American Heart Association.
American College of Sports Medicine. Physical Activity and Public Health Guidelines.
Couch to 5K Running Program
Healthways Silver Sneakers Fitness Program for Older Adults.
National Institute on Aging. U.S. National Institutes of Health. Exercise & Physical Activity: Your Everyday Guide from the National Institute on Aging.
US Department of Health and Human Services. 2008 Physical Activity Guidelines for Americans.
World Health Organization