David Roche ran 100 miles through the Colorado mountains while eating almost 600 calories of carbohydrate an hour, and it rewrote the course record books.
Story Snapshot
- David Roche set a Leadville 100 course record in 15:12:30 while targeting roughly 150 grams of carbohydrate per hour, far above older sports nutrition guidance.
- Earlier in 2025 he told Men’s Health he planned to test 120 to 140 grams per hour, equal to about 500 calories, during the race.
- Standard endurance guidance has long capped intake near 90 grams per hour, meaning Roche’s approach pushes well past the traditional ceiling.
- Roche calls the strategy a deliberate “science experiment” built through months of gut training, not a last-minute gimmick.
A Record Run Built On An Unusual Fuel Plan
Roche crossed the Leadville 100 finish line in 15 hours, 12 minutes and 30 seconds, breaking the course record at one of ultrarunning’s toughest races. Runner’s World reported he aimed for roughly 150 grams of carbohydrate and 600 calories every hour of the race, delivered through a mix of gels and sports drinks. That pace of fueling is almost unheard of in distance running, where many recreational athletes get by on a fraction of that amount during long efforts.
Months before the record run, Roche had already gone public with his plan. Men’s Health reported in July 2025 that he intended to consume 120 to 140 grams of carbohydrate per hour at Leadville, testing specific levels of 120, 130 and 140 grams along the way. That earlier target already sat well above typical advice, and his race-day numbers climbed even higher.
From Standard Advice To A New Ceiling
For years, sports nutrition guidance told endurance athletes to cap intake around 90 grams of carbohydrate per hour for events lasting more than two or three hours, usually using a mix of glucose and fructose to help the gut absorb it all. That 90-gram figure shows up again and again in nutrition research and official guidance aimed at marathoners, cyclists and ultrarunners alike. Roche’s numbers blow past that long-standing ceiling by 30 to 60 grams an hour, depending on which reported figure you use.
Newer research has started testing whether trained athletes can push past 90 grams and still perform well, with some studies now exploring 120 grams per hour as a possible new benchmark for elite competitors. That shift in the science lines up with what Roche describes doing in competition, though his race numbers run even higher than most published studies have tested. The gap between lab research and Roche’s real-world race intake is part of what makes his story stand out.
Roche Frames It As An Experiment, Not A Shortcut
Roche has been open that this is a deliberate test, not a reckless one-off decision. In a public post from November 2024, he wrote that after consuming 120 to 140 grams of carbohydrate per hour at Leadville, he “desperately wanted more data to validate the science experiment”. That statement signals he sees his own racing as an ongoing trial, something he is actively trying to refine and understand rather than a settled formula he discovered by accident.
Outside magazine reported that Roche typically targets 120 to 150 grams of carbohydrate per hour in races, a number it contrasted with the one or two 25-gram gels per hour that many recreational runners consume. That comparison highlights just how far outside normal practice his fueling sits. Getting there wasn’t instant either; reaching those intake levels without stomach trouble generally requires weeks or months of deliberate gut training beforehand.
What This Means For Everyday Runners
Roche is an elite athlete racing at altitude, with a body and training history built over years to handle extreme physical stress. His results don’t automatically prove that weekend runners or first-time ultramarathoners can safely copy his exact numbers. Trying to jump straight to 150 grams an hour without any gut training is a recipe for the kind of mid-race stomach distress that has wrecked plenty of race days for less experienced athletes.
Still, the broader trend is hard to ignore. Sports science is clearly moving past the old 90-gram ceiling, and elite performances like Roche’s are part of the reason why. For ordinary runners, the practical takeaway isn’t to instantly chase 150 grams an hour. It’s to recognize that carbohydrate limits once treated as fixed science are being retested, and gradually, carefully training the gut to handle more fuel may be worth exploring under real guidance.
Sources:
menshealth.com, sports.yahoo.com, trailia.run, irunfar.com
