Yukon Arctic UltraThe Yukon Arctic Ultra:
Ultra-Marathon Adventure Racing Across Canada's Frozen North
The Yukon Arctic Ultra has a strong claim to being the world's coldest and toughest ultra. In 2007 the race was stopped when temperatures dropped to -72C.  The trail covers more than 430 miles over frozen lakes, rivers, hills and mountains. This book is the story of how exercise physiologist Mark Hines came to be one of the first people ever to complete this epic race.
In keeping with the style and format of the other books in the 'in extremis' series, The Yukon Arctic Ultra includes an in-depth scientific review, this time on exercise in the extreme cold, and a comprehensive appendices which includes recommendations on clothing, food and equipment. The book details an extraordinary volume of training in the build-up to the event, and is permeated by tales of what many consider to be the 'Spirit of the Yukon'. The pace and distance of this event lends itself to far greater insights into the nature of ultra-endurance adventure racing, including the psychology and philosophy, which helps each racer to either succeed or fail in this harshest of environments.

From the Author:

I think that it is difficult for many people to understand how it was that I loved the Yukon Arctic Ultra as I did. Often a whole day could pass without seeing another racer, and nights would be spent in a biviouac with outside temperatures below -30C. But the scenery was staggeringly beautiful, and the serene silence was the perfect place to be able to think - outside and apart from the stresses of everyday life. Everything was in the mind, and having the right focus meant that even when things might have been perceived as difficult, I could either laugh about my own limitations or else get stuck into the challenge. Whether under brilliant blue skies during a perfect day, or on a mountain in the middle of the night, at -50C and in a snow blizzard, somehow everything just worked as it should.
It would be unfair to say that physical fitness was not a huge part of the event, and I was the fittest I had ever been, but many people who dropped out did so because they put themselves at odds with the environment - their physical fitness was not tested because mentally they lacked the right psychological approach to succeed. In the book I address both the positives and the negatives, sometimes focussing on where others failed, so as to offer a counter-point to my own experiences. It comes across as real criticism in some places, but in truth I was just so opposed to allowing myself to entertain the ideas some others did. I did not know other racers well enough to remark personally, but if someone welcomed an easy exit from the event, then I had to abhor the notion and the thought - not the individual who proposed such things - but I had to know at the deepest level that I could never think such a way myself. Those who made it to the end, and many of those who did not, adored the wilderness out there. They loved just being in the environment, and when such things were put into perspective, then all that was left was to keep putting one foot in front of the other. With that being the case, we all just moved towards our finish lines, and many who were forced out through injury later signed up to have another go. The Yukon Arctic Ultra is an incredible adventure, and one of the best endurance events in the world.
The Yukon Arctic Ultra is available to buy online at Amazon and Waterstone's.
Excerpts from the book:

Training & Preparation


"If one advances confidently in the direction of one's dreams, and endeavours to live the life which one has imagined, one will meet with a success unexpected in common hours."
- Henry David Thoreau
This Yukon training was turning out to be an entirely different animal to anything I had ever previously experienced, although a necessary and inviting beast it was.  Ideally, I should have found the preparation to be mostly interesting, rather than sufficiently daunting to instil spasm-inducing fear. A year would have been the perfect amount of time to build up my training for this event, but three months of specific training was all I had, accepting I already had an appreciable base level of running fitness under my belt and tucked into my running socks.
   Each of the three months represented its own mesocycle, with its own goals and milestones to be reached before embarking upon the following month's programme. There was a high-mileage fortnight, of two-hundred, three-hundred or four-hundred miles, followed by a low-mileage, tapering-down week in which I had more rest days than I might traditionally have had, and then the one or two weeks remaining would contain some good walks and even better distance runs.
   During the high-mileage fortnights I ensured that I was sufficiently sleep-deprived, incorporating late-night training sessions that lasted through to the morning, and permitting me to infiltrate the Land of Nod for rarely more than three hours a day. Curiously for me, I found that I adapted to this quite early on, and I did not feel particularly tired when at work. Perhaps I was aided by the tapering-down week that followed each fatiguing fortnight. I would utilise my weekends for longer, single-distance sessions, so as to ensure I would meet the fortnight's target by the morn of the fifteenth day.
