Study links extreme running to colon polyps, but experts urge caution

A small but striking study out of Virginia has introduced a quiet question into the world of endurance running: whether the body's extraordinary adaptation to extreme distances might carry unintended consequences in the colon. An oncologist who noticed an unusual cluster of young, fit patients with advanced colorectal cancer—all serious distance runners—went on to find that nearly half of 94 extreme runners carried colon polyps, with 15 percent showing advanced lesions. The science remains preliminary and no causal link has been established, yet the finding invites a deeper reflection on the l