Elderly men who walk two miles every day showed half the risk for a heart attack than men who walked only a quarter of a mile, a study suggests. The risk of a heart attack dropped 15 percent with everyadditional half mile walked per day, researchers report in the Circulation: Journal of the American Heart Association. Those findings are based on a study conducted by researchers at the University of Virginia School of Medicine in Richmond, Va. They looked at 2,678 men ages 71 to 93 and their walking habits. Study results showed that men who walked at least two miles every day had a 2.5 percent risk for a heart attack compared with a 5 percent risk for men who walked only a quarter mile a day. In an accompanying editorial, doctors from the University of Texas Southwestern Medical Center in Dallas say the finding that exercise that is neither strenuous nor prolonged can benefit an individual at any age is encouraging.