Avoiding peripheral arterial disease (PAD) may be as easy as taking a walk every day, according to a study published in the Journal of Vascular Surgery.

Light exercise, such as a daily half-hour stroll, has long been known to help protect the heart, but also helps ward off PAD, fatty deposits that limit blood flow to the extremities, usually the legs, and raise the risk of heart attack and stroke. According to the Peripheral Arterial Disease Coalition, PAD affects between 8 million and 13 million Americans, especially those over the age of 50. Although the disease sometimes shows no symptoms, it often causes leg cramps and pain.

Researchers at Stanford University Medical Center looked at 1,381 patients who were at high risk for atherosclerosis, a condition where fatty material collects on arterial walls and hardens, forming calcium deposits. About 30% of those studied said they were inactive throughout most of their lives. The scientists found that they were nearly twice as likely to have PAD as active ones.

But once a sedentary person got off the couch and exercised even a little, their risk for PAD went down, the researchers said, thanks to improved circulation and reduced "age-related arterial stiffness," among other reasons.

However, it's important to begin an exercise program before PAD sets in and pain limits activity, the researchers noted.