In this episode of Lift Heavy Run Fast, host Jeroen van der Mark sits down with Dutch ultra-athlete and physiotherapist Xander Bijsterveld, who recently completed an extreme 100 km ultratrail in the Swiss Alps with 6250 meters of elevation gain.

We dive into his full preparation: training structure, pacing, nutrition, tendon management, and how he stays strong while pushing his endurance to the limit. Xander continues to hit PRs in the gym while taking on brutal mountain ultras — how is that even possible?

Topics

• Was this the hardest challenge Xander has ever done?
• How he structured his training for a 100 km with massive elevation
• Flat ultras vs. mountain ultras: what’s the difference?
• How to prep for elevation when you live in a flat country
• Managing tendon load, niggles and accumulated fatigue
• How he tapered into race week
• Xander’s full nutrition strategy (carbs, fluids, electrolytes)
• His pacing approach for a 10+ hour effort
• Common mistakes ultra athletes make
• How he recovered physically and mentally

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👉 YouTube: Lift Heavy Run Fast