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 and functional limitations in older adults: a systematic review related to Canada's Physical Activity Guidelines
Background The purpose was to conduct systematic review s of the relationship between physical activity of healthy community-dwelling older ( > 65 years ) adults and outcomes of  functional limitations , disability , or loss of independence .  Methods Prospect i ve cohort studies with an outcome related to functional independence or to cognitive function  were search ed , as well as exercise training interventions that reported a functional outcome . Electronic data base search strategies were used to identify citations which were screened ( title and abstract ) for inclusion . Included articles were review ed to complete st and ardized data extraction tables , and assess study quality . An established system of assessing the level and grade of evidence for recommendations was employed . Results Sixty-six studies met inclusion criteria for the relationship between physical activity and functional independence , and 34 were included with a cognitive function outcome . Greater physical activity of an aerobic nature ( categorized by a variety of methods ) was associated with higher functional status ( expressed by a host of outcome measures ) in older age . For functional independence , moderate ( and high ) levels of physical activity appeared effective in conferring a reduced risk ( odds ratio ~0.5 ) of functional limitations or disability . Limitation in higher level performance outcomes was reduced ( odds ratio ~0.5 ) with vigorous ( or high ) activity with an apparent dose-response of moderate through to high activity . Exercise training interventions ( including aerobic and resistance ) of older adults showed improvement in physiological and functional measures , and suggestion of longer-term reduction in incidence of mobility disability . A relatively high level of physical activity was related to better cognitive function and reduced risk of developing dementia ; however , there were mixed results of the effects of exercise interventions on cognitive function indices . Conclusions There is a consistency of findings across studies and a range of outcome measures related to functional independence ; regular aerobic activity and short-term exercise programmes confer a reduced risk of functional limitations and disability in older age . Although a precise characterization of a minimal or effective physical activity dose to maintain functional independence is difficult , it appears moderate to higher levels of activity are effective and there may be a threshold of at least moderate activity for significant outcomes
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 .