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 .
The "weekend warrior" and risk of mortality.
Physical activity improves health , and current recommendations encourage daily exercise . However , little is known about any health benefits associated with infrequent bouts of exercise ( e.g. , 1 - 2 episodes/week ) that generate the recommended energy expenditure . The authors conducted a prospect i ve cohort study among 8,421 men ( mean age , 66 years ) in the Harvard Alumni Health Study , without major chronic diseases , who provided details about physical activity on mailed question naires in 1988 and 1993 . Men were classified as " sedentary " ( expending < 500 kcal/week ) , " insufficiently active " ( 500 - 999 kcal/week ) , " weekend warriors " ( > /=1,000 kcal/week from sports/recreation 1 - 2 times/week ) , or " regularly active " ( all others expending > /=1,000  kcal/week ) . Between 1988 and 1997 , 1,234 men died . The multivariate relative risks for mortality among the sedentary , insufficiently active , weekend warriors , and regularly active men were 1.00 ( referent ) , 0.75 ( 95 % confidence interval ( CI ) : 0.62 , 0.91 ) , 0.85 ( 95 % CI : 0.65 , 1.11 ) , and 0.64 ( 95 % CI : 0.55 , 0.73 ) , respectively . In stratified analysis , among men without major risk factors , weekend warriors had a lower risk of dying , compared with sedentary men ( relative risk = 0.41 , 95 % CI : 0.21 , 0.81 ) . This was not seen among men with at least one major risk factor ( corresponding relative risk = 1.02 , 95 % CI : 0.75 , 1.38 ) . These results suggest that regular physical activity generating 1,000 kcal/week or more should be recommended for lowering mortality rates . However , among those with no major risk factors , even 1 - 2 episodes/week generating 1,000 kcal/week or more can postpone mortality
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 .