Increase text size: A A A

Type in the condition you need,
or visit Advanced Search

Print this page

Email this to a friend

Save to my Health Library

Diabetes Special Report

Diabetes and Exercise -- Keeping Your Blood Glucose Levels in Check

Johns Hopkins Health Alerts Diabetes Diabetes and Exercise

Exercise is beneficial for all people with diabetes because it helps lower blood glucose levels. As a result, people with type 1 diabetes may need less insulin, and people with type 2 diabetes may be able to control their diabetes without medication. Exercise has other benefits as well. It helps improve cardiovascular fitness and provides a sense of psychological well-being.

However, exercise requires careful planning and monitoring, particularly for people who take oral medication or insulin to control their diabetes. These individuals may need to make adjustments to their medication and food intake to prevent blood glucose levels that are too low (hypoglycemia) or too high (hyperglycemia) during exercise.

If you have diabetes, be sure to talk to your doctor before beginning an exercise program or making any changes to your medication or diet. Getting in the habit of exercising regularly may be difficult at first, but the benefits can be great for people with diabetes.

How Exercise Affects Glucose Levels
In most cases, exercise lowers blood glucose levels. As muscles do their work, they obtain energy from glucose stored in the muscle cells as glycogen. When these supplies of glycogen run low, glucose from the bloodstream is used as an energy source. After exercise, the body replaces the stores of glycogen in the muscle cells and liver, which lowers blood glucose levels even more. This drop can take place many hours after exercising.

Exercise can also have the opposite effect and raise blood glucose. This usually occurs when blood glucose levels are too high (usually over 250 mg/dL) before exercising, which indicates that insulin activity is too low. In addition, very strenuous exercise can stimulate the liver to release extra glucose into the bloodstream, due to an increase in adrenaline.

The Best Time To Exercise
To prevent hypoglycemia, workouts should be timed in relation to meals and medication. A general rule is to exercise one to three hours after eating something. People with diabetes who take insulin should not exercise when their insulin is at its peak. Since exercise can lower blood glucose hours later, avoid exercising just before bedtime to prevent hypoglycemia in the middle of the night.

Before Exercising
If you have diabetes, you should always check your blood glucose levels twice before exercising: once 30 minutes in advance, and again just before starting. This routine will let you know whether your blood glucose is stable, rising, or dropping.

A safe pre-workout blood glucose level is between 100 mg/dL and 250 mg/dL. If the level is less than 100 mg/dL, have a carbohydrate snack (such as a piece of fruit or three graham crackers) before starting to exercise to prevent hypoglycemia.

People with type 2 diabetes should limit snacking, however, especially if they are exercising to lose weight. If this is the case, your doctor may recommend lowering the dose of your medication on the days that you exercise. If your blood sugar is above 250 mg/dL and you have type 1 diabetes, test your urine for ketones; delay exercise if ketone levels are moderate or high. Regardless of your type of diabetes, do not exercise if your blood glucose levels are 300 mg/dL or higher.

While Exercising
When you exercise for more than an hour, check your glucose every 30 minutes. If blood glucose starts to fall, have a snack. Testing your blood glucose while exercising is also important if you are trying a new exercise or changing the intensity or duration of your workout. If you start to experience symptoms of low blood glucose such as faintness, palpitations, or weakness during your workout, stop immediately. Test your blood glucose and, if necessary, have a fast-acting carbohydrate snack such as fruit juice or hard candies.

After Exercising
Blood glucose can continue to drop for hours after exercising, so test your levels at least twice: once immediately after, and again a few hours later. Since more intense exercise prolongs the glucose-lowering effect, be extra careful after strenuous workouts.

Safety Precautions
People with diabetes need to take a few extra safety measures when exercising:

  • If you take medication to control your diabetes, always carry a fast-acting source of carbohydrates (glucose tablets, hard candies, or raisins) with you while exercising in case of a hypoglycemic reaction.

  • Carry your identification and diabetes information with you. Include your name, address, phone number, doctor’s name and phone number, and type and dose of insulin or other medications.

  • Skip exercise if you feel ill. Pushing yourself too hard could make your diabetes worse.

  • Exercise with a friend whenever possible. When going out alone, tell someone where you will be and what time you plan to return.

  • For more Diabetes articles, please visit the Diabetes Topic Page


    Posted in Diabetes on February 7, 2006
    Reviewed July 2009

  • (800) 829-0422

    Registered Users Log-in:

    Email:

    Password:

    Remember me
    Forgot Password?

