Article published in SCIENCE Connection, The Ann Arbor News, Thursday, August 27, 1998.

Researcher studies whether slower walking may be better for preventing diabetes By ANNE RUETER NEWS STAFF REPORTER The more intense the workout, the better-that seems like the advice you might expect from an exercise physiolo-gist. But University of Michigan researcher Katarina Borer has no such simple answers. This fall, she's launching further studies to test surprising data from her earlier work gauging the effects of walking regimens at lower and higher intensities on middle-aged women. A small 1997 study of nine women cast doubt on any assumption that since exercise helps the body regulate blood sugar and reduce the risk of diabetes, more intense exercise will help more. In her study of 15 women this fall, Borer has enlisted Dr. Mark Supiano of the U-M Institute of Gerontology to measure insulin production in her subjects after they are given a standardized amount of sugar intravenously. They'll receive the test three times: before starting training, after 15 weeks and after 30 weeks. The study will look at the closely intertwined factors of weight loss and diabetes. Borer and her assistants will look t how weight loss, though by itself to increase insulin sensitivity, relates to theeffects of low and higher intensity exercise. "As walking speed increased, the beneficial effect of training fell off,until at the highest speed there was no benefit," says Borer. But she cautions that the result, while intriguing, is far from conclusive.Borer is now recruiting 15 healthy postmenopausal women who are overweight and not currently exercising for a more thorough study. The study will look at how weight loss, thought by itself to increase sensitivity to insulin, relates to the effects of low and higher intensity exercise. Like many things in science, her earlier finding was serendipitous, says Borer. Her 1995-97 study aimed not at studying diabetes risk but at measuring whether exercise could protect women from the effects of drops in growth hormone production, which start in a person's 30's and affect the body's ability to maintain lean body mass, as well as muscle, skin and connective tissue. They will walk three miles a day, five days a week at Briarwood Mall for 15 to 30m weeks, meeting each morning with other members of an exercising walking program sponsored by the U-M's U-Move. This study includes more subjects and a more direct measure of insulin sensitivity than the earlier one."Exercise is thought to increase your sensitivity to insulin, reducing your risk of diabetes," Borer says. She discovered the low- vs. high-intensity exercise discrepancy almost by accident when she monitored what happened to her subjects' blood sugar and insulin production after they ate a standardized meal. GO TO NEXT PAGE