This article originally appeared on Trail Runner
Last week, I wrote a primer on Kilian Jornet's training data between his course records at the Hardrock 100 and UTMB (data published by watch-maker Coros). After the article came out, Kilian messaged me a new link. In case you were wondering: finding out I was going to be a dad, my marriage, Kilian sliding into my DMs, in reverse order of importance.
I clicked the link and angels sang. Kilian wrote a post that is going to be a fundamental pillar of training theory, opening up the vault to his data, theory, and mindset. It's almost unprecedented in the history of endurance sports–an athlete at the peak of their powers being fully transparent about the how and why behind their successes.
The most recent analogue I can think of is Nils van der Poel's speed skating training. But I think Nils wrote his training manifesto with an understanding that it was unlikely that anyone was going to be able to repeat the wild block-periodization model with workout days that almost seemed impossible.
Kilian's training, on the other hand, is far more mainstream, the type of approach that almost any athlete could use with modifications for their backgrounds. The GOAT just wants to add to the body of knowledge of endurance training, where he is both a student and a teacher.
The GOAT wants us all to be the GOAT version of ourselves.
Read his full post–it's brilliant and important. In this article, I am going to provide context for his training, distilling eight takeaways that are relevant for everyone. My wife/co-coach Megan and I interviewed him on our podcast this week (listen here) for more details, one of the ultimate honors of our lives. Is it creepy if we name our kid Kilian? Before you answer, keep in mind that we already printed the sign to hang above the crib.
Kilian's 2022 was absolutely astounding.
Even as the ultimate fanboy, it's mind-blowing to me that one athlete is the best short-distance mountain racer (course record at Zegama) and the best long-distance mountain racer (course record at UTMB) in the same year. The easy response to his dominance is to say he is a genetic outlier. But at the elite level of sports, it's always a competition among outliers, and the genetic differences alone are not enough to explain dominance like Kilian's 2022. Reading his post, it's clear that he earned 2022 with a methodical, process-focused vision of long-term growth across decades of hard training.
On the podcast, he talked about how his training philosophy fundamentally shifted in 2018 and 2019, coinciding with the birth of his first child. Instead of long days in the mountains at zone 2, he shifted toward a different intensity distribution, emphasizing lots of easy volume and focused workouts. He made the changes without a coach (though he does work with exercise physiologist Jesus Alvarez-Herms). Instead, he made himself into an exercise physiology and training theory expert, applying what he learned and making changes based on what worked for him.
The GOAT wants us all to be the GOAT version of ourselves.
So his article is not a genetic outlier talking about the nuances of being an outlier. It's a brilliant scientist talking about the process of maximizing potential based on universal principles of human physiology, adapted for specific variation in genetics and goals.
Time to get to it! Let's dive into 8 takeaways from a training summary that will shape the sport for years to come.
One: Training is a long-term process of consistency and aerobic development.
A stunning figure shows Kilian's weekly training volume since April 2009. While there is variance, most weeks average around 20 hours, split between running, skiing, biking, and other sports. There are big up-swings of skimo in the winter and running starting in spring, with his training following a seasonal cycle.
At the far right of the chart is a microscopic red circle encompassing 2022. It's a striking visualization of how our brains can think short-term, but our bodies are playing on much longer time scales.
"There's no such a thing as the magical session that will make you better or a training program that will work for everyone," he says. "But the adaptations come from the repetition of training stimulus (consistency) and the individualization of those stimuli."
Kilian has consistently averaged 1000+ hours of training per year, mostly easy, across multiple sports. His aerobic roots run deep. For all of us, the first principle of endurance training is to stack up easy volume over time. The foundation for all performance from the 800 meters up to 200+ milers is how the aerobic system processes energy and associated fatigue. That ability comes from the daily grind of easy training.
So, first? Put your own roots down. It's a year-long thing, across decades.
Two: Most of his training is very easy, with a Pyramidal intensity distribution.
Now is the moment for every athlete to pay attention to specific guidance from the GOAT. You hear that most training should be easy, but what does that actually mean? Here's Kilian's breakdown of training intensity using the 5-zone model:
58% zone 1 (active recovery, nose breathing)
19% zone 2 (aerobic endurance, can keep for hours)
16% zone 3 (tempo, sustained fast and can say several sentences)
4% zone 4 (race pace, can say a sentence)
3% zone 5 (max)
58% in zone 1! That is an astonishing number, echoing the evolution of training theory more generally across endurance sports. Easy volume does not just allow recovery for harder sessions, but it provides the fuel that makes the hard sessions possible.
His intensity distribution is strongly Pyramidal with hints of Threshold, with 77% of his training in Zone 1 and Zone 2. The 16% in Zone 3 and 4% in Zone 4 is a high amount of threshold work, similar to some approaches used by Norwegian runners and triathletes. The smaller amount of Zone 5 work shows that he still develops his top-end speed, but with a much lesser focus.
