Physical activity

Benefits of physical activity Physical activity and obesity

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Benefits of physical activity

The US Surgeon General's Report on Physical Activity and Health (1996) confirmed the perception that substantial population health gains were possible if the community adopted more regular moderate physical activity. Physical inactivity is now recognised as being second only to tobacco use as a key risk factor for ill health.

The broader public health burden of physical inactivity is based on the relative risks posed by inactivity, as well as the high prevalence of sedentariness in the community. Rates of physical inactivity are usually substantially higher than adult tobacco use (about 25% of adults) or hypertension (15% of adults).

Some of the benefits of moderate physical activity include:

• halving the risk of coronary heart disease
• halving the risk of colon cancer
• lowering the risk of diabetes
• lowering the risk of osteoporosis
• lowering blood pressure
• improving lipid profile
• improving mental health

Recent epidemiological evidence suggests that regular moderate levels of physical activity confer clear health benefits. Based on this evidence the NSW Chief Health Officer has recommended that:

"Every adult in New South Wales should accumulate 30 minutes of moderate-intensity physical activity on most, preferably all, days of the week."

This activity can be accumulated in 10-minute sessions through a day, rather than necessarily in single 30-minute bouts.

Additional benefits are obtained with vigorous activity, but this may not be achievable by many people, so moderate activity remains a feasible recommendation for all adults. In particular, being more active halves the risk of coronary heart disease. Other evidence consistently suggests that activity lowers the risk of developing diabetes, prevents colon cancer and reduces the risk of osteoporosis.

Using data about the risks from physical inactivity and the prevalence of inactivity in the population, the Population Attributable Risk of inactivity can be calculated. This is the percentage of deaths in a population that could be attributed to inactivity. Around a fifth to a quarter of the mortality from heart disease, diabetes, and colon cancer could be prevented if all (or almost all) adults undertook regular moderate physical activity. Similar levels of reduced incidence might also be anticipated.

Other health benefits related to becoming more physically active include improved mental health and possibly a reduced risk of some other cancers. In addition, physical activity reduces mild to moderate hypertension, and improves the lipid profile by increasing HDL-C levels. More sustained levels of physical activity also facilitate weight loss.

The challenge for health professionals is that physical inactivity remains prevalent; about half the adult population do not meet the threshold level of around five sessions per week for half an hour each (or an accumulated total of at least 150 minutes per week). Even incidental activity, such as walking to the train station or local shop, walking the dog, or using the stairs instead of elevators remain infrequently reported. All people in the community should be encouraged to be more active.

Advice from health professionals is an important part of the solution to the societal problem of inactivity; additional supports, in terms of environmental change, and developing appropriate programs, would help to complete the picture.

See our guidelines for adults National Physical Activity Guidelines for Australians (opens in PDF) and the Childhood Obesity site.