Exercise has been called a miracle drug1 that can benefit every part of the body and substantially extend lifespan. Yet, as noted in a highly regarded paper,2 it receives little respect from doctors or society. Socially, being inactive is perceived as normal, and in fact doctors order patients to remain on bed rest far more often than they encourage exercise. This passive attitude towards inactivity, where exercise is viewed as a personal choice, is anachronistic, and is reminiscent of the battles still being fought over smoking. Smoking and physical inactivity are the two major risk factors for non-communicable diseases around the globe. Of the 36 million deaths each year from non-communicable diseases, physical inactivity and smoking each contribute about 5 million.
Physical inactivity burdens society through the hidden and growing cost of medical care and loss of productivity. Getting the public to be physically active is a public health priority. To individuals, the failure to spend 15–30 min a day in brisk walking (or similar routine activities such as cycling) increases the risk of cancer, heart disease, stroke, and diabetes by 20–30%,3,5 and shortens lifespan by 3–5 years. Although the benefits of exercise and the harms of inactivity might seem like two sides of a coin, the benefits message emphasised so far has not worked well for most of the population. In tobacco control, doctors did not the emphasise the benefits of non-smoking, but the harms of smoking. Similarly, armed with credible global and national data, we should emphasise the harms of inactivity and not merely the benefits of exercise.
Estimates of the effect of inactivity on non-communicable diseases, such as a 6–10% contribution, are very conservative. The largest health gain occurs for the first 15–29 min per day of exercise by inactive people. There is much to learn from tobacco control strategies to reduce the harms of inactivity including monitoring behaviour, protecting people from smoke, offering treatment, warning of harms, enforcing the law, and raising the price. Applied to physical inactivity, we will need to monitor inactivity prevalence and factors behind it; protect the safety of the exercisers and their built environment (including the highway environment); offer services to the inactive to gain skills for sustainable and enjoyable exercise; warn the public of the hazards of inactivity through repeated campaigns; ensure that the medical community fulfils its responsibility to reduce inactivity; and, finally, raise money or provide funding to encourage physical activity and discourage inactivity.
In addition to doctors’ traditional advocacy of the health benefits of exercise, stressing the harms of inactivity could strengthen our battle against inactivity. We (across of sectors and communities) need to view the inactive population as abnormal and consider them at high risk of disease.
2 Wen, C., Wu, X., 2012 Stressing the harms of physical inactivity to promote exercise, The Lancet, 380: pp. 192-193.