Twenty five percent of children age 2 have a television in their bedroom, as do 65% of all children. Is it any wonder that physical activity is a concern. In his opening address to the American College of Sports Medicine annual meeting in Baltimore, Jeffrey Koplan (Emory University, Atlanta) pointed out that being sedentary was the social norm in the US and that changing the social norm was the priority. It can be done, and he pointed out the social changes that have influenced smoking behaviour. No one could have been imagined how we now regard smoking. But, the challenge is to change a culture where the overall miles travelled by car have increased by 22% but walking has decreased by 71%, where urban design is dominated by the car, children are brought to school by car, and screen time ( TV computers, video games) has increased markedly. No wonder that 33.8% of Americans at age 20 have a BMI greater than 30. He described the great American anti pedestrian movement and drive-thru society. On the other hand, if medicine had a pill with the same benefits as exercise, it would be widely prescribed.

But, what if your BMI is greater than 50? Perhaps the only option is bariatric surgery. John Jakicic (Univ Pittsburgh) looked at the limitations of severe obesity and the effect of surgery. Being so obese, it is very difficult and painful to move, and with surgery, as weight goes down, activity goes up but not to a sufficient level. Because they can now get out of a chair and move around, they do, but they don’t exercise. This is not surprising, as habitual inactivity contributed to their obesity at the outset. His message was that post bariatric surgery patients need to go on an exercise regime and we cannot expect them to become more active just because they can.

With cancer patients, you might think that exercise was not an important area. The first research began in this field in 2004 and since then there has been a considerable increase in the literature. Melinda Irwin (Yale) described evidence that physical activity could help improve survival. She was quick to point out that this was observational research and subject to all the potential weaknesses. In particular she mentioned that those who were active may be more able to complete a full course of treatment, or had other healthy lifestyle attributes such as lower BMI or a healthier diet. Most of the randomised controlled trials however, focused on physical function, fatigue and quality of life. Kathleen Wolin (Washington Uni) looked at the effect of exercise after cancer treatment and pointed to the increasing volume of research especially after breast cancer. The evidence seemed generally positive with the exception of women undertaking home exercise who seemed to develop shoulder problems. Research on exercise after cancer treatment is just beginning. Areas for future research include looking at how exercise may improve immune markers and in cardiovascular disease as most treatments have cardiotoxic effects.

But, the big news of the day was the attendance of the Surgeon General, Regina Benjamin. She is interested in physical activity, the problems of obesity and the importance of exercise and, was there to promote the ACSM Exercise is Medicine initiative. She led a walk around the harbour and intends to lead many similar walks in cities throughout the US. She also intends to build up her own mileage and declared plans to walk the Grand Canyon, rim to rim, a total of 26 miles, on September 5th.

Domhnall MacAuley is primary care editor, BMJ