Exercise & T1D
Whether you’re new with diabetes or you’ve been dealing with it for a while, managing diabetes during exercise can be a daunting task. Exercise can add an unknown factor into your life, just when you thought you were figuring things out. Will your blood sugar go high when you start running after drinking that juicebox or will you go low because your body is still burning carbs a few hours after your workout?
Exercise has many unknowns but here at the U-M Pediatric Diabetes Clinic, we're here to help give your brain a break. Exercise is incredibly important for maintaining a healthy lifestyle, especially for people with diabetes. Exercise benefits the heart, which is beneficial to people with diabetes, as well as improving your ability to absorb and respond to insulin.
Your Results May Vary
T1D is a fickle beast, so it can be hard to predict how exercise and activity will impact each person. Plus, different types of activity affect your blood sugar in different ways.
We recommend that you check your blood sugar before you start exercising, during exercise when possible, and afterwards to avoid the possibility of an extreme blood sugar event. There is no one-size-fits-all solution to handling exercise corrections, so talk to your team about how to establish best practices for you and your routine. The good news is that the more routine your exercise regimen, the easier it will be for you to find the habits that work best for you! Being healthier means better control, and exercise will help you with that goal.
Whichever way your blood sugar trends when you exercise, these are the supplies you should have on-hand:
Juice or glucose tablets for treating low blood sugar (note: sports drinks may have high sugar content, but do not typically work as fast as other means of glucose delivery)
Your glucagon kit in case of emergencies
Insulin! Always bring more than you need in case of emergencies (pump failure, expired vials, etc). Check out Frio pouches to keep it cool during outdoor events. Even if you use a pump, make sure to bring your long-acting insulin in case of pump failure.
Spare pump supplies, if you use one (check if your pump is recommended for use during activity)
Your blood sugar meter and/or CGM, if you use one
Blood sugar test strips for your meter
Alcohol prep wipes, sticky adhesive, and tapes - especially helpful for physical activities or difficult terrain like sand
Plenty of water
When Your Blood Sugar Takes a Dive
Aerobic, endurance exercises like jogging, walking, or swimming will burn carbohydrates in your system and cause your blood sugar to fall. The risk for hypoglycemia increases if you skip a meal or exercise for a long time. It's important to have a source of fast-acting sugar with you at all times, especially during exercise. You should also have access to glucagon during workouts or sporting events - let others know where it is and how to administer it.
When Your Blood Sugar Goes Rock Climbing
High-intensity, anaerobic exercises like sprinting, climbing, or weight-lifting can increase your blood sugar when adrenaline levels rise. This adrenaline surge can also cause you to experience delayed lows several hours after the exercise has ended. You should perform blood sugar checks at midnight and 3 AM after intense activity to watch for delayed lows. Keep insulin on hand, and talk to your care team about possible insulin adjustments to suit your activity schedule. Be sure to keep the insulin stored at the correct temperature if you will be outdoors!
Tips for Exercise
If all this seems like a lot to keep track of, we hope we can help you feel at ease with some tips for handling exercise with T1D:
Before your Activity
Snack smart! If you notice your blood sugar tends to drop during or after exercise, it's important to have some carbs beforehand. To keep your blood sugar steady for as long as possible, it's best to choose a snack that includes complex carbs with protein. Complex carbs are high in fiber, and when combined with protein, they provide a steady source of energy. Here are some tasty snack ideas that include complex carbs and protein: whole wheat toast with peanut butter, cottage cheese with fruit, edamame, or low-fat cheese with whole wheat crackers. Check out our Physical Activity and T1D handout for guidelines about how many grams of carbs you should have before exercise based on the duration and intensity of the activity.
Fuel up! You've probably heard the term "carbo-loading." While it is true that your body needs time to fuel up with carbohydrates and store glycogen, that doesn't mean you should binge on pizza and candy! Maintain a healthy diet of grains and vegetables and avoid cramming on the day of your event.
Stay in the know! T1D athletes often find themselves increasing the number of finger pricks and blood sugar tests before an event. Many athletes with T1D, like Tim Atkins, suggest maintaining normal insulin levels in the 2-4 hours before you exercise and then raising blood sugar 30 minutes beforehand with energy gels or sports drinks.
Time your insulin! If you dose insulin right before exercise, you increase the risk that you will go low during the activity. Your muscles use the sugar in your body for energy, and once it runs out you will feel the effects of hypoglycemia.
During your Activity
Gear up! As an athlete with T1D, you have a bit more equipment to carry than your teammates or opponents. Make sure you have the supplies listed above in addition to your sporting equipment. Our T1D families find it helpful to make a checklist of items that you can leave by the door or in your locker at school.
Stay vigilant! Be aware of the intensity and length of your workout. Remember the differences between aerobic and anaerobic exercises, listed above. If you will be out for a jog, be sure you know your route and approximately how long you will be away so you can tell someone. Keep carbs on hand and take breaks to check your blood sugar so you won't go low.
Study the field! You should always be aware of the conditions where you're exercising. Things like the temperature and humidity can affect your body's consumption of glycogen which will cause you to go low much quicker.
Learn to listen! Don't try to force your body to do anything extreme or conform to what you think is right. As you exercise and become used to living with T1D, you'll be able to develop a routine and find what your preferred habits are. Talk to your care team and let them help you with some advice.
After your Activity
Refuel! After exercise, it's important to replenish your body's glycogen stores by eating carbs. Maintain a healthy diet and include some "slow" carbs - foods with carbs as well as fat or protein - to keep a steady blood sugar. You may want to consider leaving some carbs uncovered after your exercise to prevent the effects of delayed lows. It will be easier to learn your habits with regular exercise. It's also important to stay hydrated to ensure that carbs and insulin is absorbed properly.
For more tips about how to handle aerobic, anaerobic, and mixed exercise, check out this JDRF article.