Exercise Fights Diabetes at Every Weight

Sept. 25, 2003 -- If the recent avalanche of studies on the health benefits of even moderate physical activity wasn't enough to get you out the door, here's one more shove. A new study shows a brisk 30-minute walk every day can substantially lower a person's risk of diabetes, no matter how much they weigh.

Researchers found that regardless of their age or body weight, men and women who were physically active for at least 30 minutes a day were less likely to develop type 2 diabetes -- the type of diabetes more commonly seen in overweight or inactive adults.

"We have found that men and women who incorporate activity into their lifestyles are less likely to develop type 2 diabetes than those who are sedentary. This finding holds no matter what their initial weight," says researcher Andrea Kriska, PhD, associate professor of epidemiology at the University of Pittsburgh Graduate School of Public Health, in a news release.

More Active, Less Diabetes Risk

In the study, researchers followed a group of more than 1,700 men and women 15-59 years old who were at least half Pima, Tohono-O'odham, or a combination of these related American Indian tribes for six years. Both of these tribes traditionally have high rates of diabetes.

The participants were questioned about their leisure and occupational physical activity, and the amount of physical activity was calculated according to the number of hours per week and intensity of the activity.

The results appear in the Oct. 1 issue of the American Journal of Epidemiology.

Unlike previous studies that have looked at physical activity and diabetes risk, researchers say they tested for the presence of diabetes at the end of the study by using a diabetes test called an oral glucose tolerance test rather than self-reporting from the participants.

Overall, 346 participants developed type 2 diabetes during the course of the study.

Researchers found that fewer individuals who were physically active (defined as at least 30 minutes of moderate physical activity per day) developed diabetes than others.

This finding was true among both men and women, although the link between physical activity and lower diabetes risk was more consistent in women. But researchers say this disparity may have been a result of inadequately measuring the level of physical activity in the men's occupational work.

"Our feeling is that men and women likely reap the same positive results from activity, whether it is in the form of leisure activity or occupational activity," says Kriska. "This suggests that adopting and maintaining a program of regular physical activity similar to what the Surgeon General's recommendations suggest can play a significant role in preventing type 2 diabetes."

The U.S. Surgeon General recommends that adults engage in at least 30 minutes of moderate physical activity on all or most days of the week.