According to the American Diabetes Association (ADA), physical activity can help make your blood cells become more sensitive to insulin, allowing the treatment to work more effectively. Exercise can also help your cells remove glucose from your blood, which means lower blood sugar levels and improved A1C. And, of course, exercise can help you improve your overall health, maintain a healthy weight, reduce your risk for heart disease and stroke, and lower stress, among other important considerations when you have type 1 diabetes. “Exercise is really important for everybody, not just people with diabetes or at risk for diabetes,” says Anders L. Carlson, MD, medical director at Park Nicollet International Diabetes Center in Minneapolis. “Physical activity can help keep your body and in particular your cardiovascular system healthy, and it’s also good for your overall well-being and improving sleep, as well as other things we might not associate directly with exercise,” he says. “For folks with diabetes, we also are concerned about their blood sugar, and exercise is good for maintaining healthy blood sugar levels.” However, there can be risks associated with physical activity when you have type 1 diabetes. Those with the condition can develop hypoglycemia (low blood sugar) during or after exercise, especially if they don’t adjust their carbohydrate intake or insulin dose to account for physical activity. Hypoglycemia can lead to serious health complications, and even death. A fear of low blood sugar may cause some people with type 1 diabetes to avoid exercising altogether. “Although we strongly urge patients with type 1 diabetes to exercise regularly, we emphasize the importance of doing it smartly,” Dr. Carlson explains. “Exercising with type 1 diabetes requires some planning and thought, because of the risk for hypoglycemia.” Try these tips to maintain healthy blood sugar levels before, during, and after physical activity and to overcome any fears you have about exercising with type 1 diabetes.
Monitoring Matters
It’s always important for those with type 1 diabetes to carefully monitor their blood sugar levels, but it’s particularly vital when exercising. Carlson recommends you: Check blood sugar before exercising. Check blood sugar to ensure it’s at an appropriate level to start activity. According to Carlson, the target range, based on ADA guidelines, is usually 90 mg/dl to 250 mg/dl. However, “expect some trial and error,” he says. Different people respond to physical exertion in different ways. What’s more, your own response can vary based on the type of activity, what you’ve had to eat, when you took insulin, the time of day you exercise, and even stress. “Find out what works for you for different activities,” Carlson notes. For instance, if you’re going to be doing very aerobic exercise, like running, and tend to experience blood sugar crashes during or after that activity, try to get your levels toward the higher end of the target range before starting. “This usually means eating 10 to 15 grams or more of carbs beforehand,” Carlson says. “I also recommend working with your diabetes team to decide how and when a decrease in the insulin dose would help avoid hypoglycemia with exercise. For instance, if you are going to do 30 minutes of moderate-intensity aerobic exercise one to two hours after a meal, you may want to reduce your meal bolus insulin by about half.” Carlson adds that it’s helpful to keep a log of timing and amount of insulin, type and duration of exercise, and how your blood sugar responds. This way you can identify patterns and learn how your body reacts to activity. Monitor blood sugar during exercise. Monitoring blood sugar during exercise is also important, particularly if you’re newly diagnosed with type 1 diabetes or trying a new activity. “Because stopping an activity to check blood sugar isn’t always practical, or safe, I often recommend using a continuous glucose monitor during exercise,” Carlson says. “This technology not only tells you what your levels are at a given moment, but it can also tell you how they’re trending, whether they’re going down or up the more you exercise or if they’re remaining stable.” If you’re noticing a downward trend on your continuous glucose monitor, you can take a break and have a snack, like a granola bar, to add carbs and get your levels back into the normal range. Check blood sugar frequently after exercise. Heavy or prolonged exercise can cause levels to drop hours later, and even while you sleep, meaning you could be at risk for hypoglycemia overnight and into the morning after physical activity. For this reason, Carlson suggests that those with type 1 diabetes avoid exercising late at night, and schedule all activities at least two hours before bedtime. “And if you know exercise lowers your blood sugar, plan meals for afterward accordingly,” Carlson adds. A meal or snack with a good mix of carbs, protein, and fat can help keep blood sugar stable, he explains. In addition, depending on how exercise affects you, it may make sense to reduce overnight insulin to help prevent a delayed low. Of course, you should work with your care team to develop a plan that works for you and your lifestyle.
Have Carbs Ready
Another key to preventing your blood sugar from lowering to dangerous levels during exercise is being prepared. This includes: Eating well and staying hydrated. Eating before and after exercise can help prevent lows. Staying hydrated is also important, especially if you tend to have high blood sugar during or after exercise. Certain medications like blood pressure medications can also be a risk for dehydration. If you’re prone to hypoglycemia with exercise, Carlson recommends having a snack that contains 15 to 30 grams of carbs before exercise. If you plan to exercise for an hour or more, you should also include some protein in your pre-workout snack. A good option: half of a peanut butter sandwich. Be ready for a glucose fix. According to the ADA, people with type 1 diabetes should always have a healthy and fast-acting source of glucose, such as juice or glucose tabs, on hand when they exercise. Target for a snack that will give you 15 to 20 grams of carbs quickly, like a small packet of raisins or rice cake. Carlson suggests following the “15-15 rule.” This means, if you notice your blood sugar levels dropping, perhaps on your continuous glucose monitor, during exercise, stop your activity, eat 15 grams of carbs, and wait 15 minutes before checking your blood sugar level again. If it’s still low, repeat these steps every 15 minutes until your blood sugar is in a healthy range to start exercising again.
Prepare for Emergencies
The type of insulin you use can also affect your body’s response to exercise, Carlson says, so be sure to: Avoid exercise during peak insulin action. If you take fast-, short-, or intermediate-acting insulin, it’s best to avoid physical activity when your insulin action is at its peak, which may be anywhere from 30 minutes to several hours after taking it, the ADA says. Talk to your care team. Because of these and other considerations, Carlson emphasizes that it’s important to talk to your healthcare team about developing a healthy exercise plan, and adjusting both your exercise plan and your treatment schedule if low blood sugar interferes with your workout routine. “I also suggest that people with type 1 diabetes wear a medical alert bracelet or other type of device when they’re exercising, particularly if they’re exercising alone,” Carlson explains. “If people see them having a problem, they’ll know that it’s an emergency and how to deal with it.” If you plan well and take the necessary steps, however, Carlson says an emergency is unlikely. Still, anything that gives people peace of mind so that they can get out there and exercise is a good idea, he adds.
