On the surface it seemed like an easy question. A friend was getting back into running and asked me why he was getting cramps or side stitches a mile into his run. I started to reply then stopped. I knew what he was talking about. Just about everyone has gotten that familiar acute pain in their side while running at some point. But when was the last time it had happened to me? It had been a while. And what really did cause those cramps? That simple question didn’t have a simple answer.
Turns out, as common as they are, Google and most experts aren’t entirely sure why they happen.
We’re not talking about other muscle cramps that might be caused by dehydration or an electrolyte imbalance. As a definition, a side stitch is a cramp in your diaphragm, the big muscle that controls your breathing and sits underneath your lungs.
But why do we get them and how might we prevent them?
Eating right before going for a run, or eating too much right before a run, is one leading theory on side stitches. Forcing your stomach to digest diverts blood flow to the GI tract, and away from other muscles. Blood carries oxygen to your muscles and decreasing that supply can put those muscles at risk for cramps.
Eat a light breakfast, low in fiber and fat a few hours before your run.
Just being new to exercise or getting back into shape doesn’t put you at a higher risk for cramps. Studies have shown that people who exercise frequently tend to get fewer side stitches, but their side stitches are just as intense as the ones that less-conditioned people get.
What’s more likely is that more experienced runners have learned to warm-up better. If you jump in and start your run at 100% intensity, your body is going to struggle to keep up and one side effect could be a side stitch. Better to use a dynamic warm-up and to progressively increase the intensity to get the lungs, diaphragm and blood flow moving at a manageable rate.
Do a dynamic warm-up (lunges, leg swings, light foam rolling) and start your run slow and steady.
Core & IT Bands
Sorry to say, but those planks and sit-ups might be more beneficial than you knew. Some studies have shown that strengthening your trunk and core can lead to fewer side stitches.
Another theory is that side stitches could be related to tight hip flexors. The psoas and iliacus muscles (hip flexors) attach to the diaphragm. As you run, your diaphragm starts pulling more forcefully up and down as you inhale and exhale. If those muscles are already tight (very common in both experienced and new runners) that tension might be even greater.
Another reason to break out that foam roller!
Can you run through it?
Ultimately, side stitches are typically harmless and if you back off the intensity or stop and walk for a bit the pain should not persist (if it does obviously get it checked out). Of course, that doesn’t mean those cramps aren’t painful but it’s more about learning to cope with side stitches and working through them while your run. Or, better yet, learning to prevent them and avoid them entirely.
Above all, a side stitch indicates that your body is under stress. The best medicine for a side stitch? More running. The stronger and more fit you are and the better your body learns to deal with the stress of running, the less likely you’ll find yourself dealing with the dreaded side stitch.