What we do—and don't—know about exercise
Experts' advice has changed as we've learned more about the connection between physical activity and health.
If exercise could be packed into a pill, it would be the single most widely prescribed and beneficial medicine in the nation.
When Dr. Robert Butler, the founder of the National Institute on Aging, made that statement in the 1980s, he was on to something. Decades of research have determined that regular exercise is one of the most important factors in warding off cardiovascular disease, many types of cancer, diabetes, and obesity.