The OCC is one of the, if not 'the' most competitive 50 km mountain trail races in the world. The 50k category final for the UTMB World Series.
It is normally around 45 km long with 3,400 m of elevation, linking up three towns: Orsières, Champex and Chamonix. It has historically been a true test of durability or as the organisation defines: ‘The ultimate challenge for mid-distance ultra-runners’.
2025 OCC Course Changes, from 45 to 61 km
This year, it was made even more competitive by the participation of many longer-distance runners who are doubling up with the World Mountain and Trail Running Championships (due to take place at the end of September). And the weather threw an unexpected surprise, forcing the organisation to avoid some of the higher parts of the course and turning the OCC into a longer race: 61 km with the same 3,400 m of elevation.
Kris Jones’ Road to the 2025 OCC, Consistent Training and Bold Choices
Last year, Elite Trail Team Athlete, Kris Jones finished an impressive sixth in 5:27. This year, he returned to the Swiss and French Alps determined to take the next step.
That phrase 'the next step' captures Kris’s entire approach. Instead of chasing massive training jumps, he’s focused on consistent, incremental progress. But for 2025, he also made a bold decision: working parttime to invest more time in training, recovery, and the mountains. It was his first big professional shift, and it showed.
Strong Start and Weather Shift
From the start in Orsières, Kris looked composed. He stayed conservative on the first climb to Champex-Lac, running the exact same heart rate as in 2024 but with a faster split. Our Train.Red muscle oxygen data underlines that efficiency. His SmO₂ dropped with the sustained effort but recovered quickly on the descent, a sign of fitness and pacing control.
Less than 24 hours before the start of the race, marshalls notified all athletes that start time and course would be adjusted to avoid technical terrain during the rain. The altered course made the race less technical and added a flat 10 km run to Chamonix, turning the final into a durability test.
Col de Balme. Where the Race Was Decided
The real crux came on the massive climb to Col de Balme. Here Kris shone. Muscle oxygen data shows his ability to hold a strong rhythm, gradually deoxygenating as the climb wore on but never bottoming out. Just like in training, he found a smooth, efficient cadence. He moved past rivals, even catching sight of Jim Walmsley, who was leading the race.
At that point, it looked like Kris might be headed for the podium. But as he crested the climb and began descending, fatigue caught up. Cramping twinges in his calf forced him to back off. Muscle oxygen traces mirror this: instead of the typical rebound during descents, his recovery plateaued. His legs were working defensively, not offensively. Christian Minoggio and then Petter Engdahl slipped past, and Kris had to fight hard to hold onto fifth.
Muscle Oxygen Data Reveals Hidden Insights in Ultra-Trail Racing
Jim Walmsley, meanwhile, managed his race to perfection. Where Kris’s oxygenation curves showed late-race strain, Walmsley maintained rhythm and composure (except for a small sliding) all the way into Chamonix, taking the win by just over five minutes. At this level, those margins are everything.
For Kris, the result was still a success: fifth place, one better than last year, and a clear sign that the move towards greater professionalism is paying off. He executed his plan, improved on 2024, and kept himself in the fight at the sharp end of one of the deepest trail fields in the world.
Muscle oxygenation helps us see the story beneath the splits: the controlled early effort, the strong climb, the signs of fatigue on the descent. It confirms what Kris wrote himself that he is on the right path.
Progress doesn’t always come in leaps. Sometimes it’s about taking the next step, again and again, and again.
We are excited to see Kris take the next step at the World Mountain and Trail Running Championships later this month. Follow his journey and the Elite Trail Team at their respective socials.
