The Physical Activity Guidelines for Americans
The 2008 Physical Activity Guidelines for Americans describe the research supporting the health benefits of physical activity and recommended the following:
  1. Regular physical activity reduces the risk of many adverse health outcomes.
  2. Some physical activity is better than none.
  3. For most health outcomes, additional benefits occur as the amount of physical activity increases through higher intensity, greater frequency, and/or longer duration.
  4. Most health benefits occur with at least 2 hours and 30 minutes (150 minutes) a week of moderate-intensity physical activity, such as brisk walking. More benefits occur with more physical activity.
  5. Episodes of activity that are at least 10 minutes long count toward meeting the Guidelines.
  6. Both aerobic (endurance) and muscle-strengthening (resistance) physical activity are beneficial.