Physical activity may indirectly influence health behaviors such as overeating, smoking, substance abuse, stress management, risk taking, and others. Substantial evidence indicates that physical activity is positively associated with weight control and caloric intake. The data weakly support the hypothesis that physical activity and smoking are negatively associated. Few data are available to evaluate the association between activity and alcohol consumption, alcoholism, substance abuse, stress management, preventive health behaviors, and risk-taking behavior.