How to Run 100K and Actually Enjoy It

11 hours and 20 minutes is what it took me to run my very first 100 kilometres ultra-marathon. It was no smooth ride, but looking back I enjoyed every single minute of it. Especially the hard parts, because a sportsman’s mind is so crazy that it often nurtures these moments that hurt the most.

Forrest Gump running No need to grow a beard that long, fortunately!

Having come out of this alive, I want to share the journey to get there for fellow runners. I’ve heard it said that any big race is a combination of 33% training, 33% nutrition & logistics, 33% mental and 1% luck. Besides this, I would add that an ultra-marathon is a bit like a business negotiation: 80% of the effort happens before the actual event, in the preparation phase. There is so much preparation required that you should already have a fair estimate of your chances of making it even before the race starts.

A big race is a combination of 33% physical prep, 33% nutrition & logistics, 33% mental and 1% luck

So let us look at what happens before, during and after the race to make this experience a success. I’ll focus on my own experience, which of course should be complemented by your other readings. An ultra-marathon is no small feat and in such extreme conditions bodies might react differently from one person to another — so always listen to your body first and don’t take my words for granted.

Before the race

Physical training

Before starting the training, you should at least have ran several marathons, and ideally a couple of 50K-races as well. I would really not attempt a 100K run otherwise, as it might disgust you forever of long-distance running.

Ideally, your training plan should start 10 weeks before the race. It should consist of spending as much time as possible on your feet, at a pace as close as possible to your target speed (mine was 6:00/K, corresponding to 10km/h). If you come from a speedy background this may seem painfully slow. But there’s not other choices than clocking in a huge weekly volume.

Strava running bubbles Yup, that’s a ****load of bubbles — each one is a training session with #km in it

My typical training schedule consisted of approx. 65K per week at 5 sessions initially to finish with 100K per week in 4 sessions:

  • 3 sessions of 22K at dawn (from 5:50 to 8:00) during the week (typically Monday, Tuesday, Thursday)
  • 1 session of 40K on Saturday (or Sunday if you run on Friday, so you have a little bit of resting)

Initially I started with 5 sessions to get used to the volume, then once acquainted with regular long distances I switched to 4 sessions. I read in many places that there’s no need to run more than 50K during the training. Just for peace of mind, I ran 50K 2 weeks before the race. It went very well and gave me an extra confidence boost.

As I really felt the positive influence of training on my performance, I decided to keep running even on the Monday and Tuesday before the race, leaving little time for tapering (that is, resting your legs before the race). This played out nicely.

Note that after each run I took at least 10 minutes to massage my legs with Arnica and essential oils. Although the smell became omnipresent in my flat, this drained the toxins from my legs and really improved the overall experience. Before each morning run at dawn I also made sure to prepare my feet with Tiger Balm. This allowed to gently warm up my joints after the night.

Strangely enough I nearly never stretched and this gave me no problem. I’m not the flexible type — but I’m sure my performance and recuperation could improve with more stretching.

In general I tried to get more sleep than usual, typically never going to bed after 1AM and targeting 10:30PM to be in bed (useful when you need to wake up at 5:50AM).

Napolean sleeping Even Napoleon needed some sleep to prepare his future victories


This is probably the area where I really hacked the **** out of my body. Coming from 84kg, I lost 11kg in total over the course of 3.5 months. This was on purpose to gain performance by having to carry less fat on the way. At a height of of 186.5cm, this brought me from a BMI of 24 to 21. So there was so room for improvement initially (which is probably not the case with all runners, so adapt your objectives to your situation).

This decrease was mainly driven by a reduction in fat mass, moving from 15% of fat to 10%. Frankly, it has been a great satisfaction for me to see my weight decrease. Indeed, contrarily to a speed race preparation, you don’t aim to see your cruising speed increase as you train for an ultra-marathon. So, seeing your body get healthier is a proxy to performance!

Fat mass chart Gosh, where did all the fat go?

To get this decrease, I was radical on my nutrition for 8 weeks, and practiced running before eating on mornings. My eating consisted of the following rules:

  • Pasta, bread, pizza, french fries max 1x per week
  • No alcohol, no sodas
  • No snacks, candies, crisps
  • Nearly exclusively organic food (I love The Barn Bio Market for this), mostly veggie (meat 1–2x a week)
  • Porridge with almond milk, fresh fruits and cashew nuts every morning
  • From time to time, additional magnesium caps against muscle fatigue
  • Very light meals at night (typically a soup and a fruit)

Then I had my magic ingredients as well (which probably also helped with a light placebo effect):

  • About 10 grams of maca powder every morning diluted in almond milk
  • About 20 grams of spirulina per day (15 grams in the morning, 5 grams at noon), to get plentiful of proteins
  • About 1 glass of water kefir per day, which really proved ideal to kill the hunger

Runner at night Run first, eat later. That’s the spirit baby!

