Dr Darren Morton, a senior Lecturer in the Faculty of Education and Science at Avondale College of Higher Education in NSW, went on to do his PhD on stitches. These are his findings:
A fraction too much friction
The membrane lining the abdominal cavity is known as the peritoneum. It is a double-layered membrane, with the outer layer lying tight against the front abdominal wall and folding around under the diaphragm, the dome-shaped sheet of muscle that separates your chest from your abdomen. The inner layer of the membrane wraps around the contours of the abdominal organs. Between the two layers is a small amount of fluid, which helps reduce friction when your organs shift as your body moves.
Morton’s theory is that this protective system sometimes goes wrong, and there is friction between the layers, resulting in irritation and the pain we call a stitch. The lining under the diaphragm is attached to the phrenic nerve, which refers pain to the shoulder tip region, which may explain why some people get shoulder tip pain with a stitch.
The link with sugary drinks
But it can also happen when the amount of fluid in the space between the two layers drops. One thing we know can cause this is drinking concentrated fluids such as sugary drinks.
“What we know is that things like really sugary drinks draw fluid out of that space and are very provocative of stitches,” Morton says.
In experiments where people are given such drinks, like fruit juice or soft drink, and then asked to exercise “everyone sort of keels over left, right and centre with a stitch”, he explains.
Sports drinks, which are around 6 per cent sugar (compared to around 11 per cent for fruit juice), don’t have this effect. In fact, they are no worse than water at bringing on a stitch.
Sugary drinks have a “double whammy” effect – reducing the rate at which the stomach empties its contents into the intestines, which may lead to bloating and further friction through direct pressure.
While high fat foods also slow the emptying of the stomach, and hence help to bring on stitches, they’re less frequently eaten before exercise than high sugar food and drinks.
Tips to avoid a stitch
So what are Morton’s top tips to reduce the odds of a stitch next time you get active?
There’s most evidence for these three:
- Make sure you’re well hydrated by drinking lots of water in the 12 hours before you exercise. In the two hours immediately before, drink only small amounts so you stay hydrated, but your stomach’s not bloated (and therefore less likely to press on the lining of your abdominal cavity).
- Don’t eat large volumes of food for at least two hours before exercise (perhaps even three to four hours before if you’re especially prone to stitches).
- Avoid very sugary drinks, such as fruit juice or soft drinks, before or during your exercise. Sugary foods like lollies may also be a problem.
There’s less evidence for these, but they’re still worth a try:
- Get fitter: Some evidence suggests the fitter you are, the less frequently you get stitches. Exactly why isn’t understood. But plenty of very fit athletes are still plagued by them.
- Strengthen your core: Strong trunk muscles, especially the deeper abdominal muscles, the transverse abdominus, may help ward stitches off, probably by offering more support to abdominal organs. Pilates and exercises using a stability ball may help.
- Improve your posture: “We haven’t yet done intervention studies to see if changing people’s posture makes a difference but we have anecdotal reports of people who’ve done that and it’s been helpful.” A physiotherapist may be able to help.
If you do get a stitch, you might find the following techniques can bring relief:
- deep breathing
- pushing or stretching the affected area
- bending over forward.
In lab experiments, stitches generally disappeared 45 seconds to two minutes after stopping activity. Some people can still feel sore a couple of days later though.
source: ABC health and wellbeing