Working out safely with diabetes

August 19, 2010 By Jim Pugliese, exercise physiologist

If you have diabetes, your doctor may have told you to get moving. That's because regular exercise—a brisk, 30-minute walk several times a week, for example—may be as effective as diet and medication in controlling blood sugar levels.

As the main source of fuel for the body, glucose gives your cells energy. For glucose to move from the blood to the cells, it needs the hormone insulin. If you're living with diabetes, your insulin is either deficient or your body doesn't respond to it properly. This can lead to a glucose buildup in the blood, with the cells unable to tap into it for fuel.

But exercise helps. First, when you exercise, muscles contract, allowing for more glucose to enter the cells. Second, physical activity can increase your insulin sensitivity, meaning your body requires less insulin to get sugar into your cells. What's more, since diabetes is often associated with obesity, exercise plays an important role in reducing weight and keeping it off.

Exercise has also been shown to protect against heart disease and nerve damage—two disabling and sometimes deadly complications of diabetes.

Play it safe

If you have diabetes, you need to be careful when working out. But you can still get the full health benefits exercise offers by following these do's and don'ts:

DO speak to your healthcare provider about your best exercise options. For example, if you have foot problems, swimming or gardening may be safer than walking. If you have vision problems, strenuous activities like running, jumping rope and heavy weight lifting should be avoided as they can rupture blood vessels in the eye.

DON'T exercise unless you know your blood-glucose levels. Check your blood-glucose levels before, during and after your workout. If they're high, exercise can make them go higher. In other cases, exercise can cause blood-glucose levels to drop too low. For most, the safe pre-exercise blood glucose range is 100 mg/dl to 250 mg/dl. Never exercise if your fasting blood glucose exceeds 300 mg/dl. Plan to exercise about one to three hours after a meal. This ensures your body will have enough glucose to fuel your muscles. Avoid working out when insulin is at its peak to prevent low blood sugar. Ask your doctor whether it might be wise to carry glucose tablets, candy or sugared drinks with you when you exercise.

DO pay attention to your feet. Many people with diabetes have nerve damage to their feet. Before exercising, wash and bandage any irritated areas. Wear shoes that fit well and check your feet after exercise for signs of injury.

DON'T ignore your thirst. Dehydration can affect blood-sugar levels. Drink before, during and after exercise.

DO wear something that identifies you as having diabetes. In an emergency, a medical ID bracelet or medallion could mean the difference between life and death.

Jim Pugliese is an exercise physiologist and certified health fitness specialist with the Hospital of Central Connecticut Department of Health Promotion.