ACSM

September 18, 2002

ACSM Applauds Recognition of Physical Activity in New Institute of Medicine Dietary Guidelines, But Warns of Confusion and Misunderstanding about IOM Specifics
ACSM experts work to clarify the science and public health issues involving physical activity

Indianapolis - While applauding the Institute of Medicine (IOM) for including physical activity in its report on new dietary recommendations, the American College of Sports Medicine (ACSM) warned the report could lead the public to not understand nor appreciate that relatively modest amounts of physical activity will improve health.

According to Dr. Steven Blair, who served as senior scientific editor of the U.S. Surgeon General's Report on Physical Activity and Health, "The IOM report recommends that at least 60 minutes each day of moderately-intense physical activity are necessary to prevent weight gain and achieve the full health benefits of activity. Previous physical activity recommendations from the US Surgeon General, ACSM/CDC, and the National Institutes of Health underscore numerous important health benefits that are obtained when 30 minutes of moderate activity are done on most days of the week. The scientific data supporting this recommendation are conclusive, and I think sedentary adults are well advised to meet that consensus recommendation."

ACSM experts note the IOM report is primarily a dietary document, focused on diet and nutrition guidelines to meet the body's daily energy and nutritional needs while minimizing risk for chronic disease. To avoid further confusion, the College also notes that the IOM is a private organization, and recommendations from this report are not federal guidelines.

The report emphasizes the importance of balancing diet with exercise, outlining one-hour of moderately-intense physical activity to maintain "maximal" cardiovascular health for adults and children. However, the amount of physical activity required for maximal or optimal health benefits is unknown, and more research is needed to advance our understanding. "We also are uncertain about the amount of activity necessary to prevent weight gain, and there is extensive individual variation. For example, some individuals never exercise, yet also do not gain any weight over their adult years, while others gain a substantial amount of weight despite daily jogging," said Dr. Blair.

Focus on 60 minutes per day may cause Americans to be confused, and doubt that 30 minutes a day, or shorter bursts of activity such as three 10 minute walks, provides any health benefit. The earlier physical activity recommendations acknowledge additional benefits can be obtained by greater amounts of activity, but that 30 minutes of moderate intensity activity each day provides substantial health benefits for sedentary adults.

"By raising the recommendation to 60 minutes of moderate physical activity per day, the report has the potential to dissuade the most sedentary from initiating a pattern of moderate physical activity that would be a healthy lifestyle change, and could lead to additional increases in total physical activity," said Edward T. Howley, Ph.D., ACSM president.

Guidelines from ACSM and the CDC, which were repeated in the Surgeon General's Report, noted that physical activity for cardiorespiratory fitness and expanded health gains would require more than a minimum 30 minutes of moderate activity most days of the week. However, ACSM notes scientific and clinical evidence have indicated, with even more evidence today, that considerably less amounts of physical activity will provide individuals with tangible health benefits. The IOM report does mention 30 minutes of moderate intensity activity (above activities of daily living) is sufficient to raise the Physical Activity Level (PAL) of an individual from the sedentary to the low-active category.

Experts are concerned that Americans, many not active even for 30 minutes each day, will be discouraged by what may be perceived as a high, unattainable duration of daily exercise to achieve health advantages. While more physical activity is better for individuals, setting 60 minutes as a new target may cause or increase confusion until scientific evidence supports this. The "more is better" message is better conveyed when emphasizing sedentary people need to establish a regular pattern of activity first, and then ideally increase that over time.

"Given that there are 40 to 50 million US adults who are sedentary, 30 minutes of moderate intensity physical activity is a good starting point, and this message needs to be reinforced. Building up to 60 minutes of moderate intensity per day may further reduce the risk of weight gain over time and will provide additional health benefits," said Dr. Blair.

An expert panel representing ACSM including Dr. Steven Blair, who served as senior scientific editor of the US Surgeon General's Report on Physical Activity and Health; Russell Pate, Ph.D., an international expert in physical activity and youth, and lead author on the ACSM/CDC public health recommendations for physical activity; William Haskell, Ph.D., author and contributor to both the ACSM/CDC guidelines and the Surgeon General's Report; and Edward T. Howley, Ph.D., ACSM president, were assembled to address these issues in a national news teleconference Wednesday. For more information, please contact the ACSM Department of Communications and Public Information.

The American College of Sports Medicine is the largest sports medicine and exercise science organization in the world. More than 18,000 International, National and Regional members are dedicated to promoting and integrating scientific research, education and practical applications of sports medicine and exercise science to maintain and enhance physical performance, fitness, health and quality of life.

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