Experiencing pain in the side or upper abdomen while running is a common occurrence for many individuals. This sensation, often described as a sharp or cramping feeling, can be alarming and lead runners to believe their liver is the source of discomfort. However, this pain is typically not related to the liver itself and is a benign issue known as a “side stitch” or exercise-related transient abdominal pain (ETAP). Approximately 70% of runners report experiencing this phenomenon annually, and it can affect individuals of all fitness levels. While the feeling can be intense enough to disrupt a run, it is generally not a sign of a serious medical problem.
What Causes the Discomfort
The pain known as a “side stitch” or ETAP is a localized sensation most often felt in the mid-abdomen, frequently on the right side below the ribs. Researchers still do not fully understand the exact cause, but several theories exist. One theory suggests irritation of the parietal peritoneum, a thin membrane lining the abdominal and pelvic cavities, is a factor. This irritation might occur due to repetitive movements during exercise, causing friction between the membrane and internal organs, especially when the stomach is full.
Another explanation points to spasms of the diaphragm, the large, dome-shaped muscle at the base of the lungs that plays a role in breathing. Like any other muscle, the diaphragm can fatigue and cramp under stress during strenuous exercise. Shallow or chest breathing, rather than deep belly breathing, can contribute by not providing enough oxygen and placing more stress on its surrounding muscles and ligaments, leading to the diaphragm working harder and potentially spasming.
Ligamentous stress also plays a role, concerning the ligaments that connect abdominal organs to the diaphragm. The jarring, up-and-down motion of running can tug on these ligaments, especially those supporting organs like the liver, located on the right side. When exhalation occurs simultaneously with the right foot striking the ground, it can create a downward pull on the liver while the diaphragm moves upward, straining the connecting ligaments and potentially causing a stitch. Reduced blood flow to the diaphragm during exertion (diaphragmatic ischemia) is another factor, as blood redirects to working muscles.
Strategies for Prevention
Proper breathing techniques can significantly reduce the occurrence of side stitches. Deep belly breathing, or diaphragmatic breathing, helps ensure the diaphragm fully descends during inhalation and relaxes during exhalation, optimizing oxygen delivery and reducing stress on the muscle. Practicing rhythmic breathing, such as inhaling for three steps and exhaling for two, can also help regulate breath and prevent strain. Avoiding shallow, rapid chest breathing is important, as it can lead to diaphragm fatigue.
A warm-up before running prepares the body for exertion by increasing blood flow and gradually adjusting breathing patterns. Starting slowly and gradually increasing intensity allows the body to adapt to exercise demands, preventing the diaphragm from becoming overworked. Maintaining good posture while running contributes to prevention, as a slumped or hunched position can restrict breathing and increase diaphragm pressure. Running with a straight back and relaxed shoulders supports better respiratory mechanics.
Strengthening core muscles provides torso stability and supports internal organs, reducing diaphragm strain and its connecting ligaments during repetitive movements. Incorporating core-strengthening exercises like planks makes abdominal muscles more resilient to fatigue. Adequate hydration is also important, as dehydration can contribute to muscle fatigue and spasms. While staying well-hydrated throughout the day is beneficial, avoid consuming large volumes of fluids, especially sugary or carbonated drinks, immediately before a run.
Dietary choices before a run can influence the likelihood of experiencing a side stitch. Consuming large meals, particularly those high in fat or fiber, within one to two hours before exercise can divert blood flow to the digestive system, potentially reducing oxygen availability to the diaphragm. A light, easily digestible snack a couple of hours prior to running is generally recommended. Gradually increasing running intensity and distance allows the body to adapt and build endurance, making respiratory muscles more resilient.
When to Consult a Doctor
While most pain during running is side stitches, certain symptoms warrant medical evaluation. If abdominal pain is persistent, severe, or unusual, consult a healthcare professional. Pain that does not resolve with rest or home care, or occurs even when not exercising, could indicate an underlying condition.
Other symptoms prompting a doctor’s visit include fever, nausea and vomiting that do not subside, changes in bowel habits (e.g., bloody stools or severe diarrhea), or unexplained weight loss. Though rare, abdominal pain during intense exercise can sometimes be linked to serious conditions like intestinal ischemia, where blood flow to the intestines is reduced. Musculoskeletal issues, digestive problems unrelated to side stitches, or a hernia can also cause abdominal discomfort during physical activity; a medical professional can help differentiate these causes.