Wemcast

What does it take to finish one of the most extreme endurance races on the planet?In this episode of the World Extreme Medicine Podcast, host Eoin Walker is joined by ultra-endurance athlete Sébastien Marlier, who recently completed the Bretzel Ultra Triathlon — a continuous event five times longer than a standard Ironman.With 19km of swimming, 900km of cycling, and 211km of running, this race demands everything from the human body — and mind. Sébastien unpacks his physical and psychological preparation, from training his digestion system to handle real food, to using mental conditioning tools like the “thermometer” and “VACOG” techniques to stay grounded under pressure.We explore:How he adapted his nutrition and hydration to avoid fatigue and GI distressWhy mental resilience tools were key to finishing strongThe role of ego, emotion, and community in ultra-endurance performanceWhat he’d do differently next time (hint: sunscreen and compression socks!)Lessons from pain, recovery, and the post-race crashSébast