UTMB World Series - Everything You Need to Know

The Series 

Few events in the ultra calendar carry the weight and prestige of the Ultra-Trail du Mont-Blanc (UTMB) World Series. Thousands of elite athletes and passionate trail runners compete in qualifying races across the globe for a coveted spot in the Finals in Chamonix, France.

The Finals

Set against the backdrop of snow-capped Mont Blanc, the UTMB World Series Finals unfold during a week-long festival of trail running, culminating in the iconic UTMB race. It’s the pinnacle of the Series, luring huge crowds.

Whether you’re following the best (in awe) or chasing the start line yourself, here’s everything you need to know about this year’s UTMB World Series.

Key facts at a glance:

• UTMB World Series Running Festival: 25.08.25 - 31.08.25 

• UTMB Race: The apex event, held at the end of the week

• Location: Chamonix, France

• Athletes: 10,000 (across all Final races)

• Spectators: 100,000

• Tickets: Free to Spectate

What is the UTMB World Series?

The Ultra-Trail du Mont-Blanc (UTMB) began as a single event in Chamonix, with just a handful of qualifying races. But it quickly became a dream for trail runners everywhere. To meet that growing demand, the UTMB World Series was born. The idea was simple: give runners a chance to qualify closer to home, and earn their place on the start line in Chamonix.

… And the UTMB Final?

The crown jewel of the week in Chamonix is the UTMB Final. This race covers 171 km across three countries (France, Italy, and Switzerland) and climbs over 10,000 meters. That’s like scaling Everest from sea level, and then some!

Not only is the UTMB Final distance grueling, runners face unpredictable weather, mountainous terrain, and one, sometimes two, nights out on the trail. 

The entire loop can take 32 to 46 hours to conquer. Although, the world’s sharpest runners make it back in about 20 hours.

Katie Schide set a new UTMB women’s course record in 2024, finishing in a jaw-dropping time of 22:09:31, taking the title from fellow American Courtney Dauwalter. On the men’s side, Jim Walmsley holds the overall course record with his 2023 victory time of 19:37:43.

Race finishers are met with thunderous cheers from the visiting spectators, volunteers, and locals, who gather in the thousands to lift runners’ spirits and ensure they end on a high.

“The number of people cheering runners on… is like nothing I have ever witnessed… It’s magical, it lifts you up. It carries you…”

Ultra Runner Pierre Meslet

Not Forgetting: The Other Two Exhilerating Finals

Other iconic Final races in the UTMB World Series are the CCC (known as the UTMB’s ‘petit sœur’):

Distance: 101 km

Start: Courmayeur, Italy

Elevation: 6,050m+

And the challenging (yet sub-100 km) OCC:

Distance: 57km

Start: Orsières, Switzerland

Elevation: 3,500m+

The Warm Up: UTMB World Series Events (Qualifiers)

World Series qualifiers now span 28 countries. Sign-up for popular races can reach the thousands. For example, Spain’s Tenerife Bluetrail saw over 3,200 runners from 63 countries earlier in 2025.

UTMB World Series qualifiers cover 4 distance ranges, to help runners qualify for the Finals in Chamonix (which are also of varying distances):

Athletes who take part in qualifiers:

• Earn ‘Running Stones’ (lottery entries for the Finals)

• Build their UTMB Index (shows your ability to complete the race)

• Get to experience some UTMB magic, if not the Mont-Blanc race itself

Widely attended ultras, such as the Western States (competed in by Tim Gorichanaz—a professor at Drexel University and GOREWEAR athlete), are classified as UTMB qualifiers. So, athletes can build up Stones in races all over the world.

UTMB World Series Majors

Like the qualifiers, the UTMB World Series Major races are held across the Americas, Europe and Asia, covering 50K, 100K, and 100M distances. However, there are only three Major races, each carrying more clout than the qualifiers. 

The Majors are viewed as more prestigious. As such, at Majors runners can directly qualify for the Finals, if they perform exceptionally well, and the races themselves count for double the Running Stones.

The UTMB World Series Majors:

• Val d'Aran by UTMB (Europe)

• Doi Inthanon by UTMB (Asia-Pacific)

• Canyons Endurance Runs by UTMB (Americas)

The Final Heat: UTMB World Series Finals

All roads lead to Chamonix where the action reaches boiling point over one extraordinary week of races. Here’s what to expect:

What does D+ mean in trail running?

D+ stands for dénivelé positif, which refers to the total elevation climbed during a race.

For example, if a race has 3,500m D+, it means you'll climb 3,500 vertical meters over the course of the route, regardless of how many ups and downs there are along the way.

It's a key number in trail and mountain running because:

• It tells you how steep the race will be

• It helps you estimate overall difficulty (races with high D+ can take longer, even over shorter distances due to the added challenge of elevation and technical terrain)

Alternatively, D- after a distance means the overall trail has negative elevation gain — more decent than ascent. 

How to Qualify for the UTMB World Series Finals 

To nab a place in the OCC, CCC, or UTMB (aka the Finals) runners need to collect Running Stones and have a valid UTMB Index for the race they’re aiming to enter. It then comes down to a lottery system, due to limited spaces. Although, it’s possible for the elite to fast track to the Finals.

Confused? Read on for more information.

Earning Your Stripes: ‘Running Stones’ Explained

Running Stones can only be earned by finishing UTMB World Series Events and/or UTMB World Series Majors. The ‘Stones’ are basically proof you can go the distance and are serious about the Finals. They buy you entry into a lottery for a place in the Finals.

