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I am fifteen years old and currently on four injections. I was wondering if you could please give me suggestions on adjusting insulin and food intake while doing exercise.


This question was answered by several of the members of the Diabetes Team:

Answer from Ms. Schwartz and Dr. Quick:

Here's a list of suggestions:

  • Be sure to check your blood sugar before and after exercise, regularly. It would also be very helpful to check one hour before, as well as immediately before exercise, so you can tell which way your sugar is heading!

  • Usually, people with four injections a day are taking Regular insulin before meals as part of their program. We suggest that people on pre-meal Regular decrease the dose of Regular at the meal before the exercise by one-half. Sometimes the dose of Regular at the following meal also needs to be decreased (depending on the blood sugar level at that time).

  • Use the abdomen or buttocks (rather than an extremity that you'll be using during the exercise) for your shot before exercise.

  • If your exercise will occur a long time after a meal, be sure to have a snack that's high in carbohydrates before starting the exercise.

  • Of course, it would be smart to carry some carbohydrate food with you while exercising, in case you feel like you're starting to crash. And, if it's prolonged exercise, when thirsty, we advise drinking fruit juice or a commercial product like Gatorade, instead of pure water, to help keep your sugar level up.

  • For more information about carbohydrates and exercise, look at the discussion on the Internet about ExCarbs.

  • Ideally, it would also help if your exercise were at the same time every day (though this isn't realistic for most people).


Answer from Dr. Lebinger:

When you have extra exercise, you need to either eat more food and/or decrease the insulin working at the time of the exercise to prevent a low blood sugar. How you handle this will depend on the amount and intensity of exercise. For prolonged, intense exercise, you might need to eat small amounts of concentrated carbohydrate every half hour to one hour. For less intense, shorter exercise, you may do better with a combination of carbohydrate and protein eaten before. Best to discuss the specifics with your own physician and/or dietician.

Exercise increases the need for fluids. I often suggest drinking either a sugar free liquid such as water or a low carbohydrate liquid such as Gatorade. This way you can separate your fluid needs from your sugar needs. If you drink water, you drink it freely without worrying about how much sugar you are eating. If you are low or your blood sugar is dropping, then you may need fruit juice. Otherwise, you may want to get your extra carbohydrate from non-liquid food if you want it to last a work a little more slowly and last a little longer.

In some people exercise lowers the blood sugar many hours later instead of during or soon after the exercise. In this case, you may need extra food or less insulin several hours after the exercise. Remember to carry some concentrated, fast acting source of sugar for emergencies (tubes of cake decorating jel are light weight, don't take up a lot of room, and don't spoil easily).

Be prepared and have fun!


Original posting 1 Jun 96


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Last Updated: Tuesday April 06, 2010 15:08:52
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