Tender Is The Night

Daniel Issing
15 min readDec 4, 2022

On the race of a lifetime.

From the southern slopes of the Jungfrau in the heart of the Bernese Oberland, at a junction known as the Konkordiaplatz emerges the Aletsch glacier. Standing at a length of 20 kilometers and a surface of nearly 80 square kilometers, it is Europe’s largest, and a sight to behold (it is, not surprisingly, dwarfed by the massive Lambert glacier in Antarctica). Would you not be tempted to go on a tour that promised spectacular views not only of the Aletsch, but also of the Eiger north face, the Fiescher glacier (Europe’s number two), Lake Oeschinen, awe-inspiring suspension bridges, alpine meadows, waterfalls, refreshing irrigation canals known as Suonen or Bisses, with the occasional marmot or chamois thrown in for good measure?

The good news is that such a tour does exist in organized form, and it goes by the name of E250 UNESCO Jungfrau-Aletsch Trail. It’s essentially the shortest possible circumnavigation of the Jungfrau massive, and the “250” in the name is not an accident: It refers to the number of kilometers needed to cover in order to arrive back at the start in Grindelwald. Shortest possible, that is, if you’re willing to climb up a handful of mountain passes, such as the Hohtürli at 2,740m. Undertaken as a trekking tour, it typically takes experienced hikers some 15 days to arrive back at the start, so naturally the question arises how fast you could do it if you turn it into a nonstop race instead? It was a feat far surpassing anything I’ve ever done before, and partly to reminiscence the experience, partly as a FAQ for people who are curious about the “inside view”, I’ve compiled answers to a number of questions that invariable pop up whenever the conversation shifts to my ultra running exploits, starting with…

Moench, Jungfrau and Eiger as seen from Grindelwald, the starting point of the race. (Photo by Kevin McMahon on Unsplash)

Q: Why on earth?

First things first: Nobody is too surprised when I tell them I like being “out there”, that I like to challenge myself— but honestly, they will say, you can do all of this, and more, without having to commit yourself to a grueling, uninterrupted, multi-day effort. Plenty of natural beauty can be devoured in a few hours, and it’s not as if something more reasonable like a marathon wouldn’t be a challenge as well (have you tried running faster?).

Here is the cliché answer given by every trail runner and their dog: It’s all about finding your limits! See how far you can go before you collapse, mentally or physically, how far your legs (and mind) will carry you. If that sounds trite, let me reassure you that it’s just one of the things that gets repeated so often we come to believe in it. The truth about running races is much simpler: You want to finish the damn thing, and finish it well. Not figure out that your limits are 50 km short of the objective you set for yourself. Not break down and be unable to get back to your feet again. Plus, whenever people talk about their limits, it sounds like this is a fixed quantity, like your height or eye color, when so much of it depends on environmental circumstances. Had a tough week at work? An argument with your partner? Ate something you’re not digesting well? Is it too hot or too cold? Or are you plain and simply having a bad day? All of these will come to define your limits on a given day without telling you anything fundamental about what kind of person you are.

A somewhat better answer is a pronounced drive to exploit: Most of us, I submit, are probably curious about how our mind and body will react in such a situation, what sensations will dominate, and how they differ — in kind or intensity — from everyday life. Ultra runners might be different from others in that they turn this lingering desire into full-steam action. Much has been written about exercise addiction, and while genuine dependency is still a rare condition, endorphin craving is widespread, often pushing runners for longer and longer distances, because the medicine wears off quickly.

An honest answer will also attribute a heavy weight to the social dynamics of ultra running. By the time you’re starting to consider participating in these races, you are very likely already enmeshed in a community of trail runner where — although we’d never admit it — “longer, higher, faster” translates into status gain. Social media such as Strava (a kind of pissing contest for athletes) do their part by constantly teasing your imagination with your friends’ exploits. This need not be a bad thing! Status seeking appears to be very much hardwired and isn’t going away anytime soon, and if it could somehow be excised from sports it would rear its ugly head elsewhere, probably with less benign results. Still, we runners tend to overemphasize to what extent the whole thing is a wholly personal decision.

