Is it possible to climb an 8,000m mountain in two weeks? What sort of acclimatisation is necessary and how does it affect the body?
These are the questions Kilian Jornet and Emelie Forsberg were asking themselves. To find the answer they set off to climb Cho Oyu using a new method of acclimatisation that could revolutionise climbing.
Would it work?

Date of activity

24th April 2017 - 7th May 2017


Kilian Jornet
Emelie Forsberg


Cho Oyu

Technical aspects

Height: 8.201m
No oxygen
Light gear


2 week trip to climb a 8000m peak, opening new ways on climbing high summits on short period and with pre-acclimatisation.

Summit achieved

Summit or surroundings, only Kilian Jornet

Acclimatazion protocol

1 month of hipoxico sleep + training
1 week of acclimatisation in Alps (about 4000m)
3 days of travel


30 days before leaving to Himalaya sleeping at hypoxia tent: week 1 - 4000m ↗ week 4 -5800m

During those weeks we were also training in simulated altitude:

  1. Morning: long training outside (3 to 15 hours on skimountaineering and alpinism)
  2. Afternoon 6 days/week: 40 'to 1h: at 6000m tradmille - 10min warm up (10km/h) then intervals 5' slow (10km/h flat) 5' fast (12-15km/h or 10km/h at 15% incline)

Emelie was doing mostly light but mostly running up to 10km/h. After that we were going to the alps, sleeping at Plateau Rosa (3500m) and training around 4000m (Mezzalama Race).

Total of +/- 300h in altitude (280h)


Download the Acclimatasation Protocol


Short travel: made logistics to do fast travel, 3 days from Mezzalama- Geneva to Cho Oyu Base Camp: 1- GNV-KTM 2- KTM-Lhasa-Shigatse 3- Shigatse-CBC. We travel with only one bag with technical gear and clothes.

In the mountain

  1. Always sleep low (Maximmum ABC-6400m)
  2. On the mountain the first 10 days and all the days except ascents we were going really low speed (max 130ppm - speed you can talk) to do not burn the cardiovascular system
  3. 1 rest day - 1 day activity. Maximum 2 days of resting or activity
  4. Climb on a slow pace the first 2 weeks (max 130ppm) - "you can talk" pace
  5. Always climb light and hight and back down on the day