What causes a runner’s cramp?

a bad runners cramp or side stitch

Q: What is a runner’s cramp – that sharp stabbing pain that lasts for a few minutes when you run?

A: That pain you get sometimes while running or doing other endurance athletics, often referred to as a “runner’s cramp” or “side stitch,” is technically called exercise related transient abdominal pain (ETAP) in the medical world. It usually occurs on the right side of the abdomen and is described as sharp, stabbing, cramping, aching, or pulling.

It is extremely common – one research study found that 30% of runners in a single 14K race experienced a side stitch – but the reason we get them is not very well understood. There are a few theories as to what causes the pain: friction on the lining of the intestine; a lack of oxygen to the diaphragm; or maybe stretching and pulling of abdominal ligaments. This could explain why side stitches occur most commonly on the right because the liver is a large, right-sided organ with lots of ligaments.

Prevention of side stitches is not an exact science. Some research indicates that avoiding large, fatty meals three hours before running could decrease ETAP by decreasing the pulling on the abdominal ligaments. Taking a quick rest or decreasing exercise intensity can make it stop. Other maneuvers that may also be helpful include: breathing through pursed lips after deep inhalation or bending forward while tightening abdominal muscles. The most proven method, however, has been strengthening of the core muscles and improvement of general fitness.

Adam Brandeberry, Med IV (Ohio State College of Medicine)

John A. Vaughn, MD (Ohio State Student Health Services)