I put together three threads on Twitter (thread #1, thread #2, and thread #3) that included ideas, sessions, resources, and people to follow to help an athlete prepare for UTMB and then notes and reflections from UTMB. This is the initial contect from those threads, however, as other users add more ideas and content I'll update it here to create a full resource.

If you'd like to contribute any additional thoughts or ideas, please add to those threads.



UTMB is 170km and will take anywhere from 20 to 40 hours. It is definitely an endurance event and the intensity is low. Building an aerobic base of training is therefore critical.There are two important components to consider.

Weekly training volume

Building an aerobic base takes time and requires plenty of training volume. We know that elite endurance athletes do a lot of volume. Some examples are available in this paper from Stephen Seiler:

Intervals, Thresholds, and Long Slow Distance: the Role of Intensity and Duration in Endurance Training

Even though most athletes cannot complete that volume of training, it is important to fit in the highest volume you reasonably can given life constraints and physical constraints. For runners, cross-training and commuting can be good sources of extra volume.

Aerobic training has multiple benefits including improving mitochondrial health, improvements in our ability to use lactate, and increased rates of fat oxidation. Important people to follow to learn more about this are Inigo San Millan and Howard Luks.

Shock weekends

In addition to completing a good amount of weekly volume, we also need to include specific long runs. It's impossible to do the entire race distance in one day which is where shock weekends come in.

Some details on shock weekends from Guillaume Millet:

  • How much training in a weekend?
  • It depends if this is your 1st or 4th SWE of the season. Anything from 2 x 6 h to 2 x 10-12 h (can also 3 days in a row).
  • How far from the race do you plan these? 3,6,9 weeks out?
  • Minimum 3 weeks before, 4 being probably better.


UTMB includes 10000m of climbing! This means there will be uphills that can be run and uphills that need walking and uphills that will require power-hiking. It's likely that the time spend walking uphill is the largest proportion of the race.

A useful session that I learned from Antoine Guillon is weekly uphill repeats:

8-10 x 100m D+ at 75-78% max heart rate

These sessions are not too intense, provide an uphill and downhill stimulus and can be repeated frequently.

When possible (probably during shock weekends and other long runs) it's very useful to include long climbs that are similar to those in the race. Use race pace (hiking) and use your poles.

Jason Koop wrote and excellent series of articles on using poles:

The Ultimate Guide to Using Poles in Ultrarunning

And you can find information on how to store poles in your pack in my article:

Trail running poles

For more information and guidance on uphill running this webinar was excellent:

Trail running webinar part I UPHILL


What does up must come down and in UTMB there is equally 10000m of descents. "Destroyed quads" is often a reason given for DNFs and many runners know how badly this can affect their race.

We know what are the effects on the muscles downhill running and that the best way to train for it is by running downhill:

Downhill Running: What Are The Effects and How Can We Adapt?

Fortunately, even after one session we can see improvement:

Exercise-induced muscle damage and potential mechanisms for the repeated bout effect

It appears that the repeated bout effect wears off after about 3 weeks so it would be valuable to include descent training every 2-3 weeks.

Another useful training modality is strength training using eccentric-focused movements (more later).

To learn more about downhill training and descents, this webinar was excellent:

Trail running webinar part II Downhill

Some additional thoughts from replies on twitter:


I think of durability as the being able to handle the vertical, the distance, and the technicity of the terrain. This should be addressed in applying the training mentioned above, but there's always value in adding a little extra security around this area.

I really like this session from Inaki de la Parra to help with durability:

2-3 hr hard hike with lot of up/down: No running. Then immediately after go to asphalt run for 2 hrs and hit some specifics powers ( @strydrunning), HR or paces in the hard rolling surface to get some nice muscular adaptations on top of metabolic ones.

I also think strength training can help. This is where I start for runners:

Sleep and Fatigue

UTMB starts in the evening so all runners will go through one night and many will go through more. Sleep deprivation is therefore something important to consider.We know that sleep extension leading into a race can help:

Benefits of Sleep Extension on Sustained Attention and Sleep Pressure Before and During Total Sleep Deprivation and Recovery
Sleep Extension before Sleep Loss: Effects on Performance and Neuromuscular Function

An extra hour a night for the week leading into the race was beneficial. This should be first priority.

An interesting and new area of research is sleep deprivation training:

Sleep Deprivation Training to Reduce the Negative Effects of Sleep Loss on Endurance Performance

I think it's important to understand that this is a case study and new work so be cautious if you do try it.

