Diabetes and Exercise:  Get the Facts

Getting fit? Or at least trying to? You’re smart to make exercise a part of your daily routine. The Physical Activity Guidelines for Americans recommend that adults get a minimum of 150 minutes of moderate-intensity aerobic exercise (such as dancing, brisk walking, and playing soccer) on a weekly basis. For school-aged children, the aim is to get a minimum of 60 minutes each day (1).

But do these recommendations also hit the mark for people with diabetes? You bet they do. However, if you or your loved one has diabetes, take an extra precautionary step before lacing up your trainers. We’ll show you how.

Benefits of Exercise

Exercise packs a powerhouse punch in terms of benefits. It can improve your mood, promote heart and bone health, help you to maintain a healthy body weight and increase insulin sensitivity, which is important for better blood sugar control. Besides these health benefits, exercise is fun! Or at least it can be.  Remember when we were all small kids, running around outside for hours? It was technically “exercise” but it was more “fun,” and we can bring that feeling back. For example, if you don’t like playing soccer, no problem. Instead, go on a brisk walk with a friend and get some social time in. Any physical activity is better than no physical activity!

Before Exercising

Before exercising, it’s important to do a few things:

• Consult your doctor to make sure exertion is something your body can tolerate.
• Check your blood sugar level and if necessary, do what is appropriate to regulate it.
• Choose an activity that accounts for your body’s current state of ability.

Even though everyone’s “sweet spot” is different, generally speaking, you should not exercise if your blood sugar is below 100 mg/dL or higher than 250 mg/dL (2,3). If your blood sugar is lower than 100, you’ll need to eat something prior to working out. You may need anywhere between 15-30 grams of carbohydrates, depending on your age and activity level. A little trial-and-error can help you identify what your body needs. Options such as 8 ounces of milk, a yogurt cup, and 1/2 of a medium-sized banana are about fifteen grams of carbs each.

On the other hand, if your blood sugar is higher than 250 mg/dL, proceed with caution and check your ketones. Ketones are alternative fuels your body makes and uses when glucose (derived from the food you eat) is in short supply (4). If your ketones are high, do not exercise–especially if engaging in vigorous activity such as cycling, jumping rope, or swimming.

Also, have a plan. You may experience low blood sugar during exercise, so have a snack readily available. Children engage in a lot of unplanned physical activity (see aforementioned “fun”). This is common and expected. As a best practice, pay attention to your child’s blood sugar levels and have a snack readily available for every 30 minutes of continuous activity.

After Exercising

Exercise can drop your blood sugar levels long after the workout has ended, also known as a lag effect. It’s important to test your blood sugar immediately after working out and to do so frequently.  Continuous glucose monitors (CGMS) are useful tools in helping keep a watchful eye on blood sugar trends before, during, and after exercising. Frequent testing affords you the liberty of knowing in which direction your blood sugar levels are headed—increasing, decreasing, or stable. Additionally, since exercise impacts insulin sensitivity, you may need to reduce your insulin doses to prevent hypoglycemia. Hypoglycemia is defined as having a blood sugar level lower than 70 mg/dL (5). Symptoms of hypoglycemia include shakiness, sleepiness, and confusion, to name a few.

Bottom Line

Exercise is safe and effective for people who have diabetes. It’s a good idea to check with your doctor and healthcare team before engaging in any form of physical activity, just to make sure you have your bases covered. But the most important part is to get moving, stay healthy, and have fun!

References:

1. Physical Activity Guidelines for Americans
2. Exercise and Type 1
3. Diabetes and exercise: When to monitor your blood sugar
4. High blood sugar and ketones
5. Low Blood Glucose (Hypoglycemia)

Clinically reviewed by Marissa Town, RN, BSN, CDCES