Nothing Beats Moderate Exercise for Weight Loss and Good Health

(HealthDay News) -- You don’t need to be a gym rat to benefit from exercise and lose weight.

And while walking a half an hour a day won’t necessarily make your abs look like a washboard, your weight will be under control and your health will improve.

That’s all it takes… half an hour a day, the experts say.

"Thirty minutes is enough," says Cris Slentz, an exercise physiologist and senior research scientist at Duke University Medical Center in Durham, N.C., and the lead author of a study that showed benefits of moderate exercise.

This modest amount of exertion can prevent weight gain and sometimes lead to minor weight loss without changes in diet, he says, adding more exercise can result in weight loss in overweight exercisers, Slentz says.

Slentz says his study findings, which first appeared in the Jan. 12, 2004 issue of the Archives of Internal Medicine, suggest that the 60 minutes of daily exercise recommended a couple of years earlier by the Institute of Medicine may not be needed to prevent weight gain.

For the study, Slentz and his team assigned 120 subjects, ages 40 to 65, who exercised less than once a week and were overweight or obese, to one of four groups for eight months. Some did no exercise, some did low-dose moderate activity such as walking 12 miles a week, some did low-dose vigorous activity such as jogging 12 miles a week, and some did high-dose vigorous activity such as jogging 20 miles a week. Subjects could choose to exercise on treadmills, elliptical trainers, or stationary bikes.

They didn't change their diets and they were asked to maintain their starting body weight. If they dropped 2.5 percent or more of their body weight, a nutrition counselor advised them on how to increase it back to starting levels.

The high-dose, vigorous exercise group lost 3.5 percent of their weight, while the two low-dose groups had a 1 percent loss. The no-exercise group had a 1.1 percent weight gain.

"Thirty minutes daily is enough to prevent weight gain and lead to modest weight loss," says Slentz. By modest, he means about two pounds over six months.

The half hour a day is not going to make an overweight person look sculpted, he cautions. And the 30 minutes should be devoted to aerobic exercise that elevates the heart rate for the duration of the workout (such as walking or jogging), not strength training (such as lifting weights). "Weight training burns about half as many calories as does aerobic training," he says.

Probably the easiest exercise for sedentary people is walking, Slentz says. He suggests walking at a moderate to brisk pace, covering about 2 miles in a half hour.

Another expert calls the new research "an important study." But John Jakicic, an exercise research expert at the University of Pittsburgh and chair of the university’s Department of Health and Physical Activity, also says that half an hour may not be enough for some people.

"I think that the message should be that to prevent weight gain an individual should start with at least 30 minutes of at least moderate intensity exercise per day." If that doesn't prevent gain, it may be necessary to increase to as much as 60 minutes or more per day, he adds, and if that still does not prevent gain, diet changes should also be started.

On the Web

For information on how to make time for exercise, try the President's Council on Physical Fitness and Sports.

SOURCES: Cris Slentz, Ph.D., exercise physiologist, senior research scientist, Duke University Medical Center, Durham, N.C.; John M. Jakicic, Ph.D., associate professor and Chair, Department of Health and Physical Activity, University of Pittsburgh; Jan. 12, 2004, Archives of Internal Medicine
Publication date: April 16, 2007
Author: Kathleen Doheny, HealthDay Reporter
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