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.