Using cycling as an example, Andrew Hamilton explains the performance relationship between outright power and power-to-weight ratio, and how to get better when the terrain point upwards… MORE
Mountaineering: king of the death zone
King of the eight-thousanders!
Alan Hinkes is a ‘death zone conqueror’ and one of only 12 people alive to have climbed all 14 8,000m (over 26,400ft) peaks on the planet – that’s the same number of people who have stood on the moon! They are known as the eight-thousanders. What insights about 8,000m climbing can mere mortals learn from one of the world’s greatest ever climbers? Andrew Hamilton finds out
At 4,000ft (1,200m) you get a sense of achievement and some great views. At 15,000ft (4,600m), the thrill is magnified by the fitness, technical knowledge and planning required to reach the summit. At 20,000ft (6,000m) the air is so thin and depleted of oxygen that you need to spend time acclimatising at altitude in order to avoid debilitating and potentially life-threatening acute mountain sickness (AMS). At 24,000ft (7,300m), you enter another, even more deadly, world – the death zone (see figure 1).
This is a world where no amount of acclimatisation or extra oxygen will stop the brain from swelling or lungs from filling with water. In short, you start to die slowly; descent to lower altitude is all that can save you. And at these altitudes, a rescue is almost certainly out of the question; even in perfectly benign weather, the world’s most technologically advanced helicopters are virtually unflyable. You really are on your own.
For British climber Alan Hinkes, however, conquering the death zone was all part of the challenge to attain climbing excellence. Born and bred in the hills of northern England, Alan quickly developed a love of the wild open countryside in which he lived and as a teenager, relishing the challenge of navigating across the North York Moors in thick mist and driving rain with only the aid of a map and compass!
Through his late teens and time at university, he progressed up the ‘mountaineering ladder’ by first taking on the Scottish mountains and then moving on to the higher and more challenging Alpine mountains of continental Europe. Inevitably though, he succumbed to the lure of the ultimate mountaineering challenge – the Himalayas – and quickly realised that to really take on the 8,000m peaks, the time commitments involved (see box above) meant that he would have to abandon his teaching career, or at least put it on ice for a lengthy spell!
The driving force
What drives someone to abandon a secure career for the pain, uncertainties and dangers of high-altitude mountaineering? According to Alan, it’s all about the triumph of mind over matter. As he explained, ‘What I did was the ultimate test. Above 7,000 metres, no one can help you should something go wrong; helicopters can’t hover to pluck you off the mountain and you’d have actually more chance of being brought back from the moon! You can’t live at that altitude for more than five days. Your blood becomes ever more viscous because you’re continually blowing off moisture and if you fall and break a leg, you’ll almost certainly die, not of the broken leg, but by the relentless onset of AMS, which causes you to drown in your own accumulated lung fluids in a couple of days. And that’s of course assuming that the severe cold or an avalanche hasn’t already finished you off. Himalayan climbing is about more than a physical challenge – it’s about pitting yourself against your human fears and weaknesses, knowing that each climb could be your last.’
Oxygen and 8,000m climbing
Many of you reading this will be performing some kind of aerobic conditioning as part of your training programme, but what does it actually feel like to breath air containing just one third of the oxygen found at sea level? And what kind of advantage does using artificial oxygen confer?
According to Alan, the sensation of performing physically in the death zone without oxygen is almost impossible to describe. ‘Climbing at extreme altitude without oxygen feels like agony, even torture. You gasp for air while your head pounds and your body feels as though it’s being crushed in a vice. Every move you make has to be so slow and deliberate – you almost feel like you’re using a Zimmer frame! Then there are the effects of oxygen deprivation; your thought processes become slowed and the distinction between the reality of your situation and your fantasies becomes increasingly blurred. It’s this effect that leads many altitude climbers into making fatal errors of judgement.’
When it comes to the use of extra oxygen to assist extreme altitude climbs, Alan has mixed views. He believes that while many climbers brag about the fact that they have conquered high-altitude peaks without oxygen, the reality is rather different.
‘When a climber doesn’t use oxygen, it’s more than likely because of the cost. To transport pure bottled oxygen out to the Himalayas is extremely expensive – it generally has to come from Russia and costs a fortune. Secondly, although oxygen reduces risk by enabling you to think more clearly, the oxygen bottles themselves are heavy, increasing your workload; if a climber carries less water to the summit because he or she is using oxygen, that in itself may be a disadvantage, especially given the critical importance of staying hydrated. To make matters worse, if the valve on the bottle suddenly freezes up, you’re in big trouble. The sudden drop in oxygen concentration reaching the brain can be fatal.’
Alan also points out that high-altitude climbers need to be aware that no amount of oxygen will prevent the onset of AMS if something goes badly wrong above 6,000m. Unless you can get yourself back down, the end result is the always same – death. In fact, he’s only ever once used oxygen in the Himalayas and that was on Everest when a national news broadcasting company who were making a documentary on his exploits paid for it!
According to Alan, the biggest challenge of all at extreme altitude is to stay hydrated, not least because poor hydration is known to increase the severity of AMS(3). In the rarefied and dry atmosphere of high altitude, water is rapidly lost from the lungs via ventilation; not only is the air at these altitudes almost devoid of water – increasing the rate of water loss with each breath – the low oxygen content means that ventilation is increased dramatically for even very low amounts of activity, thereby further increasing water losses. This in turn makes the blood more viscous, impairing physical performance and mental judgement as well as increasing the risk of conditions such as thrombosis.
As Alan explained, ‘Everything about high-altitude climbing makes staying properly hydrated a massive challenge. Living in a tent on a Himalayan mountain slope is like living under a kitchen table in a freezer. There’s no water and it’s such a hassle to get fluid because you have to make it from snow and ice using a stove for melting.
Given the importance of fluid for performance, I’ve often wondered how on earth I survived up there. Everything’s such a huge effort at high altitude. Despite knowing you’re severely dehydrated and at risk, and even when your pee has turned a dark orange colour it’s almost as though you can’t be bothered to drink the water you’ve just made. It’s as though your body switches off. And there’s no point in trying to use these tube and bladder drinking devices either; they either freeze up, or become rancid!’
How should an 8,000m climber prepare for the rigours of this exceptionally demanding sport? According to Alan, although general aerobic conditioning is vital, the most important preparation is mental, because dealing with the never-ending cold, the squalor, the suffering and the poor diet comes a shock for someone who’s never experienced climbing an 8,000m peak.
Having said that, when back in the UK, he would run for 1-3 hours up to four times per week and included regular off-road mountain biking in his training schedule. Alan believes that the muscular demands of cycling and climbing are very similar and the problems of keeping the extremities warm on the bike in extreme winter conditions provides good mental conditioning! Gym work was performed relatively infrequently; for a sports-specific resistance workout. Alan suggests loading up your rucksack with a heavy load (even rocks!) and doing some steep climbs to try and build extra climbing strength.
I concluded by asking Alan what it felt like to face the real prospect of death on each and every one of his climbs. ‘To say I didn’t get frightened would be a lie. You do get scared sometimes – very scared. However, those are the times when you need to think clearly about your options. Faced with a decision about which way or whether to proceed for your own survival requires a clear head. You have to be able to put your fears firmly to the back of your mind especially as anxiety can waste crucial reserves of energy. Often there is only one realistic choice – to press on. If that’s the case you just have to get on with it.’
- J. Appl Physiol 1996; 81:1850–1854
- J Exp Biol 2001; 204:3115-3119
- Wilderness Environ Med 2006; 17(4):215-20