Here's What Really Makes Your Side Hurt When You Run

Have you ever felt a sharp, stabbing pain in your side while running? Side stitches and cramps while running are the worst, but there are some things you can do to ease them, and prevent further occurrences. A 2015 study published in Sports Medicine found 70 percent of runners experienced side stitches or exercise-related transient abdominal pain (ETAP). 

The cause could be a diaphragm spasm or weak core muscles. The diaphragm is a muscle that sits just below your ribs and moves up and down as you breathe in and out, and it can get fatigued just like other muscles, according to Runner's World. You'll get side stitches when you're a beginner at running, increasing your speed, increasing your distance, or are just not conditioned to the demand you're putting on your body. According to Insider, other causes of side stitches are poor posture, dehydration, overexertion, or not breathing properly. 

How to prevent side stitches when running

Prevent side stitches by strengthening your core, slowly increasing your speed or distance, paying attention to what you eat before you run, warming up properly, and focusing on your breathing. Get your core into shape with just ten minutes of exercises three times a week, which can help strengthen your diaphragm and surrounding muscles. You can also try Pilates or yoga because they have some excellent core exercises (via Runner's World).

Two hours before your run, avoid foods high in fiber and fat, as those will take longer to digest, which will make cramps or side stitches more likely. Avoid anything high in sugar as well. Keep a log of what you eat before your run and jot down when you get side stitches, so you can find out which foods trigger them (via Runner's World). Eat something healthy and light for a small meal with 17 to 20 ounces of water, three to four hours before your run, if you're running 60 to 90 minutes. If you're running less than that, choose a snack with five to ten ounces of water, 30 to 60 minutes before your run (via Healthline). Check out the best and worst foods to eat before going on a run. 

Warm up before your run so your diaphragm can get used to the steady increase of demand. Good warm-ups include walking for at least two minutes before you start getting into your usual running pace, and inhaling for two steps and exhaling for one step. Your muscles need that oxygen to work properly (via Runner's World).

How to aid a side stitch mid-run

If you do get a side-stitch while you're running, here's what to do: Slow down as soon as you feel a cramp or side stitch coming on, and keep a lower pace until it feels better. Once faded, slowly and steadily increase your pace until you get back to where you were. 

If you can't slow down (like when you're in the middle of a race), you can adjust your breathing instead. If you're already inhaling for two steps and exhaling for two, switch to breathing in for three steps and out for two, so that you're inhaling while landing on one foot and exhaling on the other. This strategy switches up the sides, evening out the impact between them.