How can I prevent low blood glucose during exercise if I have diabetes?

Phil Southerland
Healthcare Specialist

It can sometimes take two to three weeks for the body to adapt to any new exercise regime. Random bouts of hypoglycemia can be prevented by checking more and trying to be ahead of the curve instead of reacting to the curve.

Become vigilant about checking blood sugar more often or trying a continuous glucose monitor. The body will adapt. After years of cycling, I’m now training for a marathon. For me, transitioning from cycling to running, for the first two to three weeks my blood sugar was dropping immediately as soon as I set foot on the road, but now I can go for miles and miles. My body is used to running so I don’t need to eat as much out there as in the beginning.

Intermountain Registered Dietitians
Nutrition & Dietetics Specialist

Keep in mind that physical activity makes your cells burn more glucose than if you were just sitting around. If you have diabetes, to prevent a blood glucose low you may need to cut down your insulin or increase your carbohydrate during or after exercise. Follow these tips for healthy exercise:

  • Check your blood glucose before you exercise to know if you should eat a snack first.
  • Keep some carbohydrate snacks on hand to treat low blood glucose.
  • Drink plenty of water during exercise or hard play.
  • Keep track of how exercise affects your blood glucose, and discuss it with your doctor or diabetes educator at your next visit.

Keep in mind that low blood glucose can occur during or long after physical activity. Low blood glucose is most likely if you:

  • take insulin or certain diabetes pills
  • skip a meal
  • exercise for longer than usual
  • exercise strenuously

If low blood glucose is interfering with your exercise routine, eating a snack before you exercise or adjusting your medication may help. Check your blood glucose during activity if you notice symptoms such as hunger, nervousness, shakiness or sweating. If your blood glucose is 70 mg/dl or below, have 2 to 5 glucose tablets, 1/2 cup (4 ounces) of fruit juice, or 1/2 cup of a regular soft drink to raise your blood glucose. After 15 minutes, check your blood glucose again. If it's still below 70 mg/dl, have another serving and repeat these steps until your blood glucose is at least 70 mg/dl. Talk to your healthcare team about what's right for you.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.