Exercise can help control blood glucose, and trim waist size and body fat in diabetics

Diabetics who exercise can trim waist size and body fat, and control blood glucose, even if they don't see cardiorespiratory benefits, new research by UT Southwestern Medical Center cardiologists shows.

Researchers found that waist circumference, percentage of body fat, and hemoglobin A1c levels, a test of long-term blood sugar, all improved in diabetic participants who exercised compared to those who did not. And the beneficial effects of exercise were seen whether they participated in aerobics, resistance training, or a combination of the two compared to a control group that did not exercise.

'What we observed is that exercise improves diabetes control regardless of improvement in exercise capacity,' said Dr. Jarett Berry, associate professor of internal medicine and clinical sciences at UT Southwestern, and co-senior author of the study.

Following an exercise training program generally improves fitness. Researchers typically measure fitness by the ability of the respiratory system to exchange carbon dioxide and oxygen. The more you train, the better your ability to take in oxygen.

But a sub-group of exercisers, considered non-responders, are unable to improve their cardiorespiratory fitness levels despite diligent exercise, explained Dr. Ambarish Pandey, a cardiology fellow at UT Southwestern and first author on the study appearing in Diabetes Care. About 30 percent of exercisers are considered non-responders.

Why does your Blood Glucose go down with Exercise?

If you have Type 1 DM, you are very likely to be on intensive insulin therapy to keep blood glucose under control. Even though this keeps your engine running throughout the day, your glucose levels fall rapidly during exercise, when the body burns carbohydrates at a faster pace.

You may be thinking - if such an intensive therapy causes problems for me during exercise, why in the world am I on it in the first place?

The answer is simple - the tight glucose control afforded by such therapy is very important to prevent long term complications from diabetes.

Using data from the Health Benefits of Aerobic and Resistance Training in Individuals With Type 2 Diabetes (HART-D) trial, researchers looked at whether non-responders who exercised saw improvements in their diabetes control.

'We were interested in the relationship between the change in cardiorespiratory fitness, or exercise capacity, and change in metabolic parameters,' said Berry, a preventive cardiologist and Dedman Family Scholar in Clinical Care.

Researchers divided people into four groups:

Controls, who did not exercise