Have you ever been exercising and had that severe, sharp, “cramping” feeling in your side, aka “side stitch”?

Wonder that is all about?

Well, you’re not alone.

A side stitch, which is also referred to in the literature as exercise-induced transient abdominal pain (ETAP), is usually classified as a sharp stabbing pain that is severe when it flares up, and starts to feel like a cramp that is achy and pulling as it becomes less severe. Generally this pain is described as being localized pain along the bottom of the ribcage near the diaphragm is is twice as common along the right side as opposed to the left.

Although the research has not clearly identified one specific condition that is causing this, there are currently 7 accepted theories about what and where ETAP might be coming from.

Diaphragmatic ischemia- basically a muscle cramp of diaphragm, which is your primary muscle or respiration. 

Mechanical stress on visceral ligaments– several key visceral organ have ligamentous attachments to the diaphragm, and with the prevalence of ETAP usually being associated with running, mechanical stress on these ligaments is easy to understand and is widely accepted. 

Gastrointestinal disturbance- when you exercise, your body decreases splanchnic blood flow significantly, which decreases that peristalsis associated with digestion. If there is any food in the gut when this happens, it can cause irritation that is poorly identified.

Muscular cramping- more of a theory, as EMG studies have mostly ruled this one out.

Median arcuate ligament syndrome- the tops of the diaphragm is an opening that is surrounded by a ligamentous structure called the median arcuate ligament. Irritation and compression can lead to ischemic-related pain.

Neruogenic Pain- this theory suggests that the pain is coming from the spine, and is suggested to be related to poor posture.

Irritation of the parietal peritoneum- the parietal peritoneum is the outer-most layer of peritoneum that sticks to the abdominal wall and underside of the diaphragm. Many of the jarring activities associated with ETAP can cause significant friction to this area, as a result of impact and heavy breathing. This is the currently the most widely accepted answer, as the mechanism of pain and irritation are most plausible.

Unfortunately, there is no clear answer here on how to avoid ETAP. But, here is a list of some research-based suggestions:

  • Avoid large volumes of food and drink within 2 hours of exercise
  • Avoid hypertonic drinks (beverages with high sugar and salt content)
  • Improve functional core stability to limit or restrict excessive torso motion
  • Some suggest improving posture, especially in children
  • Improve overall conditioning levels

When it happens, here is a short list of what you can do

  • Deep breathing
  • Pushing on the affected area
  • Stretching the locally affected area
  • Bending over forward
  • Stop exercising


  1. Morton D, Callister R. Exercise-Related Transient Abdominal Pain (ETAP). Sports Medicine (Auckland, N.z). 2015;45:23-35. doi:10.1007/s40279-014-0245-z.