Apr 5, 2013

An Unconventional Blog about my Unconventional Bedroom - Altitude Training

One of the most rewarding 'side effects' of my high altitude experiences has been the opportunities it's presented to better understand my own physiology and the changes that are taking place within my body as I 'go to altitude'. The body's response to altitude proves, once again, what an incredible and resilient machine the human body is.
One of the key 'tools' which I've been using in preparation for expeditions to 8000m peaks including both Everest and Makalu has been an altitude tent which I rent from The Altitude Centre in London.  

Before I go into detail about what this crazy contraption is, I'll take a few seconds to outline some of the science behind it...

The Science

The lungs contain approximately 300 million tiny air sacs, called alveoli. Each of these tiny air sacs has a thin membrane, through which oxygen in the air is absorbed into the bloodstream through diffusion.  Carbon dioxide is expired from the blood to the air in the lungs, before being exhaled. Simply put, the less air pressure there is, the less oxygen there will be in each breath, and the less will pass through the membranes into the blood.

The body responds to the decreased amount of oxygen by increasing the efficiency of oxygen intake from the lungs and transport in the blood. An important part of the acclimatisation process is the production of more red blood cells, which takes place mainly during rest.  

A 'Head Start' - the Altitude Tent

To give myself a 'head start' and 'grow some additional red blood cells' before I leave, I have been spending the past month sleeping in an altitude tent. Sleeping in a 'simulated altitude environment' allows my body to achieve some of the positive adaptations to altitude while still allowing me to continue to go to 'carry on my normal life' at an oxygen-rich lower altitude where muscles can perform at their normal work level. 

Rather than simulating altitude with actual low air pressure (which would require substantial engineering!), the altitude tent remains at normal air pressure, substituting low concentration of oxygen for low pressure. While normal air contains 20.9% oxygen independent of altitude, the air in an altitude tent contains as little as 12% oxygen (the remainder being nitrogen). The partial pressure of oxygen inside the tent is the same as it is at the natural elevation that the tent is simulating.

I can’t claim that the altitude tent has done wonders for my sleep pattern and do wonder every night as I zip up the flap to ‘seal’ the tent and provide the controlled environment into which the air is pumped whether it's working! 

What's involved
A small beer-fridge size machine (the 'hypoxic air generator') which sounds like a low-decibel lawnmower is connected to the ‘tent’ by an 8 foot long clear plastic hose which pumps the low oxygen controlled air into the tent. This displaces the more oxygen-rich air inside the tent and with it the excess carbon dioxide which I exhale. The body’s response to the lack of oxygen is to stimulate the production of red blood cells, giving the blood better oxygen-carrying capacity and lowering the heart rate.  

It takes the body more than two weeks to produce new red-blood cells – hence why I’ve been sleeping in this plastic bubble for nearly 8 weeks now..!!

I must admit, I’d prefer pre-acclimatising high in the Swiss Alps in a gorgeous chalet with a fantastic mountain view while eating cheese fondue with a dreamboat ski instructor named Otto, but I’ve learned that in life (in this crazy world of high altitude mountaineering) you have to learn to make compromises….

If you're interested in altitude training or have questions about how altitude training can boost your performance at altitude or for long-distance events (eg. marathons, cycling, etc.) give The Altitude Centre a call - or better yet, pay them a visit at one of their fantasic gyms. They are a fantastic resource and I'd highly recommend giving them a call or checking out one of their high-tech gyms.



  1. What a great attitude! Reminds me of my vegetable grow tent :) http://www.greendepotdenver.com/best-led-grow-tent-complete-kits-2017-reviews/

  2. What were your test results like?