Even moderate forms of exercise like brisk walking may be enough to improve a woman’s cholesterol levels, according to a new study.

The findings, reported in the International Journal of Sports Medicine, may come as good news to those who don’t relish a grueling workout. Researchers found that young and middle-aged women who favored moderate-intensity exercise, such as walking, had lower levels of “bad” LDL cholesterol and higher levels of heart-healthy HDL cholesterol than their sedentary peers.

Women who worked out more vigorously, through activities like jogging, tended to have the greatest cardiovascular endurance of all study participants.

They did not, however, show the cholesterol benefit that moderate exercisers did.

It’s not clear why this was the case, according to the researchers. But what the findings do suggest, they say, is that women need not work out too hard to win some health benefits.

“I would say that it’s not necessary to practice high-intensity physical activity to improve (cholesterol) profile,” said study co-author Dr. Roberto Elosua, a researcher at the Institut Municipal d’Investigació Mèdica in Barcelona, Spain.

“Doing moderate-intensity physical activity is enough to obtain these type of benefits,” he told Reuters Health.

For their study, Elosua and his colleagues assessed exercise habits, cholesterol levels and fitness levels among 403 premenopausal women. They found that the more calories a woman burned through moderate exercise, the lower her LDL cholesterol and the higher her HDL levels.

On the other hand, only regular vigorous exercise appeared to improve women’s fitness levels, as measured by a treadmill test.

As for why these women didn’t show better cholesterol levels than their sedentary peers, it might be a matter of numbers, according to Elosua. That is, few women in the study actually worked out at a high intensity, and the small number may have made it hard, in statistical analysis, to detect an effect on cholesterol.

SOURCE: International Journal of Sports Medicine, November 2006.