   From early on I was more than a little anxious about how I would make the final four-hundred-miler work for me. I was also lacking some confidence that I would have sufficient time between finishing that and the start of the race. It would be tight, and less than ideal, but such was the position I had wedged myself into. I favoured an approach that I perceived would see me over-prepared rather than under-trained. Time would tell if I had misjudged my recovery needs, or if my whole approach had been bowled wide of the wicket.
   December was shaping up to be a ludicrous month. I had already ear-marked some training for either Christmas Day or Boxing Day, and somehow appreciated that this, however fruitful on the physical side, would also be doing oodles for the race-prep psychology. Pencilling-in training sessions elsewhere in the month for thirty-five or forty miles, on consecutive days, had looked shocking but such were the brutes that begged to be tamed.
* * * * *
In the early darkness of the cold, wet and windy winter nights, I instituted myself within my training and was forever contemplating the minutiae of the forthcoming race. I was satisfied far beyond any hint of a shadow of a suggestion of a doubt, that this was the most serious endeavour I had ever intended to launch myself into.
   I desired to compete because I wished to prove myself, to myself, in every naturally hostile environment on the planet. I did manifest hankerings to deploy myself to various jungles, mountain regions and the poles as well, but these could all be managed in far more refined and elegant ventures later on. I truly believed, having not been on the ultra-endurance racing circuit for that long, that the Yukon presented the most arduous and daunting of imaginable prospects.
I felt confident that I could now successfully compete in ultra-endurance adventure races anywhere in the world, save for the sub-Arctic and Arctic regions. To go back to similar environments to those I had already experienced would require nothing more than improvements brought about through fine-tuning. I would need to perform better somehow than I had managed in the past, in order that I might gain a real sense of challenge and accomplishment from the enterprise. Anything less would amount to nothing but obscure holidaymaking.
   The Yukon could not be like races elsewhere in the world. The severe cold and potential hazards of the environment presented dangers particular to the latitude. Generally speaking, heat and humidity are not such threats, in that one only needs to be able to stop, rehydrate and cool down. In the deserts or jungles, one is able to become hot, and upon realising that the core temperature is pressing a dangerously high level, one simply needs to ease off or cease activity, so as to permit the body to return to a healthier internal condition. Attention is paid especially to clothing and the quantity of water and electrolytes available. In the cold, however, one must remain ever aware of body temperature, knowing that simple mistakes can lead to a quick and potentially irreversible sequence of events in which the body cools further, until hypothermia and unconsciousness drift in. The rate of deterioration and the likelihood of experiencing serious problems are so much greater in the severe cold than in extreme heat.
   I have been informed that death from hypothermia is a fairly pleasant experience, although this has not been verified personally, as you can tell. Apparently the body ceases to feel cold and then tends to begin feeling appreciably warm. One subsequently descends into a rather cosy, albeit permanent, slumber. As much as this may represent one of the more preferable means of embarking upon the voyage of eternal rest, it was not really a part of my plan for the race. In my experience, ultra-races had always been adventurous, although not without a certain discernable hint of peril, but one never found oneself imperilled without knowing what precautions should have been taken to avoid the particular peril, and how long it might reasonably take to obtain help and to be taken to a hospital.
   During the Marathon des Sables, for example, the risks were those typically associated with endurance exercise in the supreme heat. A helicopter was incessantly overhead and 4x4s were forever driving along the side of the trail. Each man, woman and camel carried a signalling flare, and should the need have arisen then help from a doctor could be obtained within minutes, and evacuation to a hospital would presumably have taken no more than a couple of hours.
   Out in the jungle, due to the level of canopy cover there was no means of obtaining help directly, and so messages had to be carried on by passing competitors, although lingerers would in any case be discovered by the sweep team. Someone would be able to evacuate a casualty to hospital, but it would take a matter of many hours if the unfortunate soul were not found for a while, and delays subsequently incurred through the mobilisation of a boat to the scene and exfiltration to a hospital many miles away. In the jungle, of course, the risks were higher due to the oppressive humidity, and with more poisonous, biting beasties than a lifetime's worth of stick shaking could draw one's attention to.
