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 .
Exercise intensity and longevity in men. The Harvard Alumni Health Study.
OBJECTIVE To examine the independent associations of vigorous ( > or = 6 resting metabolic rate [ MET ] score ) and nonvigorous ( < 6 MET score ) physical activity with longevity . DESIGN Prospect i ve cohort study , following up men from 1962 or 1966 through 1988 . SETTING / PARTICIPANTS Subjects were Harvard University alumni , without self-reported , physician-diagnosed cardiovascular disease , cancer , or chronic obstructive pulmonary disease ( n = 17,321 ) . Men with a mean age of 46 years reported their physical activities on question naires at baseline . MAIN OUTCOME MEASURE  All-cause mortality  ( 3728 deaths ) . RESULTS Total energy expenditure and energy expenditure from vigorous activities , but not energy expenditure from nonvigorous activities , related inversely to mortality . After adjustment for potential confounders , the relative risks of dying associated with increasing quintiles of total energy expenditure were 1.00 ( referent ) , 0.94 , 0.95 , 0.91 and 0.91 , respectively ( P [ trend ] < .05 ) . The relative risks of dying associated with less than 630 , 630 to less than 1680 , 1680 to less than 3150 , 3150 to less than 6300 , and 6300 or more kJ/wk expended on vigorous activities were 1.00 ( referent ) , 0.88 , 0.92 , 0.87 , and 0.87 , respectively ( P [ trend ] = .007 ) . Corresponding relative risks for energy expended on nonvigorous activities were 1.00 ( referent ) , 0.89 , 1.00 , 0.98 , and 0.92 , respectively ( P [ trend ] = .36 ) . Analyses of vigorous and nonvigorous activities were mutually adjusted . Among men who reported only vigorous activities ( 259 deaths ) , we observed decreasing age-st and ardized mortality rates with increasing activity ( P = .05 ) ; among men who reported only nonvigorous activities ( 380 deaths ) , no trend was apparent ( P = .99 ) . CONCLUSIONS These data demonstrate a grade d inverse relationship between total physical activity and mortality . Furthermore , vigorous activities but not nonvigorous activities were associated with longevity . These findings pertain only to all-cause mortality ;  nonvigorous exercise has been shown to benefit other aspects of health
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 .