Overall , the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified .
Moreover , higher levels of physical activity reduce the risk for premature all-cause mortality .
The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality
This systematic review examines critically the scientific basis for Canada 's Physical Activity Guide for Healthy Active Living for adults .
Particular reference is given to the dose-response relationship between physical activity and premature all-cause mortality and seven chronic diseases ( cardiovascular disease , stroke , hypertension , colon cancer , breast cancer , type 2 diabetes ( diabetes mellitus ) and osteoporosis ) .
The strength of the relationship between physical activity and specific health outcomes is evaluated critically .
Physical activity and stroke risk: the Framingham Study.
The authors prospect ively examined the influence of increased levels of physical activity on risk of stroke  in members of the Framingham Study cohort . Two separate analyses were performed , one during midlife in 1,897 men ( mean age = 49.7 years ) and 2,299 women ( mean age = 49.9 years ) and another when the cohort was older ( 1,361 men ( mean age = 63.0 ) and 1,862 women ( mean age = 63.7 ) ) . A structured question naire administered at two separate examinations was used to estimate the amount of metabolic work done during a typical 24-hour period . Physical activity was categorized into tertiles , and medium and high levels of physical activity were compared with a low level of physical activity , which was used as the referent group . Cox proportional hazards , life table , and time-dependent covariate analyses were used to examine the relation between level of physical activity  and stroke risk over a follow-up period of up to 32 years . In men , adjusted analyses revealed that increased levels of physical activity were protective . The strongest effect was obtained from an analysis involving older cohort members in the medium tertile ( risk ratio = 0.41 , 95 % confidence interval 0.24 - 0.69 ) . High levels of physical activity  did not confer an additional benefit over medium levels . Adjusted analyses showed no significant protective effect in women . These results indicate that medium and high levels of physical activity among men are protective against stroke relative to low levels
Overall , the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified .
Moreover , higher levels of physical activity reduce the risk for premature all-cause mortality .
The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality
This systematic review examines critically the scientific basis for Canada 's Physical Activity Guide for Healthy Active Living for adults .
Particular reference is given to the dose-response relationship between physical activity and premature all-cause mortality and seven chronic diseases ( cardiovascular disease , stroke , hypertension , colon cancer , breast cancer , type 2 diabetes ( diabetes mellitus ) and osteoporosis ) .
The strength of the relationship between physical activity and specific health outcomes is evaluated critically .