Running on empty

I've long been bothered by the exercise addicts who break out into a sweat when they are prevented from working up a sweat on the treadmill. All I can tell them is : "Don't sweat it."

In Newsweek last month, Dr. Harvey Simon of the Harvard Medical School recanted a view he had preached for years: that the only way to benefit from exercise was through intense aerobic activity, complete with pounding heart and rivers of sweat. Now, citing the latest research, he says he was dead wrong, and that gentle, no-sweat exercise -- even walking or gardening -- is also highly effective.