AGE-RELATED DECLINE IN PHYSICAL ACTIVITY 1106

The decline in physical activity with age may be the most consistent finding in physical activity epidemiology. Although this phenomenon is well accepted, it is not well understood. A related issue is that females are typically found to have lower levels of physical activity at virtually all ages, and the age-related decline is greater in females. The purposes of this symposium are to quantify the decline in physical activity within different age ranges, determine if there are critical periods of decline, and quantify sex differences in the decline. To evaluate the generalizability of age and sex differences, data from cross-sectional and prospective studies of subjects from different age groups will be presented. The studies use a variety of self-report and objective methods of assessing physical activity, and they have been conducted in several nations. The potential biological bases of age and sex differences in physical activity will be explored in a presentation on results from studies of several species of non-human animals. It is hoped this symposium will stimulate further research on this fundamental feature of physical activity. The decline in physical activity with age is antithetical to public health goals, so methods of countering the decline need to be developed, based upon an improved understanding.