How To Finish An Ultramarathon

It’s not exactly rocket science, but that doesn’t mean any approach will do.

Daniel Issing
20 min readOct 3, 2019


[This article is part of a series: The What, How and Why of Ultra Running. Click here for part 1 and part 2.]

Three weeks ago, it finally happened. It had to, I guess. After more than a decade of competing in races of all sizes and shapes — (half) marathons, triathlons, snow trails and high alpine ultra distances — I failed to make it to the finish line. It wasn’t even my own fault, although that was certainly what I would have expected: I had decided to take on the 170 km beast that is the Ultra Tour Monte Rosa, more than 50 km longer than the longest race I’ve done so far. But instead, at about the time when the sun finally agreed to shyly emerge from behind the clouds, and everything felt like smooth sailing, we were informed that the race had been stopped in anticipation of the drastic weather changes that the night was about to bring. A fairly disappointing turn of events, I daresay.

Disappointments are part of the game, of course (think about how a moment of inattention, resulting in a sprained ankle, is enough to undo weeks and months of training!). So as I was just getting ready to wallow in self-pity about how come this has to happen to me, of all people, the very opposite question arose: You can’t control all the external factors, but what can you, personally, actively, actually do to finish such a race? Being the kind of naive writer who hasn’t yet given up hope that someone, somewhere might feel have been inspired by what I’ve written about this topic in the past, and is now looking for a place to get started, I convinced myself to commit these thoughts to (digital) paper.

At first glance, asking how to finish an ultramarathon is an odd question, when at bottom, all you have to do is putting on foot in front of the other for a really long time. Trust me, it’s not much of an intellectual task. If you feel exhausted, and cutoff times aren’t too strict, just slow down and walk (or rest for a couple of minutes) if you feel like it. What’s more, there’s a sense in which an overly analytical approach to running — one that questions the purpose of it all too often — produces inferior results.

But of course, this misses the point far and wide. If you’re entering a race, it’s because you’ve got a competitive personality. Sure you’ll usually say that your goals are to finish and enjoy the race (I’m as guilty of this as anyone), but revealed preferences tell a different story. It feels good to overtake a competitor, or to reach a checkpoint earlier than expected. So when I rhetorically ask “How do you run an ultramarathon?”, What I really mean is “How do you put on your best game?”.

The latter, of course, is a common question for both novices and veterans to ask. Hence, it’s not surprising that there are tons of articles and books out there that offer their opinion on it. And there sure is some great material to be found online (link 1, link 2, link 3), so writing about race preparation puts the author at risk to reinvent the wheel. Why should this one be different? In my perception, advice on training is often produced by (semi-)professional runners, who profit from a number of things an ordinary run-of-the-mill athlete can’t take advantage of:

  • Not everybody is fortunate enough to live in an area that resembles the kind of race(s) you want to run. Like, many of us trail runners live in big cities, far away from even a medium-size mountain range. (Check.)
  • Most likely, you’ll be working a full-time job. Maybe you have a kids to take care of as well, or you already have another time-consuming hobby. Either way, you won’t be able to train as much as the pros do. (Check.)
  • Special footwear? A crew that supports you throughout the race? Personal trainers and doctors that specialize in running injuries? There isn’t that much money in ultrarunning, but sponsored athletes do have a certain edge over the rest nevertheless. (Check again.)

Which, in turn, means that their advice, however well-meaning, is often ill-suited for people like you and me. Still, given the available resources, there are ways to improve your current approach, and I’d like to share what I’ve learned in time.

One last caveat: If you clicked on this post in the hope of learning how to win an ultra, how to crush the competitors or set a new course record, I fear I’ll have to disappoint you. I’m unlikely to ever succeed in doing so (unless, maybe, if I pick an obscure event and have an unreasonably good day), although I usually manage to rank in the top decile. That is to say, if you’re looking for the secrets to becoming a trail superstar, you’re in the wrong place. But if you want to get an idea how to finish your first ultra, or improve your performance on the margin, acknowledging all the constraints that recreational runners like us inevitably face, read on.

1. The preparation

You can enter your local 10k race without giving much thought to preparation, but good luck relying on that strategy for an ultra. Seriously: To have a realistic chance of finishing the race, you’ll have to put in quite a bit of work in advance. Some of the items below are indispensable, others are meant to help you up your game.

