Most of us experience them at one time or another. That sharp twinge of pain just below the rib cage usually on the right. It is particularly common in runners and has been known to slow some down to a walk until the pain subsides.

Up until recently there was no clear explanation for the cause of this annoying cramp, also called exercise related transient abdominal pain (ETAP). Now researchers believe that the side stitch is caused by stretching the ligaments that extend from the diaphragm to the internal organs, particularly the liver. The jarring motion of running while breathing in and out stretches these ligaments. Runners tend to exhale every two or four steps. Most people exhale as the left foot hits the ground, but some people exhale when the right foot hits the ground. It is the later group who seem more prone to get side stitches.

Exhaling when the right foot hits the ground causes greater forces on the liver (which is on the right side just below the rib cage). So just as the liver is dropping down the diaphragm raises for the exhalation. It is believed this repeated stretching leads to spasms in the diaphragm.

Stopping a Side Stitch
To stop a side stitch when running, stop running and place your hand into the right side of your belly and push up, lifting the liver slightly. Inhale and exhale evenly as you push up.

Preventing a Side Stitch
To prevent a side stitch, take even, deep breaths while running. Shallow breathing tends to increase the risk of cramping because the diaphragm is always slightly raised and never lowers far enough to allow the ligaments to relax. When this happens the diaphragm becomes stressed and a spasm or "stitch" is more likely.

Some other ways to alleviate the pain of a side stitch include:

  • Time your eating. Having food in your stomach during a workout may increase cramping by creating more force on the ligaments (avoid eating one to two hours before a workout)
  • Stretching may prevent or relieve a cramp. Raise your right arm straight up and lean toward the left. Hold for 30 seconds, release, then stretch the other side.
  • Slow down your pace until pain lessens.
  • Breathe deep to stretch the diaphragm.
  • Drink before exercise; dehydration can increase muscle cramps.
  • Massage or press on the area with pain. Bend forward to stretch the diaphragm and ease the pain.
  • * If you continue to experience pain, see your doctor.