Pain in the left side of the abdomen is a common symptom during exercise. It is more common in medium to long distance running and marathons, and may be related to spasms in the gastrointestinal tract during exercise, such as exercising too early after meals, eating too much or exercising on an empty stomach. Pain in the lower chest, located in the area covered by the ribs, may be mistaken for left abdominal pain when the breathing rhythm is not observed during exercise, causing the respiratory muscles to spasm. The pain may be misinterpreted as left abdominal pain. It is usually relieved slowly with proper rest after stopping exercise. Running left abdominal pain may be related to inflammation or lesions in the lower left abdomen itself, induced during running, commonly associated with enterocolitis, larger cysts in the left ovary, chronic pelvic inflammatory disease, etc.