MONDAY, May 11 (HealthDay News) -- For people in cardiac rehabilitation who are overweight, longer but slower walks are better for losing weight and improving heart health than shorter, brisker walks, a new study has found.

Frequent long, slow walks -- 45 minutes to 60 minutes a day at a moderate pace, five to six days a week -- were found to burn more calories, improve cardiac function, reduce weight and body fat. The standard regimen for cardiac rehabilitation involves walking, biking or rowing for 25 minutes to 40 minutes at brisk pace three times a week.

"The benefits of weight loss in cardiac patients have not been all that clear," said Dr. Philip A. Ades, a professor of medicine and director of cardiac rehabilitation and prevention at the University of Vermont College of Medicine and the study's lead researcher. "And docs are usually pessimistic that their patients can accomplish weight loss."

In fact, most cardiac rehabilitation programs have not been effective in weight loss, Ades said.

"The reason people don't lose weight in cardiac rehab is they don't burn enough calories with their exercise," he said.

Walking can burn more calories than biking or swimming, Ades explained, because walkers support their total body weight by themselves, rather than having a bike or water support their weight. People have to bike or swim a lot more, he said, to gain the same calorie-burning effect as walking.

The report is published in the May 11 online edition of Circulation.

The study involved 74 overweight people with coronary heart disease, also called coronary artery disease, who were enrolled in a cardiac rehabilitation program. They were randomly assigned to an exercise regimen designed to burn 3,000 to 3,500 calories a week or to a standard rehab exercise program designed to burn 700 to 800 calories a week.

The high-calorie expenditure program was based on exercise that was not more intensive than standard rehabilitation but was done more often (five to seven times a week, rather than three) and longer (45 minutes to 60 minutes a session, rather than 25 to 40), according to the study. Participants did not begin walking for an hour each session but gradually built up their ability, Ades said.