Pick a race and sign up early

Economists disparagingly call this the “sunk cost fallacy”: Once an investment is made, you tend to stick with that option, even if you have better alternatives. They would probably advise you to wait until the very last day to sign up to avoid wasting money on something you might not do in the end. However, for racing, that perfectly reasonable argument is the very opposite of what you should be doing. Rather than a fallacy, try to think of signing up early as a neat way to trick your psychological disposition. Every time you feel like skipping a training session (and you’ll never be short of excuses!), your initial commitment will make you feel somewhat guilty about the money already spent. You’re committed to a specific goal.

Besides, there are practical reasons to decide early: Many of the most popular races sell out quickly, and things like travel and accommodation don’t get any cheaper the closer to the event you get.

But which race to pick? My very general advice is to keep it simple, i.e.

  • Chose an event near you, in surroundings you’re familiar with. There are already plenty of things that can go awry; no need to add jet lag, food you don’t tolerate, extreme temperatures/humidity etc etc.
  • Your first race doesn’t have to be a 100 miler. Start with something more manageable, and work your way up later on if you like it.
  • Distance is by no means the only metric that determines how hard a race is. Vertical gain is another obvious candidate, but also keep an eye out for the technicality of the course. High altitude, glacier crossings, steep, rough descents and climbing passages will all slow you down. The trail running association ITRA, for example, allows you to filter by your desired criteria for affiliated races. Err on the conservative side.

Create a training schedule

Excerpt from my (very basic) training schedule. Left side: Upper numbers = plan, lower number = actual training. Right side: What I intended to run (blue) vs. what I ran (red). As you can clearly see, even with the best of intentions, some flexibility is unavoidable.

Boring, I know. But the idea is the same as for the above point — by fleshing out a schedule, you’ll create both a commitment and a feedback loop to check you’re on track. There’s obviously a lot to be said about how that schedule should look like, and competing philosophies that favor one approach or another. I don’t wish to go too much into detail (have a look here if that’s what you were searching) and instead raise some general points:

  • Be realistic about how much you can accomplish. There’s little point in drafting a schedule you can’t possibly keep up with, and then give up on it entirely because you fell short of your weekly goals.
  • Try to mimic as closely as possible the terrain of the race during your training. So for example, if the race is run in an alpine environment and you live in the flatland, try to find hills, stairs, … to prepare your legs for the climbing. Go on a weekend trip to a place where you can find trails. I’ve learned it the hard way the last time I hiked up La Jonction in Chamonix: I hadn’t been to the mountains for two months, and although I had kept up my training during that period, I woke up with surprisingly sore legs the next day.
Bossons Glaciers, Chamonix.
  • If you can get a friend to sign up for the challenge as well, amazing. The same goes for finding a training group that can push you through your low periods. I, for one thing, wouldn’t do nearly as much interval training (aka ‘speed work’) as I do if it weren’t for my local club!
  • Setting a weekly mileage goal is a good first step, but not all miles are created equal. Running the same 10k loop every day will have a very different effect than splitting your training in three sessions of 10, 20 and 40k (up to you to guess which of the two is preferable). As every personal trainer ever would remark, you don’t grow inside your comfort zone. That sounds like an odd concept when applied to ultramarathon preparation, but even here, it’s all too easy to get used to a certain type of run (speed/distance/terrain) and not really progress much despite regular training.
  • While your training should mostly be about running, it doesn’t hurt to have some variation in there, if only to keep you motivated. I’ve found that upper body/core workouts, while maybe not particularly exciting (I don’t enjoy them much), are really helpful when it comes to very long races, given all the stress on your back.
  • For trail runners: Include session where you focus on downhill running.

What (not) to buy

Compared to, say, sailing, running is a budget sport. Still, you can spend a lot of money on gear, registration fees, travel…money that you either don’t have, or prefer to spend on something else. The good news is that not everything that’s on the market is really necessary, and you can easily save a good deal if optics or brands aren’t that important to you. That being said, some things are essential, and you’d regret buying a low-end product that tips the scales against you:

  • Good shoes. Things that matter to me include grip, toe protection and not getting blisters. Take the time to test, and if you found a model that works great for you, buy several pairs.
  • Quality socks, also because of blisters. Quick-dry material (your feet will probably get wet) is what you should be looking for.
  • A shirt and pants that don’t chafe, something you don’t necessarily realize after an hour of sports. Neither have to be from a famous brand, but they will cost more than the very basic sports apparel.
  • A running backpack/hydration pack (I got this one). It should be comfortable, have space for flasks, and not move around too much (yeah, the chafing issue again). A regular backpack is a not a good idea.
  • A windbreaker. Temperatures can change quickly, and this allows you to adapt on the fly, without having to take everything off.
  • A bright, durable torch (aka headlight) for the night sections. If its batteries last only an hour, or the light is very dim, you’re in trouble.
  • (Poles. Personally, I’m a big fan of them, especially for long races with a lot of climbing. The best ones are lightweight carbon poles, of which I’d pick a pair that can be folded. But it’s not absolutely necessary.)

