UTMB Mont-Blanc on August 28, 2026 is the biggest trail ultramarathon in the world. Here is how entry works, what the course demands, and how to prepare.
UTMB Mont-Blanc on August 28, 2026 is the crown jewel of trail ultrarunning. The 171-kilometer course circles the entire Mont-Blanc massif through France, Italy, and Switzerland with over 10,000 meters of elevation gain. Finishing UTMB is one of the most significant achievements in endurance sport.
UTMB week actually includes several races of different distances:
If this is your first UTMB week, the OCC or CCC are excellent starting points. The full UTMB requires significant ultra experience and a proven track record at shorter mountain distances.
UTMB uses a points-based entry system called Running Stones. You earn points by finishing qualifying races on the UTMB Index throughout the year. For the main UTMB race, you need to accumulate enough points from races rated at the appropriate difficulty level.
The lottery draw happens in January. Having the required points gets you into the lottery — it does not guarantee a spot. Popular distances like UTMB and CCC are heavily oversubscribed.
Chamonix to Les Contamines (0-31 km): The race starts in the center of Chamonix at 6 PM on Friday. You climb immediately up to Le Delevret before descending to Saint-Gervais and then Les Contamines. Most runners hit this first aid station in 3-5 hours. The temptation to go fast while fresh is strong — resist it.
Les Contamines to Courmayeur (31-80 km): The biggest climb of the race — Col de la Seigne at 2,516 meters — comes in this section. You cross from France into Italy and descend into Courmayeur. This is where you will likely experience your first night on the course. Courmayeur has a full aid station with beds if you need a nap.
Courmayeur to Champex-Lac (80-128 km): The Grand Col Ferret crossing into Switzerland is stunning at sunrise. The terrain is technical and the descents are punishing on your quads. By Champex-Lac, you will have been running for 20-30 hours.
Champex-Lac to Chamonix (128-171 km): The final section includes two more significant climbs. The last big effort is the climb to La Tete aux Vents before the final descent into Chamonix. Running down the streets of Chamonix to the finish line with the crowds cheering is one of the greatest moments in ultrarunning.
UTMB has mandatory gear that is checked before the race:
Invest in good gear and test everything in training. A headlamp failure at 3 AM above 2,000 meters is not the time to discover your battery is dead.
You need a minimum of 2-3 years of trail ultra experience before attempting UTMB. Your training should include:
UTMB has a typical DNF rate of 30-40%. This is not a race where finishing is guaranteed, even for experienced ultra runners. Weather in the Alps can change rapidly — snow, wind, and freezing rain are all possible in late August at altitude.
The runners who finish are the ones who manage their effort, eat consistently, and stay mentally flexible when things go wrong.
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