“Every year, Sierre-Zinal is different. You have to respect the mountain and listen to your body — it’s not just about running fast, it’s about knowing when to push” – Kilian Jornet.
Sierre-Zinal – 31 kilometers, 2,200 meters of ascent, 1,100 meters of descent, and five 4,000-meter peaks in view. Few races combine alpine beauty, history, and toughness like this classic in Valais. But to succeed here, you need more than just strong legs — above all, a smart head: In hardly any other mountain race does pacing — the deliberate management of speed and effort — play such a crucial role in determining success or collapse as it does on the route between Sierre and Zinal.
What do the top athletes do differently? What does the ideal race of Kilian Jornet — the record winner with 10 victories in 13 starts — look like? And what can ambitious amateur athletes learn from it for their own race strategy?
In this article, I analyze the race progressions of the fastest runners from recent years, take a close look at Kilian Jornet’s pacing patterns, and show how to approach the key sections — after Chandolin, up to Hotel Weisshorn, and the final downhill to Zinal — in the best possible way. Whether the goal is under 3:30 or under 5:00 hours.
If you’re new here: In my last two blog posts on Sierre-Zinal, I already covered 1.) the myth and challenges of the course, and 2.) optimal race nutrition before and during the event.
Analysis of the Top 10 Times (Men & Women)
The 52nd edition of Sierre-Zinal is approaching — a classic that has attracted the world’s best mountain and trail running athletes to Valais for decades. Year after year, we witness high-level duels on this demanding course. Unforgettable was the spectacular finale in 2024, when Kilian Jornet was caught in the final meters by Philemon Kiriago, and both delivered a thrilling sprint to the finish line. In that memorable race, Jornet also set a new course record.
The women’s course record dates back to 2019 and was set in outstanding fashion by Maude Mathys.
For this analysis, the finishing times of all editions were examined — and especially for the past ten years, many intermediate splits were evaluated. Where official splits were missing, additional Strava data was used. This provides a detailed picture of the pacing strategies, strengths, and weaknesses of the fastest athletes. The pandemic years 2020 and 2021 were excluded from the analysis due to the shortened alternative course.
Women
The following chart shows the ten fastest female runners of all time in direct comparison. Particularly striking: Maude Mathys delivered an almost perfect performance in 2019 — from the steep start to the technical downhill into Zinal. In the virtual comparison, she distanced the other nine top times by at least four minutes. The remaining athletes were within four minutes of each other.
A fascinating example of individual pacing is Judith Wyder: At the intermediate split at Hotel Weisshorn, she was still behind compared to the current top 10, but in the final downhill — her specialty — she ran the fastest section time from Weisshorn to Zinal and secured second place in her debut race.
The consistency of these top performances is also reflected in the regularity of the pacing curves. Those who are leading only up to Chandolin but take too many risks often fall far behind by the end. A deeper analysis would reveal many such examples.
Ascent speed to Ponchette (first 1,300 vertical meters, 7.1 km):
- Maude Mathys (2019): approx. 4:24 min/100 m ascent
- Silvia Rampazzo (2019): approx. 4:42 min/100 m ascent
By the way, the oldest time in the top 10 comes from Angela Mudge, the British mountain running world champion, who triumphed in Zinal back in 2001 — 24 years ago.
Men
The progression among the men is equally fascinating. Jonathan Wyatt, multiple world mountain running champion from New Zealand, set a legendary record in 2003. His impressive performance on the climbs and flat sections remains remarkable to this day — even though he lost almost six minutes to the current fastest downhill runner Philemon Kiriago on the final stretch from Weisshorn to Zinal. Still, Wyatt remains ranked 5th on the all-time list.
The pacing curves of Andreu Blanes (winner 2022) and Philemon Kiriago (second 2024) show impressively that a more conservative start doesn’t have to be a disadvantage. Blanes passed the Ponchette checkpoint in 2022 in only 22nd position. Kiriago, too, trailed Jornet by over three minutes in 2024 — but still fought his way to nearly snatch victory in one of the most dramatic trail running finishes ever.
Climbing speed to Ponchette (1,300 vertical meters):
- Kilian Jornet (2024): 3:40 min/100 m
- Andreu Blanes (2022): 4:05 min/100 m
These numbers clearly show how differently athletes approach the race depending on their individual strengths — whether it’s the uphill, the flatter middle section, or the final downhill.
Kilian Jornet
No other runner has shaped Sierre-Zinal like Kilian Jornet. Since his first appearance in 2009, Kilian has competed in the race 13 times and celebrated 10 victories. The graphic shows the 11 races on the original course – the two wins in 2020 and 2021 during the Covid editions are not included.
In his recent record-setting runs in 2019 and 2024, it’s clear that Kilian made the difference on the first major climb. For these editions, he prepared specifically, set the pace early, and controlled the race from the front. While no one could follow him in 2019, he was still accompanied by other athletes in 2024. However, they paid a high price for their early effort and dropped back significantly later in the race.
Differences Between Women and Men
We analyzed all the data from last year’s race (2024) – and found striking differences in the pacing behavior of women and men. This pattern isn’t new: a similar phenomenon can also be observed in major road marathons. On average, women start more cautiously, pace more conservatively – and in the final third of the race, are often just as fast or even faster than men.
Average time comparison: Men (orange) vs. Women (blue)
A particularly interesting finding emerges in the age category Veterans 1 (40–49 years): Here, women perform better on average than their male counterparts – largely due to their more consistent pacing.
Average time comparison: Men (Vet 1) (orange) vs. Women (Vet 1) (blue)
Pacing Recommendations by Target Time
To understand how runners approached their race at Sierre-Zinal 2024, we analyzed the split times by target time groups. Participants were grouped into 10-minute finish time intervals (e.g., 3:30h ± 5 minutes) – and for each group, we calculated the average checkpoint times at key locations along the course.
This makes it possible to see how pacing strategies vary by performance level – and where on the course crucial time gains or losses occur.
The average split times calculated for each section are as follows:
Based on our own calculations and the analysis of well-paced races, we created a table of average checkpoint times for each target finish time – in 10-minute increments. Especially in a race as difficult to pace as Sierre-Zinal, this can be a valuable guide for developing a realistic and sensible race strategy.
Optimal pacing
A few important notes for interpretation:
- Every runner has different strengths. This table is not a strict prescription, but a general guideline.
- Starting conservatively almost always pays off – especially for target times over 4 hours, the beginning should feel more like an easy endurance run.
- Faster athletes are on the course for less time, but their perceived effort is higher. The race feels more intense overall.
- For runners with marathon experience but little trail or mountain running background: the perceived effort at the beginning should be slightly lower than in a marathon.
Conclusion
Which pacing strategy leads to the best finish time is ultimately very individual. However, in general — especially for amateur runners — a conservative start is the key to success.
Nutrition During the Race
Based on the planned split times, it’s also possible — as discussed in the last blog post on optimal nutrition — to plan race-day fueling more precisely. Knowing when you’ll reach each checkpoint helps you better manage when to take in energy and fluids, in order to avoid performance drops.
Data Analysis by Siarhei Thor
Author:
Gabriel Lombriser, Product Manager at running.COACH. National coach for mountain and trail running in Switzerland. Passionate about sharing his expertise and love for running — especially trail running. He also organizes trail running camps: indurance.ch