It IS undeniably very nice out there.

Q; How do you prepare for such an event?

The truth is probably that you don’t, really. While there may be some runners who approach similar distances during training, most of us remain far below the race distance in their training. Logistical and temporal constraints mean that you will only get so close to “feeling ready”. This isn’t marathon practice — it takes a leap of faith plus a lot of innocuous interpolation from your past runs to convince yourself that you can do it. Moreover, even if you could, it ̶m̶i̶g̶h̶t̶ ̶n̶o̶t̶ ̶b̶e̶ ̶a̶ ̶v̶e̶r̶y̶ ̶w̶i̶s̶e̶ ̶i̶d̶e̶a̶ is suicidal to try and reach a similar distance in the weeks leading up to the event, simply because you’d be neglecting recovery and thus significantly reducing your chances of finishing.

That is not to say that all attempts to prepare are futile. Here are some no-brainers:

  • For safety reasons, the organizers requires us to run in groups of two or three. You’ll likely be going through some very low moments, so make sure your teammates are people you can trust and rely on.
  • Don’t aim for the 250 km distance if you’ve never at least half of that (in similar conditions) before. Incrementalism is the surest way to progress.
  • Practice running at night with a headlamp: You don’t want this to be your first exposure to nocturnal descents. Do you know how long the batteries last when you set the luminosity to a level you feel comfortable with.
  • Adapt your training: Volume alone is not enough; city runs (even long ones) are no adequate replacement for trails. The best way to get good at X is to practice X a lot, rather than some activity that’s only similar to X.
  • Test your equipment before. All of it, and under comparable circumstances. (A backpack that starts chafing horribly after a couple of hours, with no replacement in sight? You won’t know about this before if you’ve only tested it half-filled during a casual workout.)
  • Take it easy before the race and sleep as much as possible. Arrive at least a day before the final countdown, and don’t work until the last minute.

I’ve previously written on the subject in more detail, so feel free to consult How To Finish An Ultramarathon if you’d like to get into the weeds.

So do you run all the time?

Hahaha, very funny.

Seriously, though: Have you ever tried running uphill for more than a couple of minutes? Did you really think the answer would be “yes”?

If all goes well, you will be able to run on flat sections and on not-too-technical downhills. In all other areas: Only if there’s a photographer around.

Sometimes not even then.

What do you eat and drink? Where and how (often)?

It’s not just that you don’t literally run all the time, sometimes you wouldn’t move forward at all to rest your feet and legs. Sounds logical, right? From there, it’s only a small step to realize that you will also have to fuel your body, and quite a bit. I have no stake in the many heated debates around optimal nutrition practices, so I’ll simply spell out what works for me.

First, water. You drink whenever you’re thirsty — simple as that. This will obviously depend on how much you perspire under normal circumstances, outside temperatures and a host of other factors, which is why I find formulas of the type “X liters per hour” misleading at best. I heartily recommend — even though it’s annoying to carry around — adding energy drink powder to it, to replenish your carb and mineral depots, which you can cheaply manufacture at home. In most races, one liter (the two flask in front of my backpack) is enough to get me from one aid station to the next; but in this particular case, they were too far apart (sometimes 8h and more) to rely on refills at the stations. There are usually enough streams (or fountains) along the way, but some planning ahead is in order: Take a water filter with you, and don’t wait until you’ve sucked the very last drop from your flask before refilling. During one particularly glorious moment, we had to filter water from an abandoned watering can found under a ski lift, dusty and covered with dead flies.

Food is a bit easier to manage, as it’s less heavy to carry. Contrary to shorter ultras, you actually have time to sit down and eat a proper meal when you’re growing tired of bars and gels. For instance, we ate a whole pizza stone-baked pizza (glorious! delicious!) at some point, and while it’s hard to get started again afterwards, it’s not impossible either. Still, don’t confuse this with a stage race: The clock keeps ticking, so even though there’s no need to gulp down your meal, this isn’t a lavish dinner with friends either.

