Slow walking, for just an hour in a week, has been shown to cut the risk of heart disease in women in half. That's the finding of a study of nearly 40,000 healthy professional women. It has long been known that women who are physically active have less coronary heart disease than inactive women. This study examined whether the intensity of the activity made a difference.

The researchers concluded that the rate or intensity of walking didn't matter. Only the elapsed time made a difference. Plus, the association was present even in women at high risk for CHD, including those who were overweight, had increased cholesterol levels, or were smokers.