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 usual occupation and risk of breast cancer (United States)
We have used data from a large population -based case-control study inthe United States to evaluate the effect of occupational physical activity onbreast  cancer risk . Women diagnosed with breast cancer identified from fourstate cancer registries , and controls r and omly selected from lists oflicensed drivers or Medicare beneficiaries , were interviewed by telephone forinformation on usual occupation and other factors . We classified usualoccupation into one of four categories of physical activity . After excludingsubjects for whom a strength rating could not be assigned , we had a final sample size of 4,863 cases and 6,783 controls . Using conditional logisticregression models , we calculated adjusted odds ratios ( OR ) and 95 percentconfidence intervals ( CI ) for occupations having light , medium , and heavyactivity compared with sedentary ones . Women with heavy-activity occupationshad a lower risk of breast cancer than women with sedentary jobs ( OR = 0.82,CI = 0.63 - 1.08 ) , as di d women with jobs with medium activity ( OR = 0.86 , CI= 0.77 - 0.97 ) or light activity ( OR = 0.92 , CI = 0.84 - 1.01 ) . There was asignificant decreasing trend in the ORs from sedentary to heavy work ( P = 0.007 ) . Although limited by exposure misclassification , these data areconsistent with the hypothesis that physical activity reduces the risk ofbreast 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 .