Furthermore, the researchers report, these beneficial effects of exercise were maintained one month after the cessation of exercise. Previous studies have shown that a single bout of exercise can improve glucose metabolism immediately after exercise; however, the Duke researchers say, the previously reported short-term effect disappears within 24 hours.
"It now appears that there is also a long-term beneficial effect from regular exercise, most likely due to the fact that a significant amount of fat is lost," said exercise physiologist Cris Slentz, Ph.D., author of a study appearing Feb. 15 in the journal Clinical Exercise Physiology. "Long-term exercise leads to loss of fat in the gut (stomach) region, which is especially beneficial since this fat is thought to be directly linked to increased risk of diabetes and heart disease."
The Duke researchers wanted to see how exercise influenced the way the body metabolized carbohydrates like glucose in people who had not yet developed diabetes, but were at high risk. Previous studies were not only short-term, but were conducted with elite or well-trained athletes who are not representative of the general population. The current study is the first of its kind using a "real-life" population of participants, the researchers said.
For their study, the Duke researchers put five overweight and sedentary people on an intensive exercise regimen for nine months, followed by a one-month "de-training" period. They measured blood levels of glucose and insulin before the exercise training began, as well as one day, five days and 30 days after the training ended. To keep these results from being influenced by w
Contact: Richard Merritt
Duke University Medical Center