Who hasn’t ever, at some point had a stitch? 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 1,000 runners that was published in the Journal of Science, Medicine & Sport highlighted that 27% had reported a stabbing side stich 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, theories abound as to why it happens. For years, it was thought that a lack of blood supply and oxygen to the diaphragm (the large muscle involved in breathing) resulted in the localized pain. Another popular 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.
So are we any closer to finding out what’s behind the debilitating pain? Earlier this year, Dr Darren Morton, an Australian scientist who has made stitch research his focus, 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 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, specialist 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 stitch, what should you do? Here are 5 top tips:
Don’t eat or consume sugary drinks (other than sports drinks)or foods within 2 hours of training or competing
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.
Strengthen your core. Evidence suggests strengthening the deeper abdominal muscles , such as the transversus abdominus, might reduce the likelihood of getting a stitch
Avoid high fat and high fibre foods before exercising. Like sugary drinks, they delay the emptying of the stomach.
If you still get a stitch, try stretching the area, breathing deeply and bending forward.
Featured in Athletics Weekly - Edited by Peta Bee.