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Race Preview: Istria 100 by UTMB

Jim Walmsley is headed to the start line of the Istria 100 in Croatia. Here's who else is competing, and what you should know about this event.

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More than 2,300 runners will line up at the 10th annual Istria 100 by UTMB this weekend in Croatia. The top male and female podium (18 total runners, nine men and nine women) of each event will get automatic entry to the event of the corresponding distance in the 2023 UTMB World Series Finals in Chamonix, and all runners who complete the event will receive stones (four for the 100M, three for the 100K, two for the 69K, and two for the 40K) for a chance to enter the lottery to compete in Chamonix in 2024. 

This race will be streamed live on Outside Watch, along with a full schedule of top-tier trail running events from UTMB. 


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This early season event is garnering attention because Jim Walmsley is slated to run the 100-mile course to earn his spot at the UTMB World Series Finals in Chamonix. Walmsley moved to France last year to focus his training efforts on the 106-mile circumnavigation of Mont Blanc, where he placed fourth in 2022. Walmsley didn’t run much for several months during the winter; instead, he focused on alpine touring skiing in and around Beaufort, France.

“Istria will provide an early season opportunity to run 100 miles, through the night, with my backpack full of mandatory gear,” Walmsley said. “I’m looking forward to traversing the peninsula of Istria, connecting ancient villages through vineyards, olive groves, and old forests along the Mediterranean coast.”

RELATED: Outside is Partnering with UTMB To Bring You Onto The Trails and Into the Action with Live and On-Demand Race Streaming

Top Contenders

In addition to Jim Walmsley, 2022’s CCC champion and World Long Trail Champion and French runner Blandine L’Hirondel will be running the 69K, as will Norwegian Stian Angermund (winner of the World Short Trail Championship in Thailand). Andreas Reiiterer (3rd, 2022 CCC) will also be stepping up to the 69K. 2022’s Istria 42K champion and French athlete Kevin Vermeulen will return to tackle the longer 69K event. 

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, from France, who came first female at the 100-miler at Kullamannen by UTMB, and the Austrian, Ulrike Striednig, who is racing in the 60-64 category with an impressive index of 651. 

Istra 100 UTMB

Course Description

There are five distances for the race in the Istrian Peninsula: 168K (104.4 miles), 110K (68.3 miles), 69K (42.8 miles), 42K (26 miles), and 21K (13 miles). While all five finish in the historic town square of Umag, on Croatia’s western coast, only the longest race distance has the benefit of touring the country’s east coast as well. A total of 2,294 runners are expected to race in the five events.

The 168K race starts in the coastal town of Labin at 5 P.M. local time, meaning runners will begin by running through the night as they trek north along the Adriatic Sea and into Uck Nature Park. After about 32 miles, they’ll head west across the country until they hit the finish in Umag. In addition to experiencing 21,620 feet of total elevation gain along the way, runners will see the beautiful country on foot through vineyards, olive fields, and medieval, stone-street towns.

Where to Stay and What to Know

The best place to stay for the race is around the finish line in Umag. All races finish there, but they also start there for most runners. Bib pickup, the race expo, and most official race events occur there. Because of this, the race offers bus rides from the finish to the start of all races. For the 168K, the bus ride is about an hour and 15 minutes. For the 21K, it’s about a 20-minute ride.

Crew and spectators cannot take the bus. However, they are allowed to watch and crew the runners from four aid stations along the course. (You can find those here.) They are accessible by car, but be warned: the race discourages crews from driving to them at night because of the narrow roads. 

For anyone looking to explore or see sites while crewing, before or after the races, Ivana Greguric, an event director for the race, recommends enjoying the local cuisine like fuži pasta, wines, prosciutto, olive oil, and wild asparagus (a springtime delicacy), or visiting historic towns like Motovun, Groznjan, Labin, and Rabac.

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