Trail running legend Kilian Jornet continued his storied career of podiums at the 2025 Western States 100 Mile Endurance Run. Key to thirty-seven year old Jornet’s longevity, endurance and recent third place finish at California’s most historic trail ultramarathon is not only his more commonly discussed training and recovery methods, but his specific pacing strategies. Featured photo courtesy: COROS / Luke Webster / Anastasia Wilde.
With wins in both short and long races, on steep and flat terrain, in hot and cold temperatures, Jornet has developed practices to pace himself in training and racing in a wide variety of conditions. Improved pacing methods have allowed Jornet to optimize his training and increase his chances of adding more podiums to his outstanding trail running resume. In the following Q and A style interview, I chat with Jornet about his pacing tips during the 2025 Western States 100, as well as dive into basic pacing advice for beginners. Pacing is not just something for elite runners to focus on. From the back to the front of the pack, all runners will find improvement in their performances and training from dialing in their paces.
[TAYTE POLLMANN] Examining your Western States 100 race data from your Coros watch, you spent the majority of your race this year in Heart Rate (HR) Zone 2. Could you explain why this is? Was this the planned zone or would you change anything about this percentage going forward?
[KILIAN JORNET] The intensity in a race like that varies a lot. In the downhills the load is metabolically low but neuromuscularly high, and the opposite in uphills, so for pacing in downhills I look more at pace and muscle feelings and in uphills at HR. With altitude in the first part and heat conditions we also need to think that HR will be higher at lower altitudes and colder temperatures, so adjust on that.
[TAYTE] How do you pace yourself? Is it better to hold a consistent pace or are there times when it makes more sense to slow and speed up a little more drastically depending on the terrain or competition?
[KILIAN] Pacing is very dynamic, and I adjust it depending on the terrain and the race conditions. On flat sections, I prefer maintaining a steady pace. But on steeper climbs or technical descents, I tend to adjust, slowing down when the terrain demands it and pushing harder when the conditions allow. Flexibility in pacing is key to managing energy effectively during a race.
[TAYTE] Are there special considerations to pacing in a net downhill race such as the Western States 100?
[KILIAN] Mostly to take into account the muscle/neuromuscular impact of the downhills, to not get too fast too early because the race is long. Then pace should be more done by pace than HR in the downhill sections.
[TAYTE] How does pacing yourself change in training versus racing? Are you going more off “feel” or exact pace in training vs racing?
[KILIAN] In both scenarios I do a mix of them, pace or HR serves to adjust that feeling that I have and understand the constraints of each. Feeling can be off for example during the first part of the race when the hormonal levels are affected by the stress or excitement so we will feel less than what we are doing, or when going to parts with lots of people cheering. On the other hand, HR can be affected by altitude and heat, so that is important to acknowledge.
[TAYTE] Do you utilize the “Effort Pace” or grade adjusted pace in your training/racing considerations?
[KILIAN] Yes I use a lot the effort pace, in mountain terrain pace is almost never used since the variations of incline are constant and is much better to have an effort-pace base for training and racing.
[TAYTE] What advice would you have for younger runners or people new to the sport who might have much less experience running by feel and pacing themselves correctly? What is a strategy to start this process of dialing in your paces?
[KILIAN] For newcomers, my advice would be to start with a focus on consistency. Don’t get caught up in trying to push the pace too hard early on. Develop an understanding of your body’s signals—when you can push and when you need to slow down. Using heart rate and effort-based metrics in training is a great way to build that awareness.
[TAYTE] How do pacing considerations change (and stay the same) with shorter vs longer trail races?
[KILIAN] In shorter races, pacing is almost never a “hold back” but the opposite, is to go at threshold effort and then just at some times, if you see that the pace/hr is low to keep up high at threshold. In long races it is different since more factors can affect you. Then it is to try to play a bit more strategically, where can I push more, uphills or downhills, when in the race do I push, how do I dial in the fueling, etc.
Editor’s note: Read a conversation with Kilian Jornet about his outdoor friendly pledge here.
