The stabbing pain of a stitch can blight performance. Sports dietician Alex Cook looks at what can cause it

Who hasn’t suffered a stitch at some point? It’s a pain that is felt by many but understood by few. And while it is dismissed as an irritating niggle, it can cause serious disruption to training or competing in some people.

Results of a survey involving almost 1000 runners published in the Journal of Science, Medicine & Sport highlighted that 27% had reported a stabbing side stitch during at least one race and all said it had adversely affected performance. Despite its prevalence, exercise scientists have remained unsure about precisely what causes a stitch and why some people are more prone to it that others.

In medical terms, a stitch is referred to by the rather long winded term ‘exercise related transient abdominal pain’. Typically, it is characterized by localized pain that is described as becoming sharp, pulling or cramping on movement.

Although the cause remains scientifically unproven, there are theories abound as to why it happens. For years, it was thought that a lack of blood supply and oxygen to the diaphragm resulted in the localized pain. Another school of thought suggests that, as a result of jolting during high impact exercise, the internal organs pull on the ligaments that connect our gut to the diaphragm. However, both of these ideas have been discounted by rigorous laboratory tests.

This year, Australian scientist Dr Darren Morton published a review of 14 studies in the Journal Sports Medicine. His verdict? It’s almost certain to be the result of an irritation to the parietal peritoneum, the layers of membrane lining the abdominal wall. In between the outer and inner layer of the membrane is a small amount of fluid that serves as a protective mechanism to reduce friction when your organs jiggle about as a result of running or jumping.

Mostly it works well, but can be thrown off kilter, resulting in the pain we know as a stitch. Friction between the membrane’s layers can be triggered when your stomach is too full prior to exercise or when levels of the protective fluid drop, something that has been linked to the consumption of sugary drinks.

In studies where athletes are given fruit juice or other sugary soft drinks before being asked to exercise, a significant number experience a stitch. Morton says the sweet drinks not only “draw fluid out of the membrane space” but delay the rate at which the stomach empties.

It’s the culmination of factors that results in the pain. Interestingly, sports drinks have been shown not to have the same effect and appear to be on a par with water in being fairly neutral when it comes to producing a stitch.

If you are prone to a stitch, what should you do?


1 Don’t eat or consume sugary drinks (other than sports drinks) or foods within 2 hours of training or competing

2 Stay hydrated but consume only small amounts of water in the 2 hours before you exercise. Too much fluid will bloat your stomach and encourage pressure on the membrane linings.

3 Strengthen your core. Evidence suggests strengthening the deeper abdominal muscles, such as the transversus abdominus, might reduce the likelihood of getting a stitch

4 Avoid high fat and high fibre foods before exercising. Like sugary drinks, they delay the emptying of the stomach.

5 If you still get a stitch, try stretching the area, breathing deeply and bending forward.

» Alex Cook is a sports dietician at