Mastering Mid-Run Fueling: Gels, Carbs & the Science of Avoiding the Bonk

New to the podcast? Start here → ⁠The Injury-Proof Half Marathon SystemMost runners hit the wall not because they’re out of fitness, but because they’re out of fuel. In this episode, Coaches Chris and Maya break down the real science behind mid-run fueling so you can avoid bonking, run stronger, and finish faster.We unpack everything from glucose vs fructose transporters, to sodium co-transport, to how caffeine enhances endurance — all in a clear, actionable way you can apply immediately to your long runs and half marathon race day.What you'll learn: Why your body only stores ~90 minutes of run-ready glycogen Why simple carbs (not bars or whole foods) are essential during long runs The gut’s “traffic jam” limit: why glucose-only gels cause GI issues How dual-fuel gels (glucose + fructose) unlock 90g/hr carb absorption How to avoid the most common fueling mistakes that lead to cramping and nausea The role of sodium in absorption, hydration, and preventing hyponatremia How and when to use caffeinated gels for a performance boost A proven mile-by-mile fueling pattern for a strong half marathon How to “train your gut” so fueling becomes effortless on race dayShow Notes: Take your first gel between minutes 45–60 Aim for 60g carbs/hour (up to 90g/hr if using glucose + fructose) Use sodium to support absorption & hydration Take caffeinated gels late in the race for a mental/physical boost Practice fueling in training to prevent stomach issuesRead more at HalfMarathonTrainingPlan.com