1. It can save your life -- really! Regularly doing cardio and strength training reduces your risk of heart disease, diabetes and endometrial, colon and breast cancers. (Dec. 1993)
2006 Update The American Heart Association recommends exercising for 30-60 minutes on most days to reduce your risk of heart disease.
2. You'll feel less stressed and be happier. Exercise (particularly cardio sessions) improves mood and decreases anxiety. Studies show that the fitter you are, the better you'll be at handling the long-term effects of stress. (Sept. 1984)
2006 Update One moderately intense 50-minute aerobic workout has been shown to significantly lower anxiety levels. What's more, a study in the British Journal of Sports Medicine found that exercise may be more effective than drugs in treating mild to moderate depression.
3. It strengthens your bones. Exercise increases bone density, helping prevent osteoporosis. (Aug. 1986)
2006 Update High-intensity activity, like jumping and running, is most beneficial for preserving bone mass.