Recently, we looked at how Kilian Jornet acclimatised before his record breaking climb of Mt Everest in 2017. A vital part of this process took place at home. Using a hypoxic chamber Kilian was able to spend 260 hours sleeping and 90 hours exercising at a simulated altitude* of between 4000 and 5000m in the weeks leading up to departure. This, together with a further 10 days preparing in the Alps, ensured that Jornet was able to summit Cho Oyu (8201m) within 10 days of arriving in Kathmandu and go on to climb Mt Everest in a record breaking 26.5 hours. Recently, a number of other mountaineers have adopted a similar approach. We were able to catch up with Roxanne Vogel who made headlines in 2019 by successfully climbing Mt Everest in a 14 day round trip from her home in San Francisco...
Congratulations Roxanne on climbing Mt Everest! Thank you for speaking to us. In a recent post on Uphill Athlete you attributed your success to a combination of diet, physical fitness and hypoxic training. Looking back now, which do you think made the biggest contribution?
I'd have to say hypoxia pre-acclimation made the biggest difference (sleeping in the tent and using our Hypoxico chamber during the workday for >12 h/daily exposure) because even if I were as fit as possible and had all the right nutrients to support the effort, I would have surely gotten AMS/HAPE/HACE had I shown up at base camp unacclimated and not been able to continue.
Roxanne Vogel is a Nutrition and Performance Research Manager at Gu Energy Labs and was approached by Adrian Ballinger of Alpenglow Expeditions to make the first "Lightning Ascent" of Mt Everest. Departing on the 10th May, she summited on the 22nd and returned to San Francisco on the 24th - just 1 hour shy of 2 weeks!
Earlier this year we reported on the hypoxic training programme undertaken by Kilian Jornet prior to his extraordinary success on Cho Oyu and Mt Everest in 2017. Can you talk us through your "Lightning Ascent" approach?
Starting in February 2019, I began sleeping in my Hypoxico tent for a minimum of 8 hours a night at simulated elevations of between 2500 and 5800m. I started sleeping at 2500m and gradually worked my way up to a high point of 5800m in the week before departure.
Roxanne's Hypoxico Tent
In March, I added daily exposure in the Hypoxico chamber at work, lasting anywhere from 2-5 hours at approximately 3075m, some of which included exercise in the form of step-ups with a weight vest.
I also spent 3 weeks in April (just prior to departure) in Mammoth Lakes where I trained and lived at altitude. Whilst I did not do much exercise in simulated altitude, during my 3 weeks in Mammoth I regularly exercised at an altitude of more than 2500m.
In total, I accumulated 1160 hours of hypoxic (real + simulated) exposure for an average of 13.8 hr/d in the 3 months preceding my departure for Everest.
Mammoth Lakes is a small town in California that is situated at an altitude of 2402m. It lies in close proximity to a number of different mountain ranges and therefore gives easy access to altitudes of 3000 to 4000m. Like Roxanne, Kilian Jornet also spent time at altitude prior to leaving for the Himalayas. In 2017 he spent 10 days in the Alps at heights of up to 4200m
Did you give yourself "holidays" – days where you didn't sleep, work or exercise in hypoxia?
Occasionally, if I felt I was getting sick, or if I had a race event I took a night or 2 out of the tent. These were rare instances, and never more than 2 consecutive nights out of the tent.
Altitudes at which Roxanne slept in the months leading up to her departure for Mt Everest
What was the highest simulated altitude you slept, worked and exercised at?
5800m (slept), 3600m (work + exercise)
You were able to summit Everest within just 12 days of leaving home. Kilian reached the summit of Cho Oyu within 10 days. These successes show that the preparations you both made were incredibly effective. But at any point along the way did you think they weren't enough?
I was nervous before I left, but once I arrived at Everest Base Camp and felt good, I thought I had a good chance of succeeding if the weather and conditions on the mountain were favourable and I maintained my health.
