The team has been enjoying the comforts of the Hilton that is our 5200m Base Camp for about 10 days now ‘recovering’ (eating everything in sight and sleeping 10 hours/day) from our last move to 7500m (above the North Col). Everyone is in good spirits - ready and waiting for the allusive weather window. Besides the usual ‘hot topics’ at lunch and dinner - weather windows, rope-fixing dates, and what exciting condiment will eaten at dinner today- a recent new ‘element of complexity’ has resurfaced entering an old, all-too-familiar bit of vocabulary back into our conversations - acclimatisation.
Acclimatisation ultimately enables humans to survive in an environment that, without acclimatisation would make them extremely ill and could ultimately kill them. In our ‘acclimatisation hikes’ up to 7500m, we were naturally acclimatising to the higher altitudes by developing an increase in the number of red blood cells to increase the oxygen carrying capacity of the blood in order to compensate for lower levels of oxygen in the air. We would then descend to ‘comfortable’ (5200m) altitudes to allow our bodies to recover before going up again. Our last ‘acclimatisation’ period was circ. 6/7th May when we were on the North Col and pushed to 7500m.
We’ve been here at Base Camp for 10 days, the weather window is still about 10 days away and physiological questions are starting to be asked….The main question being, ‘how long does one keep acclimatisation.’ How does our physiological profile (effects of staying Base Camp) compare to those of the teams who have spent the past two weeks at Advanced Base Camp (6300m)…?
An interesting breakfast debate between mouthfuls of porridge, eggs and bacon…
I’d recalled reading in some literature that 14 days is considered the ‘average’ to maintaining the physiological benefits of acclimatisation but wasn’t convinced so I contacted the expert, Richard Pullan, the Director of The Altitude Centre in London from whom I rented my ‘altitude tent’ for the month of March and who provided me with hypoxic training.
Richard promptly came back with some interesting insights…
The risk profile to how long one can stay at altitude depends on a number of factors - some of which are straight forward, others of which depend on the individual. These include the obvious - the altitude, the length of exposure, the amount of physical activity and the more subtle, the individual response.
Humans typically live up to 5300m - we seem to acclimatise well up to that height and it is life sustaining. This is one of the reasons why our Base Camp is at 5200m - so that our bodies have the ability to recover from the duress of the graft higher up the mountain and can also stay comfortably for long periods of time.
As Richard points out, “The problem that high altitude climbers face is the trade off between acclimatising and recovery. You know yourself that going high takes it out of you and it takes a while to recover at altitude. Peoples hydration routine also suffers as you go higher, this will have a knock on effect so it is important to stay hydrated.”
“Remember you are still at 5200m so you are still acclimatising you haven’t gone back to sea level so you are in top acclimatisation mode. Take some gentle exercises each day. Your body uses oxygen the more you exert yourself so going for a walk at 5200m will increase the altitude effect.”
“Your body doesn’t acclimatise above 5300m but each time you go higher and do OK, your brain relaxes a bit more and gets less stressed which is of huge benefit. So, next time you go up it feels easier. If you are stressed, you release adrenalin and cortisone ‘the fight or flight’ hormones - these are not beneficial at altitude.”
Many thanks to Richard Pullan for his advice and insights and to The Altitude Centre for its ongoing support of our climb. It’s comforting to know that we’re doing the right things here at Base Camp to prepare for the tremendous physical and mental challenges we’ll be facing in the coming 10 days. The weather window looks like it will be opening up around the 26th of May and we plan to take advantage of it then..! It will be great to get up and make the most of all the preparation and lessons learned.
The Altitude Centre
214 Stockwell Road, London, England
+44 (0)20 7193 1626