Hey! The % gain is self-reported, from post-race surveys we push to users. So it's not a controlled before/after, more a proxy. Worth flagging there's selection

Hey! The % gain is self-reported, from post-race surveys we push to users. So it's not a controlled before/after, more a proxy. Worth flagging there's selection bias too, the users motivated enough to fill out a survey after finishing a race were probably also the ones who stuck with the plan. Gut training is basically progressive overload for carb absorption. Your gut has a ceiling on how many grams of carbs it can process per hour before you get GI distress, but that ceiling isn't fixed, you raise it by repeatedly practicing high carb intake in training until your body adapts. Almost nobody trains this, then tries to hit 90g/hr for the first time on race day and blows up. It's probably the most skipped part of endurance prep.