Roxanne was accompanied on her summit day by Lydia Bradey, Mingma Tshering and Pasang Tendi. Using supplemental oxygen, the team set of from Camp 2 (7620m) at 0145 on the 22nd May, bypassed Camp 3 and reached the summit of Mt Everest at 1145. On their descent they spent the night at Camp 2 before continuing on to Base Camp the following day.
Do you think that any further acclimatisation was done on the mountain or was it all completed before you left home?
Probably some additional acclimatization occurred once I arrived in the 10 days I spent above 5300m.
Fascinatingly, you had access to DEXA scanning and were able to confirm that you hadn't lost weight or muscle mass during your trip. This is extraordinary amongst Everest summiteers. I lost more than 20kgs! Looking back do you see other advantages for the "Lightning Ascent" approach?
Less exposure to objective hazards on the mountain and illnesses picked up from other climbers, less time away from home/work/loved ones, ability to maintain performance levels after arrival (largely a result of no loss in lean body mass).
Thank you for taking the time to answer these questions!
For many years those heading to high altitude have adopted a very similar approach to acclimatisation, spending days or weeks at steadily increasing altitudes before making their summit attempt. Roxanne and the team at Alpenglow Expeditions have clearly found a very different approach. By using the right technology, it is now possible to expose yourself to increasing levels of hypoxia in the comfort of your own home and prepare your body successfully for the challenges of high altitude. The question that now needs to be answered is, "how much hypoxia is enough?". We need to know how far in advance exposure should start, how many hours are needed in hypoxic conditions each day and importantly, how should the degree of hypoxia change as individuals get closer to the day of departure. The key to all of these questions may lie in developing the right test that can monitor the degree of acclimatisation being achieved. Just like a runner using a stop watch to determine the effect of their training, the mountaineer needs to find a way to determine whether the preparation undertaken is adequate for the mountain he or she is preparing to climb. On many of the world's highest peaks this may not be enough and additional supplemental oxygen will still needed. Here's the last word from emergency physician and veteran of dozens of 8000m expeditions Monica Piris,
"Using the hypoxic tents for those who are planning on climbing with oxygen, prepares them for arriving at the altitude of base camp and slightly above (5300m). It allows them to get there quickly without having to do a long trek or approach that is almost invariably plagued with lots of upper respiratory tract infections and travellers diarrhoea. They arrive fresh and not depleted. They don't suffer as much when they get there, again retaining strength for what's ahead. Their morale doesn't dip from feeling too shitty for too long. All of these things play a large part in success rates, but the hypoxic tents don't acclimatise them to anything higher..."
In one sentence,
"It's the supplemental oxygen that gets them to the top. The hypoxic tents get them to base camp."
Thanks to Roxanne and Monica for contributing to this post.
*How does a hypoxic tent or mask system work?
As you ascend to high altitude the number of oxygen molecules that surround you falls. This results in fewer collisions and a reduction in the pressure they exert on the objects around them. Oxygen needs a differential in pressure to move from the atmosphere and into the lungs. The higher the pressure, the more rapid the movement of molecules. If this pressure falls, the movement of oxygen falters and fails to get to the body's organs. This is what happens at altitude and causes a myriad of problems for the mountaineer!
The pressure exerted by oxygen molecules is known as the partial pressure of oxygen or PO2. At sea level the PO2 is 21 Kilopascals (KPa). This is calculated by multiplying the percentage of oxygen in air (21%) by the collective pressure of all of the different gas molecules present in the air at sea level (100 KPa). At 5000m, this pressure, commonly referred to as barometric pressure, drops to 50 KPa and results in a PO2 of 10.5 KPa.
A hypoxic tent or mask system can create the same PO2 at sea level as that found at 5000m. Rather than change the barometric pressure, the hypoxic system delivers a lower percentage of oxygen. By breathing 10.5% oxygen at sea level barometric pressure (100 KPa) it is possible to obtain a PO2 of 10.5 KPa. Hence, a "simulated" altitude of 5000m!
Interested in mountain medicine? For more details take a look at this!
Unfortunately this event has been cancelled due to the coronavirus pandemic. Future events will be publicised on the blog soon!