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 .
Moderately intense physical activities and high levels of cardiorespiratory fitness reduce the risk of non-insulin-dependent diabetes mellitus in middle-aged men.
BACKGROUND Physical activity has been advocated as an important factor in the primary prevention of non-insulin-dependent diabetes mellitus ( NIDDM ) , but information concerning the specific intensities and duration s that are protective has been unavailable . OBJECTIVE To examine prospect ively the association between self-reported levels of the intensity and duration of physical activities  , and cardiorespiratory fitness ( assessed by  respiratory gas exchange )  and incident cases of NIDDM ( assessed by the oral glucose tolerance test ) in a population -based sample of 897 middle-aged Finnish men . RESULTS After adjustment for age , baseline glucose values , body mass index , serum triglyceride levels , parental history of diabetes , and alcohol consumption , moderately intense physical activities ( > or = 5.5 metabolic units ) that were undertaken for at least a 40-minute duration per week were associated with a reduced risk of NIDDM ( odds ration [ OR ] , 0.44 ; 95 % confidence interval [ CI ] , 0.22 - 0.88 ) . Activities with less than an intensity of 5.5 metabolic units , regardless of their duration , were not protective . Cardiorespiratory fitness levels greater than 31.0 mL of oxygen per kilogram per minute were protective against NIDDM ( OR , 0.26 ; 95 % CI , 0.08 - 0.82 ) . A subgroup of men at high risk of NIDDM , because they were overweight and were hypertensive and had a positive parental history of NIDDM , who engaged in moderately intense physical activities above the 40-min/wk duration reduced their risk of NIDDM by 64 % compared with men who did not participate in such activities . CONCLUSIONS After adjustment for age , baseline glucose levels , and known risk factors , physical activities with an intensity of 5.5 metabolic units or greater and a duration of 40 minutes or greater per week protected against the development of NIDDM . These protective effects were even more pronounced in a subgroup of men who were at high risk for the development of the disease
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 .