A closer look
Running 100 miles through a desert proves you have incredible stamina and zero regard for your intestinal lining. During extreme endurance sports, the body violently shunts blood away from the digestive tract to feed screaming leg muscles. This severe lack of oxygen literally causes the tight junctions in the gut barrier to fall apart. Endotoxins from fecal bacteria then leak freely into the bloodstream, triggering systemic inflammation and proving that ultramarathons are fundamentally an exercise in controlled self-poisoning.
