Evidence-informed physical activity guidelines for Canadian adults

This review of the literature provides an update on the scientific biological and psychosocial bases for Canada's physical activity guide for healthy active living, with particular reference to the effect of physical activity on the health of adults aged 20-55 years. Existing physical activity guidelines for adults from around the world are summarized briefly and compared with the Canadian guidelines. The descriptive epidemiology of physical activity and inactivity in Canada is presented, and the strength of the relationship between physical activity and specific health outcomes is evaluated, with particular emphasis on minimal and optimal physical activity requirements. Finally, areas requiring further investigation are highlighted. Summarizing the findings, Canadian and most international physical activity guidelines advocate moderate-intensity physical activity on most days of the week. Physical activity appears to reduce the risk for over 25 chronic conditions, in particular coronary heart disease, stroke, hypertension, breast cancer, colon cancer, type 2 diabetes, and osteoporosis. Current literature suggests that if the entire Canadian population followed current physical activity guidelines, approximately one third of deaths related to coronary heart disease, one quarter of deaths related to stroke and osteoporosis, 20% of deaths related to colon cancer, hypertension, and type 2 diabetes, and 14% of deaths related to breast cancer could be prevented. It also appears that the prevention of weight gain and the maintenance of weight loss require greater physical activity levels than current recommendations. Cet article fait le tour des dernières études scientifiques sur les fondements biologiques et psychosociaux du Guide d'activité physique canadien pour une vie active saine et porte une attention particulière à l'effet de l'activité physique sur la santé des adultes âgés de 20 à 55 ans. Nous exposons brièvement les directives provenant d'un peu partout dans le monde en matière d'activité physique à l'intention des adultes et nous les comparons aux directives canadiennes. Nous présentons l'épidémiologie descriptive de l'activité physique et de l'inactivité physique et nous analysons l'importance de la relation entre l'activité physique et certaines répercussions sur la santé en mettant l'accent sur les quantités minimale et optimale requises à cette fin. En conclusion, nous mentionnons des pistes de recherche particulières. En bref, les directives can