Physiological, nutritional and thermoregulatory responses of a world-class ultra-endurance athlete during Western States ⛰️
Coolest study of the year?
Physiological, nutritional and thermoregulatory responses of a world-class mountain-ultramarathon athlete during the 2025 Western States Endurance Run 100.
Study Details
This new case study examined Kilian Jornet’s 2025 Western States 100 mile race performance where he finished in…
⏱️ 14:19:22
🥉 3rd place overall
🏆 Within 10 mins of the course record
Here are the facts behind his performance ⬇️
Key Findings
🔥 Total energy expenditure = 16,104 kcal (18.8 kcal/min)
🍽️ Total energy intake = 6,720 kcal
🍞 Carbohydrate intake = 86 g/hr
🥤 Total fluid intake = 12.5 L
💧 Drinking rate = 0.87 L/hr
🧂 Total sodium intake = 18.5 g
⚖️ Bodyweight loss = -2.5 kg (-4.3%)
🌡️ Mean core temperature = 37.1 °C
📈 Peak core temperature = 39.4 °C
🥣 Pre-race meal = overnight oats, berries and honey (350 kcal, 60g carbs, < 10g fat)
In-race nutrition (0 - 4 hrs / 0 - 46 km):
🎯 50% carbs / 50% fat mix
🥑 Avocado, coconut oil, nuts, dates, banana, overnight oats, cacao powder, beetroot
In-race nutrition (4 - 9 hrs / 46 - 102 km):
🎯 80 g/hr carbs + 10 g/hr fat
🍫 Maurten 160 gels, jellies/soft bars, rice cakes, 50% fat + 50% carb drinks
In-race nutrition (9 - 14.3 hrs / 102 - 161 km):
🎯 110 g/hr via gels (Maurten 160)
Conclusion
Ridiculously cool study and some of the most interesting data exploring the limits of human endurance performance 🫀
An important note that even world class athletes incorporate whole foods as part of their race nutrition strategy 🍽️
Reference
https://journals.physiology.org/doi/abs/10.1152/japplphysiol.01048.2025
Performance Nutrition Digest is powered by Healthspan Elite ⚡️
Healthspan Elite is a science-led sports nutrition range developed in collaboration with leading experts to support athletic performance, recovery, and health.
Use code: TCDIGEST25 for 25% off at https://www.healthspanelite.co.uk/ 💪