Ask Us Anything: What causes side stitches when you exercise?

The truth about that stabbing, inconvenient exercise pain.
The Ask Us Anything logo with a tired runner in the background
Most people know that jabbing side pain that happens smack in the middle of a good workout. But what's the culprit? Katie Belloff/Popular Science

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The sharp pain while exercising is dreaded and all too common. Despite our best efforts to stay well-hydrated, warm-up, and take it easy when needed, side-stitches still plague as many as two in three runners each year. And the stabbing ache doesn’t just plague joggers, but nearly every exerciser from swimmers to horseback riders. And though many may experience it, the science behind it isn’t well understood. 

Researchers have a handful of theories they’ve been bouncing around for the past few decades, at least, to attempt to explain the physiological underpinnings of the humble side stitch. Still the stitch endures, and remains somewhat of a mystery. Listen to this week’s episode to hear how close scientists are to solving the mystery of the side stitch and what you might be able to do to prevent yourself from getting one.