    Become a Registered User!
    It's fast and FREE!
    The Benefits of Being A Registered User

    Health Topic Pages

    Arthritis +Add
    Back Pain & Osteoporosis +Add
    Cancer
    Caregivers | Caregiving
    Colon Cancer +Add
    Complementary Medicine
    Depression & Anxiety +Add
    Diabetes +Add
    Digestive Health +Add
    Enlarged Prostate +Add
    Exercise and Fitness
    Healthy Living +Add
    Heart Health +Add
    Hypertension & Stroke +Add
    Lung Disorders +Add
    Memory +Add
    Men's Health
    Nutrition +Add
    Prescription Drugs +Add
    Prostate Disorders +Add
    Sexual Health
    Vision +Add
    Weight Control +Add
    Women's Health
    Health Alert Special Report



    Johns Hopkins’ Bestsellers

    Diabetes

    Our Featured Title:

    Johns Hopkins White Paper 2009: Diabetes

  • 2009 Diabetes White Paper
    The 2009 Diabetes White Paper teaches you how to manage your Type 1 and Type 2 diabetes and avoid complications, such as foot problems and vision changes. It reviews the latest tools for monitoring your blood glucose and the newest medications for controlling it.PLUS, get your special discount and FREE Special Report: Dealing with Diabetes through this exclusive web-only offer.
    Read more or order the INSTANT PDF DOWNLOAD EDITION
    Read more or order the PRINT EDITION


    Related Titles:

  • The Johns Hopkins Heart Bulletin
    A must-have health journal for anyone concerned about their heart health. Each packed quarterly issue brings you the latest research and findings on coronary heart disease, including the latest breakthroughs on such conditions as: coronary artery disease, congestive heart failure, angina, atrial fibrilliation and other arrhythmias, pacemakers and defibrillators, and many other cardiac conditions and their treatments. Heart attack prevention, diet, weight loss, smoking cessation, how to reduce cholesterol, and other heart health concerns are also covered in-depth.
    Subscribe now, and you’ll also get a FREE Cardiac Glossary, PLUS 4 FREE Johns Hopkins Heart Health Special Reports, all available as instant downloads.Read more...

  • 2009 Vision White Paper
    Reviews current research on cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy.PLUS, get your special discount and FREE Special Report: Eye Problems and Solutions through this exclusive web-only offer.
    Read more or order the INSTANT PDF DOWNLOAD EDITION
    Read more or order the PRINT EDITION

  • 2009 Heart Attack Prevention White Paper
    PLUS, get your special discount and FREE Special Report: Tested, Proven Ways to Save Your Heart through this exclusive web-only offer.
    Read more or order the INSTANT PDF DOWNLOAD EDITION
    Read more or order the PRINT EDITION

  • 2009 Coronary Heart Disease White Paper
    This White Paper reports on the latest life-saving advances for your heart health, to help you prevent or treat coronary heart disease. Topics include angina; cardiac arrhythmias; and congestive heart failure. PLUS, get your special discount and FREE Special Report: Healthier Heart, Longer Life through this exclusive web-only offer.
    Read more or order the INSTANT PDF DOWNLOAD EDITION
    Read more or order the PRINT EDITION

  • 2009 Hypertension & Stroke White Paper
    High blood pressure, or hypertension, gives few or no warning signs before it erupts with major complications, such as a stroke.
    Read more or order the INSTANT PDF DOWNLOAD EDITION
    Read more or order the PRINT EDITION

  • The Johns Hopkins Medical Letter: Health After 50
    Since 1988, Hopkins experts have been reporting on the latest cutting edge information on treating the major medical conditions affecting the over 50s. Women's health, men's medical concerns, nutrition, weight control, breakthroughs on diabetes, and more, direct to you every month from our specialists. Read more, collect your FREE trial issue, or order now and receive two FREE Special Reports...


    Reference Books

  • The Johns Hopkins Medical Guide to Health After 50
    A comprehensive home medical encyclopedia that gives you a "crash course" on more than 100 major medical concerns of men and women over 50, organized in an easy-to-use A to Z format. Read more…


  • ALL NEW!Number One of America's Best Hospitals 2009: Johns Hopkins

    The Johns Hopkins Hospital has been ranked #1 again in the Honor Roll of America's Best Hospitals by
    U.S. News and World Report for the 19th consecutive year.


    Please visit here for more information about Johns Hopkins Patient Services

    Please send me The Johns Hopkins Medical Guide to
    Health After 50




    Yes! Please send me The Johns Hopkins Medical Guide to Health After 50 for just $29.85, plus shipping and handling. I may review it risk-FREE for 30 days. If not completely satisfied, I may return the book, no questions asked.



    The Johns Hopkins Medical Guide to Health After 50 is a contemporary health handbook for your home with the authority of America’s #1 medical center behind it. Only one book brings the full force of the world’s renowned health experts to bear on the unique health issues affecting men and women after 50.



    Risk-FREE.
    Fill out the form and click "Submit my order."

    First Name

    Last Name

    Address

    Address2

    City

    State

    Zip

    Email Address (required)

    Please send me FREE monthly Johns Hopkins Healthy Living
    Health Alerts

    Your risk-free review. Yours to review risk-free. If you are not satisfied with The Johns Hopkins Medical Guide to Health After 50 for any reason, simply return the book, no questions asked.

    Why Johns Hopkins?



    © 2009 MediZine LLC. All rights reserved.
    Contact Us
    customerservice@johnshopkinshealthalerts.com