Jim Walmsley - Trail Runner Profile
Jim Walmsley is an American ultrarunner who won the Western States 100 four times (2018, 2019, 2021 and 2024), setting a 14:09:28 course record in 2019 that stood until 2026, and became the first American man to win UTMB in 2023 in a course record 19:37:43. In 2025 he added the world title in the Lo
Jim Walmsley quick facts
- Age: 36 (born 17 January 1990)
- Nationality: United States
- From: Phoenix, Arizona
- UTMB Index: 959 (as of 6 October 2026, UTMB profile)
- ITRA score: 957 (as of 27 August 2026, ITRA profile)
- Key results: Western States wins: 4 (2018, 2019, 2021, 2024); UTMB: Winner 2023, course record 19:37:43; World title: Long Trail 82km, 2025
UTMB Index and ITRA scores change after every race. The dates are when each number was read from the official profile.
Country: United States · Team: HOKA · Specialities: 100 miles, 50–100km
Right now: Did not finish the 2026 Western States 100 and withdrew from the 2026 UTMB with a knee injury and illness.
Key facts
- Western States wins: 4 (2018, 2019, 2021, 2024)
- UTMB: Winner 2023, course record 19:37:43
- World title: Long Trail 82km, 2025
Front-running as a strategy
Walmsley built his reputation by going out harder than the field could justify and making it stick. Two Western States course records came from that approach, in 2018 and then a 14:09:28 in 2019 that was twenty-one minutes faster, and so did the 4:50:07 he ran for 50 miles that same year. It also produced his most public failures, including early Western States blow-ups and four unsuccessful UTMB attempts.
The Chamonix project
Rather than fly in for UTMB, Walmsley moved to the French Alps in spring 2022 and trained on the course with François D'Haene. It took until his fifth attempt: in 2023 he won in 19:37:43, taking almost twelve minutes off Kilian Jornet's course record and becoming the first American man to win the race in its history.
Where he is right now
In 2025 he won the Chianti Ultra Trail by UTMB ahead of Jornet, took the OCC on its storm-altered course during UTMB week, and won Long Trail gold at the World Championships in Canfranc in 8:35:11. He returned to Western States in June 2026, on the day his own 2019 course record finally fell to Vincent Bouillard, but dropped out at Foresthill with persistent hip pain after slipping to 19th place. He withdrew from the 2026 UTMB on August 21, a week before the race, citing a combination of a knee issue and illness.
How Jim runs
Walmsley came to trail running from collegiate track and cross-country at the US Air Force Academy, where he was a second-team All-American in the steeplechase, and his racing still looks like it. His strength is a very high sustainable pace on runnable terrain: smooth, economical running on fire roads, canyon trails and long descents, held for hours at a speed few ultrarunners can approach.
For most of his career he raced from the front by choice. He would set an aggressive early pace and dare the field to follow, which produced two Western States course records and a reputation for spectacular wins and equally spectacular blow-ups. When it failed, the causes varied: a wrong turn at mile 92 of Western States in 2016 while well under record pace, a stomach that gave out in high-90s heat after a fast start in 2017, and legs that fell apart early at UTMB in 2018.
His UTMB win showed a more complete version of the same athlete. He began Nordic skiing and ski mountaineering in the winter of 2020-21, which taught him to climb with poles, and in spring 2022 he moved to Arêches in the Beaufortain, within sight of Mont Blanc, to train on UTMB terrain and learn to hold back in the first half. He still won from the front, but with a level of mountain-specific skill and restraint that his earlier attempts lacked.
Where Jim is strongest
Fast, runnable 100-milers and 50 to 100km races where sustained pace matters more than technical skill. Western States, with its long downhill canyons and runnable final third, is the archetype, and he has won it four times.
His years in the Alps have made him competitive on steep European courses too, as his UTMB course record and his 2025 world title over 82km at Canfranc show. Very technical, high-altitude courses remain less natural to him than to specialists like Kilian Jornet.
The edge. Aerobic ceiling. His flat-and-rolling pace late in a 100-miler is still the benchmark in the sport.