Note that different races might require vastly more than this very basic setup, such as rain jackets, rain pants, survival blankets/bivvy bags, a hat/buff, gloves, extra thermal layers and so on. Check mandatory equipment well ahead of time, and if you have to stock up, go for items that are lightweight and functional. This won’t be cheap, but you can get decent bargains if you don’t insist on buying something from the latest collection.

At the same time, there are things you’ll get along without just fine:

  • A GPS watch. I still don’t own one, since I usually take my phone to record the run. If you decide later on you really really need to know your splits in real time, you can still buy one later on.
  • Compression wear. Yes, there’s some research suggestion that maybe, potentially, there might be *some* benefits to be gained from it…but these studies are never done with ultra runners, and I strongly suspect they have tons of replication issues. IMHO: No game changer.
  • Gaiters (they probably won’t stay in their place anyway, so you’ll have remove the dirt one way or the other). Fancy sunglasses (this isn’t cycling; a cheap pair will provide you with all you need). Anything on this ridiculous list.

Again: If you have too much money to spend, and buying shiny new running gear motivates you to train, by all means go for it. Just don’t think you have to.

Resting and (re)fueling

Be aware that training for ultramarathon will take its toll, and the most obvious manifestation is the need for more sleep. I went from somewhere around the 6-hour mark to almost 8 hours per night, and if I get significantly less, I’ll be tired and dreary all day. Plus, if you want to do your long runs on the weekends, you might consider getting up early and cutting back a bit on the nightlife. You’ve been warned.

This is also the time to discover what kind of food you tolerate when running. Unlike shorter (street) races, you won’t finish an ultra if you don’t replenish your reserves. Much of what I typically consume during ultras is sugar in one form or another — gels, energy drinks, cereal bars, cake, bananas and what have you — but the longer it gets, the more you will need fats, proteins and salt as well. It should be easy to digest, but apart from that, my best advice is to eat what appeals, instead of what you’ve been told to eat on some forum on the internet. Start experimenting with different things early on, so that for your race, you know what to rely on.

There’s also a bit of a controversy around the so-called “refueling window” — a time span of roughly 30 minutes after exercising during which you’re supposed to fill up your depleted system. I tend to follow this advice, because I’m generally quite hungry after long workouts, and the few times I didn’t/couldn’t eat after a long run ended badly for me, but it turns out there isn’t even a mild consensus in favor of it. (As one somewhat older meta-study puts it, “ Distilling the data into firm, specific recommendations is difficult due to the inconsistency of findings and scarcity of systematic investigations seeking to optimize pre- and/or post-exercise protein dosage and timing.”) See what works for you, I guess.

2. The days before

Now that the event is approaching, you want to make sure that you don’t screw things up right before, like by playing soccer with your friends and suffering an MCL sprain (you won’t guess who had this brilliant idea!).

Slowing things down

A no-brainer? Peut-être. I would think it’s rather obvious that a week prior to the race, you no longer do any heavy-intensity workouts and try to get as much sleep as possible. How could you miss it?

Response №1 is that you didn’t quite follow your training schedule, and you try to make up for it by squeezing in some extra miles as the race draws closer. Don’t do it; it will only make matters worse.

Response №2 is that miscellaneous duties come up and that sleeping habits are hard to change — perhaps you can’t fall asleep easily early at night, but still have to get up on time for work. My only advise is to be aware of it and anticipate these issues. I find that the second night before a race is particularly important, if only because the night immediately before will be short (races tend to start early), and the few hours you get aren’t gonna be of outstanding quality either (the brain is a bit of a restless demon on the eve of a race). It will happen, and the best way not to stress out too much about it (talk about making matters worse) is to get some good sleep the days before.

