Behavior Change and Health News


Updated Physical Activity Guidelines Provide More Specific Guidance

The American College of Sports Medicine (ACSM) and the American Heart Association released new physical activity guidelines on August 1, 2007. Updating the 1995 ACSM and Centers for Disease Control and Prevention (CDC) directives, the most recent guidelines more clearly describe the public health recommendations for adults based on the widely researched health benefits of physical activity.

The basis of the original recommendation still holds true: Significant health benefits can be obtained by accumulating at least 30 minutes of moderate-intensity physical activity on most, preferably all, days of the week. Using evidence that has since strengthened the recommendation and clarifying the types and benefits of regular physical activity, the update aims to reduce the risk of chronic disease and premature death.

The following are specific changes to the recommendations: (This list is from the ACSM press release at www.acsm.org):

  • Moderate-intensity physical activity has been clarified.
    The 1995 document specified “most, preferably all, days per week” as the recommended frequency, while the new recommendation identifies five days per week as the recommended minimum.
  • Vigorous-intensity physical activity has been explicitly incorporated into the recommendation.
    To acknowledge both the preferences of some adults for vigorous-intensity physical activity and the substantial science base related to participation in such activity, the recommendation has been clarified to encourage participation in either moderate-intensity or vigorous-intensity physical activity.
  • Moderate- and vigorous-intensity activities are complementary in producing health benefits, and a variety of activities can be combined to meet the recommendation.
    This combining of activities is based on the amount (intensity multiplied by duration) of activity performed during the week and uses the concept of METs (metabolic equivalents) to assign an intensity value to a specific activity.
  • Aerobic activity is needed in addition to routine activities of daily life.
    The updated recommendation now clearly states that the amount of aerobic activity (whether of moderate or vigorous intensity) is in addition to routine, light-intensity activities of daily living, such as self-care, casual walking, or grocery shopping, or activities that last less than 10 minutes, such as walking to the parking lot or taking out the trash. Few activities in contemporary life are conducted routinely at a moderate intensity and last for at least 10 minutes. However, moderate- or vigorous-intensity activities performed as a part of daily life (such as brisk walking to work, gardening with a shovel, carpentry) performed in bouts of 10 minutes or more can be counted toward the recommendation. This concept was implied but not effectively communicated in the original recommendation.
  • More is better.
    The new recommendation emphasizes the important fact that physical activity exceeding the recommended minimum amount provides even greater health benefits. The point of maximum benefit for most health benefits has not been established but likely varies with genetic endowment, age, sex, health status, body composition, and other factors. Exceeding the minimum recommendation further reduces the risk of inactivity-related chronic disease.
  • Short bouts of exercise are OK.
    The original recommendation introduced the concept of accumulating short bouts of physical activity toward the 30-minute goal, but there was confusion about how short those episodes could be. For consistency, the minimum length of the short bouts is clarified as being 10 minutes.
  • A muscle-strengthening recommendation is now included.
    Muscle-strengthening activities have now been incorporated into the physical activity recommendation. The 1995 recommendation mentioned the importance of muscular strength and endurance but stopped short of making specific declarations in this area. Available evidence now allows the integration of muscle-strengthening activities into the core recommendation.
  • Wording has been clarified.
    Minor wording changes in the recommendation have been made to enhance clarity in communications. For example, the term “aerobic,” or endurance, has been added to clarify the type of physical activity recommended and to differentiate it from muscle-strengthening exercises, which are now part of the core recommendation.

Programs such as Active Living Every Day—which stresses the value of moderate-intensity physical activity on five or more days of the week—can provide practical support for people who want to increase their levels of physical activity. For more information, visit www.ActiveLiving.info.

For more information on the new physical activity guidelines, see www.acsm.org.

Sources

American College of Sports Medicine. August 1, 2007. Updated physical activity guidelines released today. Press release. www.acsm.org.

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