ABSTRACT

Overweight/obesity and physical inactivity are each responsible for approximately one in ten deaths annually in the United States. Epidemiology is concerned with consequences of inactivity, such as the rates of morbidity and mortality. In general, an indirect relationship exists between physical activity and morbidity/mortality: those who engage in the greatest amount of activity tend to achieve longer and more healthy lives. In general, physical activity measures tend to fall into one of three categories, based on the primary means of assessment—namely, subjective/self-report, objective/technological, and observation. The trend toward reducing one's level of physical activity as one age is a widely understood and accepted reality worldwide. In the United States, physical activity rates vary tremendously by education level. The most extreme example may be found in the sedentary rates, which decline precipitously with increased education level. The poor rates of leisure and general forms of physical activity can be traced to a number of wide-ranging social events and innovations.