The sharp, localized discomfort known as a “stitch” is familiar to nearly everyone who exercises regularly. This sudden pain in the side, often occurring during running or swimming, can be intense enough to force a stop in activity. It is generally a harmless and temporary experience that resolves quickly after slowing down or resting.
What is a Stitch and Where Does it Occur
The medical term for this common athletic complaint is Exercise-Related Transient Abdominal Pain (ETAP). This name reflects the condition’s nature: temporary abdominal pain brought on by physical exertion. Studies show that a large percentage of runners experience an episode each year.
The location of the pain is typically felt just below the rib cage, most frequently in the right upper quadrant of the abdomen. Although the pain can be sharp and stabbing, it is considered a benign condition that does not indicate a serious underlying health problem.
Primary Scientific Theories for the Pain
Scientists have explored several distinct hypotheses to explain the mechanism behind ETAP, as no single cause has been definitively proven.
Visceral Ligament Stress
One leading theory focuses on the stress placed on the visceral ligaments, which are connective tissues that anchor internal organs like the liver and stomach to the diaphragm. The repetitive jarring motion of activities such as running causes these organs to tug downward, pulling on the ligaments and irritating the diaphragm. This mechanical stress is intensified when the stomach is full, which is why a stitch is more likely after eating or drinking.
Parietal Peritoneum Irritation
A second theory suggests the pain originates from the irritation of the parietal peritoneum, a thin membrane that lines the inner abdominal wall. This membrane is rich in nerve endings, making it highly sensitive to friction or movement. Friction between the abdominal organs and this lining, possibly due to a full stomach, causes the sharp, localized pain.
Diaphragmatic Ischemia
A third explanation centers on the diaphragm, the dome-shaped muscle responsible for breathing, proposing that the pain is a type of muscle cramp or spasm. This diaphragmatic ischemia theory suggests that during intense exercise, blood is diverted away from the diaphragm to the working limb muscles. The resulting lack of sufficient oxygen supply causes the muscle to cramp. However, evidence that ETAP occurs in activities of low respiratory demand, like horseback riding, suggests the mechanism is more complex than simple oxygen deprivation.
Stopping a Stitch Once it Starts
Once a stitch begins, the priority is to reduce the intensity of the pain and allow the affected area to recover. The most direct approach is to slow the exercise pace or stop completely, switching to a walk until the discomfort subsides. This reduction in activity lessens the jarring motion that may be irritating the abdominal structures.
Focusing on deep, controlled breathing can also help ease a stitch. Techniques like taking deep “belly breaths,” which fully engage the diaphragm, can help stretch the muscle and increase oxygen flow to the area. Some individuals find relief by exhaling forcefully through pursed lips while simultaneously engaging the abdominal muscles.
Physical interventions can also be applied directly to the site of the pain. Pressing two fingers firmly into the painful area and holding the pressure for several seconds while breathing deeply can often reduce the severity of the cramp. Additionally, stretching the affected side by raising the arm overhead and gently bending the torso away from the pain can help lengthen the abdominal muscles and surrounding ligaments.
Strategies for Long-Term Prevention
Preventing a stitch involves pre-exercise planning and adjustments to form and fitness level.
Dietary Adjustments
Timing meals correctly is a simple yet effective preventative measure, as a full stomach exacerbates the visceral traction theory. Experts advise avoiding large meals for at least two hours before engaging in physical activity. Highly concentrated sugary drinks should also be avoided immediately before exercise, as they can slow stomach emptying and increase the likelihood of a stitch.
Warm-up and Pacing
Proper preparation for activity, including a thorough warm-up, can also reduce the risk of an ETAP episode. Gradually increasing exercise intensity allows the body to adapt to the demands of the workout. Starting too fast can shock the system and trigger the pain.
Core Strengthening
Strengthening the core muscles plays a structural role in long-term prevention. Stronger abdominal and trunk muscles help stabilize the torso, which limits the excessive movement and strain on the ligaments that connect the organs to the diaphragm. This improved stability can reduce the jarring impact during high-motion activities like running, thus decreasing the likelihood of irritation to the abdominal lining.