Exercise is so powerful it’s almost like taking medicine. But a prescription that works for you won’t be ideal for everybody with diabetes. That’s why it’s important to work with your doctor to customize your exercise plan to fit your circumstances, starting with which kind of diabetes you have and how you’re treating it now.
Whichever strategy you choose, you’ll want to bring blood sugar down — but not too far. To keep close tabs on it, test an hour before your workout, then again a half hour later to find out if your levels are rising or falling. If they’re falling and on the low side, you may want to eat about 15 grams of carbohydrate before you start exercising. If your blood sugar is high and rising, you may need more insulin. Once your blood sugar becomes more stable, your doctor may allow you to monitor less often, but self-testing following a workout is always a good idea. The readings you get will help clarify how exercise should work into your overall diabetes-management plan, which will vary from one situation to the next.
People with type 1 diabetes need to approach exercise with extra caution. If you work out too soon after taking insulin, the glucose-lowering tag team of insulin plus exercise can be too much of a good thing and lower your blood sugar to dangerous levels. On the flip side, having too little insulin in your blood while you exercise can make blood sugar build up and potentially cause ketoacidosis. To ensure your safety, check with your doctor about taking steps like the following:
Avoid peak hours. Try to time your workout so that you’re not exercising when insulin activity peaks, often within the first hour or two of an injection, depending on which type you use.
Adjust your dose. You may be able to drop your daily insulin requirements by as much as 20 to 30 percent if you cutyour dose before a workout. Ask your doctor how much of an adjustment to make based on your current dosage and how hard you exercise — then be sure to actually do your workout.
Exercise after eating. You’re less likely to be hit by hypoglycemia if you wait to work out until an hour or two after a meal, when your blood sugar will be naturally high and plenty of glucose will be on hand to fuel your muscles.
Inject into the abdomen. Problem: If you inject insulin into muscles you’ll be using, they will absorb it faster and send your blood sugar plummeting. Solution: Unless you’re going straight into sit-ups, inject into the softer folds of your midsection. If you’re working your abs, wait to exercise until about an hour after your injection to give the insulin a chance to disperse throughout the body.
Have a snack. Eating a small, low-fat snack containing about 20 grams of carbohydrate (two rolled fruit snacks, for example) during your workout can help keep blood sugar from falling too low, especially during vigorous exercise or workout sessions lasting an hour or more.
The great promise of exercise for people with type 2 diabetes is that — unlike with type 1 — it can actually throw the condition into reverse. Boosting your insulin sensitivity could bring your blood sugar back into the normal range, especially if you’re controlling your diet as well, and could permanently reduce the amount of insulin you need — or even get you off insulin altogether.
Some practical advice:
Proceed with caution. While keeping your eyes on the prize — less insulin or none at all — remember to keep your goals reasonable at first. If you’re taking insulin, you stand the same risk of hypoglycemia during exercise that a type 1 person does. Take a look at the above list of recommendations for people with type 1 — they also apply to you.
Try not to snack. If you’re in danger of hypoglycemia during exercise, you may need a snack to bring your blood sugar back up. But this solution can ultimately work against you because it adds calories you’re probably better off avoiding. So instead of relying on snacks to head off hypoglycemia, be diligent about planning to exercise after a meal so blood sugar is high during your workout.
Stick to your meal plan. If you do eat an unplanned snack during your workout, don’t make up for it by subtracting calories from your after-exercise meals. It’s just as important to keep calories up after a workout as before, since exercise can make blood sugar dip dangerously for as long as a day.
If you take a drug like metformin to control your blood sugar, you may be able to get by with less — or stop taking it altogether — by adding more physical activity to your life. Once you figure out how exercise affects your blood sugar, you’ll want to talk with your doctor about how to adjust your drug regimen accordingly. Keep in mind, though, that exercise and diet aren’t automatic substitutes for diabetes drugs — and taking drugs doesn’t excuse you from working out. In fact, drugs often work their best only when combined with other measures, such as meal planning and exercise.
Time your workouts. If you’re using medication, avoid exercising when the drug is reaching its peak effectiveness so that your blood sugar doesn’t drop dangerously low. If you’re working to cut back on or eliminate your drug use, your doctor may start by having you take less (or none) before your workout. In effect, you may be able to exercise in place of taking your medication if the effects on blood sugar prove to be similar.
Be alert to side effects. Some diabetes medications can cause muscle ache or fatigue, while others can make you dizzy or nauseated. Be sure you and your doctor are clear about how intensely you intend to exercise and how your medication’s side effects may limit your activities.
Drink plenty of water. It takes about eight 8-ounce glasses of water a day to keep the body hydrated — and you’ll need more when you’re sweating. Don’t wait for thirst to hit before drinking; that’s a sign of high blood sugar and could bring your workout to a halt while you check for hyperglycemia. Instead, drink one to two cups 15 minutes before exercising, at least a half cup every 15 minutes during your workout, and another one to two cups afterward.
The best evidence for exercise’s effectiveness against diabetes comes from research in people with impaired glucose tolerance. In one University of Pennsylvania study, every 2,000 calories burned per week through exercise dropped the risk of diabetes by 24 percent, with people at greatest risk gaining the most benefits.
To take advantage:
Get started immediately. Just because full-blown diabetes lies “out there” over the distant horizon doesn’t mean you have time to spare. If you don’t start making changes now, insulin resistance is only likely to get worse. But if you jump on the exercise bandwagon right away, you can boost your cells’ insulin sensitivity within a week, even if you’re obese, giving you a good chance of dodging a diagnosis of diabetes.
Track your blood sugar. Don’t assume that because you haven’t developed diabetes you don’t have to worry about blood sugar. You may not need to test as often as a person with a diabetes diagnosis, but you should still keep track of your glucose levels with self-monitoring and regular checkups to make sure your condition remains under control.
Keep it up. It’s just as important for you to keep workouts regular and consistent as it is for a person with diabetes. Controlling the risk of developing the disease will never be easier than it is now — and you should aim to keep it that way.