Even if you do not have a medical condition that affects blood sugar levels, you may still experience hypoglycemia during or after exercise and intense physical activities.

Exercising may leave you sweating and tired, but it can also lead to hypoglycemia. This can bring on an unusually fast heart rate, dizziness, and confusion.

You use up more energy during exercising, and so if you don’t have enough glucose in your body then you can experience low blood sugar during or after a workout.

This article explains more about hypoglycemia and why it can happen because of exercise, as well as how you can prevent it from happening and what to discuss with your healthcare team.

Hypoglycemia is a blood glucose level of 70 mg/dL or below. But your symptoms may vary and the exact level you experience symptoms is different for everyone and may change each time. Clinicians generally define severe hypoglycemia at 55 mg/dl or below.

When exercising, you use up more energy, and the glucose in your body provides you with that needed energy.

Active use of muscles in exercise produces extra demands on the body’s energy supplies. Low blood glucose levels can develop for up to 24 hours after a workout if the body doesn’t have enough energy stores.

Exercise can also make the body more sensitive to insulin. When this happens, insulin works more effectively and lowers glucose levels faster. This can place you at a greater risk of hypoglycemia, especially if you take medications to lower insulin levels.

You can experience exercise-induced even if you don’t have diabetes.

People are more likely to experience hypoglycemia for the following reasons:

  • engage in a high intensity workout
  • already have low blood glucose from not eating for a while
  • are sick
  • do not consume enough carbohydrates
  • work out right after eating a meal
  • have an insulin sensitivity
  • drink alcohol, which can lower your blood sugars several hours after you’ve stopped drinking

People with type 2 diabetes may also experience exercise-induced hypoglycemia.

To reduce your risk of experiencing exercised-induced hypoglycemia when you have diabetes you can:

  • talk with your doctors about the best times for you to exercise
  • discuss with your doctors whether you should adjust the amount of insulin you use before or after exercise
  • check your blood glucose level before, during, and after working out
  • increase the amount of time you spend exercising slowly

If you have hypoglycemia while exercising, it’s important to stop your workout and consume something with fast-acting carbohydrates. This may include a glass of juice, a piece of hard candy, or glucose tablets or sugar to help raise your glucose levels.

You’ll need to rest and give your blood sugar levels a chance to rise before resuming activity.

Also, be aware that fast-acting carbs will only boost your blood sugars temporarily. Once your blood sugars are at safe levels above 70 mg/dL, you may consider eating something with more substance — such as a piece of toast with peanut butter.

Mild exercise-induced hypoglycemia may not need any serious treatment.

For many people, eating or drinking some carbohydrates and then resting is all they need to treat it. To prevent it in the future, you might eat a small meal an hour or two before working out.

It’s also a good idea to slowly build up the length and intensity of workouts.

If you have diabetes and experience hypoglycemia related to exercise, you may need to adjust your medication and carbohydrate levels before and after exercising.

It’s important to monitor your glucose levels for several hours after working out to ensure that they aren’t dropping too low even though you’re no longer working out.

It’s important to seek emergency medical help if you experience signs of severe hypoglycemia. These include:

You might consider consulting your doctor if symptoms remain after resting and consuming carbohydrates, or if you experience exercise-related hypoglycemia frequently.

They can help guide you toward any needed medication or routine changes to prevent this from happening in the future.

Working out makes your body use up more energy than usual and can increase insulin sensitivity. Especially if a workout is intense, it may cause hypoglycemia to occur whether you have diabetes or not.

If you experience frequent or severe exercise-induced hypoglycemia, you may want to talk with your doctor or healthcare team.

They can rule out any related medical conditions and offer recommendations to prevent hypoglycemia in the future.