Stitches (or side stitches, side cramps, or even exercise-related transient abdominal pain (ETAP) – its official scholarly name) happen to everyone, doing almost every form of exercise – although they are a lot more common in runners and athletes where running is involved in their sports (up to 10 times more common than in exercises such as cycling).

However, as common as they are, they have not been studied in great detail until recently, meaning that their exact cause is still not fully understood – although we have been able to rule out a few of the more well known theories. The good news is that we know a number of ways to help relieve ETAP, and to reduce the likelihood of them happening in the first place. The bad news is that, similar to the Blood Lactate/Lactic Acid Myths, there is a lot of incorrect and misinformation out there – in the form of the internet, athletes, the general population and even some coaches & doctors!

Some quick stitch facts:

Stitches occur in both trained and untrained athletes, are more common in younger athletes, consuming certain foods & drinks prior to exercise increases the risk, higher intensity workouts increase the risk – as does missing out/improperly completing your warm up, and are more common on the right hand side of the body.

The Theories…

A lack of blood flow to the diaphragm/stomach/liver/other organs.
A lack of oxygen to the diaphragm/stomach/liver/other organs.
Stretching of the visceral ligaments (ligaments which attach to the diaphragm – in running this is thought to be from the continued jolting/jarring on impact).
Spasming/cramping of the diaphragm.
Irritation of the parietal peritoneum (this is the membrane which surround the internal organs in the abdomen, separating them from the abdominal muscles).

So let’s look a little more closely at each of these.

A lack of blood flow/oxygen to the diaphragm/stomach/ liver/other organs…

These 2 link in together, as the main reason (in this case) we’re looking at blood flow is for the delivery of oxygen to the muscle (diaphragm) or other organs close by. For the diaphragm – it’s in the wrong place – the pain is felt further down the abdomen, and any lack of blood or oxygen is unlikely as there is no effect on breathing or lung function. One other thing that doesn’t make sense with this theory is the fact that some low intensity activities – such as horse riding – can also produce ETAP, but there is no lack of blood flow or oxygen involved. So this theory falls by the wayside.

But looking at horse riding leads us nicely into our next theory.

Stretching of the visceral ligaments…

So, this one works – both running and horse riding – 2 activities that cause a large number of stitches both involve the body being subjected to a lot of jolting/jarring forces. These forces cause the stomach and liver to pull down on the diaphragm, by pulling on the visceral ligaments which connect them – This must by why eating prior to exercise can cause stitches – it weighs down the stomach causing an increase in these forces! So this must be the reason, right?

Oh, wait… What about swimmers?

The stitch is also common in swimmers, where there are no (or at least, very, very little) downward forces pulling on and stretching the visceral ligaments. But the muscle could still be spasming in all these activities!

Spasming/cramping of the diaphragm…

This one seems to fit with the activities, and a stronger core can help to reduce ETAP… One thing is missing though. When this theory was studied in the lab, it was found that there was no electromyographic (EMG) activity, as there is when a muscle cramps.

So yet another theory that seems plausible in the real world just isn’t backed up by the science. This just leaves…

Irritation of the parietal peritoneum…

The parietal peritoneum is easily irritated by movement, so once you stop moving the pain should stop relatively quickly – as is the case with ETAP. When you eat/drink a lot before a run, it increases the size of the stomach, causing it to… rub on the parietal peritoneum! But wait… most (or at very least, a lot of) stitches occur on the right hand side of the body, and the stomach is on the left hand side? This is where the spleen and liver come into play. During exercise, both of these try to increase the number of red blood cells in circulation, which causes them to increase in size… which causes them to… rub on the parietal peritoneum!

So what does this mean? How do you get rid of a stitch, or stop it from happening in the first place?

To stop/reduce the pain or discomfort of a stitch, there are a few easy things you can do:

  • Stop running – simple, but effective. Wait 15-30 seconds and then continue on your run. Repeat if the ETAP persists.
  • Bend over and touch your toes.
  • Press 2 fingers firmly into you torso, where the pain is (usually this is just below your ribcage).
  • Or the best thing to do is all 3! Stop, press in, and then bend over.

To reduce the likelihood of getting one in the first place, you should:

  • Warm up properly.
  • Take deep breaths.
  • Belly Breathe” – breathe by moving your abdomen in and out, not your ribcage.
  • Exhale when landing on the foot of the opposite side to the pain (usually the left foot).
  • Avoid eating/drinking too much before a run.
  • Keep hydrated in the 24 hours leading up to a run.
  • Avoid becoming dehydrated while running.
  • Strengthen the core muscles.
  • Run on softer ground.

Let us know if any of these help you, or what you usually do when you get a stitch in the comments…