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Diabetes and Exercise: The Importance of Regular Activity

Exercise, exercise, exercise — advice that diabetics get all the time. But while any activity is better than none at all, it also is important for diabetics to understand that they should take special precautions before starting any exercise program.

Going from an inactive lifestyle to a sudden burst of activity is not recommended. Indeed, fitness and health experts suggest easing into an exercise plan, especially as diabetics learn what adjustments they need to make to their insulin and dietary habits. A lack of insulin may cause a hyperglycemic effect, and too much insulin can adversely lower blood glucose levels.

But the risks shouldn't scare people away from exercising. Indeed, fitness experts say, there are potentially greater risks associated with not exercising.

"Exercise plays an important role in controlling Type 2 diabetes by reducing both cholesterol levels and weight," says Marlene Coates, a personal trainer and group fitness instructor. Since a vast majority of diabetics are overweight, she says, losing weight through exercise should be a primary goal. According to the President's Council on Physical Fitness and Sports, exercise lowers blood sugar levels and helps the body make better use of its food supply. Exercise also improves blood flow through small blood vessels, increases the efficiency of the heart and may aid in improving the work of insulin.

General guidelines suggest aiming for 30 minutes of aerobic activity at least three times a week. In the early days, you may want to try doing that in three sets of 10 minutes each for three days, or two sets of 15 minutes each, then work up to 30 minutes at a time. And start with something reasonable — a walk at a brisk pace, low-impact aerobics — rather than training for a marathon right away.

Most types of exercise are considered safe for diabetics, except for people with eye problems, who should talk to their doctors before running and participating in other activities that increase pressure on the eyes.

Diabetics also should avoid exercising when their urine ketone level is high or moderate, according to the University of Michigan Health System, because during these times exercise can raise one's ketone level even more. The Health System recommends that diabetics check their urine ketones before exercising if they are not feeling well or if their blood sugar is higher than 250 mg/dL.

Other risks include problems with the feet; diabetics should check regularly for cuts, blisters and infections. Some less common risks include problems related to the heart rate, numbness in the extremities, vision or kidney problems, or pain or fatigue in the arms and legs because of poor supply of oxygen to the muscles.

While exercising and losing weight can have tremendous benefits, the most important thing to consider when exercising is safety. Here are some safety tips:

• Check your blood sugar before and after you exercise.
• Eat before exercising.
• Carry glucose tablets, hard candy or juice with you when you exercise.
• Carry diabetes identification.
• Check with your doctor before beginning a new exercise regimen.

According to the American Diabetes Association, the benefits of exercising are tremendous and necessary. You can increase your metabolism and muscle mass, improve your body's response to insulin, lower your blood glucose levels, increase your ability to lose weight, and reduce your risk of heart disease and stroke.

Adapted by Editorial Staff, February, 2005
Last update, July 2008