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Diabetes: Exercise



  • Having diabetes means that there is too much sugar (glucose) in your child’s blood. Exercise helps your child’s body burn more sugar and use insulin better. Exercise can help your child lose weight and keep a normal weight. It also helps lower blood pressure and keep blood fat levels normal.
  • Make sure you talk with your child’s healthcare provider before your child starts an exercise program.
  • If your child takes insulin or other diabetes medicines, be careful that his blood sugar doesn’t get too low when he exercises. Your child can avoid problems by keeping good exercise records and learning when to check his blood sugar and how to adjust medicine, what he eats, and his exercise schedule.


What is diabetes?

Having diabetes means that there is too much sugar (glucose) in your child’s blood. The body breaks down some of the foods your child eats into sugar. The blood carries the sugar to the cells of the body. Your child needs some sugar in the cells for energy, but too much sugar in the blood is not good for your child’s health.

Diabetes is caused by a problem with the way your child’s body makes or uses insulin. Insulin is made by the pancreas, which is an organ in the upper belly. Your child’s body uses insulin to help move sugar from the blood into the cells. When your child does not have enough insulin or your child has trouble using the insulin the body makes, sugar cannot get into the cells and builds up in the blood.

Why is exercise important when my child has diabetes?

Exercise helps your child in many ways:

  • It helps the body burn more sugar. Your child’s body is able to use insulin better during exercise. As a result, exercise usually helps lower blood sugar.
  • Your child will feel better. Your child will have more energy and tire less easily. Exercise can also lift your child’s mood when he feels down and help reduce stress.
  • It helps keep the body in good shape. Exercise can help your child lose weight and keep a normal weight. It also keeps the muscles and bones strong.
  • It helps keep the heart rate and blood pressure lower. This helps prevent stroke and problems with the heart, eyes, and kidneys.
  • It helps keep blood fat levels normal. Many people with diabetes have high levels of blood fats (cholesterol and triglycerides). High blood fats can lead to early aging of blood vessels. Exercise and a healthy diet are the best ways to keep blood fats low.
  • It helps your child have normal blood flow to the feet. This can help prevent foot problems.

Which kinds of exercise are best?

The best exercise is exercise your child enjoys. It’s easier to make a habit of exercising if your child enjoys the activity. If your child has eye problems, talk to your child’s healthcare provider before your child starts a new activity. Boxing, jogging, or weight lifting may increase the risk of eye injuries.

Warming up and cooling down

Muscles that are warmed-up before exercise are more flexible and less likely to be injured. Brisk walking, easy jogging, or jumping jacks are good ways to get muscles warm and ready to go. After your child’s muscles are warmed up, he may also want to stretch. Stretching after exercise is more important than stretching before exercise. It decreases the risk for being sore or injured. When your child is ready to stop, it’s good to cool down by gradually slowing his activity.

Aerobic exercise

Aerobic exercise increases breathing and heart rate. This is important because it helps keep your child’s heart and lungs healthy. Examples include walking, swimming, riding a bike, and dancing. If your child has nerve damage or foot problems, it’s best to avoid walking long distances and treadmill or step exercises. Instead, he can try activities like bicycling or swimming.

A healthy goal for children is to exercise for 60 minutes every day, in addition to regular activities. Your child doesn't need to do 60 minutes of activity all at once. He can do shorter periods, at least 10 minutes each time. He should aim for a moderate level of effort that lets him talk while moving, but without getting out of breath.


Exercise to strengthen all major muscle groups (legs, back, chest, belly, and arms) is recommended for most people. It includes weight lifting, stair stepping, carrying groceries, doing sit-ups or push-ups, and exercising with large elastic bands. Strength training can help your child control his blood sugar. Muscle mass burns more calories than fat, so as muscle increases, so does your child’s ability to burn calories. A healthy goal is to do strengthening exercises on 2 days each week (skip at least 1 day in between). However, this kind of exercise can be harmful if your child has certain medical conditions, such as high blood pressure. Always check with your healthcare provider about the best exercise program for your child.


Flexibility exercises can help your child move about more easily and have better posture. Being flexible makes it easier to do many activities and also decreases the risk for getting hurt. Examples include stretching, yoga, and tai chi.

How do I get my child’s exercise program started?

Try to be a good example by exercising regularly yourself. It helps if you can have fun with your child in the activity.

