Exercise And Diabetes: What to Expect and How to Adjust

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Exercise And Diabetes: What to Expect and How to Adjust

Kathryn GentileContributor: Kathryn Gentile, MS, ACSM-CEP, CPT, CDCES
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Does living with diabetes cause you to avoid physical activity due to a fear that it will lead to hypoglycemia or hyperglycemia? You aren't alone! The good news is, with preparation, most people with diabetes can exercise without restriction. (Those with underlying complications may need to limit some activities.)

Important things to consider before exercising are the time of day, insulin on board (if applicable), meal timing, and type of activity. Two main tools you can use to help keep blood glucose in your desired target range are fast-acting carbohydrates and, for those on insulin therapy, adjustments to your dose. Typically, cardio-based exercises will cause a decline in blood sugar, and strength-based will cause a rise due to hormone production. Here are tips for both situations:

  • Hypoglycemia is typically defined as a blood sugar value of less than 70 mg/dl.
    • Setting a higher glucose target range for exercise may prevent hypos.
    • If you're on meal-time insulin, ask your healthcare team for recommendations on decreasing insulin for meals consumed within 2 hours before exercise.
    • Temp basal adjustments can be utilized for those on a pump. Basal insulin changes should be made 1-2 hours before any activity. These work best for long-duration exercises (over 90 minutes).
    • Carb supplementation with a high glycemic index (or fast-acting carbohydrate), such as glucose tabs/gels/liquid or sports drinks, can be utilized intermittently.
    • Consider planning your exercise in the morning when you're more insulin resistant and, if in a fasted state, have no insulin on board. (As a bonus, research shows you are more likely to stick with your exercise program if you work out in the morning.)
    • If you're on a sulfonylurea, discuss other medication options with your healthcare provider.
  • Hyperglycemia is typically caused by hormones. This is often seen with weight lifting, competitive sports, and high-intensity exercise like sprinting.
    • A corrective dose of insulin might be necessary to avoid the initial rise. But keep in mind that you will still be more insulin sensitive from the activity, so you must reduce the amount you would typically take. Ask your healthcare team for guidance.
    • Make sure you do a warm-up and cool down.
    • Stay hydrated!

There's much to learn about glucose management around physical activity, but it's worth it for all its benefits. Plus, there are many resources (books, videos, blogs, research, etc.) for tips and tricks. Never let diabetes hold you back, but before beginning exercise, talk to your healthcare provider about what's safe for you.

Kathryn Gentile, MS, ACSM-CEP, CPT, CDCES, lives with type 1 diabetes and works at Integrated Diabetes Services as an Exercise Physiologist. She provides one-on-one guidance for patients looking for individualized exercise plans and diabetes education. Connect with Kathryn on Instagram at @kathryngentile, and follow Integrated Diabetes on Twitter, Facebook, and Instagram.