Exercise in behavioral medicine.

Research on the preventive and rehabilitative applications of exercise and literature on exercise adherence from the past 10 years are briefly reviewed. Although there is now substantial evidence that a low level of physical activity is associated with decreased life expectancy for both men and women and contributes independently to the development of many prevalent chronic diseases, most adults and children lead sedentary lives. Recent intervention studies suggest exercise adherence can be improved in a variety of populations. Researchers in the next decade should continue to elaborate the population- and disease-specific effects of physical activity and exercise and give priority to the problem of exercise adherence, which limits the effectiveness of exercise interventions and remains a significant challenge to behavioral medicine.