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 .
Recreational Physical Activity and Cancer Risk in Subsites of the Colon (the Nord-Trøndelag Health Study)
Physical activity may reduce colon cancer risk , but the underlying mechanisms remain unclear . Relating physical activity to cancer risk in anatomic segments of the colon may advance our underst and ing of possible mechanisms . We conducted a prospect i ve study of 59,369 Norwegian men and women who were followed up for cancer incidence and mortality . Cox proportional hazards models were used to estimate multivariably adjusted hazard ratios ( HR ) and 95 % confidence intervals ( 95 % CI ) . All statistical tests were two sided . During 17 years of follow-up , 736 colon cancers and 294 rectal cancers were diagnosed . Overall , we found an inverse association between  recreational physical activity  and colon cancer risk , but subsite analyses showed that the association was confined to cancer in the transverse and sigmoid colon . The adjusted HR , comparing people who reported high versus no physical activity , was 0.44 ( 95 % CI , 0.25 - 0.78 ) for cancer in the transverse colon and 0.48 ( 95 % CI , 0.31 - 0.75 ) for cancer in the sigmoid colon . The corresponding HR for cancer mortality was 0.33 ( 95 % CI , 0.14 - 0.76 ) for the transverse colon and 0.29 ( 95 % CI , 0.15 - 0.56 ) for the sigmoid colon . For rectal cancer , there was no association with physical activity in these data . In conclusion , the inverse association of recreational physical activity with cancer risk and mortality in the transverse and sigmoid segments of the colon may point at increased colon motility and reduced fecal transit time as possible underlying mechanisms . ( Cancer Epidemiol Biomarkers Prev 2008;17(1):183–8
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 .