What have 70% of regular runners suffered from within the past year? Blisters... no, shin splints... no. Well I'll put you out of your misery - stitches. Stitches are a pain in the... well you know what I mean, and they are not confined to the running fraternity; in fact, just about anyone taking part in a sporting activity, be it swimming, team sports, aerobics or even just running for an occasional bus will have experienced a stitch at some point. There are many theories and quite a few old wives' tales about stitches, but now a couple of exercise physiologists based in New South Wales, Australia, have put together a list of the top 10 facts and fallacies.

1. A stitch occurs in both fit and unfit people, and research suggests it is unrelated to training frequency, training volume or performance level.

2. A stitch is most prevalent among younger athletes, but older athletes can still suffer.

3. Yes you can get a stitch in the shoulder! It appears that when the diaphragm and neighbouring tissues become irritated they can refer pain to the tip of the shoulder.

4. Studies have shown that you are more likely to suffer from a stitch if you eat before a run. Drinking before a run can also be a contributing factor, but less so than eating a meal. Obviously you need to eat and drink before exercise to ensure an adequate energy supply, but research and anecdotal evidence suggests you should avoid the following:
 

• carbonated drinks and those with a high concentration of sugar and salt;
• fatty foods;
• apples, bananas and chocolate.

5. The risk of a stitch may be increased by exercising at high intensity, failing to warm up and working out in cold conditions. Best not go for a really hard run on a cold day without warming up then!

6. The theory that stitch is caused by lack of blood flow to the diaphragm doesn't hold up for three main reasons:

1. it does not account for why pain occurs low in the abdomen;
2. it does not explain why stitches occur during activities that do not seem to require high levels of respiratory activity (eg horse riding);
3. it is not consistent with the evidence that neither lung function nor breathing is affected by a stitch.

7. One of the most widely-accepted theories that stitches are caused by stress on the ligaments that attach the abdominal organs to the diaphragm during jolting activities like running may also be false. If it were true, why would swimmers - whose sport is relatively free from jolting movements - experience stitches?

8. The tissue that may be responsible for the pain is the parietal peritoneum, which envelops the abdominal cavity, separating the abdominal organs from the stomach muscles. This piece of tissue is sensitive to movement when irritated, which would explain why rest quickly relieves the pain. Additionally, part of the parietal peritoneum extends up and under the diaphragm, giving rise to the referred shoulder pain when irritated. What could cause this tissue to become irritated? One obvious answer is that if you fill your stomach with food and drink it's going to get bigger, causing it to push against - and so irritate - the parietal peritoneum.

9. Some breathing techniques may help to alleviate the problem. These include:

• taking deeps breaths;
• grunting as you exhale;
• holding your breath;
• breathing by bloating your abdomen in and out (belly breathing).

10. Most sufferers experience a stitch in the same place each time, and the pain is commonly described as sharp or stabbing when severe, and cramping, aching or pulling when less severe.

Sports Coach, vol 24, no 3, 29-30

Nick Grantham