But the killer to really take my weight down was definitely running without having eaten in the morning. It takes extra caution to not hurt your body with too intense efforts, but once mastered this strategy provides impressive results. I ran 10x 10km then 10x 22km with just a little piece of sugar to kickstart the fat burning process (if you follow me on Strava, you’ll love the Burn This Fat Series). Also, don’t forget to drink at least 500ml of water before starting the training (ideally straight after you’re out of bed), and definitely 1 more litre during the training. This is all required to burn the fat! Then eat like mad for breakfast.

Again, note that these tips are highly dependent on your initial health state. Don’t play with these things, right?


I cannot overemphasise how much I actually trained my mental without actually noticing it in the weeks leading to the race.

Runner at night Do develop your power like a freakin’ mentalist, dude!

The thing that really struck me a posteriori regarding mental preparation is that all the energy that it takes to wake up at 5:50 several times a week to go running in the cold with an empty stomach, the willpower it takes to avoid alcohol and crisps at social gathering, the time invested in taking care of your body, all these mental exercises, ultimately have a profound impact on your capacity to not give up during the race. It is very fortunate that physical and nutritional preps actually cross-fertilise your mental!

Then you have the explicit mental preparation. For me, most of that preparation was geared towards visualisation of the race, especially about imagining its toughest moments and thinking about the joy I would be feeling at the finish line. Somehow I even told myself I would deserve a tattoo for nailing the race, and I thought often about this potential battle scar to get me going…but now frankly I’m not sure I want it anymore. It just proved to be a nice carrot.

A key point of the mental preparation is also about boredom management. Because let’s face it, at some point you’ll get tired of internal conversations with yourself if you run during more than 10 hours. Same for long training sessions! My trick there was to listen to a lot of long podcasts, 1 hour episodes that would get me going for some time without having to think about the actual run.

During the race

Now come the fun part. But remember, there is so much training involved that you should already feel pretty confident you’re gonna make it when the race starts. All it takes is a bit of courage, good weather and a bit of luck. The rest is all about enjoying the ride!

Morcheeba Enjoy the Ride One of the funny characters from Morcheeba’s Enjoy the Ride song — love that one!

Physical efforts

It’s really all about pacing your efforts during the race. Take good care in not starting too fast, which is a common pitfall if you start at dawn in the night. Be aware that an ultra-marathon is quite different from a marathon and other sub-50K distance just because of the sheer time that you’ll spend on your legs. Imagine repeating the same running move for about 12 hours in a row…

This has consequences that can be expected but that still managed to surprise me: blisters get gigantic as you step several thousand times on them, your muscles get absurdly tired, your back gets compressed because of the repetitive shocks on your spine. For me this last point was a real pain and at the end it became tough even to keep my head high — it just felt like my neck wanted to vanish inside my body, with each new step acting like a hammer impact on my head.

Looney Tunes hammer Be ready for some shocks on your spine

I would thus recommend practicing general postural reinforcements to ensure you can bear the load of yourself for a straight 12 hours.


You’ll often hear it said that very-long-distance races closely resemble eating competitions. You gotta manage your innards to ensure you keep transforming food into calories and stay rightly hydrated, all the while running non-stop. This can prove extremely challenging for unprepared bodies!

During the race, you will probably burn as much as 10.000 Calories (about 1.000 per hour — I burned about 11.000). Consider this figure in light of the normal daily Calorie intake: 2.500 for men and 2.000 for women. So to compensate you should eat actually 5 times a normal day’s food during the race. Pretty tricky right? The challenge is thus to ingurgitate enough food to sustain the effort, while not destroying your digestive system, all this trying not to disgust you from too much sugar for example.

Hot dog eating contest Ultra-marathon = eating contest

The trick for me was to rely on a wide variety of snacks, both sweet and savoury. The best food was definitely these Lucho Dillitos, a wonderful natural fruit paste from Columbia. I ate about 10 of these during the race, about 1 every 1 hour. Next to this, I always love Doritos Bits as a salty treat.

