The OCC has seen a massive 29% increase in elite participation compared to 2024. And a big part of that is likely due to the close proximity of the World Championships in Canfranc, Spain which take place every two years and this year will be held from, September 24–27.
Some federations have stopped their athletes from running both the full UTMB and the World Champs, while in other cases some athletes appear to have decided for themselves that it would be difficult to be in peak form for both events.
However that’s good news for OCC and the 2023 UTMB winner Jim Walmsley lines up here after what’s been a stop-start season due to injury.
While it’s a 57km route, the OCC is the 50K category final for the UTMB World Series.
Read on to find out more about the route, the event’s history and those super-strong fields as we run through some of the leading contenders.
Follow LIVE
There’s better coverage than ever this year for OCC, CCC and UTMB.
The OCC coverage starts at 07:45 local (CET) time on Thursday 28th August 2025, with the race itself getting under way at 08:15. That’s 07:15 in the UK and 02:15 Eastern Time.
The livestream, live tracking and live results will all be available via this link.
The broadcast will be available in five languages (French, English, Spanish, Italian and Chinese) and brought to life by 15 commentators.
You can also follow the event via the following major broadcasters:
In France (Groupe L’Équipe), United States and Canada (Outside TV and Trail Runner), and China (Shinai Sports / iQIYI Sports and RunYeah). The UTMB World Series has also teamed up with DAZN, the world’s leading live sports streaming service, and Eurovision Sport, EBU’s streaming platform, to strengthen coverage across Europe and worldwide.
UTMB OCC
start list
Click here for the full start list and check out the analysis section below for our run through the leading contenders.
Notable runners
Route
The OCC begins in Orsières in Switzerland and finishes in Chamonix, France. The route offers up breathtaking views of the valley and the peaks of the eastern flanks of Mont Blanc.
This year (there are often tiny changes each edition) it covers 57km and features just over 3,500 metres of climbing.
Beginning with the unique Swiss landscapes, the route heads to Champex-Lac and Trient. Runners then cross the Franco-Swiss border by the Balme pass.
The final climb heads up to La Flégère and then it’s downhill all the way to the centre of Chamonix.
Analysis
Given Jim Walmsley‘s presence, we’ll start with the men.
The American has the highest UTMB Index rating of 945 and is dropping down markedly in trip. While there have been frustrations this year, it shouldn’t be forgotten that he won the battle of the last three UTMB winners when seeing off Kilian Jornet and Vincent Bouillard in brilliant style at Chianti Ultra Trail by UTMB in March.
Italy also fields Luca Del Pero (UTMB Index 918) and Davide Magnini (UTMB Index 913), both proven over short, high-intensity formats. Antonio Martinez Perez (ESP, UTMB Index 913) adds speed and technical flair, while Andrzej Witek (POL, UTMB Index 905) and Ezekiel Rutto (KEN, UTMB Index 901) complete an international top 10 of outstanding quality.
In terms of the women’s field, Swiss athlete Judith Wyder (UTMB Index 804), a former orienteering star turned trail runner, starts as the favourite.
She will face defending champion OCC Miao Yao (CHN, UTMB Index 800), renowned for her strength on fast courses, and Joyline Chepngeno (KEN, UTMB Index 797), who burst onto the scene in 2024 with victory at the iconic Sierre-Zinal and now lines up as one of the favourites.
Completing the top contenders are Theres Leboeuf (SUI, UTMB Index 770), Jazmine Lowther (CAN, UTMB Index 769), and Rosanna Buchauer (GER, UTMB Index 768), all well-suited to this profile.
Previous winners
The winners from the last 10 years of OCC are as follows:
Men
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- 2015 Marc Pinsach Rubirola (ESP)
- 2016 Xavier Thevenard (FRA)
- 2017 Marc Lauenstein (SUI)
- 2018 Erenjia Jia (CHI)
- 2019 Stian Angermund (NOR)
- 2020 Cancelled
- 2021 Jon Albon (UK)
- 2022 Manuel Merillas (ESP)
- 2023 Stian Angermund (NOR)
- 2024 Eli Hemming (USA)
Women
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- 2015 Celia Chiron (FRA)
- 2016 Mercedes Arcos Zafra (ESP)
- 2017 Eli Gordon Rodriguez (ESP)
- 2018 Ruth Croft (NZ)
- 2019 Ruth Croft (NZ)
- 2020 Cancelled
- 2021 Blandine L’Hirondel (FRA)
- 2022 Sheila Aviles Castano (ESP)
- 2023 Toni McCann (RSA)
- 2024 Miao Yao (CHN)
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Past winners
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