Understanding policies and physical activity: frontiers of knowledge to improve population health.

With increasing evidence of the detrimental effects of physical inactivity, there is interest in enhancing research on policies that may influence physical activity in communities. Given the potential policy impact, a framework that organized and conceptualized policy interventions and priorities for public health efforts to promote physical activity was developed. In addition, the Physical Activity Policy Research Network (PAPRN) was formed as a way to operationalize the contents of the framework. Recommendations for future work in this area include enhancing transdisciplinary collaborations, raising the priority of policy evaluation, studying policies at all levels, and emphasizing dissemination of findings.