A brisk pace sidelines diabetes


If you have diabetes and you're a walker, you're a step ahead in combating the effects of your condition. "Exercise helps improve blood-sugar control by making the muscles more sensitive to insulin," says Neil F. Gordon, M.D., Ph.D., M.P.H., author of Diabetes: Your Complete Exercise Guide (Human Kinetics Publishers, 1993). "But even if the blood-sugar level is not affected, we know that exercise reduces the risk of coronary heart disease, which is what most people with diabetes eventually die of."

People with diabetes who aren't insulin dependent (type II) can sometimes normalize their blood-sugar levels completely through exercise and proper nutrition and may never have to take any medication. Those using insulin or oral blood-sugar-lowering medications can often reduce their dosages. People with type-I or insulin-dependent diabetes and those with type II who take medication need to work closely with their doctors to develop an exercise, diet and medication regimen that prevents potentially dangerous bouts of low blood sugar (hypoglycemia).

People with type-II diabetes who aren't taking any medications can feel safe developing a walking program after a complete physical to rule out any heart or neurological problems. Dr. Gordon, formally with the Cooper Institute for Aerobics Research, Dallas, Texas, and now director of preventive cardiology at the Dallas Heart Group and Institute of Exercise and Environmental Medicine, Presbyterian Hospital, gives his patients with diabetes the following exercise guidelines.

"I believe walking is one of the best exercises for people with diabetes," says Dr. Gordon, "Why? Because it is convenient and very easy to control the intensity, which is important: People with diabetes shouldn't go too fast or too slow. Walking is simple, requires no equipment and is very unlikely to cause musculoskeletal injuries."

Research has shown that an energy expenditure of 700 to 2,000 calories per week is necessary to produce major health benefits; in particular, a reduced risk of heart disease. It's important that exercise is spaced evenly through the week. The effect of exercise on blood-sugar regulation seems to last no more than two or three days at the most. So if you walk Monday, Tuesday and Wednesday and slack off the rest of the week, your body will lose some of its sensitivity to insulin and you won't derive optimum benefits from your exercise program in terms of blood sugar. (Cardiovascular improvements and muscle-toning effects last longer.)

To achieve the proper caloric expenditure, you will need to walk 20 to 60 minutes, three to five days a week, at an intensity of 60 to 80 percent of your maximum heart rate. The most accurate way to determine your maximum heart rate is through an exercise stress test. (To estimate your maximum heart rate, subtract your age from 220. For example, if you're 40 years old, your maximum heart rate is 180 beats per minute. Sixty percent of your maximum would be about 108 beats [0.60 x 180] per minute, and you should go no higher than about 144 beats [0.80 x 180] per minute.) This formula may be inaccurate for certain people with diabetes with complications or on medications that slow heart rate.

Remember, if you exercise at a higher intensity, you can spend less time exercising. If you prefer a slower pace, you'll need to spend more time per session or work out more days per week. "If you just stroll, you probably won't improve your insulin sensitivity," says Dr. Gordon. "And if you work too hard, you may actually raise your blood-sugar level. Also, exercising too vigorously may precipitate a heart attack in someone with cardiovascular disease."

Another way for most people to check their exercise intensity is to use the Borg Scale of Perceived Exertion, named after Gunnar Borg, the Swedish exercise physiologist who developed it. (See box on page 102.)

"People with diabetes want to remain in the 12 to 13 area of effort," says Dr. Gordon. "This means you feel as though you are working somewhat hard but not so hard that you can't continue exercising. It's the equivalent of a brisk walk. You should feel energized, not depleted."

You may want to double-check your intensity, especially at first, by calculating your appropriate heart rate to make sure you're within 60 to 80 percent of your maximum, especially if you have any complications or heart disease.

Everyone should learn to warm up and cool down before and after their walk. But it may be more crucial for people with diabetes who also have heart disease. Sudden changes in exertion can cause dangerous arrythmias, which may lead to sudden death.

Five minutes of relaxed walking before and after a brisk session should be enough. If you're not working too hard, you shouldn't need too long a time to cool down.

Dr. Gordon also advises 5 to 10 minutes of stretching before and/or after your walk. "It relaxes you mentally and physically," says Dr. Gordon, "and probably helps to prevent injuries by increasing your flexibility and widening your range of motion." He recommends stretching your calves, hamstrings, lower back, hips and shoulders.

If you're new to exercise in general or walking in particular, give yourself plenty of time to work up to the recommended workouts. Start with just 10 minutes and add 5 minutes every week until you're walking 20 to 60 minutes a session.

Because of problems with circulation or loss of feeling, people with diabetes must be extra careful with their feet. Even minor cuts or infections can lead to gangrene if not treated properly.

Walking doesn't require any equipment, but make sure you have the best pair of walking shoes you can afford and buy them from someone who can fit you. Wear a nice, cushiony pair of socks for additional protection from bruising, abrasion or blisters. Make sure you have those socks on when you buy your walking shoes. Always wear fresh, dry socks and change them right after you walk. It's important to keep your feet dry to avoid athlete's foot. But if they get dry to the point of cracking, you may need a moisturizer. Check with your doctor.

Check your feet every day even if you did not exercise that day. See your doctor if you detect any signs of infection or athlete's foot.

Have your feet checked by your doctor whenever you have an appointment, even if you think they look O.K. In 1985, more than 50,000 amputations were performed on diabetic patients. According to Dr. Gordon, some clinics have reduced the rate of amputations among people with diabetes by 44 to 85 percent just by implementing foot-care education programs. Gangrene is preventable, not inevitable!


Rating of
Perceived How it
Exertion feels
--------- ------
7 Very, very light

9 Very light

11 Fairly light

13 Somewhat hard

15 Hard

17 Very hard

20 Very, very hard
With this scale, by subjectively rating your at-the-moment perception of how the exercise feels to you, you can monitor how hard you're exerting yourself. The ideal range for people with diabetes is 12 to 13. This level of exertion generally keeps your heart working at 60 to 80 percent of your maximum heart rate.


By Maggie Spilner

The symptoms of heart disease can be similar to the symptoms of hypoglycemia and hyperthermia (heat stroke).

People with diabetes are prone to hyperthermia and should refrain from exercise during extreme heat or humidity. They need to be conscious of how the body is reacting to exercise. If any of these symptoms occur, slow down and stop completely, if necessary. If the symptoms have not subsided within 15 minutes of stopping, contact your doctor immediately. Definitely see your doctor before resuming exercise. Symptoms include:

Pain or discomfort in the chest, abdomen, back, neck, jaw or arms
Nausea during or after exercise
Unaccustomed shortness of breath during exercise
Dizziness or fainting
Irregular pulse, especially if it's been regular in past exercise sessions

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