Next to this, you should really consider a robust intake of antioxidants using gels such as Isostar’s Energy Booster. Just to keep the machine going.

And then finally don’t forget to drink like mad! Ideally one should drink about 1 liter per hour. So that would be about 10–12 litres of water in total, which was close to my water intake.


There is no choice here but to pretend you’re a damn Spartan — all the while wearing your fancy neon-coloured clothes and shoes and your baby gels and vitamins, yup.

Sparta 300 rallying cry Spartaaa I’m gonna cross this damned finish line, so I get my Cecemel (see below)!

I did use a lot of classic mental tricks to fight the overwhelming idea of having to run such a long distance. The most important is probably to split the race in many little pieces, and run one piece at a time.

What I had planned was the following:

  • 0–20K: Not even notice that I was running until 20K (helped by the night, feeling a bit sleepy)
  • 20–40K: Start warming up and wonder at the sunrise
  • 40–50K: Rejoice about the fact that I would soon be crossing 50K, knowing that in a long-distance race like that the interesting part only really begins after that point
  • 50–70K: Hold on and feel like under a strong anaesthetic, helped by a podcast to get lost in my thoughts
  • 70–100K: Lie to myself 3 times by telling me that I would only have to run 10K each time. 10K is short, right?

Light at the end of the tunnel That’s what the end of the race felt like in my mind

What actually happened was that after 70K things got really bad mentally because of physical fatigue. My pace slowed down drastically to 8K/hour, and it became hard to put one foot in front of the other. My ability to focus narrowed down so much that I could not think longer that in terms of the next 5K. And I would count each of these portions by looking at my watch every 5 minutes, constantly asking myself “are we there yet?” like some horrible kid.

Then after 95K the thing happened: my mind and heart suddenly got awake, being yelled at by all my previous selves

I have to say I even walked at some point for probably 1500m in total.

Then at some point (95K actually) the thing happened: my mind and heart suddenly got awake — as it seemed they were yelled at by all my previous selves, the Thomases that woke up at dawn to train, that went through a though diet, that rejoiced so much about this upcoming challenge. It occurred to me that I could not disappoint all these hopes, that it was my sacred duty to fulfil this objective.

Sunrise The end was so strong

So I took a strong gel (Coup de Fouet), I turned the music very loud and told myself I would have to sprint for just 10 songs and it would all be over. So I sprinted for 8 songs, and made it. I crossed the finish line listening to a crazy remix of Amazing Grace, actually half crying under the setting sun. What a dose of endorphins it was! That was really one of the most intense moments of the race, and it gets me shivering to think about it now.

After the race

Well done! If you got there, you deserve to take extreme good care of your body and soul, so you can rapidly recover and aim for a new challenge.

Physical efforts

Do not stretch after such a long race. Your muscles are so stressed that they would be torn apart by stretching.

Do cover yourself in coats and blankets, as your body probably can’t heat itself anymore.

Later then, do not run for 1 week — you can go to the swimming pool for a light session afterwards. Personally I did nothing but a bit of biking to go to work, then ran 3 lights sessions after 1 week of recovery (no more than 10K). Now I feel nearly ready to start some sprinting again.


Tired person A tired ultra-marathon runner, before getting a well-deserved pizza

This is probably one of the most satisfying parts if you love eating! Straight after the race, I drank 2 liters of Cécémel bottoms-up. Did you know this drink has magical effects on your recovery? I’ve heard this of many folks, never really taking the time to understand why. But it seemed to do only good. Then eat like mad if your stomach allows, on the evening of the race and the days afterwards.

Prefer a varied diet (I had loads of different fruits and vegetables), as your body lost most of its precious nutriments (especially minerals). You need to make sure you recover them with a wide meals offering. I also continued eating spirulina to catch up on proteins that were probably eaten during the race. You might notice that your body weight continues going down after the race — nothing too bad as it should not continue for long.


Sunrise Well, things escalated quickly

Have you ever heard of Baby Blues? This kind of sense of mental emptiness is the closest that comes to describe your mental after the race (at least for me!). You gave it all during the race, and now you feel very weak, proud to have achieved something but with the objective behind you and none to long for. The week after the race felt really emotionless for me, probably also because of fatigue. But 2 weeks down the road, it feels great again!


If you made it this far it probably means you’re willing to run an ultra-marathon too. Well, congrats for this objective! All the best for your race and I wish you will enjoy it as much as I did — I really hope these tips and tricks will help!