Explaining: Keto vs High-Carb for Marathon Training

MARATHON Readiness Quiz:https://marathon-readiness-quiz.scoreapp.comMarathon Carb and Fuelling Guide:https://www.runfastandfree.com/free-tools⸻In this video, I wanted to give my take on the debate surrounding Keto (high-fat) vs high-carb diets for marathon training from a competitive performance perspective.Yes, fat adaptation is trending (something always is 🙄). But what actually happens when you test it at marathon pace?I approached this topic from all angles while giving fat adaptation a fair shake. Starting with the physiology and why carbohydrate and fat aren’t interchangeable at race intensity, how glycogen depletion actually happens, and why running economy changes when fuel availability shifts. From there, we look at the most rigorous research ever conducted on this topic: the Supernova studies led by Louise Burke at the Australian Institute of Sport. Before finally breaking down the applied side of the debate: practical marathon fuelling strategies, carbohydrate intake per hour, glucose-to-fructose ratios, gut training, and what I’ve observed over 15 years coaching more than 1,500 runners preparing for everything from Boston qualifiers to international competition.If you’ve ever hit the wall late in a marathon, questioned whether cutting carbs might make you more efficient, or wondered how to fuel properly for marathon pace, this video should hopefully give you a clearer framework for thinking about performance at competitive intensity.Happy Training!⸻Relevant LinksOriginal Supernova Study:https://pmc.ncbi.nlm.nih.gov/articles/PMC5407976/Get my book, Fast and Free:https://a.co/d/00twBZ6dGet coached by Brant Stachel: https://teamrunrun.com/coach/brant-stachel-kingston-ontario-running-coach/Mental Performance Coaching with Brant Stachel: https://calendly.com/cepadminteam/15-minute-intake-call-clone?month=2026-01Learn More about Team RunRun: https://teamrunrun.com/Fuel your training: https://fuelgoods.com/?ref=Brant⸻About MeI’m Brant Stachel — former National Team running coach, Registered Psychotherapist, and Mental Performance Coach. I work with runners across all levels, helping them train smarter, pace races properly, and perform when it counts.⸻Follow Fast & Free CoachingInstagram: www.instagram.com/fastandfreecoaching/YouTube: @FastandFreeCoachingWebsite: http://runfastandfree.comSubstack: https://fastandfree.substack.com/TikTok: https://www.tiktok.com/@brantstachel