June 3, 2013
Imaging how easy climbing Mt. Everest would be if high altitude was taken out of the equation.
Anyway you look at it, high altitude is the biggest challenge in climbing almost all of the world’s tallest mountains. Many of these peaks could be reached from base to summit in 1 day if not for the need to acclimatize to the increasing altitude. What’s more, some climbers train as hard Olympic distance runners only to be turned back with HACE of HAPE far below the summit. They are then told “you just are not genetically predisposed to high altitude mountaineering.”
The truth is, genetics do play a huge part in our ability to endure life in the death zone. Still, losing the genetic lottery doesn’t seal your fate as a flatlander. As an altitude training laboratory, we are always proposing and testing new ways to accelerate and heighten the process of acclimatization to high altitude. As of late we have been focusing on different breathing techniques that may be employed to improve extreme altitude tolerance. This post is about one of those techniques that we call neuro-respiratory programming (NPR).
Warning! It gets pretty nerdy from here, but pay attention because it may save your life.
NPR involves the use of breath holds and hyperventilation to program the body to be more responsive to hypoxia.
The logic behind NPR flows as such:
If that explanation didn’t drive the point home, here is some elaboration.
When you are trekking up Kilimanjaro and your guide insists that you spend a day acclimatizing before you climb up to the next base camp, he is mainly referring to the hypoxic ventilatory response (HVR). Many people believe that elevated red blood cell production is the major way the body protects us from high altitude. This is not true. The HVR is the fastest acting and most “oxygenating” response your body has to hypoxia. A weak HVR has been linked to both HAPE and faster onset of fatigue.
So how do we enhance the HVR? First lets get a basic understanding of how it works.
The HVR is governed by both blood oxygen sensors in your carotid bodies (gatherings of cells along your carotid artery) and a respiratory control center in your brain stem. When carotid bodies detect low SP02, they signal the respiratory center to increase the rate and volume of breathing. If we enhance the sensitivity of either or both of these steps in the system we can theoretically strengthen the HVR.
Free-divers, a class of extreme athletes who continue to defy basic scientific assumptions about the human body, are very interested in adapting their bodies endure extreme hypoxia. They commonly employ a training technique that involves maximal breath holds, followed by a period of manual hyperventilation. They hyperventilate to re-saturate the blood with O2 and remove excess CO2 from the body to make conditions optimal for their next “set” Scientists have found that in addition to being able to hold their breath longer, up to 10 minutes in some cases, they can more rapidly recover to a normal 02 : C02 balance afterwards.
Even though, divers are manually/consciously driving up their breathing rate to recover, their is evidence that is technique improves their subconscious ability to do so as well. A few studies have shown some significant alterations in the structure of the respiratory center. This area of the brain not only govern’s subconscious breathing patterns, but also our pulmonary response to high altitude.
At this point, there is not enough evidence to say, unequivocally, that NPR can improve tolerance of extreme altitudes. However, here is what we have shown.
2 months ago I spent 1 hour per day of apnea-hyperventilation (or NPR) for 4 weeks. Afterwards, I was able to sustain an average of 7% higher SP02 after immediately exposing myself to 16,000 ft for 1 hour. I did not use any fancy technique for monitoring my HVR like I should have, but this is certainly early evidence of a new way to train for altitude. We will continue to assess this technique on different athletes with more sophisticated measuring techniques and encourage other physiology labs to do so as well.
We encourage any feedback or questions about this post! What are your tricks for coping with high altitude?