David Roche's record run puts endurance fueling in the spotlight
Ultrarunner and coach David Roche has helped bring a high-carbohydrate fueling strategy into focus after setting a new Leadville Trail 100 record. In August 2025, he completed the Colorado race in 15:12:30, improving on his previous record of 15:26:34.
Roche has described consuming roughly 120 to 140 grams of carbohydrates per hour during races. The approach aims to supply energy for sustained effort, and he has said it also supports his training and recovery. He built up to that intake gradually, practicing with gels and drinks to help his stomach adapt.
But his results do not establish that very high carbohydrate intake is right for every runner. Coaches interviewed in the article say fueling needs depend on factors such as pace, race duration, fitness and an athlete's ability to tolerate food while running. Taking in more than the body can use may cause gastrointestinal discomfort, while slower efforts generally demand less energy per hour.
The evidence for high-carb fueling in ultrarunning remains limited, in part because it is difficult to conduct controlled studies of all-out, 100-mile races. The strategy has a longer history in elite cycling, but experts caution against copying top athletes' intake without preparation. Their common advice: test a personal plan during training and increase intake carefully.
Roche's performances make high-carb fueling an intriguing option, not a universal formula. As endurance science develops, more individualized nutrition plans may help runners match their fueling to the demands of their own races.
