Complete Guide to UTMB: Ultra-Trail du Mont-Blanc Ultramarathon

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If you’re a trail runner, then you’ve likely heard of the Ultra-Trail du Mont-Blanc or UTMB.

It is considered one of the most significant, competitive, beautiful, and challenging ultramarathon trail races in the world.  

Each year in the summer, tens of thousands of outdoor adventurers from around the world gather in Chamonix, France to take part in the weeklong celebration leading up a series of 7 races, with the headline UTMB 100+ mile race being the main event.

The race is a spectacle in the picturesque town of Chamonix, situated at the base of the highest point in the Alps, glacier-covered Mont Blanc. The peak is flanked by granite spires making it an awe-inspiring sight.

The UTMB has allured most ultra-running legends such as Kilian Jornet, Courtney Dauwalter, Francesca Canepa, Rory Bario, Jim Walmsley, Tim Tollefson, and Scott Jurek, to name a few.

In this article, we will learn all about the UTMB, with a focus on the capstone 100+ mile race.

Guide to UTMB Ultra-Trail du Mont Blanc Ultramarathon

What is the UTMB Mont-Blanc race?

The UTMB is regarded as one of the most challenging (and largest) trail running events in the world, as well as an essential experience for many ultra-loving trail runners.

Each year, the best athletes meet in Chamonix, France where there is a week of festivities leading up the races. 

The premiere race, the UTMB, is part of the Ultra-Trail World Tour and has a strict entry policy using a point system from qualifying races around the world over a two-year period and a lottery. 

How many people run the UTMB a year?

The UTMB is one of the largest trail running events with more than 2,500 starters in the main race.

A total of 10,000 runners participate in the 7 events. 

The fans that come for the weeklong festivities double the size of Chamonix’s population of 10,000. The runners wait in the corral for up to two hours, in rain or shine, to get a good spot in front of the iconic St. Michael’s church in the center of town, according to Runner’s World

There is music, announcers, and fans all around the town center. The atmosphere is described as “electric.”

  • Related: The World’s 10 Toughest Races
  • Guide to UTMB Ultra-Trail du Mont Blanc Ultramarathon
    The UTMB start line in Chamonix
    Credit / license: “IMGP0118” by “mako10” is licensed under CC BY 2.0

    What are the 7 races in the UTMB?

    The 7 races of the UTMB week are:

    • the UTMB® (Ultra-Trail du Mont-Blanc),
    • the CCC (Courmayeur – Champex – Chamonix),
    • the TDS (Sur les Traces des Ducs de Savoie),
    • the OCC (Orsières – Champex – Chamonix),
    • the PTL (La Petite Trotte à Léon – non-competitive),
    • the MCC (De Martigny-Combe à Chamonix),
    • and the YCC (Youth Chamonix Courmayeur – junior event).

    How do you qualify for the UTMB?

    Entry to UTMB is notoriously tough, and runners are required to have several recent ultramarathons under their belt to be even considered for the lottery.

    To have a chance to enter the lottery to register for UTMB, a runner must have accumulated 10 “points” by running qualifying races during a set timeframe. 

    Runners can increase their chances of being selected through the lottery by acquiring a “Running Stone” which is awarded when a runner completes one of the 7 UTMB events. 

    For example, if a runner has 9 Running Stones, their name appears 9 times in the lottery, thus tripling their odds in the lottery versus someone who only has 3 Running Stones. Get more information on Running Stones.

    Related: The Badwater 135 Explained

    Guide to UTMB Ultra-Trail du Mont Blanc Ultramarathon
    Runners threading the foothills en route to tougher terrain.
    Credit / license: “IMGP0217” by “mako10” is licensed under CC BY 2.0

    What are the qualifying races for the UTMB?

    There exists a list of the qualifying races (and timeframe) in the UTMB website database – they include many ultras throughout the world. The harder – or longer – the race, the more UTMB points associated with it.

    What is the UTMB World Series?

    In 2021, the UTMB organizers united with the premiere ultra races in the world to launch an international competition called the UTMB World Series. The first series competition will take place in 2022.

    All the races take place in exceptional locations in the heart of unspoiled nature, notes the race site. 

    The site says: Open to all, the UTMB World Series is designed to meet the expectations of both elite and amateur runners and aims to offer every trail running enthusiast an extraordinary adventure. 

    For runners, it is the gateway to the UTMB Mont-Blanc, which will host the UTMB World Series Finals in the 50km, 100km and 170km distances.

    The UTMB World Series has 4 levels. A list of the races which take place in countries such as China, New Zealand, Austria, and Australia, can be found here.

    Where is the UTMB?

    The UTMB is on a course in the Alps in France, Italy, and Switzerland, in the heart of the area called Pays du Mont-Blanc. It circles Mont Blanc, the highest summit in the Alps.

