Following the much needed rest day in Pheriche at 4200 m, we set out for Lobuche at 4900 m, which was our biggest ascent of the trek (700 m). In order to avoid Acute Mountain Sickness (AMS), it’s recommended that trekkers gain no more 600 m per day. However, given that our ascent profile leading up to our push to Lobuche was gradual and included 3 rest days, Nima Sherpa felt confident that our group would safely tolerate 700 m of elevation gain.
The hike to Lobuche was very slow (by design) and upon arriving at the lodge, it appeared as though a wave of fatigue and general malaise washed over the group. That, however, did not stop our team from exploring the Italian Pyramid lab at 5050 m, just around the corner from Lobuche.
The Pyramid Lab was established by Italian scientists in the 90’s and has since served as the lab for 520 (and counting) scientific endeavours in areas of climate, environment, human physiology, and geology. The Pyramid Lab is a perfect space to perform high-altitude physiological research and has a lot to do with why we are on our current trek.
Dr. Trevor Day, the lead scientist and organizer of our current trek, was part of a research team in 2012 that went to the Pyramid Lab for 3 weeks of intensive physiogical experiments. And it was this experience that inspired Trevor to conceive of and organize the current research trek.
During dinner, following our visit to Pyramid Lab, there was an obvious edge of excitement and trepidation amongst our group, as in the morning we would set out to hike 4900 m to 5364 m at Everest Base Camp. Despite this excitement, the effect of the high altitude, stomach bugs, and chest infections were taking a significant toll on a number of our team members, which would ultimately prevent some members from hiking to 5600 m at Kala Patthar.