Tips for Exercising Safely When You Have Diabetes

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Tips for Exercising Safely When You Have Diabetes

Topic Overview

You should try to get at least 30 minutes of moderate physical activity most days of the week. Some tips for safe exercise when you have diabetes:

Before starting an exercise program

  • Talk to your doctor about how and when to exercise. You may need to have a medical examination and tests (such as a treadmill test) before you begin. In addition, some types of exercise can be harmful if you have complications from diabetes. Your doctor can tell you whether you need to avoid certain kinds of exercise.
  • Choose a type of exercise that you like and that fits easily into your daily schedule. If you choose something you like, you will be more willing to continue the program.
  • Plan to exercise at about the same time and for the same length of time each day to help keep your blood sugar levels in the same range. If you want to increase your exercise, increase the intensity or the duration in small amounts.
  • Have someone with you when you exercise, if possible. You may need help if your blood sugar level drops below a target range.

Starting a program

Start slowly so that you don't overdo it. Build up your exercise program bit by bit, and aim for at least 2½ hours of moderate to vigorous activity a week. It's fine to be active in blocks of 10 minutes or more throughout your day and week.1

If you take certain pills used to treat type 2 diabetes or if you take insulin:2

  • Check your blood sugar level before and right after you exercise until you can predict the effect of exercise on your blood sugar. Check your blood sugar more often if you greatly increase how long or how strenuously you exercise.
  • Have some type of quick-sugar food with you when you exercise. You may develop symptoms of low blood sugar while you are exercising or up to 24 hours after you finish.
  • Check with your doctor if you have been gradually increasing your exercise and have felt the symptoms of low blood sugar more than 2 or 3 times during 1 week. Your dose of medication or insulin may need to be adjusted.
  • Avoid exercising during times when your blood sugar is too low (less than 4.0 millimoles per litre [mmol/L]).
    • If your blood sugar is less than 5.5 mmol/L before you start exercising, eat a snack that contains carbohydrate.
    • If your blood sugar is over 14.0 mmol/L (8 hours after you have eaten) and you have ketones in your urine, do not exercise.
    • If your blood sugar is over 17.0 mmol/L and you do not have ketones in your urine, exercise with caution.
  • Check with your doctor about changing the time and amount of insulin you take when you have been exercising regularly for several weeks. Your body tissues may absorb more insulin.

During exercise

  • Before you exercise, check your blood sugar level.
  • Wear shoes that fit well and polyester or blend (cotton-polyester) socks to keep your feet comfortable and prevent blisters. Use silica gel or air midsoles in your shoes.
  • Drink extra liquids before and during exercise to prevent dehydration.
  • Wear medical identification at all times. You can get medical identification, such as a bracelet, from a pharmacy or on the Internet.
  • Carry a quick-sugar food with you while you exercise.



  1. Canadian Diabetes Association (2008). Clinical practice guidelines for the prevention and management of diabetes in Canada. Available online:
  2. American Diabetes Association (2004). Physical activity/exercise in diabetes. Clinical Practice Recommendations 2004. Diabetes Care, 27(Suppl 1): S58–S62.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Adam Husney, MD, MD - Family Medicine
Specialist Medical Reviewer Brian D. O'Brien, MD - Internal Medicine
Last Revised December 9, 2009

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.