It's tempting to get on the trails and assume that faster is better. But stacking up faster work causes everything to decline after an initial period of growth, as the musculoskeletal system wears down, the endocrine system gets overstressed, and the aerobic system erodes via less efficient lipid metabolism and mitochondrial function.
Admittedly, 58% of training in Zone 1 may be Kilian-specific, requiring wonderful aerobic efficiency and very high volume. On our podcast, he talked about moving quickly through the mountains at 110 to 120 beats per minute heart rate, which is my heart rate when getting food from the top shelf of the pantry. But every athlete should probably have a more even split between Zone 1 and Zone 2 than might be our natural baselines, with those percentages adding up to around 80%. All easy is not created equal, and it's valuable to slow down some of those days for workout quality, longevity, and growth along the entire aerobic spectrum.
Pyramidal training intensity is the predominant approach used by elite athletes whose training has been the subject of studies, meaning the next biggest proportion of training is tempo/threshold, with a much smaller portion faster than Critical Velocity and VO2 max. Lots easy, some moderate, just a bit hard (and make sure that hard work has a focused rationale for improving mechanical output).
Kilian leaves room for disagreement. "I know, for example, that I can absorb a great amount of volume and Z2 and Z3 training, but if I do more speed work for several continuous weeks (Z4 and Z5) I will get injured or metabolically not as efficient," he says. "For other athletes, it is the opposite."
What's fascinating in the research is that an approach with a higher proportion of top-end Zone 4 and Zone 5 work (known as Polarized training) is very rarely used long-term due to its tendency to cause quick adaptations, followed by stagnation (or injury).
Three: Kilian periodizes his training across the year, with a base period preceding specific training blocks.
Kilian's winter is spent on skis, where he's a world-class skimo athlete. From December to March, he would do 2-4 hours on skis (mostly in Zone 2) in the AM, followed by a 40-60 minute easy treadmill run in the PM. His training graphs show no hard workouts that entire time. Interestingly, he did a 100-mile race in February to test fueling. As much as I think Kilian's approach has lessons for all of us, doing a 100-mile race off a ski-focus may just be a Kilian thing. It's like wearing white spandex at Western States–don't try this at home.
That base period reinforced an already-monstrous aerobic system. The fact that he didn't only ski shows a lesson that might be important for athletes that get lots of cross training time. It can be helpful to reinforce mechanical adaptations for running year-round, even if it's not the primary focus.
Starting in March, he trained for Zegama at the end of May, emphasizing big volume (150-190km / 93-118 miles per week) with 2 quality workouts. In June and July leading up to the Hardrock 100, he increased training volume up to 200km (124 miles) per week, but did no longer sessions, and kept doing 2 speed workouts a week. From Hardrock to UTMB, he primarily focused on recovery and maintenance (read about that period here).
Reinforcing an aerobic base year-round is key for all endurance athletes, and it may help to have a more focused block of aerobic development in the off-season. This winter in coaching, motivated by Kilian and Nils, I am going to focus more on dedicated base periods, particularly for elite athletes. For athletes that don't have Kilian's background and VO2 max, it may include a small amount of intensity like in a classic Lydiard model, emphasizing the mechanical adaptations to handle faster work (like hill strides).
Kilian kept that aerobic focus going even when training for short races like Zegama. The benefits accumulate over time, so keep stacking those bricks.
Four: Most of his training sessions were relatively short, but with tons of doubles.
A big change in Kilian's life was when he became a dad a few years ago. His wife Emelie Forsberg is one of the GOATs herself, and they balance the demands of family life, business, and training as a team. In practice, that means that one gets the early block, one gets the afternoon block, and then their nights are free after the kids go to sleep.
And that seismic shift in life's demands may have also unlocked a training secret: Kilian rarely does "long" training sessions. Almost all of his runs didn't exceed 4 hours in 2022 (with most far shorter), a major change from what I had heard in whispers about his training in the early 2010s. However, he still accumulated massive volume week after week. How does that math add up?
The answer is by using doubles–two sessions in one day. On our podcast, he said that he completed doubles almost every day. For all athletes, doubles may improve hormonal response to training, and avoiding excessively long sessions could reduce some of the chronic stress of high-volume training. These sessions can likely be as short as 10-15 minutes, running or cross training, and may have outsized influence on fitness growth. There's a reason that almost every elite athlete training log includes doubles, even if we aren't 100% sure on the mechanism of action that makes them nearly universal.
The outstanding question is whether other ultra athletes could excel from so few extra-long efforts in training. Kilian has completed so many ultras and long sessions that he has no doubts about his aerobic abilities, or how his body will respond late in events. Most of us step into the unknown, but nothing is unknown to Kilian. Interestingly, this approach focused on training frequency to accumulate volume rather than supersized single days overlaps with some of the training of ultra champion Camille Herron (and others), so it's possible that very long efforts are an overrated part of ultra training.
Five: Kilian does workouts that focus on the specific demands of his events.
