A brief overview of UTMB 2026 and what’s happening this week in Chamonix, France.
Chamonix, France, is buzzing as the UTMB 2026 festival of trail running gets underway. Eight total races will unfold across the Alps from August 24-30, including the three UTMB World Series Finals championship races.
The week carries an unmistakable edge of drama and anticipation: late withdrawals from stars like Kilian Jornet, Jim Walmsley, Tom Evans, Molly Seidel and Katie Schide have reshuffled the contenders in nearly every marquee race, opening the door for a fresh wave of favorites to make their mark. With new rules, expanded doping controls, and mounting local scrutiny over the event’s growth all playing out alongside the racing itself, this year’s edition promises as much intrigue off the trails as on them.
Here’s an overview of what’s on tap this week in Chamonix in advance of UTMB 2026.
(Note: All times are listed in CEST, which is six hours ahead of ET in the U.S. and nine hours ahead of PT.)
The Championship Races
The UTMB World Series Finals in Chamonix feature three championship-distance races this week, each tracing a different portion of the route around the Mont Blanc massif.
The OCC 50K
The OCC (Aug. 27, 8:15 a.m. CEST) is the shortest of the three, covering roughly 60K (about 37 miles) with 11,480 feet of climbing. It starts in the Swiss village of Orsières and finishes in Chamonix, France. There is big course change this year, featuring a redesigned high-altitude sector between Col de Balme and Col des Posettes, removing the traditional climb to La Flégère, and introducing a new high point at Tête de Balme (7,500 feet).
Women: Short-course trail world champion Tove Alexandersson of Sweden is the favorite stepping up in distance, but Swiss duo Judith Wyder and Maude Mathys are real threats. Ameriacns Lauren Gregory, Tabor Hemming, Ellaney Matarese and Makena Morley should also be top contenders. Olympic marathon bronze medalist Molly Seidel would have added star power in her trail crossover, but she decided on her arrival into Chamonix that she won’t be running afterall.
Men: Arguably the week’s deepest field pound-for-pound is the men’s OCC with Rémi Bonnet and Francesco Puppi rated above every runner at UTMB, including the 100-milers. World champ Frédéric Tranchand (France) joins them up front, with Christian Allen (U.S.), Daniel Pattis (Italy), Petter Engdahl (Sweden), and Roberto Delorenzi (Switzerland) filling out a fast, stacked start line.
MORE: Singletrack’s OCC Preview Show, Freetrail’s OCC Preview Show
The CCC 100K
The CCC (Aug. 28, 9:00 a.m. CEST) stretches about 101K (roughly 63 miles) with 19,900 feet of elevation gain. It begins in Courmayeur, Italy, crosses into Switzerland at the Grand Col Ferrett, send runners past Champex Lac, and finishes back in Chamonix—tracing the second half of the full UTMB route.
Women: Ameican Jenn Lichter, a breakout star of 2026, arrives as the clear favorite in the CCC after a record-breaking Western States win, especially because defending champ Martyna Mlynarczyk (Poland) is sitting this one out. China’s Miao Yao and past champions Yngvild Kaspersen (2023) and Toni McCann (2024) are her closest challengers while Americans Dani Moreno, Robyn Lesh, Klaire Rhodes, and Erin Clark also figure to be in the mix.
Men: With 2025 winner Francesco Puppi moving down to OCC, the CCC will have a first-time champion. Cristian Minoggio (Italy), David Sinclair (U.S.), and Daniel Jones (New Zealand) lead a wide-open contender group, backed by a strong Hannes Namberger (Germany) and additional American depth of Adam Peterman, Hans Troyer, Drew Holmen and Eli Hemming.
MORE: Freetrail’s CCC Preview Show, Singletrack’s CCC Preview Show
UTMB
UTMB (Aug. 28 at 5:45 p.m. CEST) itself is the flagship event: a full 174K (about 108 miles) loop around the Mont Blanc massif with roughly 33,000 feet of climbing. Unlike CCC and OCC, it both starts and finishes in Chamonix, passing through Italy and Switzerland before returning to where it began. Minor course changes include the famous Hoka light tunnel being pulled back closer to Les Contamines and the aid station of Trient no longer being accessible by runner support crews. (Learn more about the course and the best place to watch runners.)
