Modest Exercise Prevents Weight Gain
Walking 30 minutes a day keeps extra pounds away without dieting
Jan. 12, 2004 -- Preventing weight gain may be as easy as taking a walk.
New research suggests that walking as little as 30 minutes a day or 12 miles
a week may be enough to keep extra pounds at bay or even lose weight -- all
Modest Activity Fights Obesity
More than half of Americans are overweight or obese, and the prevalence of
obesity has increased by nearly 50% from 1991 to 1998. Obesity is associated
with a variety of health problems from heart disease to diabetes, but
researchers say extra fat around the midsection can be especially hazardous to
Although diet and exercise are widely known to help promote a healthy
weight, researchers say it's unclear just how much exercise is needed to
prevent weight gain.
In this study, which appears in the Jan. 12 issue of the Archives of
Internal Medicine, researchers compared the effects of three different
exercise programs vs. no exercise at all on the weight and waist circumference
of 120 sedentary overweight adults.
Each of the participants were told not to change their diet and was assigned
to one of the following three exercise intensity groups or a fourth group that
did not exercise for eight months:
- High amount/vigorous: Equivalent to jogging about 20 miles per week at
60%-80% of maximal heart rate
- Low amount/vigorous: Equivalent to jogging 12 miles per week at 60%-80% of
maximal heart rate
- Low amount/moderate: Equivalent to walking 12 miles per week at 40%-50% of
maximal heart rate
Not surprisingly, researchers found that the more the participants
exercised, the more weight they lost.
But the low-amount/moderate intensity groups also showed significantly
greater improvements than the non-exercise group. For example, compared with
the non-exercisers, all groups significantly decreased their waist
These findings strongly suggest that, absent other changes in diet, a higher
amount of activity is necessary for weight maintenance, write researcher Cris
A. Slentz, PhD, of Duke University Medical Center, and colleagues. "Most
individuals can accomplish this by walking 30 minutes a day."