   For the Yukon, we were advised to carry avalanche shovels and two-days' worth of emergency rations. We would have the capacity to alert the organisers to any life-threatening predicament via the use of satellite-based SPOT devices, which would enable us to bounce a help message to those monitoring them. However, in truly adverse conditions, and particularly if other racers simultaneously found themselves in similarly problem-filled boats, then it might be impossible to respond to all, or even any, calls for help.
   This is not a criticism of the organisers, as the weather and the ability for snowmobiles and helicopters to manage their way through it is beyond their control. As with other events in potentially dangerous environments, I perceive the role of the organisers and support crews as one of support: to help facilitate the movement of willing participants from a start line to a finish line. For optimal safety, one would be better off remaining at home, enjoying a nice cup of tea and a sit down in a comfy chair.
To Indian River
"Endurance is not just the ability to bear a hard thing, but to turn it into glory."
-William Barclay
 Trail heads north from Scroggie Creek onto Stewart River, then northeast - trail leaves river and heads north - deeper into Black Hills along Black Hill Creek - mining buildings, equipment and vehicles visible - trail leads up and around Eureka Dome; 3,500 ft, steep climb - long ridge at high elevation before descent to Indian River - mining buildings in final five or so kilometres before river - ~55 miles
As the sun rose and came into view it failed to project the warmth that it had previously mastered. The air remained cold and the morning's breaks were kept short and to the point. I would still take a moment each time to bask in the pleasure of the respite, in this most breathtaking land of the Yukon, but I would rest briefly, move on again quickly, and guard my hands well from the cold.
   The way the cold crept in had become unnerving. This was not simply a chill that could easily be compensated for by pulling on the down mitts. The cold air often seemed innocuous, yet by the time my fingers reported upon the effects of the local temperature, they might already have been requiring ten minutes or so of re-warming in the mitts before feeling safe and out of harm's way.
   The initial sensation of dulling cold alerted one to the dilemma in a moment, yet to adequately re-warm chilled fingers seemed to take an age. Mental focus became sharpened and focussed, needed as it was to reject complacency, as I perpetually tensed and relaxed the muscles of the fingers and hands, in an attempt to promote blood flow to the extremities and thereby facilitate movement of warmth into the tissues. I was carrying hand-warmers, but was reluctant to use them out of habit, as I felt I should be protecting myself effectively without relying on the chemical intervention. They had to be regarded as a luxury rather than a requirement.
   The first part of today seemed far gentler than anything I had faced during the previous two days. The climbs were fewer in number and gentler than those on the way to Scroggie Creek. The valleys seemed more peaceful and calm too, and somehow less threatening. This gave me ample opportunity for a psychological breather, whilst also harvesting energy during this lull before the approaching storm of the mountain.
* * * * *
One key contrast today was in the growing number of relics one could see of the gold mining industry. This trend would continue now all the way into Dawson, and it was a good reminder for me of where I was. The great gold rush of 1896 led so many thousands of ill-equipped men and their horses across the mountains towards Dawson City. Such a comparative few made it by the land route: many were fortunate enough to see sense and turn back, but the gold rush fever and a weak American economy had caused so many to press on for the sake of those back home.
   Many horses died as they were disembowelled climbing over fallen trees. Some, no longer able to withstand the work and the beating of their masters, were said to have leapt from the high trails into gorges and to their deaths. So many men, expecting to reach Dawson City within months and well before the winter freeze, were out here for two full winters. Many built makeshift cabins to protect themselves from the elements. Such cabins invariably became their coffins; their wooden tombs.
   To read such things in the various books on the Yukon, from the comfort of a warm home at a lower latitude further east, as I had enjoyed doing, permitted a certain detachment. Out here I felt that everything became real; lifted from the pages of history and laid out all around where I could reach out and touch it. To those unable to take care of themselves, this frozen landscape became their nemesis, and what they had been sold as an easy walk turned out to be their death march. It was an assault of desperate cold, forbidding mountains, and ravenous hunger.
