In the journals: Even a little exercise is good for the heart - especially a woman's
Physical activity confers important health benefits, reducing the risk for many chronic conditions, including heart disease. Federal guidelines recommend that we get at least 150 minutes (2.5 hours) of moderately intense physical activity such as brisk walking each week, with greater benefits if we do even more. But even 2.5 hours a week is too much for some people, including those who are strapped for time. They'll be glad to hear that, according to a study, you can significantly lower your risk for heart disease by getting as little as 15 minutes of exercise most days of the week.
The study, led by researchers at Harvard School of Public Health, is the first to quantify just how much exercise is needed to reduce the risk of heart disease. It found, as expected, that you can lower the risk more by exercising longer. Interestingly, the effect was stronger for women than for men. Results were published in Circulation: Journal of the American Heart Association (Aug. 16, 2011).
The study. Researchers combined and analyzed data from many previous studies in what is called a meta-analysis. From a pool of 3,194 studies, they chose 33 that correlated the risk of heart disease with physical activity levels. Nine of these studies provided sufficient data to calculate the amount of exercise needed for cardiovascular benefits.