What you can learn from Jim
1. Train for the course, not just for fitness
Walmsley only cracked UTMB after living in the Alps and training on its climbs and descents. For an everyday runner, that means matching your training terrain to your race. If your goal race has long steep climbs, your key sessions need long steep climbs; if it is runnable, you need sustained running at goal effort on similar ground.
2. Road speed is an asset in trail racing
His track and road background is the source of his pace on runnable ground. Many trail runners avoid flat, fast running entirely, but a weekly tempo run or a block of road-race preparation raises the speed you can hold on easy trail sections. On runnable courses, that speed is free time.
3. An aggressive race plan needs a fuelling plan that survives it
His 2017 Western States ended when his stomach gave out in the afternoon heat after a fast start; the people around him agreed he had gone out too hard. If you want to race near your limit, practise eating at that effort in training, in the heat if your race is hot, and carry more fuel than you think you need. The pace is only sustainable if the fuelling is.
4. Failure at a race is information, not a verdict
He started UTMB four times without winning before his 2023 course record, and changed something specific each time, from learning poles to moving to the Alps. After a bad race, write down exactly what went wrong and what you would change, then build your next training block around those points. Repeat attempts at a hard race usually get better when they are treated as experiments rather than reruns.
Selected results
| Year | Race | Result |
|---|---|---|
| 2026 | Western States 100 | DNF (dropped at Foresthill with hip pain) |
| 2023 | UTMB | 1st (19:37:43, course record; first American man to win) |
| 2024 | Western States 100 | 1st (fourth win, after 2018, 2019 and 2021) |
| 2019 | Western States 100 | 1st (14:09:28 course record, unbeaten until 2026) |
| 2025 | World Championships Long Trail 82km | 1st (8:35:11, Canfranc-Pirineos) |
| 2025 | OCC | 1st (raced on an alternate course) |
| 2025 | Chianti Ultra Trail by UTMB | 1st (ahead of Kilian Jornet) |
A selection, not a complete race history.
Official profiles
Compare yourself with Jim
- ITRA index calculator: estimate the km-effort and an indicative performance band for your own race result (not an official ITRA Performance Index).
- Trail pace calculator: turn your road pace into a trail pace and finish time for a given elevation profile.
Frequently asked questions
Does Jim Walmsley still hold the Western States course record?
No. His 14:09:28 from 2019 stood for seven years and was broken in June 2026 by Vincent Bouillard, who ran 13:46:15.
How many times has Jim Walmsley won Western States?
Four: 2018, 2019, 2021 and 2024.
Is Jim Walmsley racing UTMB in 2026?
No. He withdrew on August 21, 2026, a week before the race, citing a knee issue and illness, and is among the withdrawals from the 2026 edition along with Kilian Jornet and Tom Evans.
How did Jim Walmsley do at the 2026 Western States 100?
He did not finish. He had slipped to 19th place by Foresthill and dropped out there with persistent hip pain, on the same day his 2019 course record was broken by Vincent Bouillard.
Runners with a similar profile
- Katie Schide (United States): UTMB course-record holder, Western States champion, Hardrock record-breaker and world champion over 82km.
- Ruth Croft (New Zealand): The first woman to win the OCC, the CCC and UTMB: the complete Chamonix set.
- Blandine L'Hirondel (France): A practising OB-GYN who became only the second athlete to win the OCC, the CCC and UTMB, after two Trail World Championship titles.
- Vincent Bouillard (France): Won UTMB as an unsponsored shoe engineer in 2024, then broke the Western States course record and became the first man under 14 hours.
Sources and verification
Checked against the following sources on 2026-08-27:
- LetsRun: Walmsley becomes first American man to win UTMB
- ITRA: Walmsley and Schide take Long Trail gold at Canfranc-Pirineos
- ITRA runner profile
- RUN247: Jim Walmsley the latest big name ruled out of UTMB
- Trail Runner Magazine: what happened to Walmsley, Seidel, Jornet and others at Western States
- Wikipedia: Jim Walmsley
- LEKI: Jim Walmsley, from road runner to pole specialist
- Outside: Jim Walmsley shattered the Western States 100 record
- UTMB Index profile (official)
Canonical page: https://trailia.run/best-trail-runners/jim-walmsley
Published by Trailia (https://trailia.run), a personalised trail running coaching platform. This profile is a factual reference, not a ranking.