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 incidence of non-insulin-dependent diabetes mellitus in women
The potential role of physical activity in the primary prevention of  non-insulin-dependent diabetes mellitus ( NIDDM ) is largely unknown . We examined the association between regular vigorous exercise and the subsequent incidence of NIDDM in a prospect i ve cohort of 87,253 US women aged 34 - 59 years and free of diagnosed diabetes , cardiovascular disease , and cancer in 1980 . During 8 years of follow-up , we confirmed 1303 cases of NIDDM . Women who engaged in vigorous exercise at least once per week had an age-adjusted relative risk ( RR ) of NIDDM of 0.67 ( p less than 0.0001 ) compared with women who did not exercise weekly . After adjustment for body-mass index , the reduction in risk was attenuated but remained statistically significant ( RR = 0.84 , p = 0.005 ) . When analysis was restricted to the first 2 years after ascertainment of physical activity level and to symptomatic NIDDM as the outcome , age-adjusted RR of those who exercised was 0.5 , and age and body-mass index adjusted RR was 0.69 . Among women who exercised at least once per week , there was no clear dose-response gradient according to frequency of exercise . Family history of diabetes did not modify the effect of exercise , and risk reduction with exercise  was evident among both obese and nonobese women . Multivariate adjustments for age , body-mass index , family history of diabetes , and other variables did not alter the reduced risk found with exercise . Our results indicate that physical activity may be a promising approach to the primary prevention of NIDDM
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 .