Walking far and often may be the best exercise prescription for overweight adults with heart disease, a study published Monday suggests.

In a clinical trial of 74 overweight heart disease patients, researchers found that a calorie-burning regimen of longer-distance, moderately paced walking improved patients' risk factors to a greater degree than shorter, more-intense bouts of exercise.

After five months, patients in the former group had lost twice as much weight and body fat. They also showed greater improvements in cholesterol, blood pressure and other risk factors for heart attack and stroke.

Dr. Philip A. Ades and his colleagues at the University of Vermont in Burlington report the findings in the American Heart Association journal Circulation.

Exercise is one of the key components of cardiac rehabilitation, a therapy often used to help people recover from a heart attack or heart surgery, or to manage chronic cardiac pain in the chest, called angina.

However, the exercise regimen typically involves a short time on a treadmill or stationary bike, which burns relatively few calories.

The problem with that, according to Ades and his colleagues, is that most patients entering cardiac rehab today are overweight and need to shed pounds.

For their study, the investigators randomly assigned half of the patients to walk at a moderate pace for 45 to 60 minutes, five to seven times per week. The goal was for them to burn 3,000 to 3,500 calories each week.

The rest of the patients followed a standard exercise prescription of

25 minutes on a treadmill and 8 minutes on an ergometer — such as a stationary bike or rowing machine — three times per week.

As mentioned, along with their greater weight loss, patients who walked farther and more often tended to show bigger improvements in cholesterol, blood pressure and, in particular, sensitivity to the blood-sugar-regulating hormone insulin. Problems with insulin sensitivity can lead to type 2 diabetes and contribute to heart disease.

The findings suggest that cardiac rehab programs should remodel their exercise regimens on the "walk daily and walk far" principle, according to Ades.

Cardiac rehab exercise protocols were developed in the 1970s, he told Reuters Health, when patients recovering from a heart attack or heart surgery spent up to two weeks in the hospital, and were then advised to rest for a month or two before starting rehab.

At that point, patients would be so deconditioned that the focus was mainly on boosting their fitness levels with short, relatively intense bouts of exercise.

But now, Ades said, patients enter rehab much sooner and are less likely to be out of shape. However, 80 percent are overweight — making weight loss a priority.

Walking farther, while keeping the pace moderate, is also something most heart disease patients can manage, according to Ades. Patients who have the go-ahead to exercise can gradually build up the distance of their walks without special supervision, he said.