Men: The race lost its top two names in one week—four-time winner Kilian Jornet withdrew ahead of planned knee surgery, while top American Jim Walmsley, the 2023 champion, scratched with knee trouble and illness, on top of defending champ Tom Evans’ earlier exit.
That clears the way for Americans Ben Dhiman (last year’s UTMB runner-up), Caleb Olson (the 2025 Western States 100 champion), Chris Myers (2025 Western States runner-up) and Rod Farvard (the 2024 Western States runner-up) to figure more prominently, with 2024 champ Vincent Bouillard (fresh off obliterating the Western States 100 course record), Frenchman Baptiste Chassagne, Germany’s Hannes Namberger, and Brits Jonathan Albon and Josh Wade all in the mix. Also, don’t sleep on American Zach Miller, who was second at UTMB in 2023 (his best among several strong finishes at UTMB since 2016) and fifth at Western States this year.
MORE: Singletrack’s UTMB Preview Show, Freetrail’s UTMB Preview Show
Read More: iRunFar’s UTMB Men’s Preview
Women: Course-record holder Katie Schide, an American who lives full-time in France, is out injured, but the rest of the star power remains. Defending champ Ruth Croft of New Zealand and three-time winner Courtney Dauwalter (U.S.), coming off another Hardrock 100 win, are the top headliners, but rumors have suggested that Croft is going to pull out this week. Americans Riley Brady (second at Western States), Rachel Entrekin (the outright winner of Cocodona 250), Abby Hall (2025 Western States champion) and Shea Aquilano (second at the JFK 50 last year), China’s Fuzhao Xiang, Nepal’s Sunmaya Budha, and France’s Blandine L’Hirondel are positioned as top threats to the podium.
Read More: iRunFar’s UTMB Women’s Preview
The Other Races
Beyond the three championship races, the UTMB 2026 week of racing includes five smaller events that round out the festival.
The MCC (Aug. 24 at 8:15 a.m.. CEST) covers about 40K with roughly 7,500 feet of climbing. It starts in Martigny-Combe, Switzerland, and finishes in Chamonix, but registration is prioritized for UTMB volunteers, local residents, and event partners rather than the general public.
The PTL (Aug. 24 at 8:00 a.m.. CEST) is the outlier of the week—a roughly 300K (186-mile), self-navigated team expedition with about 82,000 feet of climbing, done in teams of two or three without course markings or timed for an official ranking. It starts and finishes in Chamonix, opening the week with a Monday morning start and running on a time limit of around 151–152 hours, making it as much an endurance expedition as a race.
The TDS (Aug. 24 at 11:50 p.m. CEST) is the most prominent of these secondary races and is widely regarded as the week’s most technical and demanding course. It covers about 145K (about 90 miles) with roughly 31,000 feet of climbing—nearly as much elevation gain as the full UTMB in significantly less distance. It starts in Courmayeur, Italy, late at night and finishes in Chamonix, with the race running in the opposite direction around the massif from the UTMB and CCC. [Upate: Alyssa Clark finished third in the TDS on Tuesday night, crossing the line in 22 hours, 54 minutes and 19 seconds.]
The ETC (Aug. 25 at 2 p.m. CEST) is a shorter, more festival-style event: a 15K (9-mile) loop with about 3,937 feet of climbing, entirely within Courmayeur, Italy, where it both starts and finishes. Americans Taylor Stack and Courtney Coppinger could be contenders in this unique race.
The YCC (Aug. 26 at 11 a.m. CEST) consists of six different distances reserved for young runners, split into age-based formats (roughly 4K to 15K or 2.5 to 9 miles), based around Chamonix and Courmayeur.
UTMB Mont-Blac Race Livestream
How can you watch the racing action at UTMB 2026? You can watch the OCC, CCC and UTMB races play out in real time for free on the official livestream on FloTrack (registration required), which took over as UTMB’s official North American broadcast partner this year, joining a lineup of regional partners that carry the races elsewhere around the world. The same coverage is mirrored on UTMB’s own live platform. If you’d rather skip the full broadcast, a condensed highlight video for each race typically lands on the UTMB World Series YouTube channel within a couple of days of the finish, making that a solid free alternative to watching hours of live coverage.
