DEAR DOCTOR K: You frequently write that exercising regularly may be the best thing you can do to improve your health. I don't doubt that's true. But have scientists figured out what it is about exercise that promotes health?
DEAR READER: You've asked a very interesting question. Perhaps you're thinking, as do some of my patients, that exercise leads the body to produce certain natural chemicals that promote health. And that if you could make pills out of those health-promoting chemicals, maybe you wouldn't need to exercise. Actually, research here at Harvard in the past few years may have made a step in that direction. The research is primarily in mice, but it probably applies in humans as well.