Little exercise is better than none, and this may be especially true for women, a study published in the latest issue of Circulation suggested. U.S. health experts based their conclusions on 33 previous studies of physical exercise and heart disease. The study said that 150 minutes of exercise weekly is good for our bodies. It showed that even people who exercised less than that had a lower risk of coronary heart disease than those who did not exercise. People who got 150 minutes of moderate exercise weekly had a 14 percent lower risk of catching coronary heart disease than those who did not exercise at all, according to the study. And those who exercised 300 minutes a week had 20 percent lower risk of developing coronary heart disease than those who did not exercise. The association between more exercise and greater health benefits is stronger in women than it is in men, the study said. Though the reason for the association is not clear, probably the diet factors are in effect, it added.