[Physical activity and chronic illness, a theoretical framework]

The positive effects of adapted physical activity (PA) in patients with chronic illness are scientifically recognized, and PA promotion is part and parcel of public policy. In this context, one task in public health research consists in improving knowledge of PA practice in persons with chronic illnesses. As a complement to studies evaluating the importance of various determinants of PA practice, qualitative research is called for. In this framework, the present article will propose a theoretical analytical framework for study of PA in chronic illness. It will be built around two key concepts, namely the "standards of life" drawn from the notion of health in the philosophy of Georges Canguilhem and the "illness trajectory" drawn from the interactionist sociology of Anselm Strauss. We will attempt to improve understanding of the important yet frangible "labor" of patients at work in transformation of their habits and life standards involving PA professionals.