Exercise can cause acid reflux in some people. This is called exercise-induced gastroesophageal reflux, and is exacerbated by excessive contracting of the stomach muscles.

So if you’re wondering why you have heartburn during or after exercising, this may be the cause. What can you do to avoid it? Here are a few tips:

Don’t eat right before exercise. In fact, you shouldn’t eat any later than 60 minutes prior to your workout.

Avoid large meals, even if it’s a full hour before exercise, especially those foods that are heavy on the protein or fat.

Don’t drink an excessive amount of water right before you exercise. Drinking 8-16 ounces of cold water within the 30 minutes before exercise is plenty.

To keep yourself hydrated, sip on 4-8 ounces of cold water every 10-15 minutes during exercise and drink 16-24 ounces of cold water after you’re done.

Persistent heartburn despite these changes may require the attention of your physician, so don’t hesitate to get checked out if you feel your problem persists or is severe.