To learn more about fatigue, I recommend this excellent resources from Thomas Solomon:

What is fatigue?


The climbs at UTMB pass over some high points near 3000m. This altitude will affect you and if possible, it's beneficial to prepare for the altitude. The best option is to go on an altitude training camp.

The recommended does is at 14-18 days at 2000m.

In Europe there are multiple options: Font Romeu, Sierra Nevada, St Moritz, etc. This year Tignes appears very popular with the elite UTMB athletes.

If you can't go on an altitude training camp, and if you can afford it, an altitude tent is the next best option. Follow Gregoire Millet and Santiago Sanz.

Managing training load

Following all of this advice is important, but it's also very important to consider how our bodies are adapting to the training. I recommend using heart rate variability to help understand the rate of adaptation and to adjust training accordingly. A short measurement each morning is all that is needed.

To learn more about HRV, the best starting point is Marco Altini's guide:

The Ultimate Guide to Heart Rate Variability

And you can find the HRV4Training app in the app store.


Notes and thoughts on nutrition were the most requested. I agree this is critical and a worthwhile area for adding more notes. I will prepare an additional thread that covers this in the future. For now, I'd guide you to my resources page where you can find a whole range of papers with notes and practical takeaways on nutrition.

Foot care

Another excellent suggestion from twitter to extend the resource to include foot care. I've written about this before and this article may prove useful:

Looking after your feet



A second thread on twitter, this time with lessons from UTMB. I'll continue to update this as we learn more.


Here are a few insights from some of the top athletes. It's hard to replicate their training, but it can be insightful to see what they do and to adapt our training to what may be best practice.

Matthieu Blanchard (UTMB 2nd)

Matthieu's training is on Strava here. There are two aspects in particular that I'd like to highlight.

  1. 3 weeks before the race he did a massive training week: 39.5hrs in total with 256km and 14300m of that running. He did the UTMB route over 4 days and then after an "easy" day of 3.5hrs cycling he did another run of 10hrs (60km, 4500m D+).
  2. He raced three times in the 5 weeks before the race: La Thuile trail = 57km and 3300m D+; Megeve stage race = 42km and 2600m (day 1) + 28km and 1600m (day 2); Sierre-Zinal = 31km and 2000m D+.

Katie Schide (UTMB 1st)

Jason Koop shared an excellent article covering both training, the days leading into the race, and his ADAPT method for handling adversity. One training note I took from this was:

As a result, what I decided to do with Katie was to keep her volume more or less the same. At the same time, I reorganized the overall training into a block style structure. She focused on one particular intensity for several weeks before moving on to the anther stimulus.

Petter Engdahl (CCC 1st)

He spent 4 months in Chamonix over the summer preparing for CCC increasing his training volume from previous years to: 120-180km and 6000-12000m D+ per week. His race report here.

Race Strategy

It's not always easy to identify and understand a race strategy from outside the race, but there are two interesting articles that give us some insight into this.

Kilian's strategy

This very detailed article provides plenty of information gathered from Kilian's GPS from during the race. With regards to strategy they outline 3 phases in the race:

  1. Tactic #1: Surging for 80km
  2. Tactic #2 Recovery Mid-Race
  3. Tactic #3: Winning Move on Final Climb

David Roche's "How to race UTMB" article

This excellent article looked at the positions of athletes throughout the race.He notes:

There are plenty of athletes that were outside of the top 10 through 50k and even 80k that finished in the top 5. For top 10, you can be well outside the top 20 at 80k and still have an incredible finish.

My sense on race day was that there was less movement in the top 20 this year (TBC).


I didn't cover this in a previous thread and many people requested information on it. Here's what I've found so far.


In this Maurten blog post they mention that Kilian was testing during a 100 mile race early in 2022 with 100g/hr of CHO. Maybe more coming from Mautren soon?

Tom Evans

Tom mentioned on an Instagram Q and A that he was aiming for 90g/hr during the race. He showed some of his nutrition options too from the Feed Zone Portables book. His crew also explained at Vallorcine that he shifts towards more liquid later in the race.

Petter Engdahl

His race nutrition was:

  1. 16 Maurten Gels
  2. 6 Maurten 320
  3. 4 Maurten 160
  4. 2 Maurten Solid Bars
  5. 2 Redbull
  6. 1 banana
  7. 56 Gummy Bears

I think that's ~120g/hr!

