Stitch Pain: New light on stitch

A new Australian study offers valuable insights into the common but potentially disabling sport-related condition known colloquially as ‘stitch’ (‘Epidemiology of exercise-related transient abdominal pain at the Sydney City to Surf community run’, J Sci Med Sport 2005; 8:2:152-162).

In a previous study – the largest published on the subject – the researchers found that 60% of runners had experienced exercise-related transient abdominal pain (ETAP) while running within the past year, but this was a retrospective study based on recall.

The aim of the current study was to investigate the acute experience of ETAP in a single running event to develop a better understanding of its prevalence and characteristics and assess the influence of personal characteristics and pre-event nutrition on its development.

A detailed questionnaire about ETAP was completed by 848 participants (76% runners and 24% walkers) at the conclusion of the 14k City to Surf event – Australia’s largest community run which attracts some 50,000 participants every August, ranging from children to elite athletes.

The main findings were:

• 27% of respondents reported experiencing ETAP during the event, with the condition almost twice as common among runners as walkers;
• The most commonly reported sites of the pain, most often described as aching, sharp or cramping, were the right (46%) and left (23%) lumbar regions of the abdomen (waist level);
• 42% of those experiencing ETAP found it detrimental to performance, with 36% forced to reduce their activity level and 6% to stop entirely until the pain subsided;
• Reports of ETAP decreased with age, with a prevalence of 50% in the under- 20s declining to 5.4% in the 51-60 age group. However, it was unrelated to gender, body mass index or performance level, as reflected in finish time;
• Most respondents reported that the pain developed on the flat (42%) or while running uphill (28%), thus putting paid to the theory that it is provoked by downhill running;
• Among respondents who ran, those who consumed a large mass of food relative to body weight one to two hours before the event were more likely to develop ETAP, although the nutritional content of the meal was irrelevant;
• Only 35% of symptomatic respondents claimed to experience ETAP within the first third of the event, suggesting that the condition is not caused by insufficient warm-up, as previously claimed.

According to the researchers, the findings of this study suggest that stitch is a single condition, common in its manifestation to most sufferers and therefore probably also common in its cause. What that cause is remains unknown.

Isabel Walker is the editor of Peak Performance