ISTRIA 100 BY UTMB set to welcome international trail elite for the race's tenth anniversary!

By 03 Απρ 2023
Photo copyright: Bogo Trontelj Photo copyright: Bogo Trontelj

In just over two weeks, a host of international trail runners will descend on Croatia for Europe’s first UTMB World Series race of the season, Istria 100 by UTMB®.  Amongst them, will be American trail royalty, Jim Walmsley, who will be racing the 100miler distance (168.6km/6590m+), in hope that this will be his getaway to the UTMB World Series Finals in August. Wearing bib number one, Walmsley will be joined by other UTMB Mont-Blanc hopefuls, including Frenchmen Noël Yannick and Arthur Joyeux-Bouillon, who both have a UTMB index of 847 and 848 respectively.


The Wahoo and Hoka-sponsored athlete who recently moved to France to practice training in the Alps and introduce more snow sports cross-training to his plan will undoubtedly be looking to make a statement against the Frenchmen.  

Walmsley commented: “Istria will provide an early season opportunity to run 100 miles, through the night, with my backpack full of mandatory gear.”

“I’m looking forward to traversing the peninsula of Istria, connecting ancient villages through vineyards, olive groves, and old forests along the Mediterranean coast.” He added.

Celebrating its tenth anniversary, Istria 100 by UTMB originally started in 2013 with only 237 competitors, and now it has evolved into +2300 competitors from all around the world. The race, which which takes place over three days, is made up of five different distances: 168k, 110k, 69k, 42k and 21k, all with varying levels of elevation, making it perfect for seasoned trail runners and beginners alike.

The race will be broadcast live on from 14th April 2023.  

Also set to race the 100miler is Guillaume Deneffe (BEL) who came second in the 100miler at Kullamannen by UTMB and Petr Jiří (CZE) who won the Sky Trail at last year’s Julian Alps Trail run by UTMB. 

The women’s field is just as exciting with Austrian trail runner Esther Fellhofer (UTMB index of 714) who will undoubtedly be hunting down a ticket to the UTMB World Series Finals after a disappointing DNF in last year’s TDS® Mont-Blanc.

Other elite women include Claire Bannwarth (FRA) who came first female at in the 100miler at Kullamannen by UTMB and Austrian, Ulrike Striednig who is racing in the 60-64 category with an impressive index of 651.

In the 100km (110km/3860m+) race British Harry Jones boasts the highest index (871). Jones took the win at last year’s mozart 100 by UTMB in the 100km category, securing him a place at UTMB Mont Blanc 2022.

He will be challenged by Jesus Gil Garcia (ESP) and Riccardo Borgialli (ITA) who share the same index of 864 and Martin Halász (SVK) and Helio Fumo (POR) who are both familiar with the course and conditions after coming first and second respectively in the 50k category at Istria 100 by UTMB last year.

In the women’s field, last year’s female 100km winner, Ildikó Wermescher (HUN), will be looking to retain her title. However, she will be challenged by the likes of Sarah Vieuille (FRA), and Paulina Tracz (POL) who both boast UTMB indexes of over 700.

The 50k distance, will see the and Scotty Hawker (NZL) go head to head with Andreas Reiterer (ITA), both of whom came in the top three for the CCC® in 2021 and 2022 respectively. 

Anna-Stiina Erkkilä (FIN), Kim Schrieber (GER) will be amongst the favourites for the women. 

All runners will have the opportunity to run through the heart of the Istrian peninsula, enabling them to experience every possible aspect of trail running, from technical terrain and forests to medieval towns, hilltop towns, city centers and of course, stunning panoramic views.

All courses finish on the western part of the peninsula, in Umag, a town with around 13,000 inhabitants with about 45km of coastline.

The top 3 male and top 3 female runners in each category will win a slot for the 2023 UTMB World Series Finals race of the same category.

All finishers of UTMB World Series events are awarded Running Stones which can be used to enter the lottery for the UTMB World Series Finals, which will take place in the UTMB, CCC and OCC races of the UTMB Mont-Blanc in 2023.

To request media accreditation for Istria 100 by UTMB, please e-mail: [email protected]

To request an interview with any of the athletes racing at Istria 100 by UTMB, please e-mail: [email protected]


UTMB® World Series 

UTMB® World Series is the world's ultimate trail-running circuit that unites the sport's biggest stars and passionate runners through the best, leading international events in the most stunning locations. Built on a passion for the mountains with sustainability at its heart, UTMB® World Series gives all trail runners the chance to experience the UTMB ® adventure across the world, with events taking place across Asia, Oceania, Europe, Africa and the Americas. It is the only place where runners can begin their quest to UTMB® Mont-Blanc, France, where the prestigious UTMB® World Series Finals will be held. For more information, visit

About UTMB Group 

Since the creation of UTMB® Mont-Blanc in 2003 by a group of passionate friends, UTMB Group has been the driving force behind the development of trail running. The UTMB® Mont-Blanc is the sports pinnacle event, and every year, 10,000 runners earn their place on the start line. UTMB Group also pioneered the LiveTrail® technology, an innovative digital service that supports the management of endurance races. Revered by hundreds of thousands of athletes, UTMB® has become a global, premium, and leading brand. In May 2021, UTMB Group partnered with The IRONMAN Group to launch the UTMB® World Series, which from 2022, will bring together many of the best international events on the planet to provide exclusive access to the sport's pinnacle event, UTMB® Mont-Blanc. The UTMB® World Series is built on the founding principles of UTMB® Mont-Blanc: surpassing oneself; fair-play; respect for people and the environment; and solidarity. Find out more at

About The IRONMAN Group 

The IRONMAN Group operates a global portfolio of events that includes the IRONMAN® Triathlon Series, the IRONMAN® 70.3® Triathlon Series, 5150™ Triathlon Series, the Rock ‘n’ Roll® Running Series, IRONKIDS®, World Triathlon Championship Series, premier running events including the Standard Chartered Singapore Marathon™ and City2Surf®, UTMB® World Series events including the Canyons Endurance Runs™, Tarawera Ultra and Ultra-Trail Australia™, Epic Series™ mountain bike races including the Absa Cape Epic®, road cycling events including Haute Route®, and other multisport races. The IRONMAN Group is the largest operator of mass participation sports in the world and provides more than a million participants annually the benefits of endurance sports through the company's vast offerings. Catering to the full athlete experience, the company portfolio also includes FulGaz® virtual cycling, the most realistic indoor riding experience connected fitness application aimed at preparing athletes for real-world events. Since the inception of the iconic IRONMAN® brand and its first event in 1978, athletes have proven that ANYTHING IS POSSIBLE® by crossing finish lines around the world. Beginning as a single race, The IRONMAN Group has grown to become a global sensation with hundreds of events across 55+ countries. The IRONMAN Group is owned by Advance, a private, family-owned business. For more information, visit