What the Pros ate

In this video from Mayayo Oxigeno he shows what the pros ate at 153km.



In the past there have been discussions about whether or not to use poles. In this edition of the race all the podium finishers used poles. Manuel Merrillas even used them in OCC!


Coros, Garmin, and Suunto dominated. I was surprised at how many Coros watches there were - they've made huge inroads into trail running. Many more details in this excellent article (in French).


As always, TrailRunningReview has all the details:

Shoes for athletes on the podium
Most used shoes


utrition is a difficult topic because there are evidence-based recommendations, but they are not always followed.

In this paper we see that elite athletes did follow guidelines (71g/hr CHO).

Yet, this study of amateur athletes doing 24 and 48 hour races they did not meet recommendations (mean of 33g/hr CHO). And this paper on pre-exercise nutrition showed a large number of athletes not following guidelines.

To understand these evidence-based recommendation, a good starting point is Asker Jeukendrup's 2011 paper on nutrition for endurance sports.

Outside of these studies and guidelines we see athletes succeeding in endurance events using a wide range of different nutrition strategies. Maybe a good starting point is to ask:

What's possible

There are examples of athletes succeeding with nutrition strategies ranging from very low CHO to very high CHO, from all-liquid sports nutrition to only real food, from carrying their own nutrition to only relying on aid stations.


Eating and digesting is easier in cycling compared to running and easier in running compared to swimming.


Eating a certainly hourly rate is easier in a 4-5 hour event or as an elite running 14hrs at Western States compared to an amateur at UTMB or an athlete during a 24 or 48 hour race.


Food availability for an elite with a crew or an athlete at a 24 hour race is very different to a self-supported athlete at an ultra with few aid stations.

Clearly "what's possible" may not always meet the recommendations even if that is the goal.

Fuel the work required

In this paper the authors recommend a periodized approach to nutrition in training. And this article explains a "right fuel, right time" approach to nutrition.

Race nutrition should also follow the "work required" paradigm. A shorter ultra at high intensity may necessitate more exogenous CHO intake than a long, low-intensity ultra where fat oxidation can be relied on more heavily.

Training nutrition intake

This 12-week guide from Aitor is an excellent resource on gut training. And in this twitter thread there is plenty of advice on gut training.

Alternatively, if you want to increase your fat oxidation to use a lower CHO approach you will also need some adjustments to your diet and training nutrition. This guide suggests that may be more beneficial than training the gut.

Whichever approach you choose, it's important to make sure that you do the training necessary for that approach and that you don't do something new on race day.

High CHO + examples

The potential to use a high CHO approach in mountain ultras along with the benefits were shown in this paper. There have also been many examples of World Tour cycling teams using up to 120g/hr CHO.

Stian Angermud has shared his race nutrition from Sky races and he was consuming ~100g/hr (1, 2, and 3).

Petter Engdahl shared his CCC nutrition and he consumed ~120g/hr of drinks and gels.

Tom Evans reported that for UTMB he used ~95g/hr of mostly Maurten and Red Bull.

Mid-range CHO example

According to the data shared in this post and my calculations, Kilian's nutrition during his races this year was:

  • Hardrock = ~55g/hr
  • UTMB = ~75g/hr

Low CHO examples

Zach Bitter has reported using 40g/hr during his races (primarily 100mi).

Jeff Browning has reported using 40-50g/hr during his races (primarily 100mi).

Dan Plews reported using 50g/hr during the bike and a total of 40g during the run in Kona.

Resolving gut issues

Nausea and/or vomiting is the primary cause of a DNF at ultramarathons. Therefore figuring out a nutrition strategy that works for you is vital.

If you are struggling with stomach issues, then a very useful resource is Patrick Wilson's book: The Athlete's Gut.

Practical takeaways

A good place to start is the evidence-based recommendations of 60g/hr CHO.

If you know the intensity of your race is going to be high and you have access to your own in-race nutrition, considering increasing CHO intake. Increasing CHO intake will require training and practice at race intensity. We've seen up to 120g/hr for a 10hr ultra and up to 95g/hr for a 20hr ultra are possible.

If you're having stomach issues or the pace of your race is lower consider either trying to resolve these issues using the Athletes' Gut book (mentioned above) or start working towards a low CHO strategy. Again this will take training and time to develop.

Additional input on nutrition

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