypertension. However, more powerful cohort studies tend to support the hypothesis but indicate that the effect, if any, is not great. Conditioning level experimental exercise studies suggest, but do not establish, a lowering effect of activity on normal and elevated blood pressure. However, the potential effect of regular physical activity in the population is considered to be great in the prevention of high blood pressure because of the influence of a small beneficial effect acting on large numbers of people over time.