Diabetes and Exercise

Article by Kristi Tuck, BS, ACSM
Posted on March 06, 2007

Exercise is an important part of any diabetes treatment program. However, if you are a diabetic it is important that you do a couple of things before getting started. To avoid potential problems, make sure that your doctor has consented to having you participate in an exercise program. Next, make sure that you check your blood sugar before, during and after exercise.

Exercise can help improve your blood sugar control; this is why diabetes and exercise go hand in hand in the management of diabetes. Remembering to check your blood sugar before, during and after exercise will reveal how your body responds to exercise so that you can monitor your activity accordingly.

BEFORE EXERCISE: Check your blood sugar.

Remember, before becoming more active it is important to get your doctor’s OK to exercise, especially if you have been previously sedentary. Discussing your goals and plan of action with your health care professional is important. Knowing the best time to exercise as well as the potential impact of medications on your blood sugar before you become more active is really important to good blood sugar control.

If you are taking insulin or medications that can cause low blood sugar (hypoglycemia), test your blood sugar 30 minutes before exercising and once again immediately before exercising. This will help you determine if your level is stable, rising or falling and, if it is safe to exercise.

These are general guidelines:

• Lower than 100 mg/dL. Your blood sugar may be too low to exercise safely. Eat a small carbohydrate snack before you begin your workout.
• 100 to 250 mg/dL. You are good to go. For most people, this is a safe pre-exercise blood sugar range.
• 250 mg/dL or higher is a caution zone. To make sure it is safe, you should test your ketones. If you have a high level of ketones in your urine, wait to exercise until your levels drop.
• 300 mg/dL or higher. Your blood sugar may be too high to exercise safely, putting you at risk of ketoacidosis. It is best to postpone your workout until your blood sugar drops to a safe range.

During exercise, low blood sugar can be a concern. If you are planning a longer workout, check your blood sugar every 30 minutes, especially if you have made changes to your current workout program. With any changes in activity, speed, duration or intensity, it is important to monitor your blood sugar more closely.

If you are a beginner, the best exercise to start with is walking. Walking is an excellent activity that almost anyone can do. As I have previously stated, the important thing about walking, or any activity, is your shoe wear. As a diabetic, it is extremely important that you buy and maintain proper shoe wear for your activity. Spend the extra time and money to make sure you are in the most comfortable, supportive shoe there is. Make sure that you check you feet often for sores and abrasions that may be appearing due to rubbing socks or improperly fitted shoes.
Once you have found your activity and have purchased the appropriate gear to get started, you want to make sure that you increase gradually. Once your body has become accustomed to an activity, it is time to increase the frequency, intensity or duration of that activity. The best guideline is to increase about 10% a week and no more.

AFTER EXERCISE: Check your blood sugar
Once you are done with your activity, check your blood sugar right away and then several times during the next few hours. That is why it is important to find the right time to exercise. You don’t want to exercise late at night and then go home and go to bed. Exercise draws on reserve sugar stored in your muscles and liver. As your body rebuilds these stores, it takes sugar from your blood. Low blood sugar is possible even hours after your exercise session has ended.

The bottom line is that if you have diabetes, you should be exercising under the care of your physician. Everyone begins at a different level, find your level and begin to increase your activity over time and you will see amazing results.