Ultra-Trail du Mont-Blanc
The ultimate mountain ultra -- a circumnavigation of Mont Blanc through three countries.
Chamonix, France
Late August
171 km
10,000 m
~2,500 (UTMB race) athletes
Course Highlights
- Chamonix start/finish with Mont Blanc views
- Crossing into Italy via Col de la Seigne
- Courmayeur Valley in Italy
- Swiss Alps through Champex-Lac
- La Flégère with panoramic Mont Blanc views
- Night running through Alpine passes
The Course
The UTMB begins and ends in Chamonix, France, at the foot of Mont Blanc, Western Europe's highest peak. The course travels counterclockwise around the entire Mont Blanc massif, crossing into Italy through the Courmayeur valley and into Switzerland through the Champex-Lac area before returning to France over the final mountain passes.
The terrain is pure mountain trail, with steep, technical ascents and descents over high Alpine passes reaching altitudes above 2,500 meters. Runners traverse snow fields, rocky ridgelines, alpine meadows, and deep forest valleys. The cumulative elevation gain of approximately 10,000 meters is spread across roughly a dozen major climbs, each demanding careful pacing and mountain navigation skills.
The final descent into Chamonix is one of the most emotional moments in ultrarunning, as exhausted athletes are greeted by thousands of cheering spectators lining the streets of the Alpine town. Most participants take 30-46 hours to complete the course, running through two nights in the mountains. The combination of extreme distance, altitude, technical terrain, and the beauty of the Alps makes UTMB the crown jewel of mountain ultrarunning.
History
The UTMB was first held in 2003, created by a group of trail runners led by Michel Poletti and Catherine Poletti who wanted to establish a race around the Tour du Mont Blanc, one of Europe's most famous long-distance hiking routes. The inaugural event attracted 722 runners.
The race has since grown into the most prestigious mountain ultramarathon in the world, attracting over 10,000 runners across its multiple race formats (UTMB, CCC, TDS, OCC, and others during the UTMB Mont-Blanc festival week). The UTMB by Dacia brand has expanded globally with qualifying races on every continent, creating a worldwide trail running community.
How to Train for UTMB
Accumulate massive vertical
With 10,000 meters of climbing, your legs must be conditioned for relentless ascents and descents. Aim for 3,000-4,000 meters of climbing per week in peak training. Back-to-back mountain days are essential to simulate the cumulative fatigue.
Train for night running
You will run through two nights on the course. Practice running in darkness with a headlamp on technical terrain. Your pace and confidence will drop significantly at night, so building familiarity with nighttime mountain running is critical.
Earn your qualifying points
UTMB requires runners to accumulate qualifying points from designated trail races over a two-year period. Plan your race calendar strategically to earn enough points while leaving adequate recovery time before UTMB itself.
Practice altitude management
The course reaches above 2,500 meters multiple times. If you live at low altitude, consider a pre-race altitude camp in the Alps. Even a week at altitude can significantly improve your comfort and performance on the high passes.
Qualification
Runners must accumulate a minimum number of qualifying points (currently 10 UTMB Index points) from designated trail races within a two-year qualifying period. Entry is then by lottery for qualified runners.
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