In recent years, the benefits of a physically active lifestyle have been well established with respect to chronic health problems such as coronary heart disease, hypertension, obesity and osteoporosis. However, the extent to which physical activity influences health care utilization is less clear. If physical activity levels are inversely associated with utilization patterns, then policies encouraging exercise may produce short-term reduction in health care costs. The purpose of the proposed study is to determine the magnitude of the relationship between physical activity level and subsequent health care utilization over a 7-to-10 week period in a general population. A multivariate regression analysis will be conducted for representative sample of more than 600 adults who participated in a longitudinal field trial of health risk appraisal instruments. Using the Harvard Alumni Activity Survey as the physical activity measure, the analysis will control for a variety of predisposing, enabling, and need characteristics that also influence utilization behavior.