Severe abdominal pain after running may be related to factors such as gas, cholecystitis or dysmenorrhea. 1. Breathlessness: When you suddenly do a lot of activities after a long period of lack of exercise or without doing the necessary preparatory activities, it is easy to cause diaphragmatic spasm, resulting in severe abdominal pain after running. 2. Cholecystitis: If the gallbladder is infected by bacteria or there are gallbladder stones, running can easily bring stimulation to the gallbladder area, inducing cholecystitis, which can cause severe abdominal pain after running. 3. Menstrual cramps: If women run a lot during menstruation, it will cause strong stimulation to the uterus, which will easily lead to severe contractions causing menstrual cramps and severe abdominal pain after running. There are many other causes of severe abdominal pain after running, if the symptoms are serious or continue to see no improvement, it is recommended to go to the regular hospital in a timely manner, after clarifying the cause of the disease, under the guidance of the doctor for targeted treatment.