• Each Stone = 1 entry in the lottery

• More Stones = more chances in the draw

• Runners’ Stones don’t expire annually — they carry over until you are selected and only reset once you get a place in a Final

Here’s an example of how it works:

Not all races carry equal Stones. It depends on the category and distance:

What is a UTMB Index?

Alongside collecting Running Stones, you’ll also need a valid UTMB Index in the race category you’re aiming for at the Finals. Here’s how it works:

To enter CCC (a 100K race), you need a valid UTMB Index in the 100K category

To enter UTMB (a 100M race), you’ll need a valid Index in the 100M category

You’ll get a separate UTMB Index for each distance (20K, 50K, 100K, and 100M) as long as you finish a race that counts. And it’s not just UTMB World Series events that qualify. Plenty of other certified races around the world are part of the UTMB Index network too.

So, what exactly is the UTMB Index?

It’s a score that ranks your performance in trail races by:

• Comparing your finish time to a reference time (usually based on how elites perform on that course)

• Factoring in how tough the course is — think distance, elevation, and terrain

• Averaging your best results over the past two years, from any UTMB Index-certified races 

Direct Qualification

Elite runners can skip the lottery and qualify directly for the Finals based on their performance at UTMB Majors.

The top 10 men and women in each distance — 50K, 100K, and 100M — at a Major automatically earn a spot in the corresponding Finals race (OCC, CCC, or UTMB).

If you’re an age group winner at a Major, you’ll also get guaranteed entry.

Want In? Here’s How to Get Involved

You don’t have to be in Chamonix to soak up the action.

How to Train for Challenging Trail Runs

Dreams of making the UTMB one day? Or inspired by its incredible athletes? There’s beautiful routes the world over, of varying difficulties, so you can find a trail anywhere and take it at your own pace.

Check out these guides: 

• The 10 Best Running Trails in Europe 

• 10 Unmissable Trails Runs in the US

• Master Downhill Running for Speed and Safety

Gear Up for Mountain Climes

The rush of running trails in the untamed mountains is like no other. And the steep peaks of the Alps are a major draw for trail hunters, not just during the UTMB Finals. But the conditions can change quickly, so runners need to prepare.

Essentials for the Trail:

• Sun protection: At higher elevations, UV rays are stronger, so pack sunscreen and sunglasses, even when it’s overcast. Pack a mesh cap, too, so the sun can’t beat down on you harshly.

• Fuel and fluids: Keep your energy up during long runs with plenty of water and snacks made for the trail.

What to Wear on the Mountain:

• Breathable clothing: Start with a moisture-wicking base to keep the sweat off your skin

• Layer with a lightweight shirt

• Add a protective jacket, to cut off mountain breezes and protect from downpours. You need a waterproof jacket with a hood to take part in UTMB, so a CONCURVE GORE-TEX Jacket is a great pick

• Running shorts that are comfortable. Options like our 2in1 shorts come with integrated tights, which offer a supportive, ‘second skin’-like fit

• Reliable footwear: Trails can get slippery or rocky, so sturdy shoes are a must. As are the right socks!

Watching the UTMB from Home?

There are many ways to cheer on the elite and follow the drama as it happens. The UTMB Live season kicked off on world TV screens with the Chianti Ultra Trail and Tenerife Bluetrail in March. 

Up-coming UTMB races that will also be broadcast via UTMB Live include:

UTMB Mont-Blanc (Finals)

August 25–31, 2025

Chamonix, France

Wildstrubel by UTMB

August 30, 2025

Kandersteg, Bernese Oberland, Switzerland

A challenging 50km race with significant elevation gain, offering breathtaking alpine views.

Nice Côte d'Azur by UTMB

September 13, 2025

Nice, France

A scenic race along the Mediterranean coast, combining beautiful trails with the charm of the French Riviera.

Kodiak Ultra Marathons by UTMB (Americas Major)

October 10–11, 2025

Big Bear Lake, California, USA

An iconic trail race in the San Bernardino Mountains, offering distances from 50K to 100M.

Chiang Mai Thailand by UTMB (Asia-Pacific Major)

December 5–8, 2025

Chiang Mai, Thailand

A unique trail running experience through the lush jungles and mountainous terrain of northern Thailand.

If a race isn’t livestreamed, tune into live.utmb.world for real-time updates on who’s leading the trail.

FAQs about the UTMB World Series

Got more questions about the UTMB? Find the answers to frequently asked questions here:

• How hard is it to get into the UTMB Final? UTMB entry takes dedication. Accumulate Stones through tough qualifying races, maintain a solid UTMB Index, and cross your fingers in the lottery.

• How long are Running Stones valid? Running Stones are valid until you’re selected in a UTMB World Series Finals lottery (UTMB, CCC, or OCC). Once selected in a lottery, all your Running Stones reset to zero.

• Do they sleep in the UTMB Final? Yes, most runners sleep during the UTMB Final. The 170 km UTMB typically takes 30 to 46 hours to complete. So, while runners will go through the night and push hard to the finish, they will take ‘micro-sleeps’ (sometimes for as short as 15–30 minutes) at aid stations or designated rest spots.

• When is the UTMB World Series? The UTMB World Series runs throughout most of the year. Qualifying races take place all over the globe, leading up to the Finals in Chamonix, France.

• Who is running at UTMB Finals Week, 2025? Many top athletes are taking part. Elite male contenders include former course record holder Jim Walmsley (USA), Petter Engdahl (Sweden), Mathieu Blanchard (France), and Germain Grangier (France). While female athletes include Courtney Dauwalter (USA) — a two-time UTMB winner (2019, 2021) — Ruth Croft (New Zealand), Martina Valmassoi (Italy), and Blandine L'Hirondel (France).