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 in relation to colon cancer in middle-aged men and women.
A population -based case-control study was conducted to assess the relation between physical activity  and colon cancer among men and women aged 30 - 62 years . Cases were 251 men and 193 women diagnosed with colon cancer in 1985 - 1989 in three countries in the Seattle metropolitan area who were identified from the Seattle-Puget Sound Surveillance , Epidemiology , and End Results registry . Controls were 233 men 194 women identified by r and om digit telephone dialing who were selected by stratified r and om sampling to approximate the age , sex , and county distribution of cases .  Physical activity  was assessed by questions on frequency and duration of types of recreational and occupational activities  during the 10-year period ending 2 years before diagnosis . Each activity was classified as low intensity ( < 4.5 METs ) or moderate to high intensity ( > or = 4.5 METs ) . For men and women combined , moderate or high intensity recreational activity was associated with a decreased risk of colon cancer ( relative risk ( RR ) for two or more times per week vs. none = 0.70 , 95 % confidence interval ( CI ) 0.49 - 1.00 ) . This relation was stronger for men than women . Occupational activity was not associated with colon cancer , except among men younger than 55 ( RR for > or = 14.5 hours per week of moderate activity vs. none = 0.29 , 95 % CI 0.12 - 0.69 ) . Among men and women combined , total moderate or high intensity activity ( occupational plus recreational ) was marginally related to colon cancer ( RR for > or = 5 hours per week vs. none = 0.78 , 95 % CI 0.55 - 1.10 ) . These results were adjusted for age ( and sex in the combined sex analyses ) and were not confounded by body mass index , dietary factors , or other measured health behaviors . The results of this study provide modest support to the growing number of studies showing that recreational and /or occupational physical activity is associated with a reduced risk of colon cancer
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 .