What a day in Valais! With a sweltering 32°C already at the start and a cloudless sky, last Saturday saw the 52nd edition of Sierre-Zinal take place. Kenyan favorites Philemon Kirago and Joylene Chempengeno asserted themselves impressively and celebrated dominant victories. We analyzed the race and compiled statistics.
All along the course, countless spectators lined the route, turning the race into a continuous 31-kilometer ribbon of atmosphere. The electrifying mood wasn’t only felt on site – thanks to Eurosport and numerous other TV broadcasts, the whole world could follow along live.
From a Swiss perspective, Adrien Briffod delivered the sporting highlight of the day: with a sensational time, he broke Marc Lauenstein’s 12-year-old Swiss record – albeit narrowly – by 8 seconds.
In this article, I look at exciting statistics, analyze the pacing of the top athletes, and show how the race unfolded under these extreme conditions. Two new names in the all-time top 10 round off this exceptional year.
Results lists: Datasport link
Facts and Figures
We analyzed all finisher numbers (Coureurs and Touristes).
Finishers:
- Total: 5430
- Men: 3726 (68%)
- Women: 1704 (32%)
Winning times:
- Men: Philemon Kirago (23 years) – 2:28:45
- Women: Joylene Chempengeno (27 years) – 2:54:49
Average finish times:
- Overall: 05:13:00
- Women: 05:40:59
- Men: 05:00:12
Per category:
- Elites Men: 04:16:52
- Elites Women: 04:28:24
- Veterans I: 04:34:45
- Veterans II: 04:47:47
- Women I: 04:50:54
- Veterans III: 05:04:49
- Women III: 05:05:36
- Tourists: 05:33:06
Nations
In this year’s edition, runners from 73 nations crossed the finish line.
With 68% or 3,701 finishers, Switzerland naturally made up the largest group. Behind them:
- France: 12.5% (677)
- Belgium: 7.5% (405)
- Italy: 1.8% (100)
- Spain: 1.4% (80)
- Germany: 1.4% (80)
- United Kingdom: 1.1% (61)
The biggest surprise: Belgium. The country isn’t exactly known as a classic trail running nation – and yet it formed the third-largest participant group.
Distribution of finishers by age and gender
Most participants per age are around 30 years old.
- Overall: 31 (born 1994) – total 274 participants
- Women: 29 (born 1996) – 194 participants
- Men: 31 (born 1994) – 105 participants
Average finish time by year of birth
Average time:
- Women: 05:18:48 – 27 (born 1998)
- Men: 04:30:15 – 25 (born 2000)
Race progress – Top athletes
When we look at the race progress of the best athletes, this year again shows how important good pacing is. In the following graphics, the race development is shown based on split times.
Race progress – Men
A look at the race progress of the best men also clearly shows in 2025 how crucial smart pacing is. The lines of the top three illustrate how disciplined they were through the first part up to Chandolin. While many competitors ran above their level there, Philemon Kiriago, Patrick Kingeno, and Michael Saoli ran in control – laying the foundation for their podium places.
Particularly noteworthy: Saoli was still in 11th place at Ponchette, about 3:30 minutes behind the leader. In the second part of the race, he fully played to his strengths on the slightly technical trails. Here, it’s key to “let the legs run” and fly smoothly over the terrain. Many athletes lost valuable time in this section – due to suboptimal pacing, insufficient fueling, or lack of skills in rolling and downhill terrain.
Race progress – Women
In the women’s race, there were fewer position changes within the top 10. This points on one hand to good pacing, but also to a slightly bigger time gap between 1st and 10th place (12 minutes) compared to the men (9 minutes).
It’s striking that the final downhill often made the difference: Katie Schide, currently one of the best ultra-distance trail runners, overtook two competitors here. Conversely, runners with a stronger road or vertical background – such as Laura Hottentrott and Susanna Saapunki – lost significant time in this section.
At the front, Joylene Chepngeno pulled away. Her experience paid off especially in the second third of the race, where she created the decisive gap over her teammate Caroline Kimutai. Record holder Maude Mathys, despite a difficult preparation and not being in peak form, once again showed her class: with smart race management, she fought for 4th place and even stayed under the 3-hour mark.
Top 20 analysis at Ponchette
Looking not only at the top 10 (men) but also the 20 fastest at the first split in Ponchette makes the effect of good pacing even clearer.
Several runners were still within reach of the lead after the first third of the race – some only a few seconds behind. In the last two sections, however, they lost multiple times that amount of time and dropped far back.
Pacing analysis – Mass participation
To illustrate pacing, we also analyzed for every half-hour finish time the next 5 men and women. This gives an interesting picture and shows the different race profiles. The time differences during the race are sometimes striking.
(Women: orange, Men: black)
Finish time: 3:00h
Finish time: 3:30h
Finish time: 4:00h
Finish time: 4:30h
Finish time: 5:00h
Finish time: 5:30h
Finish time: 6:00h
Conclusion
- Men use their advantage of a better power-to-weight ratio in the first climb
- Women tend to have more consistent pacing and gain time especially in the middle section
- The higher the finish time, the greater the fluctuations in split times
- Good pacing, based on one’s own abilities and strengths, pays off in any race with highly varied topography
All-time Top 10 list
We updated the all-time top 10 list. There’s a new name in both the men’s and women’s lists. All other athletes who were already in the top 10 and raced this year did not improve their personal best. The new entries are Kenyan athletes Caroline Kimutai (6th) and Michael Saoli (6th). They pushed their compatriots Joyce Njeru and Robert Pkemoi out of the top 10.
All-time Men’s Top 10
All-time Women’s Top 10
If you’re new here: In my last three blog articles on Sierre-Zinal, I have already covered 1.) the myth and challenges of the course, as well as 2.) optimal race nutrition before and during the race and optimal pacing.
Data Analysis by Siarhei Thor
Author: Gabriel Lombriser
running.COACH Product Manager. National mountain/trail running coach in Switzerland. Loves sharing his passion and expertise in running, especially trail running. Also organizes trail running camps: indurance.ch