Runners who have been plagued with painful side stitches during a workout should check their posture.
The "Really?" column in the New York Times today checks out the claim that a side stitch occurs when the diaphragm spasms from being worked too hard.
"In one recent study, researchers used a device to measure muscle activity as people were experiencing side stitches," the NYT's Anahad O'Connor reports. "They found no evidence of increased activity or spasms in the diaphragm area during the onset of stitches."
Furthermore, the same team published a study last year in which they found that "those who regularly slouched or hunched their backs were more likely to experience side stitches, and the poorer their posture, the more severe their stitches in exercise," O'Connor reports.