Dallas ? By lifting weights twice a week for an hour, women can battle the buildup of tummy fat that often takes hold with aging, a new study suggests.

And they didn’t even diet.

The study focused on intra-abdominal fat, the deep fat that wraps itself around organs and is the most unhealthy because it is linked with heart disease.

The study was funded by the National Institutes of Health and was presented Friday at an American Heart Assn. conference in Phoenix.

In it, 164 overweight and obese Minnesota women ages 24 to 44 were divided into two groups. One group participated in a two-year weight-training program and the other was simply given a brochure recommending exercise of 30 minutes to an hour most days of the week. Both groups were told not to change their diets in a way that might lead to weight changes.

Women who did the weight-training for two years had only a 7 percent increase in intra-abdominal fat, compared with a 21 percent increase in the group given exercise advice.