And since what goes in also has to go out at some point: It’s great if you can use the toilets provided by the organizers, but it would be naïve to rely on this only (remember how it might often take 8h and more to get to the next aid station?). It’s never mentioned on even the most impressive lists of mandatory equipment, but you always want to carry some tissues with you.

What’s the biggest challenge, the most important limitation?

Managing your sleep.

This may well be a temporary snapshot and change with experience, but clearly that part was the great unknown for me. The longest race I’ve done before was the emblematic UTMB, which is technically “just” 80 km shorter (170 km in total) yet a completely different story. At the time, I finished it just short of the 32h mark, which is essentially one nuite blanche and still within the limits of what your body can handle. The Eiger Ultra Trail, by contrast, took 62h, or three days and two nights, to complete, and it was clear from the get-go that sleep deprivation would set in at some point.

I did not find much material on how to deal with this primal necessity online, not even in the form of personal recollections. Having a strategy, however likely to be rendered obsolete by the realities on the ground, is extremely helpful psychologically, but it seems that all you ever hear about it is runner boasting how little they slept during the event. But that may well be because the alternative — admitting that we don’t have a clue, that what looked like a successful strategy once turned out to be a disaster the next time — sounds vastly less attractive.

Do these people look like they know what they’re doing?

Keeping in mind that what works for one person may not work well for another, and the seemingly total absence of studies on this exact subject, here are nevertheless some things I learned: Most importantly, you can indeed get away with very little sleep. Everyday experience — where a short night turns you into a walking dead the next day — does not generalize to this particular situation, and my best guess is that I effectively slept something like three hours during the race. If runners’ testimonies are to be trusted, that puts us rather to the right side of the distribution! I say “effectively” because these naps were distributed over the course of three days; instead of sleeping a couple of hours in one go we tried to go for half-hour to one-hour naps. Somewhat to my surprise, you can even feel revigorated after a few minutes, if during the short period you manage to doze off (this even happened to us while sitting on a bench). By contrast, just lying down and not falling asleep was usually even worse than not resting at all, and I often felt horribly tired when this happened. Since whether or not you’ll manage to actually sleep is hard to predict, my only recommendation is not to force it: If you find yourself tossing and turning for more than, say, 10–15 minutes, just get up and start moving.

Many people told me that the second night would be tough, and I wholeheartedly agree. Doubly so if it’s very warm during the race, as was the case for us. To save energy, we decided to profit from the relatively cool nights as much as possible, when moving forward was less onerous. The price we paid for this strategy was that the demand for sleep didn’t always coincide with our presence at an aid station, so at one point we just put on whatever extra layers we had and lay down somewhere in a forest.

Isn’t this super dangerous?

Depends on what you mean by it. It is probably more dangerous than playing chess. It is quite a bit less dangerous than alpinism proper. Numbers are a bit hard to come by, because no central databank exists, and there’s a bit of debate of what should count towards it: If you go for a run in the forest and get hit by a car, well, technically that’s trail running. But to give you some idea: In 2018, there were apparently some 600,000 people participating in at least one ultra, of which maybe a third attempted a distance above 50 miles. From 2008 to 2019, 51 people died in Western Europe either during races or while training, with the leading cause of death being cardiac arrest.

It would seem like falls should occur much more often, given the exhaustion and treacherous terrain, but somehow this is not the case. My best bet is that you’re less vulnerable to things that typically do in ski mountaineers: Falling into crevasses, rockfalls, avalanches. This may sound self-righteous but my gut feeling is that few people die in the mountains because of dumb mistakes of the slip and trip sort, but because the underestimated the forces of nature. Case in point: The sad, long list of professional mountaineers who met their end doing what they did best.

So all in all it could be much worse, but it may give a fall sense of security: In the biggest tragedy of the still young sport, 21 runners died in a race in China when the weather took a turn for the worse. The danger of extreme outliers is always there.

Besides the obvious: What are some lesser known strategies to do well?