Now it's time for some workout porn. I know that Kilian doesn't want us to read too deeply into any specific session, but these are too good to pass up. He groups his sessions into 3 groups: speed, threshold, and tempo.
For pure flat speed training, he only did 4 workouts all year long. WOW! That includes track staples like 10 x 400 meters, which he says he limited due to risk of injury, a problem he faced in the past when focusing on road training. This may be a place where his genetic ability matters–he is very fast naturally, so it might not be an element that he needs to reinforce much, at least on flat ground. Most trail runners can probably limit their flat ground work, with just enough reinforcement to help hill strength translate into flat speed.
His staple session was an uphill/flat combination workout (like what I wrote about here). He starts with 1 or 2 intervals up a steep climb, with the downhill for recovery. After, he does a flat workout, such as a 10km tempo, 2 x 5km tempo, or 10 x 1k. On the podcast, he said that it improves his ability to run uphill fast and then on flats fast, like in a race. All athletes can likely use combination workouts, but scaled down to current levels.
His third big type of session was a longer steady run. He starts at high Zone 2 before increasing the effort, usually over 20 km to 30 km (12 – 18 miles). These long, steady runs are likely underutilized by many athletes in training, and they are a great opportunity to build specific endurance and musculoskeletal resilience. Just be careful not to turn them into races, since the intensity control is key to avoid an excessive amount of time in the upper intensity zones, undercutting aerobic growth.
The magic simplicity of Kilian's training is that it's usually 2 of those workouts a week plus easy running across daily doubles. Rinse and repeat, with specificity before races indicating higher volume preceding long ultras and a greater workout focus preceding shorter events. Finish up with a taper that is very easy and includes rest days for ultras, and a bit less easy with fewer rest days for shorter races.
Six: Most of his aerobic training is on steep and technical trails.
While Kilian consistently does moderate/hard workouts on flat ground or non-technical trails, many of his easy runs are on the trails where he lives in Norway. Just looking at a photo of those trails gives me a stress ulcer–they are steep and technical in ways that are rarely seen in the US outside of climbing routes.
He likes workouts to be on smoother and/or flatter surfaces to "privilege the metabolic and muscular capacities"–optimizing raw output. He likes slower days "on terrain that challenges other aspects (cognitive, mental, technique, visualization...and they're much more fun!)."
Make sure that you aren't sacrificing output in your harder sessions. On a steep and technical climb, an athlete's grade-adjusted pace may be 1-2 minutes per mile slower than on a less technical climb. While the efforts feel equally hard, that translates to lower output, and likely to fewer adaptations. However, on purely easy days, you can have fun with it! Plus, working on technical abilities requires constant reinforcement, like all cognitively and neuromuscularly demanding physical movements.
Seven: Strength work is not a part of his training.
Readers, I know that you know that I am not a big fan of a heavy emphasis on strength training. But my views are far outdone by Kilian's views. "I don't do any strength sessions," he says. "Having limited time for training, I believe that the stress to the body from strength training would be too much to be able to give the best at the running or skiing sessions, where I want to put the focus because they are more specific."
However, it's important to note that skiing is a bit like one long strength session, and the way Kilian runs up hills is similar to plyometrics. So he may be playing by a different set of rules than most athletes. I like a minimal-dose program, focused on the least amount possible to get the necessary adaptations, often as little as a few minutes 2-3 times per week.
Eight: It's all about the process.
Near the end of our podcast, we asked Kilian about the one piece of advice he'd give an aspiring young pro. We had been diving deep into training theory, so I was trying to ask a leading question for him to give away his ultimate methodological secret. Instead, he swerved the conversation.
"Focus on the process, not on the results."
He described the importance of developing a deep love of daily training, through ups and downs, wins and losses. It's going to take many years to see where the limits are, and it's way better when it's fun.
Kilian talking about training is Kilian talking about anything. He's a founder of the shoe company NNormal, which is set to be a major player in the future of the sport. Yet even as he's probably being roped into conversations on growth models and projections, he's still focused on the process of making a fulfilling workplace for himself and his employees. The same goes for parenting, with his eyes lighting up at the mention of fatherhood and all the new stressors that come with it.
Over the last few weeks, I have learned that Kilian is not the GOAT because of genetics. He is the GOAT because he loves it. We asked him how he reconciled a love of the mountains with all of the data he collects on his training. He had a genius reply: to him, science is a manifestation of his love, of his respect for the sport and the mountains and what they require.
I have never been so motivated to get out there tomorrow and run. I'll be doing it for the love of the process, and all the messy narratives that entails. I hope you are as inspired by Kilian as I am, helping you get out tomorrow and embrace a love of that messy process.
And I hope that we all can do that year-round for a few decades in a row to find our true limits…with a substantial portion of those days in Zone 1.
David Roche partners with runners of all abilities through his coaching service, Some Work, All Play. With Megan Roche, M.D., he hosts the Some Work, All Play podcast on running (and other things), and they answer training questions in a bonus podcast and newsletter on their Patreon page starting at $5 a month.
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