The abdominal muscles, collectively known as the core, support the trunk and link the upper and lower body. Soreness in this area after a run is a frequent complaint among runners of all ability levels. This post-run discomfort often signals that these muscles have been significantly engaged. This article explores the reasons why abdominal pain occurs after running, ranging from normal muscle adaptation to issues with running mechanics.
Explaining the Core’s Role in Running
The core’s primary function during running is not to create movement but to prevent unwanted movement, acting as a crucial stabilizer for the spine and pelvis. When running, the arms and legs move in opposition, naturally creating significant rotational forces throughout the torso. The abdominal muscles, including the obliques and the deeper transverse abdominis, work tirelessly to resist this twisting motion, a function known as anti-rotation.
With every foot strike, the core also engages in anti-extension, preventing the lower back from arching excessively due to the repetitive ground reaction forces. This constant, high-demand isometric and eccentric control leads to microscopic damage in the muscle fibers. This is the source of Delayed Onset Muscle Soreness (DOMS), which typically peaks 24 to 72 hours after a challenging run. If the core fatigues, other muscles must compensate, which can result in generalized soreness across the entire abdominal region.
Specific Causes Related to Running Form
Beyond general fatigue, specific issues with running form can place unusual stress on the abdominal muscles, leading to pain. Poor posture, such as slouching or an excessive forward lean from the hips, can limit the diaphragm’s movement and shorten or over-lengthen certain core muscles. This misalignment forces the abdominal wall to work inefficiently to maintain balance, accelerating muscle fatigue.
Another common issue is Exercise-Related Transient Abdominal Pain (ETAP), more commonly known as a side stitch. This sharp, stabbing pain occurs just under the lower edge of the ribcage. While its precise cause is unknown, one prominent theory suggests it results from irritation of the parietal peritoneum, the membrane lining the abdominal cavity. This irritation is often exacerbated by a full stomach or shallow breathing, which prevents the diaphragm from fully descending. This puts additional strain on surrounding ligaments, manifesting as the cramping sensation of a side stitch.
When to Seek Medical Advice and Prevention
While most post-run abdominal pain is temporary muscle soreness, some symptoms warrant medical attention to rule out a more serious condition. A sharp, sudden pain that occurs during the run, accompanied by a visible bulge or lump in the abdomen, could indicate a muscle strain or a hernia. Pain that does not subside with rest, is severe, or is accompanied by nausea, vomiting, or fever should be evaluated by a healthcare professional immediately.
To prevent common core soreness, focus on incorporating anti-movement exercises into your strength routine, such as planks, side planks, and dead bugs. These movements specifically train the core to resist rotation and extension, mirroring its function during running. Proper hydration and allowing a two to three-hour window between a large meal and running can help reduce the likelihood of a side stitch. Finally, concentrating on a tall, upright posture with a slight forward lean from the ankles, along with maintaining an efficient running cadence, will help minimize unnecessary torso movement and reduce the load on the stabilizing core muscles.