Most people know that exercise can help with type. 2 diabetes, but one fitness regimen might work best.
Specifically, workouts that combine aerobic and resistance training exercises appear better at controlling blood sugar than either type of activity alone, researchers say.
The finding is new, because "most other studies have looked at just one kind of exercise, either aerobic or resistance," noted lead researcher Ronald J. Sigal, MD, an associate professor of medicine and cardiac sciences at the University of Calgary, in Alberta, Canada.
Dr. Sigal's team evaluated 251 adults, ages 39 to 70, with type2 diabetes who did not exercise regularly. The participants were assigned to one of four groups: those who did 45 minutes of aerobic training three times a week, those who did45 minutes of resistance training three times a week, those who did 45 minutes each of both forms of exercise three times a week, and those who did no exercise at all.
The aerobic group worked out on a treadmill or a bike at the gym. The resistance group also worked out at the gym doing seven different exercises on weight machines.
Dr. Sigal's team evaluated changes in A1c values—a measurement reflecting blood sugar concentrations over the previous two to three months. A1c is expressed as a percentage.
As expected, blood sugar control improved in all the exercise groups. In those who did either aerobic or resistance exercise, the A1c value declined by about 0.5% compared to the non-exercisers. Those who did both kinds of exercise had double that level of success, with their A1c value dropping by 0.97% compared to the non-exercising group. Non-exercisers experienced no change in their A1c values over the 26-week study.
He said the decrease of nearly 1% of A1c seen in the study "translates to a 15% to 20% reduction in risk of heart attack or stroke and a 25% to 40% reduced risk of other complications, such as retinopathy," an eye problem related to diabetes.
How does physical activity fight type 2 diabetes? According to Dr, Sigal, "exercise decreases insulin resistance. It makes the transport of glucose [blood sugar] more efficient."
Cathy Nonas, RD, director of physical activity and nutrition for the New York City Department of Health and Mental Hygiene and a registered dietitian and certified diabetes educator cautions that couch potatoes often need to ease into exercise to maintain a fitness regimen over time.
The study participants built up to their 45-minute fitness sessions, Dr. Nonas noted, and the combination group ended up doing about 4.5 hours of exercise a week—an amount some might find daunting.