Some men, and a few women, did succeed in battling their way to Dawson City, staking their claims and subsequently working their land. Soon after, the heavy machinery came in and those who could not find gold on plots of their own found work in the larger mines.
   The mining machinery, the cabins and the warehouses stood silently now as shells: the evidence of the great industry that developed and died here, mostly in the space of a few years. Some mines did stand the test of time though, thanks to the efforts and persistence of those that made it through to Dawson and dedicated themselves to the work.
   The allure of gold is such a curious thing to me, being a man that considers a watch to be almost too much jewellery. I can understand the wonder of it all though, how the tales of riches and fortune spread the initial fever, and yet it is still difficult to imagine people facing this land ill-equipped, following false promises of an easy journey by the American media machine.
   Despite the treasures and success brought to the owners of some of these mines, the current silence and the abandoned, rusting relics, betrayed a sad memory of those who failed. So many men had left their wives and children, their homes and their jobs, all with the dream that they would find gold so easily and return home proud and triumphant. Those who perished and were not buried deep enough would have been food for scavenging animals.
   It seemed tragic that so many died on a journey to where I was now going. It was nigh on agonizing to consider that this environment in which I was moving was the same as that in which so many others perished. There was so much of the spirit of hope - of finding better things - that created a romantic forlornness as I gazed upon these antique vans and lorries. My own aspirations seemed so unimportant when considered alongside those of the people gone before, with their grand hopes of fortune. But then, part of the allure of the region was its happier ghosts; the memories of those who triumphed here and made their dreams come true. I felt satisfied to celebrate their successes.
   As for me: I was grateful for my modern clothing and equipment, and all of the kit that I had with me that I could call to arms should the need arise. The Yukon Quest is held very much in honour and respect to those who raced into the Klondike for their gold, and it is impossible for the Yukon Arctic Ultra to not be similarly associated.
   The mines had been here for decades, some in use until very recently, and in other areas a few are still in operation. Many men did find their gold here: their riches and glory. Some even managed not to spend it all on dance hall girls, alcohol and gambling. Families made homes in Dawson City and lived well from the money brought in from the mines. Men and women did come here and fulfil their dreams.
   Whilst my own dreams and aspirations were humbled by the enormity and grandeur of their triumphs, it was as though being here somehow made me a part of it all; part of the history of the people that have headed into Dawson, on foot, so that they might realise and live their dreams, such as they may be. Such things came to mind whilst I was walking here, just the ghosts and myself, and I was grateful for the company.
* * * * *
As I moved up through a valley I reached an area of overflow. It led down a gentle incline from my right to left, directly across the trail, before descending down a narrow embankment to a frozen river. The distance from one side of the overflow to the other was only about fifteen metres, but a multitude of varied angles betrayed a problematical passing here.
   I stepped onto the overflow, hoping that the consistency would be right for my feet to sink just enough millimetres to give me grip on the ice, but I had no such luck. My shoes found no purchase and I slipped back. With the uneven surface the danger was that I would slip and be pulled down the slope by my pulk - down onto the main river - from where my life would become both more interesting and complicated.
   I removed the harness and retrieved my Microspikes from the pulk bag. This was all going to amount to a significant delay, but the risks of falling and then having to scramble up the embankment, lugging the pulk and feeling like an ass, involved delays of much greater magnitude and complexity.
   I sat down and attempted to pull on the Microspikes. They consisted of an intricate rubber periphery, which had to be stretched over my shoes, and a complex array of metal chains and rather small metal spikes. The contraptions were nightmarish, and it took several minutes to pull the things on. This seemed entirely due to how nearly impossible it was to stretch the rubber out over my fairly large shoes. For a number of attempts, all that would happen would be that the rubber would go round the front of the shoe, before promptly pinging off as soon as I stretched them towards the heel, sending the ridiculous things flying away from me onto the ice.
