ABSTRACT
In 2007 updated recommendations for adults aged 18-65 were published jointly by the ACSM and the American Heart Association (Haskell et al. 2007). These largely confirmed the guidance included in the 1996 Surgeon General’s Report, while placing greater emphasis on the possibility to combine moderate and vigorous activities and on the benefits from this. They also specified that aerobic activity is needed in addition to activities of daily living that are of light intensity, and that ‘short’ bouts of activity should last at least ten minutes. The core recommendations from the 2007 statement are given in Box 13.1, alongside important differences in guidance for older adults, published in a companion paper by the same two authoritative bodies (Nelson et al. 2007). There is concern that minimal compliance with the recommendations summarized in Box 13.1 may be insufficient to prevent the gradual transition in adulthood to overweight or obesity. For the prevention of unhealthy weight gain, Dietary Guidelines for Americans specify approximately 60 minutes of moderate-to-vigorous-intensity activity on most days of the week, while not exceeding energy intake requirements (US Department of Health and Human Services and US Department of Agriculture 2005). These guidelines, also adopted by the WHO, have their roots in earlier reports from the Institute of Medicine (2002) and the International Association for the Study of Obesity (Saris et al. 2003). To sustain weight loss in adults who were formerly overweight or obese, Dietary Guidelines for Americans recommend at least 60-90 minutes
BOX 13.1 US RECOMMENDATIONS FOR pHYSICAL ACTIVITY TO MAINTAIN AND IMpROVE THE HEALTH OF ADULTS 2007
• Adults aged 18-65 need moderate-intensity aerobic activity for a minimum of 30 minutes on five days each week or vigorous-intensity aerobic activity for a minimum of 20 minutes on three days each week.
