11/01/2026
One runner ate 26,000 calories to conquer 100 miles—and still lost weight.
Ultrarunner Camille Herron recently set the 100-mile world record at 12:41:11, and Outside Online tracked every detail of her nutrition strategy. She consumed 26,000 calories over those 12+ hours—roughly 2,000 calories per hour—including gels, sports drinks, soup, and even a burrito. Despite this massive intake, she still finished in a caloric deficit and lost weight during the race.
The eye-opening lesson: even when you're fueling aggressively, your body can't always absorb calories as fast as it burns them during intense endurance efforts. Herron's strategy focused on consuming easily digestible carbohydrates and minimizing the deficit as much as possible.
For those of us running marathons or long training runs, this shows why you can still bonk even when you think you're eating enough. Your gut has limits on how quickly it can process fuel, especially at higher intensities. The key is practicing your nutrition strategy during training—not just what you eat, but when and how much. Start fueling early in your run, before you feel depleted, and train your gut to handle nutrition on the move. What works in the kitchen doesn't always work at mile 20.