   Eventually, however, I managed to wrestle the preposterous things on and once again I resumed my position at the helm. This time, as I stepped upon my icy promiser of doom and misadventure, the spikes ground themselves in, and I had perfect purchase upon the ice. I later discovered that my problem with the Microspikes had been mostly due to my lack of experience in using them, and have since found them remarkably easy to pull on. Cold hands and frustration were probably the most significant causes of delay with fitting them.
   I was concerned that the spikes would cause the ice to break and me to fall all the way through, but the chains did their bit to distribute the forces evenly, and instead I found the progress across the fifteen metres of overflow quite straightforward. The ice did do its thing with the pulk, but my spikes were good enough to ensure I was not pulled after it, and following the occasional cheeky tug this way and that, I was able to work my way across with everything behaving admirably.
   Once at the other side, I deharnessed and repositioned myself upon the pulk, as I removed the Microspikes and reinserted them into the pulk bag. All such potential necessities had been stored within easy grasp, and despite the bother of fitting the things in the first place, everything had gone off without a hitch and as smoothly and efficiently as I could have hoped. Onwards and upwards, as it were, and back to the pace and making up for lost time.
   My mood was somewhat melancholy and contemplative, following that brief sojourn across the perilous overflow. There was nothing quite like imperilling oneself to fill the mind with all the 'what ifs?' regarding the various manifestations of the aforementioned peril. What if I had persevered without the spikes? What if I had fallen and smashed my patellae to smithereens on the ice? And what if the weight of the pulk had dragged my flailing carcass across the ice and down the bank onto the river, and thence southwards to the Pacific or wherever? Such were my meditations as I sauntered along the trail. Within a few moments more I had mustered an improved form and gathered my pace.
   A break was due as I made my way up through the valley. The land rose abruptly at the end, just beyond a frozen river crossing by a dilapidated log bridge. I chose the path around the bridge, rather than over it, spying as I went the greater peril of the high road, compared with the sturdy and predictable river at my feet. To my fore was now a steep climb, but I dug in and went for it, taking some delight and satisfaction in the demands of the trail.
   Upon reaching the top I took what I considered to be my well-deserved break, and the last one before the mountain. I was expecting to reach it within another hour or so, although the sooner the better. This would also be the last break before dusk. Having made it up this climb, I could see a shallow descent a little further along, followed by another short hill. I knew there would be a rise of some description before the main climb up onto the mountain, but I had no idea how high it would be or if I would know when I had reached it. Perhaps this next climb would be the one, perhaps not.
   I sat there upon my pulk and atop the plateau, glad that I had chosen to make the effort to get here rather than take the break near the base. I looked back over the ground I had just passed, at the river running alongside the flat ground, with its relics of the industry that once thrived here. I was not sure if it was the air that had become less chilled, or I that had become warm from the day's efforts, but I found myself sitting there enjoying the sun immensely. The willow trees were short over to my left, and there was no white snow supported atop their branches, but rather ice hung instead like large clear baubles underneath. As I sat there, fuelling up for the mountain ahead, I enjoyed another perfect break in bliss.
   I finished up and continued on my way, with a sense of anticipation and impatience to get stuck into the most demanding scramble of the race. Following one steep climb Greg found me, and I was duly informed that I still had a short way to go before I got onto the mountain proper, and he hoped he would see me at the summit for some photographs as the sun set.
   The climb was certainly gentle enough at first. I had not even noticed I was gaining elevation but for when I gazed down to my left and saw the river falling away beneath me. Then the trail began leading up. It became steep and for the first time at walking pace I was puffing and beginning to work hard. Resting was not as easy as I might have liked, as the weight of the pulk behind me would pull me back whenever I paused for breath. The best I could manage was to take a few breaths as I lent forwards onto my poles.
   The trail would work its way up, steeply, and then curve off to one side and then back again, always obscuring a view of the top. All I could see was one short section at a time, which saved me from the potentially overbearing realisation of the full beast from early on, whilst simultaneously betraying promises of a summit after each turn.
   Someone, either Greg or Klaus or Joachim, had written the names of various peaks, such as K2, in the snow at various points on the way up. I was not ready to surrender to any such likeness just yet, but this was nevertheless an entirely new experience for me. I had climbed mountains before, and I now had some experience of hauling a pulk about, but lugging the thing up a mountain was an exclusively new adventure. The time to grin and bear it - to grit ones teeth and fire up the eyes - had most certainly arrived.