  • Make sure you talk with your child’s healthcare provider before your child starts an exercise program.
  • It’s always best to start a new exercise program slowly. Your child can slowly increase how long and how hard he or she exercises.
  • If your child is taking insulin or other diabetes medicine, ask your provider when the blood sugar needs to be checked. Also ask if your child should check for ketones, and how doses of insulin may need to be adjusted before and after exercise.
  • Keep sugar tablets or a high carbohydrate and protein snack (such as crackers with cheese or peanut butter) on hand in case your child’s blood sugar drops during or after exercise.
  • Protect your child’s feet during exercise. Make sure your child’s socks and shoes fit well. Check your child’s feet every day. Watch for blisters, warm areas, or redness. If your child has any kind of sore on the feet, see your child’s provider right away. If your child has foot problems cause by diabetes, bicycling or swimming may be safer than walking or running.

When should my child avoid exercise?

If your child has type 1 diabetes, vigorous physical activity should be avoided if urine or blood tests are positive for ketones. If the urine ketone level is large or moderate, exercise can raise the ketone level even more. Check the urine for ketones before exercise if your child is not feeling well or the blood sugar is staying higher than recommended by your healthcare provider. Your child can usually still exercise when blood sugar is high as long as he or she feels well and there are no ketones in the blood or urine.

Avoid exercise when it’s very hot or very cold. Ask your child’s healthcare provider if there are other times when your child should not exercise—for example, when your child feels sick or has a fever.

How can I help prevent low blood sugar reactions during exercise?

If your child is taking insulin or other diabetes medicines that can lower blood sugar, you need to be careful that his blood sugar doesn’t get too low when he exercises. You can avoid problems by keeping good exercise records and learning:

  • When to check the blood sugar
  • How to adjust your child’s medicine, what your child eats, and the exercise schedule

Check blood sugar before, during, and after exercise.

This is especially important if your child has just been recently diagnosed with diabetes, is starting or changing an exercise program, or has had a change in medicines. Keep careful records of your child’s exercise and blood tests. If your child does the same exercise at the same time of with the usual meal schedule, 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:

  • The date and the time your child started exercising
  • Blood sugar levels:
    • Just before exercise
    • After 15 minutes of exercise
    • After 30 minutes of exercise, whether your child is still exercising or finished
    • Right after exercise
  • What the last dose of insulin or medicine was before exercise
  • The time your child took insulin or medicine
  • The time your child stopped exercising

Check blood sugar every few hours until bedtime. Your child’s blood sugar may stay lower than usual for several hours. 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. It’s not understood why this happens in some children who use insulin to help control their blood sugar.

Eat before and during exercise.

If your child is going to exercise around mealtime, your child should eat the meal before exercising. It’s best to exercise 30 to 60 minutes after a meal or snack.

  • The body absorbs liquids more quickly than solid food. Liquids generally prevent low blood sugar reactions for just 30 to 60 minutes after your child drinks them.
  • The body digests solid foods more slowly. Solid foods usually keep your child’s blood sugar level up for at least 2 to 3 hours.

Have extra snacks available during exercise.

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. If the blood sugar is low, 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.

  • Your child should always have a source of sugar handy. Keep sugar packets, sugar cubes, or glucose tablets with you for an emergency. The effects of a sugar packet on the blood sugar may last only a few minutes.
  • Snacks such as milk or juice are used for short-term activities of 30 to 60-minutes because they are quickly absorbed. Milk is better than juice because it has protein. Add more food, such as crackers or bread, if the activity is going to last longer.
  • Snacks that include protein and fat along with carbohydrate are good for long-term activities. Combining sugar and protein will help keep the blood sugar up for a longer time. Keep a sandwich or similar snack, like peanuts, a granola bar, or cheese, nearby. It is a good idea to keep packets of cheese and crackers in the 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.

Extra water is also important, especially in hot weather. A general rule is to drink 8 ounces of liquid for every 30 minutes of vigorous activity. Liquids such as milk, sports drinks, and fruit juices help replace water, salts, and carbs.

You may need to change the insulin dosage or injection site

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.

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.

  • If insulin is injected into an arm or leg that your child will be using a lot during exercise, your child’s body may absorb the insulin too fast. For example, if your child is going to run, don't inject insulin into the leg. If your child is going to play tennis, avoid injecting into the tennis arm.
  • The belly is usually a good injection site before strenuous exercise.

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. 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.

Temperature can make a difference.

  • High temperature tends to spread insulin more rapidly through the body. If sports activities are done outdoors on a hot day, there may be a higher risk of low blood sugar.
  • Low temperature tends to decrease how quickly insulin is absorbed. Keep this in mind when exercising outdoors on a cold day.
  • Results of blood glucose meters may not be accurate in very hot or cold temperatures.
Developed by Change Healthcare.
Pediatric Advisor 2018.1 published by Change Healthcare.
Last modified: 2017-01-28
Last reviewed: 2017-01-27
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2018 Change Healthcare LLC and/or one of its subsidiaries
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