Physical exercise has been related with both beneficial effects on the gastrointestinal tract as with adverse effects on the latter. Gastrointestinal bleeding is one of these. In general, gastrointestinal bleeding is transient and mild. However, some cases caused by intestinal ischemia can sometimes be more serious due to the amount of bleeding and the presence of mucosal lesions. We present the case of a patient with abdominal pain and rectal bleeding caused by an extensive ischemic colitis due to vigorous physical exercise.