By “the obvious”, I mean stuff like “don’t burn yourself on the first climb, don’t run with gear you never tried”. None of this is rocket science, and I would argue that it mostly boils down to plain old common sense. Apart from that, unfortunately there are no “ultra hacks” or other shenanigans to improve effortlessly, but I can think of a few tips to avoid unnecessary complications.

Number 1, ultrarunning is an expensive sport, and you don’t want to be penny-wise in the wrong situation. Buying second-hand apparel can relief the financial burden a bit, but don’t cut too many corners: Blisters and chafed skin not only make running super uncomfortable, they can get so bad you’ll have to abandon altogether.

Number 2, don’t neglect the route planning. A special (and often ignored) aspect of this is knowing what the aid stations are like, and planning accordingly. Not all checkpoints are created equal, and their quality sometimes differs by orders of magnitude. It is, unfortunately, one of the hardest things to figure out (you’ll hardly ever find a good description on the website), especially if it’s the first edition of a race. The point is that you’ll ideally stop longer at the better stations. Believe me, the difference between a watery vegetable soup and a rich, steaming lasagna, or between a gym mattress and a real bed, is vastly magnified when you’re exhausted.

Number 3, take a shower if you can (and if there’s hot water..)! I had serious doubts about it, believing that I would never be able to start again afterwards, but that’s not true: The brain just doesn’t seem to switch off and slip out of competition mode, so it’s actually just a really nice feeling — a small, intermediary reward to keep your spirits high. Provided, of course, that you have fresh clothes to change into afterwards, which is another thing that’s easy to forget when planning the route and what goes into the drop bag.

Number 4 would be cryotherapy. I have no evidence to back this up, but for me, putting my legs in a cold mountain stream works wonders for tired muscles. I furthermore discovered that fully submerging my head (rather than just splashing water in my face) is an excellent way to wake you up.

This would count as a sufficiently cold body of water.

How do you navigate the way? Don’t you get lost all the time?

Unlike every other race I’ve ever done before, this one wasn’t marked, so you had to find the way yourself, using a GPS track provided by the organizers. This may seem like a recipe for disaster, especially when you’re getting tired and your concentration diminishes. I was somewhat worried about this, since I tend to get lost even on shorter runs in unknown terrain, but this fear proved largely unjustified.

It’s actually not particularly hard once you accept that you will, in fact, sometimes get lost. A GPS watch that not only contains the track, but also a map of the area is a big plus, and a phone with the same map downloaded before you start as a backup is indispensable. But even though you mostly stay on the official hiking paths, and navigation technology is quite advanced, it will happen. The good news is that it happens to everyone (though not always at the same point), so relax — it mostly cancels out.

There’s a temptation, once you’ve taken a wrong turn, to continue along this way and try connect to the original route via some alternative path. While sometimes justified, this is almost always the wrong decision, and — I suspect — typically chosen because it’s psychologically harder to turn around and go all the bloody way you did for no reason back again. When in doubt, always choose this option.

Now you’ll stop doing these unreasonable things, right?

Fair question. My honest answer is that I don’t know. For one thing, I was expecting 250 km to be an even worse version of UTMB — twice the amount of struggle for a slightly more euphoric feeling upon arrival. Instead, I actually liked it a lot more! A typical experience for me during very long races is that after enough hours spent on the trails, I stop caring about what’s going on around me and just advance one step at a time, counting turns, kilometers, aid stations or whatever else I can come up with, which is neither exciting nor pleasant. In contrast and unless I misremember (not unheard of under these conditions) that I was still taking in the scenery the third day. And I didn’t feel nearly as bad afterwards: Even though my feet were quite swollen, the rest of my body was alright, given the circumstances, and I managed to eat and sleep normally afterwards. At least physiologically, it seems less violent.

Now “less bad than expected” isn’t exactly a great reason to push for more. I know very well what went into this race in terms of preparation, and I can’t say I loved every minute of it. Opportunity costs… And there’s of course the pseudo-philosophical question whether “longer, harder, faster” is indeed a great maxim to chase. Time will tell, and all I can say with certainty is that I sure as hell have no regrets about it.

I thought this was an appropriate team name.



Daniel Issing

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