Stay fit safely: 4 tips for people with diabetes

Staying physically active is a powerful tool for managing diabetes—but as with any tool, you want to use it safely. These four tips can help you do just that.

Get a "preflight" check

Talk with your doctor before you start or change a fitness routine. This is especially important if you are overweight or have a history of heart disease, peripheral vascular disease, or diabetic neuropathy.
Current recommendations include a complete physical exam and possibly an exercise stress test for people who are 35 or older and who have had diabetes for more than 10 years. This test measures your heart's performance and your blood pressure while you walk on a treadmill for about 10 minutes. The results can help determine the safest way for you to increase physical activity.

Spread your activity throughout the week

The U.S. Department of Health and Human Services urges that adults aim for a weekly total of at least 150 minutes of moderate aerobic activity, or 75 minutes of vigorous activity, or an equivalent mix of the two. While the guidelines don't spell out how many days a week you should exercise, experts recommend being active at least three to five days a week.

Time your exercise wisely

In general, the best time to exercise is one to three hours after eating, when your blood sugar level is likely to be higher. If you use insulin, it's important to test your blood sugar before exercising. If it is below 100 mg/dL, eat a piece of fruit or have a small snack to boost it and help you avoid hypoglycemia. Test again 30 minutes later to see if your blood sugar level is stable.

It's also wise to check your blood sugar after any particularly grueling workout or activity. If you use insulin, your risk of developing hypoglycemia may be highest six to 12 hours after exercising. Experts also caution against exercising if your blood sugar is too high (over 250).

Be prepared

Should you experience a medical problem while exercising (or at any time) it is important that the people who care for you know that you have diabetes. One easy way to do that is to wear a bracelet, watch, or other jewelry item or accessory that indicates you have diabetes (and whether you take insulin). Also keep hard candy or glucose tablets with you while exercising in case your blood sugar takes a sudden nosedive.

For more information on preventing, diagnosing and managing diabetes, purchase Diabetes: A plan for living by Harvard Medical School