PHYSICAL ACTIVITY and Health: A Report of the Surgeon General was released on July 11, 1996, by the Public Health Service, U.S. Department of Health and Human Services.1 This report assesses the role of physical activity in preventing disease and concludes that regular physical activity reduces the risk for developing or dying from coronary heart disease, noninsulin-dependent diabetes, hypertension, and colon cancer; reduces symptoms of anxiety and depression; contributes to the development and maintenance of healthier bones, muscles, and joints; and helps control weight. Physical activity also may help older adults maintain the ability to live independently and help prevent falling and fractures.
The Surgeon General's report emphasizes two important findings. First, demonstrated health benefits occur at a "moderate" level of activity—a level sufficient to expend about 150 calories of energy per day, or 1000 calories per week (e.g., walking briskly for 30 minutes each day). Second,