What is runner's belly?

This question is about Running

Sarah Achleithner

Runner’s belly or runner’s gut occurs when the digestive system becomes irritated during long-distance running [


]. Running is one of the most strenuous forms of exercise on the gastrointestinal (GI) tract, with some studies indicating that up to 80% of runners experience gastrointestinal symptoms during a run [


]. Symptoms associated with a runner's belly include bloating, stomach pain, gas, vomiting, diarrhea, and nausea. These gastrointestinal (GI) issues often occur in runners who are anxious, nervous and/or younger in age, and are often exacerbated by a higher intensity [



Causes of runner’s belly include dehydration, high-carbohydrate fluids, lack of blood flow to the gut, pre-existing medical conditions, genetics, and timing and composition of meals before a run. Runner’s belly can be avoided through planning food intake around exercise, staying hydrated, wearing loose clothing, and reducing exercise duration [




]. Practicing your pre workout nutrition routine during training is essential for minimizing your risk of runner’s gut during a race.

For more information on runner’s belly see

this article


woman with ponytail running along road against a fenced background


  1. Laskowski, E.R. (2019). Runner’s Diarrhea: How Can I Prevent It? Mayo Clinic. Retrieved from


  2. Erdman, K. A., Jones, K. W., Madden, R. F., Gammack, N., & Parnell, J. A. (2021). Dietary Patterns in Runners with Gastrointestinal Disorders. Nutrients, 13(2), 448. https://doi.org/10.3390/nu13020448

  3. Runner’s Gut. Sports Dietitians Australia. Retrieved from