The 2008 Physical Activity Guidelines for Americans published by the U.S. Department of Health and Human Services (HHS) is designed to provide information and guidance on the types and amounts of physical activity that provide substantial health benefits for Americans aged 6 years and older. The main idea behind the Guidelines is that regular physical activity over months and years can produce long-term health benefits.
You can access more information at http://www.health.gov/paguidelines
The Physical Activity Guidelines are new because they represent:
1) The first major review of the science on benefits of physical activity in more than a decade.
2) A range of physical activity: the more you do, the more benefits you gain.
3) A total amount of activity per week that allows people to design their own way of meeting the guidelines.
4) Physical activity recommendations for groups such as children and adolescents, adults, older adults, persons with disabilities, pregnant and postpartum women, and persons with some chronic conditions.