Exercise has many benefits, including a healthier heart and healthier blood vessels. In addition, it usually helps lower blood sugar by helping the body burn more sugar. This is because insulin works better during exercise.
Exercise can usually be a good way to lower a high blood sugar. However, sometimes it may lower the blood sugar too much. You and your child can avoid problems with changing levels of blood sugar if you keep good records of exercise and blood sugar.
If your child is taking insulin or other diabetes medicines that can lower blood sugar, you need to take precautions against the blood sugar getting too low when your child exercises. You can avoid problems by keeping good exercise records and learning:
Check blood sugars before, during, and after exercise.
The best way to know how exercise affects your child’s blood sugar is to do a blood sugar test before, during, and after exercise. This is especially important if your child has just been recently diagnosed with diabetes or if your child is starting an exercise program. Keep good records of your child’s exercise and the results of blood tests. If your child does the same exercise at the same time of day and with the usual insulin dose and a similar starting blood sugar level, you will learn the effect of exercise on your child’s blood sugar. You will know how insulin and snacks need to be adjusted to avoid low blood sugar. In the records include:
If your child is starting an exercise program or if your child has had a change in medicines, it’s important to track the blood sugar response to exercise. Check blood sugar every few hours until bedtime. It’s also important to do this if your child has changed the type of exercise or how long he or she exercises. The blood sugar may stay lower than usual for several hours.
These records can be very helpful to your child’s provider as she or he works with you and your child to control your child’s blood sugar.
Eat before heavy exercise.
If your child is going to exercise around mealtime, your child should eat the meal before exercising. When it’s possible to choose the exercise time, try to start the exercise 30 to 60 minutes after a meal or snack.
If your child’s blood sugar is less than 100 milligrams per deciliter (mg/dL), he or she should eat a carbohydrate snack (that is, at least 15 grams of carb) before exercise. Test the blood sugar 15 to 30 minutes later. Your child should wait to exercise until the blood sugar is higher than 100 mg/dL.
Have extra snacks handy during exercise.
Your child must always have a source of sugar handy.
It’s often hard to guess the amount of a snack your child will need for a particular activity. If your child exercises within an hour after a meal, an extra snack may not be needed. If your child is not physically fit, the blood sugar may drop more quickly than if your child were fitter. It’s very useful to check the blood sugar to figure out what snack works best for your child. If the blood sugar is low (for example, below 100 mg/dL), your child needs a larger snack than when the blood sugar is high.
The type of snack may depend on the length of the activity.
Extra water is also important, especially in hot weather. A general rule is to drink 8 ounces of fluid for every 30 minutes of vigorous activity. Liquids such as milk, sports drinks, and fruit juices help replace water, salts, and carbs.
It is a good idea to keep packets of cheese and crackers in the glove box of your car for your child to eat before or after an activity. This is especially important if the distance is far between home and the activity.
You may need to change the insulin dose.
Before your child tries a new activity, talk with your healthcare provider about any changes that might need to be made in your child’s insulin doses. Your child should avoid exercising when insulin is working at peak level because that is when it is keeping the blood sugar at its lowest level. Your provider can tell you when your child’s insulin is at its peak. Talk to your child’s provider about adjusting the insulin dose to fit your child’s exercise needs and schedule.
The injection site may need to change.
Your child’s activity and where the insulin is injected can affect how quickly your child absorbs the insulin. Exercise increases blood flow in the part of the body that is moving. The increased blood flow causes a faster absorption of insulin.
Temperature can make a difference.
Make sure others know.
Your child should wear a medical alert bracelet or necklace. If your child is on a team, it’s important for teammates and the coach to know about the diabetes. Make sure the coach and teammates know where sugar snacks are kept. Remember that when your child has a low blood sugar level during a sporting event, he or she needs to rest at least 10 minutes after eating some sugar to let the blood sugar go up.
Delayed hypoglycemia means that your child has low blood sugar several hours after the exercise is over. It may happen as much as 3 to 12 hours after exercise. It may cause an insulin reaction in the middle of the night. If your child is having delayed hypoglycemia after exercise, discuss it with your healthcare provider. You may need to change the medicine dosage or schedule.