Highs, lows & emergencies Guide

Managing hypos during exercise

A guide on recognising and treating hypoglycaemia during and after exercise, including practical tips on what to carry and when to check glucose levels.

Written by Updated 23 July 2026 2 min read
Woman running on track at sunset.
Photo by McCarthy Beckan on Unsplash
The 60-second answer

Exercise can affect your blood glucose levels, especially if you have type 1 diabetes. It’s important to monitor your levels and be prepared for changes. If your blood glucose level falls below 4mmol/L, treat it quickly with a sugary drink or snack.

  • Check your blood glucose before, during, and after exercise to prevent hypos (low blood glucose).
  • Carry something that will raise your blood glucose quickly, like sugary drinks, sweets, or glucose tablets.
  • Gentle exercise tends to lower glucose, while intense exercise can raise it.
  • A hypo can happen during exercise or hours later, including overnight, so stay vigilant.
  • Extra carbohydrate is something you can manage yourself; insulin adjustments are worked out with your diabetes team.
Exercise and glucose

How exercise affects glucose levels

Exercise can have varying effects on your blood glucose levels. Gentle or steady exercise, like walking or cycling, usually lowers glucose levels. This happens because your muscles use up glucose for energy. However, intense exercise, such as sprinting or heavy weightlifting, can raise your glucose levels due to the release of stress hormones.

Preventing hypos

Preventing hypos during exercise

To prevent hypos during exercise, you may need to adjust your carbohydrate intake. Carry fast-acting carbohydrates, such as glucose tablets or sugary drinks, to quickly raise your blood glucose if it drops. Monitor your levels closely before, during, and after exercise, and again before bed if you’ve been active. Extra carbohydrate is something you can manage yourself; insulin adjustments are worked out with your diabetes team.

What varies

What varies between people and days

The impact of exercise on blood glucose can vary based on the intensity and duration of the activity, as well as individual factors like insulin sensitivity. Some people may experience a drop in glucose during exercise, while others might see a rise. It’s important to learn how your body responds and adjust accordingly.

intensity of exerciseduration of activityindividual insulin sensitivity
What to notice

Worth paying attention to

Check blood glucose before, during, and after exercise, and before bed on active days.
Carry fast-acting carbs to treat potential hypos.
Be aware of delayed hypos, which can occur hours after exercise, especially overnight.
What to ask your team

Questions that make an appointment useful

"How should I adjust my insulin dose for different types of exercise?"
"What specific carbohydrate intake should I consider before and after exercise?"
"How can I better monitor my glucose levels during physical activity?"
Sources