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What Causes Side Pain When You Run (and How to Prevent It)


If you’ve ever had your exercise interrupted by a sharp pain in your side, you’re not alone. Here’s why it happens and how you can try to avoid it in the future.

In this video from the SciShow YouTube channel, host Hank Green explains whats really going on inside your body when your pleasant jog turns into side-splitting pain. Scientists aren’t completely certain what cause it, but the sharp pain, or “stitch in your side,” is likely caused by one of these three possibilities:

  1. Your diaphragm muscle strains from over-extending itself during exercise.

  2. The forceful movement of your exercise bounces some of your internal organs around.

  3. There’s not enough fluid between the layers of your peritoneum (the membrane that forms the lining of your abdominal cavity), or a large meal is pushing out on the inner layer.

If you want to avoid side pain, Green recommends you wait a little to exercise after eating a large meal, work to strengthen your core muscles so there’s less movement in your abdomen while exercising, and make sure you stay hydrated. Unfortunately, the only way to stop it once it happens is to stop exercising for a few minutes and wait.

What’s Causing That Stitch in Your Side? | YouTube