Minimum amount of physical activity for reduced mortality and extended life expectancy: a prospective cohort study.https://www.ncbi.nlm.nih.gov/pubmed/21846575/
Compared with individuals in the inactive group, those in the low-volume activity group, who exercised for an average of 92 min per week (95% CI 71-112) or 15 min a day (SD 1·8), had a 14% reduced risk of all-cause mortality (0·86, 0·81-0·91), and had a 3 year longer life expectancy. Every additional 15 min of daily exercise beyond the minimum amount of 15 min a day further reduced all-cause mortality by 4% (95% CI 2·5-7·0) and all-cancer mortality by 1% (0·3-4·5). These benefits were applicable to all age groups and both sexes, and to those with cardiovascular disease risks. Individuals who were inactive had a 17% (HR 1·17, 95% CI 1·10-1·24) increased risk of mortality compared with individuals in the low-volume group.
Potential benefits of exercise training
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2665984/
Related to coronary heart disease risk factors
Increases serum high-density lipoprotein cholesterol levels
Reduces serum triglyceride and possibly low-density lipoprotein cholesterol levels
Reduces indices of obesity
Reduces arterial blood pressure
Improves insulin sensitivity and glucose levels
Improves endothelial function
Helps with smoking cessation efforts
Reduces psychological stress
Hematologic
Decreases hematocrit and blood viscosity
Expands blood plasma volume
Increases red blood cell deformability and tissue-level perfusion
Increases circulatory fibrinolytic activity
Other
Increases coronary flow reserve
Increases coronary collateral circulation
Increases tolerance of ischemia
Increases myocardial capillary density
Increases ventricular fibrillation thresholds
Reduces atherosclerosis
Possibly increases epicardial coronary artery size
Reduces major morbidity and mortality
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2665984/
Related to coronary heart disease risk factors
Increases serum high-density lipoprotein cholesterol levels
Reduces serum triglyceride and possibly low-density lipoprotein cholesterol levels
Reduces indices of obesity
Reduces arterial blood pressure
Improves insulin sensitivity and glucose levels
Improves endothelial function
Helps with smoking cessation efforts
Reduces psychological stress
Hematologic
Decreases hematocrit and blood viscosity
Expands blood plasma volume
Increases red blood cell deformability and tissue-level perfusion
Increases circulatory fibrinolytic activity
Other
Increases coronary flow reserve
Increases coronary collateral circulation
Increases tolerance of ischemia
Increases myocardial capillary density
Increases ventricular fibrillation thresholds
Reduces atherosclerosis
Possibly increases epicardial coronary artery size
Reduces major morbidity and mortality