Physical activity guidelines today
Having looked at the history of where exercise prescription came from, we now turn to evidence-based physical activity recommendations issued in the early 2000s.
American College of Sports Medicine (ACSM) and American Heart Association (AHA)
In 2007, the ACSM and AHA published, ‘Physical Activity and the Public Health: Updated Recommendations for Adults’. This report states clearly that:
Healthy adults should perform moderate-intensity aerobic PA, for a minimum of 30 minutes duration, on five days each week or vigorous intensity aerobic exercise, for a minimum of 20 minutes, on three days each week.
According to these guidelines a person can meet recommendations by combining moderate and vigorous intensity exercise. This update clearly states that the recommended amount of aerobic activity (whether of moderate or vigorous intensity) is in addition to routine activities of daily living which are of light intensity, such as self-care, casual walking or grocery shopping, or activities less than 10 minutes in duration such as walking to the parking lot or taking out the bins.
In addition, at least twice each week, every adult should perform activities using the major muscles of the body that maintain or increase muscular strength and endurance. Recommendations state that 8 to 10 exercises should be performed on non-consecutive days each week using the major muscle groups. To maximise strength development, a weight should be used that allows 8 to 12 repetitions of each exercise resulting in volitional fatigue.
Because of the dose response relation between physical activity and health, many adults, including those who wish to improve their personal fitness or further reduce their risk for premature chronic health conditions, or prevent unhealthy weight gain will likely benefit from exceeding the minimum recommended amounts of physical activity.
US Department of Health and Human Services (USDHHS)
The second major publication was the 2008 ‘Physical Activity Guidelines Advisory Committee Report’ by the US Department of Health and Human Services (USDHHS). This was a very comprehensive and evidence-based review that was adopted by the WHO and used to create the 2008 ‘Global Recommendations on Physical Activity for Health’.
The review suggests that all adults should avoid inactivity; that some physical activity is better than none, and that adults who participate in any amount of physical activity gain some health benefits.
For substantial health benefits, adults should do at least:
- 150 minutes a week of moderate-intensity, or 75 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate and vigorous intensity aerobic activity.
- This aerobic activity should be performed in episodes of at least 10 minutes, and preferably, it should be spread throughout the week.
Additional health benefits are gained by engaging in physical activity beyond this amount.
- Adults should also do muscle-strengthening activities that are moderate or of high-intensity and involve all major muscle groups on two or more days a week, as these activities provide additional health benefits.
The ‘Physical Activity Guidelines for Americans’ affirms that it is acceptable to follow the CDC/ACSM recommendation and similar recommendations. However, according to the Advisory Committee report, the CDC/ACSM guideline was too specific. In other words, existing scientific evidence does not allow researchers to say, for example, whether the health benefits of 30 minutes on 5 days a week are any different from the health benefits of 50 minutes on 3 days a week.
As a result, the new guidelines allow a person to accumulate 150 minutes a week in various ways.
A common guideline used by many organisations is the number of steps per day an individual should take. The following table from Tudor-Locke et al. (2011) describes step-based recommendations from around the world. Although there is variation, 10,000 steps/day is generally used as a reasonable target for healthy adults.
Tudor-Locke et al (2011). (Click to expand)
Guidelines for targeted populations
Other guidelines are also available for targeted populations such as older adults, children and adolescents. These can be accessed in the links below.
- The ACSM & AHA (2007) target apparently healthy adults and older adults.
- The USDHHS (2008) target children and adolescents, adults, older adults, pregnancy and post partum, adults with disabilities, adults with medical conditions, and weight loss and maintenance.
- The WHO (2010) target 5-17 year-olds, 16-64 year-olds, and those over age 65.
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