Side Stitch

Causes

Side stitches among runners may be the result of the pumping action of legs putting pressure on the diaphragm from below, with the rapid breathing associated with strenuous physical activity expanding the lungs and placing pressure on the diaphragm from above at the same time. The combined effect is one of pinching the diaphragm, reducing the flow of blood and oxygen, and causing noticeable pain in the side. While this scenario seems plausible, it is a theory that has not been proven by scientific research and one that does not seem to account for side stitches in exercisers who do not walk or run.

When a fitness walker or distance runner pounds his or her legs against the ground while taking rapid breaths, the connective tissue that extends from the diaphragm to the liver can be stretched. That stretched, stressed tissue could also be responsible for causing pain in the side.

The amount and type of food consumed before an exercise session may place an additional stress on the diaphragm, again potentially causing side stitches. Whether the food-exercise association is real, there are ways to minimize the negative effects of foods and beverages on exercise without compromising athletic performance. These strategies are discussed below, in the Prevention section.

Although not warming up adequately before exercise has been mentioned as a possible cause of side stitches, there is no evidence to support that claim. In fact, the Australian study found that the incidence of side pain occurred equally during the first, middle, and latter segments of the 14-kilometer race. If the side stitches had occurred only during the initial part of the race, an inadequate warm-up might have been the cause. That was not the case.

In spite of some logical explanations and a few well-designed studies, the exact cause of side stitches remains an exercise science mystery. Nevertheless, scientists, sports medicine physicians, elite athletes, and weekend exercisers agree that the pain is as real as it is temporary and that the discomfort can be minimized, if not eliminated.

Symptoms

Side stitches have two distinguishing symptoms. The first is a stabbing pain on the lower right side of the abdomen, and the second is pain that subsides almost immediately after the cessation of exercise. Side pain that persists regardless of exercise patterns is not exercise-related transient abdominal pain, and people who have that symptom should seek medical attention.

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