Beyond the video feed, live.utmb.world is worth having open alongside the stream—it layers GPS live tracking, course maps, current standings, and projected arrival times onto the broadcast, which is especially handy if you’re mainly trying to follow one or two specific runners rather than watch the whole field.
A Challenge to Downsize
For trail runners and fans, there are 147 brand activations, fun runs, shoe drops and events all week long, including numerous fun runs. (There are more events in Chamonix than during the leadup to this year’s Boston Marathon!) However, UTMB is under pressure from the local citizens and new Chamonix mayor François-Xavier Laffin (who is a trail runner) has vowed to tone things down, asking brands not to host fun runs from the city center during UTMB 2026. However, it remains to be seen if or how that will be enforced.
Smaller regional disputes are simmering too. Outside of Chamonix, other communities that host UTMB-affiliated races elsewhere in France have started pushing back on similar grounds—some towns have restricted nighttime access to communal forests or refused to allow races through their land entirely, forcing the organization to reroute future events. It’s part of a broader pattern of local governments testing the limits of how much large-scale trail racing their landscapes can absorb.
New Headlamp Rule
For the first time, runners in UTMB 2026 must carry a headlamp with a red-light setting, and that setting becomes mandatory through the Réserve des Contamines-Montjoie section of the course. Organizers say the rule is meant to protect the reserve’s nocturnal wildlife from the disruption of thousands of white headlamps passing through overnight. Petzl has been distributing free red filters compatible with its headlamps at retailers in Chamonix and Courmayeur to help runners comply.
The mandatory kit list—including the two-headlamp requirement—is shared across the UTMB, CCC, OCC, and TDS, but the red-light requirement itself applies only to the UTMB, within a roughly 6K to 7K stretch of the Contamines-Montjoie Nature Reserve around the 40K mark, between the Nant-Borrant refuge and the Col du Bonhomme. That section is mostly uphill and non-technical, which is part of why organizers felt comfortable requiring the dimmer light there.
Drug Testing Has Doubled
The race organization says it has roughly doubled the number of drug tests conducted across the UTMB 2026 week of racing, and for the first time the expanded testing reaches age-group and recreational entrants, not just the elite fields. The move comes a year after Kenyan runner Joyline Chepngeno was stripped of her 2025 OCC title following a doping violation detected at an unrelated race, with the title retroactively awarded to runner-up Miao Yao.
Other Interesting UTMB Bits
- There are several film premieres happening during UTMB 2026, including “Lazarus Lake, The Hillbilly Scientist” about Barkley Marathons founder Gary Cantrell, “One Step at a Time” about Francessco Puppi’s second-place finish at Western States, and “Ultra-trail du Mont-Blanc, la Course de Leur Vie,” the documentary about Ruth Croft’s UTMB win last year.
- Check out this reel about six women from Renegade Running’s trail running program who will be racing the OCC or CCC in Chamonix.
- Meta Endurance did an analysis of the entries of all the races this week, while Matt Trappe opines aloud that UTMB might be on the verge of a turning point.
- Running influencer Laura Green did her best imitation of Courtney Dauwalter—at least the candy part—with a kit that Salomon sent her.
- British ultrarunner Jake Catterall completed all eight of the races of UTMB week on his own this past week with help of a support crew in what he called one super loop. That’s 892K (or 554 miles) and 200,131 feet of vertical gain and loss in about 12.5 days.
- Running Crews highlights UTMB’s growth in this article about “How Brands Took Over UTMB.”
- In this video, American ultra legend Karl Meltzer talks about the details of selling his Speedgoat trail running race to UTMB.
- A little more than a week after participating in Last Soul Ultra (21 loops, 87.5 miles) in Germany, Andrew Glaze finished the Leadville 100 early Sunday morning in Colorado. Now he’s traveling to Chamonix to run UTMB.
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