時常走，走得遠，速度慢，有助心髒

Walk Long, Slow and Often to Help the Heart
http://yourtotalhealth.ivillage.com/diet-fitness/walk-long-slow-often-help-heart.html?nlcid=hr|05-22-2009|

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.

Exercise for the standard rehabilitation group included a combination of walking and biking or rowing.

Being overweight increases the risk of heart attacks and increases other risks factors, including cholesterol, high blood pressure and diabetes, the researchers noted.

After five months, people in the high-calorie-burning group -- those taking the longer, slower, more frequent walks -- had greater improvement in insulin sensitivity, cholesterol, blood pressure and cardio and respiratory fitness than did people in the standard exercise group, the researchers found.

In addition, the long, slow walkers lost an average of 18 pounds, compared with 8 pounds among those in the standard rehabilitation group, and they lost more body fat (13 pounds versus 6) and inches from their waistlines (2.7 versus 2 inches) than the others.

A year after the study ended, people in the high-calorie-burning group had regained an average of 2.9 pounds and those in the standard treatment group had regained about two pounds. Weight and body fat remained lower in both groups than it had been when they started, the researchers said.

"However you lose weight is good for heart patients and should reduce their risk," Ades said. "But don't forget the exercise. It's a big part of how to lose weight. Walking daily, walking far, really made a big difference in reducing cardiac risk."

Dr. Gregg C. Fonarow, a cardiology professor at the University of California, Los Angeles, said he thinks the regimen from the study would be worth trying in people in cardiac rehabilitation programs.

"There is an ever-increasing proportion of individuals who are overweight or obese," Fonarow said. "Achieving a healthy body weight is a challenge, even among patients who are referred to formal cardiac rehabilitation programs."

The study demonstrated that a new exercise protocol aimed at maximizing exercise-related calorie expenditures was more effective in achieving weight loss than a standard cardiac rehabilitation exercise regimen, Fonarow said. "There was also improved insulin sensitivity, lipid levels and inflammatory markers with the high-calorie expenditure regimen," he said.

"This new high-calorie expenditure protocol should be considered for overweight and obese patients referred to cardiac rehabilitation who are eligible for a five-to-six-times-a-week exercise regimen," he said.

SOURCES: Philip A. Ades, M.D., professor of medicine, director of cardiac rehabilitation and prevention, University of Vermont College of Medicine, Burlington, Vt.; Gregg C. Fonarow, M.D., professor, cardiology, University of California, Los Angeles; May 11, 2009, Circulation, online