Editorials

Lessons from a cyclist

Doctors should do more to promote physical activity 

One hundred years ago the BMJ reported that "In France the bicycle has done wonders, as those who remember Paris, Fontainebleau, and the intervening districts thirty years ago can bear witness if they once more revisit that pleasant part of the world."¹ For three weeks in July the bicycle in France was, once again, the source of wonderment, as Lance Armstrong won the world's premier cycling race, the Tour de France. Armstrong's quest for victory during the gruelling event not only captured the attention of sports enthusiasts but also that of the media and the public at large, because just three years ago Armstrong was diagnosed with metastatic testicular cancer. He began his racing comeback early in 1998 after four rounds of chemotherapy and two operations. Acknowledging the role of modern medicine in his achievement, Armstrong noted that "Fifteen or 20 years ago, I wouldn't be alive, much less riding a bike or winning the Tour de France." Beyond this remarkable story of determination and courage, the Tour de France reminds us of the health benefits of exercise and physical activity.

Although the effects of physical activity on testicular cancer have not been reported, physical activity reduces the risk of cancer of the breast² and colon,³ diabetes, coronary heart disease, and several other diseases. ^{3 4} Participants in the Tour de France engaged in vigorous activity for several hours each day, but increasing evidence suggests that health benefits can occur with activity of much lesser intensity. The US Surgeon General's report on physical activity recommended 30 minutes of moderate physical activity on most, if not all, days of the week.⁴ Lifestyle activities such as walking or working in the garden seem as beneficial to health as more structured exercise, at least for sedentary middle aged people. ^{5 6}

Achieving the Surgeon General's recommendations for the population will be as challenging as winning the Tour de France. More than 60% of Americans do not engage in regular physical activity, and 25% are sedentary.⁴ Despite the beneficial effects of physical activity, only 20% of US physicians advise their patients about physical activity.⁷ However, doctors can play an important part in preventing chronic disease, as shown by observations that more counselling by doctors about physical activity increased physical activity levels among sedentary adults in Australia⁸ and New Zealand.⁹

Doctors represent only one part of the solution of how to raise physical activity levels. Community structure may directly affect daily physical activity. For example, in the Netherlands 30% of all trips are by bicycle and 18% are by walking.¹⁰ Comparable figures for England and Wales are 8% by bicycle and 12% by walking, and for the United States 1% by bicycle and 9% by walking. Lack of community infrastructure that supports physical activity, like sidewalks or bicycle trails, as well as cultural norms that favour car use over physical activity as part of daily living, probably account for some of these differences. Improved design of communities to include sidewalks and bicycle trails represents an important environmental intervention to promote physical activity. Such changes will also foster the development of future generations of athletes like Lance Armstrong.

(Credit: LAURENT REBOURS/AP)

William H Dietz, director. 

Division of Nutrition and Physical Activity, National Center for Chronic Disease Prevention and Health Promotion, US Centers for Disease Control and Prevention, Mailstop K-24, Atlanta, GA 30341-3717, USA (wcd4{at}cdc.gov)

Ron Davis, North American editor,  BMJ.

(rdavis1{at}hfhs.org)

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