Know thy course

You’d be surprised to learn how many runners — including experienced ones, including myself at various times — have a very poor idea of the race ahead of them. They sure have memorized The Big Facts (distance, elevation gain, highest point of the race), but not much besides that. How many aid stations are there? What do they serve (only water or also solid food)? Are they inside or outside? How do the climbs look like? Which are the tough parts of the race? (The list goes on, but I’ll stop here.) The reason for this, I suspect, is at least partly that we overestimate how much we’ll be able to remember by looking at the race profile. What’s worse, volunteers can’t necessarily be counted on either to refresh your memory on the course, and might even give you misleading information.

(I feel very guilty writing this. Volunteers are amazing people that make these races possible in the first place, and I don’t ever want to blame them for anything. If they didn’t know these things, they probably weren’t briefed properly. Just be aware this might happen.)

Now, the point of this is not that you should note down every single switchback that you’ll encounter in a roadbook; a small drawing of the profile (your race number might be a good place for this), for example, will suffice. Boil it down to things that matter, like the distance to the next aid station — not only because you need to estimate how much liquids and food you’ll take with you, but also because, as I’ve argued elsewhere, so much of the challenge is purely mental. A rough section you didn’t foresee or forgot about is a serious attack on your willpower, and believe me when I say there are only so many of them that you can parry.

Prepare for the avoidable

As with any sports, there are inhibiting factors that lie either outside of your control, or whose rarity does not justify extensive countermeasures. You cannot (and should not) be prepared for every eventuality — a severe snowstorm, a broken bone, and animal attack (God forbid), a shoe that falls apart with no warning — , but in many cases, packing smart can make a difference when it comes to finishing.

Depending on the race, you’ll either carry everything with you in one backpack and just refill food & water on the way, or you’re allowed to drop bags at designated aid stations. If this opportunity is offered, definitely take advantage of it! A couple of things to watch out for:

  • Don’t pack your bag the night before, it increases the chance to forget something important. I have an extensive list of items that I pull out every time to go through and check which of those I’m gonna take with me. Weather forecast, distance, terrain and the organizer’s mandatory equipment all influence what should go in.
  • A mini pharmacy to treat light injuries or discomfort can save your day; I usually carry a needle, band aid/blistering plasters, charcoal tablets, painkillers (headaches, altitude sickness) and kinesio tape. Do not use painkillers if you don’t know where the pain is coming from and suppress your body’s warning signal.
  • When preparing the drop bags, it’s important to strike the balance between too much and too little. Too much means that you’re gonna waste time trying to find what you need, too little could mean having to continue with shoes that cause blisters. Separate the items according to their functions (food, technical objects, clothing). You won’t regret putting an extra pair of shoes, a fresh shirt and socks, spare batteries or some tasty (but hard-to-carry) food in there.
Gear for race day.

3. During the race

It’s early in the morning when your alarm rings after a restless night. You’ve put in months of preparation, ran mile after mile and meticulously arranged your backpack. You put on your running gear with a thrill of anticipation. The big day has finally arrived. Will you make it till the end?

Getting started

Unlike what you’d do for a marathon, you don’t need to get up several hours before the race to eat and digest, as the pace will be much slower, and, well, you’ll eat during the race as well. An empty stomach isn’t a great idea either, just get a small breakfast 1–2 hours before the start.

Similarly, for shorter races, the start is very important, whereas for an ultra, early advantages tend to peter out. How you start is of some importance, though: While it is almost impossible to start too slowly, almost everyone — including experienced runners — begins too fast. The price you pay for it often comes in the form of sore muscles, fatigue or cramps. That being said, I’d still recommend showing up early and securing a spot near the front, at least if it’s a trail race where narrow passages quickly lead to congestion.

The path…consists of many goals

Is it possible to write about long-distance running without trotting out the tritest cliche of all? I firmly resisted quoting the Buddha verbatim until here, but somehow, this piece of ancient wisdom is hard to circumvent. Anyway…at any given point during the race, the finish line is probably in the back of beyond. Divert your focus away from it and towards more manageable, intermediate goals, which really can be anything — an aid station, a summit, the next lamppost. The trick is to first get there and only then think about the next goal, the same way you’d break a big, complex problem into digestible parts.

Before this begins to sound like I’m offering cheap life hacks, shortcuts that let you avoid most, if not all, of the suffering and hardship you’d rightly associate with ultras, let me be very frank: This journey will be deeply uncomfortable. After the first couple of hours, pain will be a constant companion, and it takes tremendous determination to go on. You really have to be 100% committed to reaching the finish line, and be equally convinced that you’ve got what it takes to do so. Whenever I feel like abandoning, I sometimes think of somebody who didn’t believe I could deliver, and picture that person standing next to the track, smirking, with that dreaded told-you-so look on their face — it sounds silly, but it evokes a now-more-than-ever attitude the helps me to push through.

