Overweight But Active: Vascular Benefits From Exercise

Vascular function is important because of its relationship to cardiovascular disease.

The active cohort saw an average 24 percent improvement in their vascular function, compared to the 32 percent decrease observed in the inactive group. The results were published in the journal "Obesity."

"This overweight-obesity phenomenon is an epidemic in today's society," said Ryan A. Harris, who led the study while a doctoral student in the School of Health, Physical Education and Recreation's Department of Kinesiology. "This study supports that being consistent with daily physical activity is beneficial to cardiovascular health. Being active may not drop the pounds as quickly as you'd like, but it still is beneficial."

Obesity contributes to a variety of diseases, including diabetes and heart disease.

"But being overweight isn't hopeless," said Janet P. Wallace, professor of exercise physiology in the Department of Kinesiology. "This study shows you can still do some measures to help yourself while you work to lose weight."

The study involved 16 overweight men ages 46-68. Half were active, performing at least 30 minutes of moderate activity on most days. For the study, they performed low, moderate or high intensity treadmill walking for 45 minutes. The researchers examined the brachial artery flow-mediated dilation -- how well the artery can expand to accommodate an increase in blood flow. The brachial artery was examined because it has been related to coronary function. The beneficial effect observed in the active group lasted for about an hour, said Harris, now a post-doctoral research fellow in the Department of Medicine at the University of California in San Diego.

Wallace said this is the first study to examine the vascular effect of exercise in overweight men despite the growing belief among some health and fitness experts that active, overweight people might be healthier in some ways than lean, sedentary people. She said managing weight is still important because of the relationship between obesity and a host of diseases and conditions.

Co-authors of the study are Jaume Padilla, doctoral student in IU's Department of Kinesiology, Kevin P. Hanlon, an undergraduate student in the department, and Lawrence D. Rink, M.D., with Internal Medicine Associates in Bloomington.

The study was supported by the Gatorade Sports Science Institute and a research grant in aid from the School of HPER.

Journal reference: "The Flow-mediated Dilation Response to Acute Exercise in Overweight Active and Inactive Men," Obesity, Jan. 2008, doi:10.1038/oby.2007.120.