   I was feeling hot, on the brink of sweating, and with a quickened heart rate and greater depth of breathing. I was managing well though, and without any doubts of my imminent success upon the mountain. However, despite being only a day and a half from Dawson City, I was calling upon my body to muster efforts greater than ever.
   The last mountains I had climbed were in the Lake District and Snowdonia, about a year earlier, and I was of a sufficiently sensible mind not to have been dragging a pulk when I had climbed them. Here, my legs were becoming warm and I was growing hot, but I did not welcome the idea of stepping from the trail and getting the pulk perpendicular to it for a good rest, only to then have to negotiate it back out to get going again. I kept Helvellyn in mind, considering that this was of a similar height, and I knew I would reach the top soon. Eventually, and not before time, I could see a point where the end of the visible trail presented a plateau, and only a paltry fifty metres further up. It had to be the end of the climb.
   To my left there was an opening in the trees, revealing the Black Hills and the valley all round, with the sun setting upon it. I staggered left, hauling my pulk off the trail, bringing it to a secure rest in the deep snow at right angles to the incline. The harness came off and I retrieved my camera from the pulk bag. Just because I had managed an enormously tough climb, I could find no excuses to miss a sterling photo opportunity, along with an astonishing view and realisation of how far I had travelled from Pelly Farm. The sun was setting directly ahead of me now, the clouding sky aglow with dark orange tones and magnificent reds.
   The climb so far had been justified by this view alone. The elevation seemed incredible, as I looked out at all the shorter hills around me, for I could see none higher than this. The hills out from Pelly similarly held no candles to this one, and yet those had been harder than anything that had come before them. I could taste success in the air now; a dangerous thought indeed, but I was relishing the challenge and knew that soon I would have only King Solomon's Dome ahead of me, a far easier climb according to the maps.
   Greg had advised me that when I reached the summit there would be a short descent and then another climb before I would commence the main descent proper. I arrived at the summit and the trail led me clockwise from the south around to the north side and then due east. I searched ahead along an adjoining ridge to the peaks out in front of me, but there was not one I could identify as being on the logical route of the trail. A long and shallow descent would be followed by a gradual climb, but where could the climb be?
   I seemed to remain moving along the top of the ridge for hours. The views in the failing light were beautiful but alluded to this being a dangerous time to be so exposed. The cold, the night and the winds would all be threatening my safety soon, and I needed and craved the protection of the valley of Indian River.
   As I progressed away from the summit, around the horseshoe and along the ridge, the maddening truth of reality settled in. The ridge was wide but the winds were being funnelled up to me on both sides; the night had descended upon me and in the darkness the invisible winds were buffeting my clothing hard.
   I felt entirely exposed, mostly because I was, but there was nothing for it but to rely on my kit and stay focussed on making good progress. The ridge was far sharper and more aggressive than its mere outline suggested. The going was daunting, for I knew that I was generating warmth by motion now, but would soon be forced to stop for food and fluids, before being able to descend into the security and relative warmth a little lower down. I would not be riled by the knowledge of the dangers of this; I knew what I was doing was absurd, but then it was never supposed to be easy. Without conscious intervention I soon realised that I had gathered speed.
   Small ups and downs and plenty of flat sections abounded. It was cold now and clouds obscured the starlight. I was still continuing along the high mountain ridge between peaks, fatigue searching for a way in, but adrenaline was focussing my mind on swift progress from these heights. I would not have wanted to be on Helvellyn after dark in the winter, let alone a high exposed mountain ridge in the sub-Arctic.
   I told myself it was madness. I was not in a normal situation, but then if I took each of the factors in turn - the ground conditions, the temperature, the gentle yet threatening wind and my own fatigue - then I knew I could deal with each potential cause of danger with whatever I had about my person. I had the best kit, and had not been really cold once. I had protection, I had warmth and I had food and water. No, what I was doing was not normal, but it did not have to be because I could deal with it regardless. And that was all that mattered. I kept pressing on, forcing a strong pace and looking ahead across the ridge and the peaks for where I might be led down into the valley.
