Promoting physical activity: the new imperative for public health

The aim of this essay is to provide an overview of initiatives designed to increase physical activity among different populations and in different set tings, and to set the context for the major challenges that lie ahead. The decline in habitual physical activity with modernization, and the causal li nk between physical activity and health are briefly reviewed. The need to u nderstand physical activity as a health behavior and examples of behavior c hange theories that have been applied to the promotion of physical activity are discussed. Diverse projects and campaigns in three countries, i.e. Sou th Africa, Australia and the US, are highlighted. Common themes found in th ese physical activity initiatives include the development of a theory-drive n research base, inclusion of behavioral and social scientists on multidisc iplinary teams, and advocacy for environmental changes that promote physica l activity. Within the next decade, research projects and national campaign s such as those described herein will yield important new findings on how t o increase physical activity levels among targeted sectors of the populatio n. The research agenda for the future includes development of both basic an d applied research on physical activity, and the integration of theory acro ss social, behavioral and biomedical disciplines.