Side stitch while running

A side stitch is a sharp, stabbing pain just under the ribs, usually on one side, that turns up in the middle of a run. Almost every runner gets one sometimes. It's harmless and goes away — but it can make you stop.

Researchers call it exercise-related transient abdominal pain, and it's surprisingly poorly understood. The leading explanation is irritation of the lining of the abdominal wall, made worse by jolting movement and a full stomach (Morton & Callister, Sports Medicine, 2015).

What helps in the moment

• Slow down or walk until it eases. This works best.
• Breathe out slowly and fully, a few times.
• Press firmly on the painful spot with your fingers while walking.
• Bend forward slightly while pressing.
• Stretch: raise the arm on the painful side over your head and lean away.

Usually it's gone within a few minutes.

What makes stitches more likely

• Eating or drinking a lot in the 1–2 hours before a run, especially large meals, sugary or fizzy drinks.
• Running too fast, particularly early in a run.
• Being new to running. Stitches tend to become rarer as you get fitter.

How to prevent them

• Leave two hours after a full meal before running; a small snack an hour before is usually fine.
• Sip, don't gulp, before and during your run.
• Start slowly. A five-minute walk and an easy first few minutes help a lot.
• Strengthen your core. Some runners find planks and similar exercises reduce stitches.

When it's not a stitch

Pain in the chest, pain that spreads to your arm, jaw or back, or pain with shortness of breath, dizziness or nausea is not a side stitch. Stop and seek medical help.

Stitches and run-walk

If stitches keep stopping you mid-run, a run-walk rhythm is a good fix: the walk breaks let your breathing and stomach settle before a stitch builds up.