Even a little exercise spells big help for heart

A little exercise can do a lot for your heart. That's the message from Harvard researchers after a new study showed that as little as 2.5 hours of exercise a week can dramatically cut heart disease risk.

The U.S. Department of Health and Human Service recommends 2 hours 30 minutes of exercise per week. Researchers looked at 33 studies on exercise's benefits to see if working out for that amount of time reduced heart disease risk for the study published in the August 1 issue of Circulation. Their analysis found that 2 hours 30 minutes of exercise cut heart disease risk by 14 percent. Even people who exercised less than the recommended time allotment decreased their risk more than those that did nothing. 

Heart disease is the number one killer in the U.S. taking more than 631,000 lives each year -one in four deaths. It's caused by plaque buildup in the coronary arteries which impedes blood flow, resulting in a potentially deadly heart attack.

Besides exercise, maintaining a healthy weight, eating a low-salt diet that's rich in fruits and vegetables, and not smoking are ways to reduce heart disease risk.

WebMD has more on exercise and heart disease.