How Does Exercise Affect Diabetes?

Exercise helps improve glucose control. With exercise, the body becomes more efficient at using glucose. Exercising regularly can improve your quality of life, sleep, mood, and how you do in school. It is recommended that all kids exercise or engage in any physical activity 60 minutes daily on most days of the week. If you don’t play a sport, you can jump rope or use a hula hoop. Your local library may have exercise DVDs. You can also find exercise videos on TV or on Youtube. When there is snow on the ground, go sledding or build a snowman. Exercise can be fun! Approaches to exercise vary according to whether you receive insulin by injection or by pump therapy. Diabetes management for exercise also varies whether the activity is spontaneous or if it is planned. It is always wise to check a blood glucose level before exercise, often during exercise, and again after exercise.

Most people know that exercise lowers the blood glucose level. So, you have to eat extra carbs or plan ahead by reducing the insulin dose. If exercise is consistent on a daily basis, it may not be necessary to adjust the insulin dose downward, as your insulin plan will likely have already incorporated the daily, consistent exercise routine into the dosing. There are a few rules of thumb. For example, if you are going to exercise, it is important to check your blood glucose level to ensure that it is not extremely high or low. If your blood glucose exceeds 300 mg/dl, check for ketones because you should not exercise with ketones. A high blood glucose with ketones means that there is a need for MORE insulin. If the blood glucose is low, do not exercise until the blood glucose is back in the target range by eating some carbs. Next, consider the planned duration of exercise. As a rule of thumb (if the glucose level is in range at the start of exercise), a person needs 1/4 –1/2-1 gram of carbs per minute of moderate to vigorous physical activity, depending on the age and size of the child. So, if a child will be attending a 60 minute soccer practice, s/he will likely need to eat 15-30 grams of carbs to prevent low glucose during the activity level, if the insulin dose has not been decreased in advance of the exercise. Since exercise can lower blood glucose even hours after the activity is over (the lag effect of exercise), often happening overnight, be sure to check your blood glucose often. Discuss your activity plan with your health care team or see one of the Joslin exercise physiologists by calling 617-309-2440 (these visits are often covered by insurance).
-Jacqueline Shahar, M.Ed., RCEP, CDE and Georgia Feuer, BA

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