   An hour after reaching the summit I was still exposed to the strong cold winds that were being funnelled up to me. How could I ever justify that this was not pure recklessness? Would the reality that this was all in the nature of the race make everything all right and entirely excusable? Hardly. In what world would I consider it a reasonable thing to be at this elevation, and this exposed after dark in an environment such as this?
   During the winter months in Britain I would ensure that I was making my way off a mountain long before the sun had set. What made my current situation fine and acceptable? It was a question I had no answer for. My whole focus was on what was required to begin the main descent and reach relative safety. Perhaps even more questionable then, was my decision to stop and take a break up there.
   Ideally, I would have been off the top off the ridge, but as I could not perceive for how long I would be up there, I had to assume that my current predicament would continue unabated. I was at risk of dehydration so I needed water, and some food would help to fuel me to Indian River and keep me warm along the way. When I came to sit down, though, the relief was immense. I melted into the pulk bag and all of the tension that had built-up during the climb and rush around the mountaintops was released into the earth, causing me to feel instantly refreshed and peaceful again. I felt the cold attacking my clothing too, as it searched and probed for a way through.
   I maintained focus on timings during the break; I had to be on the move again before I cooled down. I also needed to reach Indian River before I became too dehydrated. The water was beginning to freeze within the Thermos flasks now; the caps had been frozen in place and had taken some effort to crack free.
   It was not that I had an insufficient capacity to carry water; it was that the spreading ice within the flasks threatened to steal my water away from me. I did not want the delays of melting snow for water, particularly if I had nothing serviceable to pour the water into. Were I to attempt to drink directly from the metal pot, I would then have the excitement of working out how to detach the pot from my lips to manage.
   On the move again and I found it was not merely the elements that were trying to test me. Fatigue now wanted to join in the fun too. Once more the sleepmonsters were coming out to play. As I headed down one short descent I spied a beast stood by the side of the trail. Frozen in time the ten-foot giant leered across the trail, awaiting the moment that I would pass along directly in front of him.
   A part of me still knew that it was just a tree; its top metre or so bent forward over the trail due to the weight of snow; snow which had built up on that rounded top to give the appearance of a head, with a large dark eye created by a circular area devoid of snow in just the right place. I knew it was a tree with snow on it, but my eyes were fixed on it during the approach and as I passed. As I moved in front and beyond I stared over my right shoulder; waiting for him to pounce out after me. He let me pass; perhaps he had already laid a trap for me further along. I remained vigilant to this as my encroaching tiredness clawed after my pace and attempted to freeze my momentum.
   By the time I began my descent into the valley I was feeling exhausted. Where oh where was the checkpoint? How much further could it be? I descended into another mining area, the trail snaking its way through. The associated machinery and buildings gave me something to stare at and focus upon. An old dormitory building looked appealing as a safe shelter. But I did not wish to stray so many metres through deep snow for the sake of a break, and I expected to arrive at the checkpoint in good time to sleep for the remainder of the night. To the front, the hills on the other side of the valley were silhouetted by the starlight, and wisps of what at first appeared to be cloud betrayed the subtle movements of the Aurora borealis, its green tinge the irrefutable confirmation.
   As the trail led around a right turn I came across the five-kilometre marker for the checkpoint. I did not believe it. I did not think that I was close enough yet, and the sign had only rarely been used during the race thus far. I stopped and looked around, half expecting someone to jump out and declare that they were just kidding, and that this was all a part of some absolutely hilarious ruse. I even made the point of tapping the sign a few times with my trekking pole, rather firmly to be entirely honest, just to check if it was, as far as my senses could discern, really there.
   The sign was, of course, really there. The checkpoint itself even appeared earlier than I had thought, at what I perceived to be a distance of much less than five kilometres from the sign. Perhaps I was still carrying some momentum from the descent, or perhaps my mind was just blanking out blocks of time.
The Yukon Arctic Ultra is available to buy online at Amazon and Waterstone's.