Regular, Moderate Exercise Best for Glucose Control in People With Pre-Diabetes

Walking briskly on a regular basis may be more effective than vigorous jogging for improving glucose control in people with pre-diabetes, according to new research published in Diabetologia. The findings are the result of a randomized 6-month study of 150 people, each of whom was designated as having pre-diabetes based on their elevated fasting glucose levels.

Lead author William Kraus, MD, professor of medicine in the Division of Cardiology at Duke University School of Medicine, and colleagues randomized study participants into 4 groups. The first group followed an intervention based on the Diabetes Prevention Program (DPP), which aims to achieve a 7% body weight reduction over 6 months by cutting calories, eating a low-fat diet, and exercising. The participants in this group adopted dietary changes and performed moderate-intensity exercise equivalent to 7.5 miles of brisk walking in 1 week.

Other study participants were randomly assigned to receive exercise only, using different amounts and intensities: low amount at moderate intensity (walking briskly for 7.5 miles per week), high amount at moderate intensity (equivalent to walking briskly for 11.5 miles per week), and high amount at vigorous intensity (equivalent to jogging for 11.5 miles per week).

“We wanted to know how much of the effect of the DPP could be accomplished with exercise alone and which intensity of exercise is better for controlling metabolism in individuals at risk for diabetes,” Kraus said in a statement.

Participants in the DPP group experienced the greatest benefit, with a 9% improvement in oral glucose tolerance, a measure used to predict progression to diabetes. One of the exercise-only groups was a close second. Participants in the 11.5-mile moderate-intensity group saw, on average, a 7% improvement in glucose tolerance. The 7.5-mile moderate-intensity group had a 5% improvement on average. The lowest improvement was experienced by those in the 11.5-mile vigorous intensity group, which showed only a 2% average improvement.

The researchers said the high amount of moderate-intensity exercise alone provided nearly the same benefit on glucose tolerance that we see in the “gold standard” of fat and calorie restriction along with exercise.

“High-intensity exercise tends to burn glucose more than fat, while moderate-intensity exercise tends to burn fat more than glucose,” Kraus noted. “We believe that one benefit of moderate-intensity exercise is that it burns off fat in the muscles, which relieves the block of glucose uptake by the muscles.” This is important because muscle is the major place to store glucose after a meal.

The study suggests that you can achieve nearly 80% of the effect of doing weight loss, diet, and exercise with just a high amount of moderate-intensity exercise.

“I was heartened by the fact that I found out that I can give patients one message and they can get nearly the same effect as when required to exercise, diet, and lose weight all at the same time, Kraus said.