I’d like to add a word of caution here: The fact that you’ll likely feel tired and sore for long stretches of time doesn’t mean that you should ignore painful signals. Decide well before the start under what circumstances you’ll continue, and when you should better call it a day. Some examples: Cramps shortly before the finish line are painful but manageable. If, however, you suffer them already mid-race, then don’t risk your health. Getting wet towards the end is usually not a problem; being completely soaked after the first few kilometers and not carrying adequate clothes might cause hypothermia. Stomach cramps may come and go, but prolonged GI problems are dangerous and may lead to dehydration. You can still walk with a sprain ankle, but don’t force it for tens of kilometers. Blurred vision and circulatory problems sometimes require little more than a nap to overcome, but are usually signals that your body can’t do what you’re asking of it. The list certainly isn’t exhaustive, but watch out for these signals.

Please do stop the music

Just like everyone else, I do greatly enjoy listening to my favorite tunes during a run at times, and I sure don’t want to play the puritan grandmother when I urge you to remove the earbuds while out there. I’m familiar with studies showing a significant performance boost under the influence of music, but — important caveat — all of this applies to short workouts only. The positive effects fade out over time, and by the time you could really need a push (several hours into a race, probably) they will have all but disappeared.

So yes, if that’s your kind of thing, by all means take your headphones with you! I’d just recommend to wait until the tougher parts of the race until you use them. The additional benefit of running without them — apart from a kind of immersion in the environment you’re moving in that’s hard to achieve when you’re cut off from nature’s very own soundtrack — is that it allows you to meet other runners on the route. I met a very good friend this way, amusingly while I almost led the two of us away from the official path.

It goes without saying that there may be sections on which it is positively dangerous to cancel out all ambient noise; an exposed cliffs where it’s vital to hear falling rocks in time is one such example. Use common sense as to when it’s better not to have the earplugs in. In case of a phone, the shortened battery life is another obvious factor to take into account.

Aid station 101

Aid stations become pivotal points during an ultra. They’re temporary safe havens, a shelter from hostile forces, and as such should be dreaded.


Aid stations are not the finish line, although they often come deceiving close, with all the food and comfort and human contact. Some are actually rather big, so you can easily feel a bit overwhelmed there. Either way, it’s very easy to lose a lot of time there if you arrive clueless. There is no reason to rush through it, but come prepared. Even before arriving, ask yourself the following questions:

  • How far is it to the next place where I can refill my bottles? Should I take more (or less) water with me than usually?
  • What kind of food am I craving? Do I need to refill my food reserves? I often carry a ziplock bag with me that I fill with whatever appeals at the moment, and start walking again while eating.
  • Do I have any blisters that I should take care of? If so, now is the time.
  • Do I have to sit down? Do some stretching?
  • Do I have any more serious medical issues? This is probably the place where you can find someone to help you.
  • Do I need to change any clothes, whether from the drop bag or from the backpack I’m carrying with me? Do I need to reapply sunscreen?
  • Immediately before leaving: Did I put everything back in my bag?

Although you shouldn’t stay there for long, aid stations are usually the best places to meet family or friends that came to support you. Let them know in advance what to expect and how they can help you (e.g. bringing you food, refilling your bottles) to avoid unpleasant surprises.

Find joy amid the misery

I concur that the overall tenor of the article was somewhat negative, focusing on all the things that could go wrong, and all the physical and psychological suffering you will probably encounter. This is the truth, and I see no good reasons to gloss over it. Nevertheless, I urge you not to forget about the bright side of things; after all, there was a reason why you decided to do this. Relish the moments of ecstasy, the spectacular views, the slightest of surprises as often as you can. You will be richly rewarded.

There are undoubtedly many details I omitted. While writing it, I realized that I was walking a fine line between a no-effort-required, vaguely-hinting-at-certain concepts piece full of broad, pointless generalities that will leave readers back as clueless as before, and a mechanical, instruction-manual-like assault on aesthetics that would bore them to death. While I hope that I escaped both Scylla and Charybdis, I’m not sure I succeeded, so I’d be more than happy to answer questions in the comments if you want me to dig deeper.



Daniel Issing

Book reviews, trail running, physics, and whatever else I feel like writing about.