# Why Side Pain Strikes Runners and How to Stop It
Side stitches plague up to 70 percent of runners annually, yet the exact cause remains debated among exercise scientists. The condition, formally called exercise-related transient abdominal pain or ETAP, appears to stem from multiple triggers working together.
Breathing patterns likely play a central role. When runners synchronize their breath with footfalls, irregular breathing may irritate the phrenic nerve, which controls the diaphragm. Changes in blood flow around the diaphragm during intense exercise may also contribute. Poor posture creates additional strain on the core muscles and abdominal tissues, making pain more likely.
Several practical steps address ETAP during a run. Slowing your pace reduces the mechanical stress on your diaphragm. Stretching by raising your arms overhead and leaning away from the pain site lengthens the affected muscles. Applying gentle pressure to the cramped area while breathing deeply sometimes provides immediate relief.
Prevention works better than treatment. Runners should practice mindful breathing during exercise rather than letting it happen unconsciously. Timing matters for nutrition: avoid large meals or beverages two hours before running. Core strength training strengthens the stabilizing muscles that support your diaphragm and abdominal wall. Proper hydration prevents cramping, though excessive fluid intake right before exercise can trigger problems.
Gradual increases in running intensity and distance give your body time to adapt. When you ramp up too quickly, your breathing system cannot keep pace with your body's demands, increasing ETAP risk.
Most side stitches resolve on their own within minutes of slowing down or stopping. They cause no lasting damage, though the sharp pain feels concerning in the moment. Runners who consistently address breathing, posture, and core strength rarely experience repeat episodes.