    Guide to UTMB Ultra-Trail du Mont Blanc Ultramarathon
    UTMB in winter, Europe’s highest peak.

    How long is the UTMB?

    The primary UTMB race is approximately 171 km long (106 miles).

    Related: What is Ultra Running? The Ultramarathon Explained

    What is the elevation of UTMB?

    The UTMB race elevation is just over 10,000 meters (32,900 feet).

    Some of the climbs are 3,000 meters high.

    Some of the best runners manage to finish in just over 20 hours.

    When was the UTMB race started?

    The first UTMB race was started in 2003. It has grown dramatically since then, but the organisers have kept it at a reasonable size with a cap of 2,500 runners.

    When is the UTMB Race?

    UTMB is usually held in late August or early September. It was held August 23th to August 29th in 2021.

    Related: The Barkley Marathons: All You Need to Know

    Guide to UTMB Ultra-Trail du Mont Blanc Ultramarathon
    Resting – and sleeping – is common, if not mandatory, in UTMB.
    Credit / license: “UTMB 2008 (353)” by “akunamatata” is licensed under CC BY-ND 2.0

    What makes the UTMB unique?

    According to the race site: Running around Mont-Blanc is above all an inner adventure, a unique experience where each participant has to rely on their strength and push their mental and physical limits to cross the finish line. This extraordinary journey in the heart of the range allows runners to cross valleys and ridges in a unique alpine environment. 

    The event is one of the largest ultra trail races in the world, amassing an army of volunteers, about 2,000, from 15 countries and 18 French, Italian and Swiss municipalities of the Mont-Blanc region.

    More than 20,000 fans cheer on the runners and more than 50,000 spectators take part in the activities in the villages of the Pays du Mont-Blanc.

    As UTMB participant Billy McArthur shares:

    “UTMB is like no other race.

    It’s a true festival of the sport, where people from all over the world gather for a week of mountain running

    “Everyone in Chamonix that week understands the beauty and challenges of ultra-running so there’s a huge sense of camaraderie everywhere you go.

    The place itself is like no other and the scenery takes your breath away every step. These races brutal, but there’s always someone around to share the pain.”

    What makes the UTMB so challenging?

    The distance, elevation, and weather make the UTMB so challenging: More than 100 miles is a long way.

    The elevation of 32,900 feet makes it one of the steepest routes in the world. And the weather is extreme—often going from freezing at night to blistering hot during the middle of the day.

    McArthur almost got hypothermia after falling asleep at an aid station.

    As with most ultras, not being about to sleep also makes it challenging. 

    Guide to UTMB Ultra-Trail du Mont Blanc Ultramarathon
    Anton Krupicka at UTMB 2014.
    Credit / license: “Anton Krupicka at UTMB 2014” by “pete” is licensed under CC BY-NC-SA 2.0

    What is the course description of the UTMB?

    The UTMB route follows the Tour du Mont Blanc hiking path that is usually completed in 7 to 9 days by hikers. The is a loop around the highest point in the Alps, Mont Blanc.

    It starts from Chamonix, France, climbing through France to Italy before crossing the border into Switzerland, and re-entering France to end at the starting point. The route varies slightly each year for safety reasons.

    How long do you have to finish the UTMB?

    Runners have 46 hours and 30 minutes to finish the UTMB.

    What is the course record for the UTMB?

    France’s Francois D’Haene set the UTMB course record in 2017 with a time of 19:01:32. 

    What is the DNF rate of the UTMB?

    In 2016 and 2017, 42 percent and 35 percent of runners did not finish the UTMB race.

    How long does it take to run the UTMB?

    The best runners complete the loop in slightly more than 20 hours. Most runners take 32 to 46 hours to reach the finish line, having to spend two nights to complete the race.

    How do you train for the UTMB?

    Due to the extreme elevation and tough course, most runners aim to train at altitude on rigorous terrain to prepare for the UTMB. 

    McArthur did hundreds of miles on the treadmill at a 15 percent incline to prepare for the elevation gains.

    In retrospect, he wishes he had trained for downhills as well and ensured he had enough batteries to power equipment like a GPS watch or headlamp throughout the race. 

    What do runners eat during the UTMB?

    Runners eat all sorts of foods from energy gels and bars to potatoes, sandwiches, eggs, bananas, nuts, rice, cookies, peanut butter and jelly sandwiches. If it is easy to eat, runners eat it. 

    To find out more about the UTMB and its 7 events, visit the UTMB race website.

    Interested in Ultra Running? Check out my Ultra Running training resources!

    Photo of author
    Whitney Heins is the founder of The Mother Runners and a VDOT-O2 certified running coach. She lives in Knoxville, TN with her two crazy, beautiful kids, pups, and husband. She is currently training to qualify for the US Olympic Trials marathon.

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