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 .
Walking compared with vigorous physical activity and risk of type 2 diabetes in women: a prospective study.
CONTEXT Although many studies suggest that physical activity may reduce risk of type 2 diabetes , the role of moderate-intensity activity such as walking is not well understood . OBJECTIVES To examine the relationship of total physical activity and incidence of type 2 diabetes in women and to compare the benefits of walking vs vigorous activity as predictors of subsequent risk of type 2 diabetes . DESIGN AND SETTING The Nurses ' Health Study , a prospect i ve cohort study that included detailed data for physical activity from women surveyed in 11 US states in 1986 , with up date s in 1988 and 1992 . PARTICIPANTS A total of 70,102 female nurses aged 40 to 65 years who did not have diabetes , cardiovascular disease , or cancer at baseline ( 1986 ) . MAIN OUTCOME MEASURE Risk of type 2 diabetes by quintile of metabolic equivalent task ( MET ) score , based on time spent per week on each of 8 common physical activities , including  walking .  RESULTS During 8 years of follow-up ( 534 , 928 person-years ) , we documented 1419 incident cases of type 2 diabetes . After adjusting for age , smoking , alcohol use , history of hypertension , history of high cholesterol level , and other covariates , the relative risks ( RRs ) of developing type 2 diabetes across quintiles of physical activity ( least to most ) were 1.0 , 0.77 , 0.75 , 0.62 , and 0.54 ( P for trend < .001 ) ; after adjusting for body mass index ( BMI ) , RRs were 1.0 , 0.84 , 0.87 , 0.77 , and 0.74 ( P for trend = .002 ) . Among women who did not perform vigorous activity , multivariate RRs of type 2 diabetes across quintiles of MET score for walking were 1.0 , 0.91,0.73 , 0.69 , and 0.58 ( P for trend < .001 ) . After adjusting for BMI , the trend remained statistically significant ( RRs were 1.0 , 0.95 , 0.80 , 0.81 , 0.74 ; P for trend = .01 ) . Faster usual walking pace was independently associated with decreased risk . Equivalent energy expenditures from walking and vigorous activity result ed in comparable magnitudes of risk reduction . CONCLUSIONS Our data suggest that greater physical activity level is associated with substantial reduction in risk of type 2 diabetes , including physical activity of moderate intensity and duration
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 .