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Sports, Exercise, and Diabetes

Medically reviewed by: Steven Dowshen, MD

People with diabetes can exercise and play sports, just like everyone else. Whether you want to go for the gold or just go hiking in your hometown, diabetes shouldn't hold you back.

How Exercise Helps People With Diabetes

Exercise offers many benefits. It:

  • strengthens bones and muscles
  • reduces your risk of heart disease and some types of cancer
  • improves coordination, balance, strength, and endurance
  • can increase your energy level
  • helps insulin work better in the body, which helps blood sugar levels stay in a healthy range
  • burns calories, which helps you reach and stay at a healthy weight
  • teaches you about teamwork, competition, and courage
  • helps boost self-esteem and confidence
  • relieves tension and stress, relaxes you, and boosts your mood, too
  • can even help you clear your mind and focus your attention better

All exercise is great — whether it's walking the dog or playing team sports. Just be sure to do it every day. Changing exercise habits can be hard for everyone at first. But most people say that once they start feeling the benefits, they're hooked. After that, it's a lot easier to keep going. But there are some facts you need to know about exercise and diabetes.

What Happens During Exercise?

The muscles need more energy during exercise, so the body releases extra sugar, or glucose. For people with diabetes, this can have some side effects. For example, if the body doesn't have enough insulin to use the glucose that's released during exercise, then the glucose stays in the blood, which leads to high blood sugar levels. This is called hyperglycemia (pronounced: hy-pur-gly-SEE-mee-uh).

Not having enough insulin to use the sugar in the blood can also cause the body to burn fat for fuel. When the body starts to burn fat for fuel, substances called ketones are produced. People with diabetes shouldn't exercise if they have high levels of ketones in their blood because this can make them really sick. If you have type 1 diabetes, your doctor will tell you how to check for ketones (you may need to take a urine test before exercising) and treat yourself to get back on track.

The body's need for extra glucose during exercise can also cause low blood sugar levels (called hypoglycemia, pronounced: hy-po-gly-SEE-mee-uh). Low blood sugar can happen when the body uses up all the sugar that it's stored so there's no more to be released as glucose when the muscles demand it. This is especially true if insulin levels in the blood are still high after taking an injection.

You may need to check blood sugar levels and have an extra snack to prevent low blood sugar levels. If you're starting a rigorous exercise schedule, like training for a sport, your doctor may recommend that you adjust your insulin dosage to prevent low blood sugar levels.

Getting Ready to Exercise

All teens — not just those with diabetes — need to get a physical before they play a sport. Your doctor will let you know about any changes you should make to your testing schedule or medication while exercising or playing sports.

The doctor is likely to give the green light to any activities you want to start — after all, exercise is an important part of diabetes management. However, doctors may recommend that you steer clear of certain adventure sports like rock climbing, hang gliding, or scuba diving. That's because a person could be seriously hurt if he or she has low blood sugar levels while doing these sports.


Exercise Tips for People With Diabetes

These tips can help you avoid diabetes problems during exercise:

  • Test yourself. Your doctor will tell you when to test your glucose levels — often you'll need to check them before, during, and after exercise.
  • Take the right dose of insulin. Your doctor might recommend adjusting your insulin dosage for exercise or sports. If you inject insulin, you might not want to inject a part of your body used for your sport before exercise (like injecting your leg before soccer). This could cause the insulin to be absorbed too quickly. If you wear an insulin pump, be sure that it won't be in the way for exercise and that it won't get disconnected. Talk to your doctor about what you should do when you want to go without the pump.
  • Eat right. Your diabetes health care team will also help you adjust your meal plan so you have enough energy for exercise. For example, you might need to eat extra snacks before, during, or after working out. Be sure to maintain the proper diet for your diabetes — don't try strategies like loading up on extra carbs before running or cutting back on food or water to get down to a certain weight for wrestling. These activities can be dangerous for people with diabetes.
  • Bring snacks and water. Whether you're playing football at the school or swimming in your backyard, keep snacks and water nearby.
  • Pack it up. If you'll be exercising away from home, pack your testing supplies, medications, medical alert bracelet, emergency contact information, and a copy of your diabetes management plan. Keep these items in a special bag that you don't have to pack and repack every time you go out.
  • Tell your coaches. Be sure that your coaches know about your diabetes. Tell them about the things you need to do to control diabetes that might happen before, during, or after a game.
  • Take control. Don't hesitate to stop playing or take a break in your exercise routine if you need to eat a snack, drink water, or go to the bathroom. You should also take a break if you feel any signs that something is wrong.

What to Watch Out for

Your doctor will help you learn what blood sugar levels make it a good or bad time to exercise. He or she will also explain how to take action and get back in the game. If you notice any of the signs listed below, stop exercising and follow your diabetes management plan.

You may have low blood sugar if you are:

  • sweating
  • lightheaded
  • shaky
  • weak
  • anxious
  • hungry
  • having a headache
  • having problems concentrating
  • confused

You may have high blood sugar if you:

  • feel very thirsty
  • have to pee a lot
  • feel very tired
  • have blurry vision

Also, keep an eye on any cuts, scrapes, or blisters, and talk to your doctor if they're really red, swollen, or oozing pus — these could be signs of infection.

By being prepared and knowing how to follow your diabetes management plan, you'll be able to prevent diabetes problems during exercise. After all, professional athletes follow a training and nutrition program to keep them playing their best — just think of your diabetes management plan as your own personal roadmap to exercise success.

Medically reviewed by: Steven Dowshen, MD
Date reviewed: June 2018