Everyone has at some point experienced a ‘side stitch’ during a run. The more formal diagnostic term for a stitch is exercise related transient abdominal pain (ETAP) and describes pain which comes on during exercise (commonly running) but can also occur with other activities such as swimming.


Pain is normally described as sharp or stabbing and is felt on one side of the abdomen on the lower edge of the ribcage. They are normally manageable to the point where you can keep exercising through it but sometimes the pain can be very sharp to the point where you need to stop exercising.


The exact cause of a stitch is uncertain, but there are several theories as to the possible causes or predisposing factors to their onset.

One popular theory is ischemia (lack of blood flow) to the diaphragm, which is the muscle that sits at the base of the ribcage and is responsible for lung expansion. Lack of blood flow and hence poorer oxygen supply to the diaphragm may occur during exercise and result in irritation, cramping and pain.

Other theories include stretching of the ligaments which connect the diaphragm to the liver and irritation of the membrane lining the abdominal cavity.

What you eat and drink before running may be a contributing factor for stitches as some types of food/drink and the timing of when you have these before a run may lead to abdominal irritation.

Prevention and Treatment

Sticking to the theory that what you eat and drink before running may predispose a stitch, make sure that you are very conscious of what and when your pre run meal is. These strategies may help:

  • Avoid eating a large meal within 2 hours before your run
  • Make sure you are well hydrated during the 12 hours before running and avoid large volumes of fluid in the two hours before your run, instead just have small sips during this time.
  • Avoid fatty, high fibre foods in the 2 hours pre run, as these foods take longer to digest and may cause abdominal upset
  • Everyone is different so take note of what you have eaten before a run in which you experience a stitch and modify your habits as you learn what works for your body

Make sure you complete a proper warm-up before quality training sessions as rapid changes in your breathing patterns may cause irritation and result in pain. Be mindful of your breathing pattern during your run and try to focus on breathing evenly with your stride pattern.

If you are unlucky and a stitch does come on during a run it is best to slow down a bit and focus on normalising your breathing pattern. If you need to stop, try some gentle self massage to the painful area under your rib cage which may help release the muscle spasm.


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