TUESDAY, April 4, 2006 (HealthDay News) -- Fat around the middle is a more significant factor in exercise-induced shortness of breath than overall body fat or lung function, according to a new study.
Researchers at the University of Texas Southwestern Medical Center and at Presbyterian Hospital, Dallas, found that women with higher amounts of abdominal fat needed more oxygen during exercise.
The study results may aid researchers in finding ways to help obese people better tolerate exercise and lose weight. The findings were expected to be presented Tuesday at the Federation of American Societies for Experimental Biology meeting in San Francisco.
Researchers tested eight mild-to-moderately obese women with similar age, height, weight, body mass index, and pulmonary function at rest.
MRIs of the women's upper bodies revealed significant differences in fat distribution between four women who suffered exercise-induced shortness of breath and four women who did not have that problem.
There was a significant correlation between the amount of abdominal fat -- fat under the skin of the abdomen, instead of fat actually inside the abdominal cavity where the stomach and other organs are located -- and the "oxygen cost" of breathing. Oxygen cost is a measurement of how much oxygen is utilized for breathing.
It's not clear whether the exercise-induced shortness of breath in these women is due to increased weight and forces on the lungs or if the higher levels of abdominal fat decrease their lung volume, resulting in the women feeling that they were short of breath, the researchers said.
However, the findings suggest that some obese patients with exercise-induced shortness of breath may not be as out of shape as previously thought, but may have respiratory limitations. Doctors need to instruct these people to focus on weight loss and to do special types of exercise, the researchers said.
The American Academy of Family Physicians offers advice on weight control.