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 .
Leisure-time physical activity and ischemic stroke risk: the Northern Manhattan Stroke Study.
BACKGROUND AND PURPOSE Physical activity reduces the risk of premature death and cardiovascular disease , but the relationship to stroke is less well studied . The objective of this study was to investigate the association between leisure-time physical activity and  ischemic stroke in an urban , elderly , multiethnic population . METHODS The Northern Manhattan Stroke Study is a population -based incidence and case-control study . Case subjects had first ischemic stroke , and control subjects were derived through r and om-digit dialing with 1:2 matching for age , sex , and race/ethnicity .  Physical activity  was recorded through a st and ardized in-person interview regarding the frequency and duration of 14 activities over the 2 prior weeks . Conditional logistic regression was used to calculate odds ratios ( OR ) and 95 % confidence intervals after adjustment for medical and socioeconomic confounders . RESULTS Over 30 months , 369 case subjects and 678 control subjects were enrolled . Mean age was 69.9 + /- 12 years ; 57 % were women , 18 % whites , 30 % blacks , and 52 % Hispanics .  Leisure-time physical activity  was significantly protective for stroke after adjustment for cardiac disease , peripheral vascular disease , hypertension , diabetes , smoking , alcohol use , obesity , medical reasons for limited activity , education , and season of enrollment ( OR = 0.37 ; 95 % confidence interval=0.25 to 0.55 ) . The protective effect of  physical activity  was detected in both younger and older groups , in men and women , and in whites , blacks , and Hispanics . A dose-response relationship was shown for both intensity ( light-moderate activity OR = 0.39 ; heavy OR = 0.23 ) and duration ( < 2 h/wk OR = 0.42 ; 2 to < 5 h/wk OR = 0.35 ; > or = 5 h/wk OR = 0.31 ) of physical activity . CONCLUSIONS Leisure-time physical activity was related to a decreased occurrence of ischemic stroke in our elderly , multiethnic , urban subjects . More emphasis on physical activity in stroke prevention campaigns is needed among the elderly
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 .