A chance encounter
The data from Denali and my 2014 Everest preparation
Whoa! Now that figure above shows a HUGE improvement. Note that my spO2 (O2Sat in the figure above) never dips below about 83%. My training data had spO2 values well below 75%. Also note that I kept my spO2 above 90% up to 15,000 feet. Not bad if you ask me. I felt great for most of this time and certainly better than how I felt on Denali. How am I doing this time around? Well, here (below) are my data in the morning after sleeping in the tent:
Note all values above are above 91%. I have yet to wake up with spO2 values below 90%. Now there are some reasons for these high values. I changed my acclimatization approach this year and intend to test the approach on Rainier and Aconcagua. Instead of pushing the envelope in the tent (live high - train low), I chose to train harder and higher - climb high - and then sleep low at about 12,000 feet. Below is a figure that shows my hypoxic training values.
I plotted each "test set" or simulated climb in its own panel so I could compare my progression by week. The earliest date was August 9th and the data contains simulated climbs through last Saturday (October 25th, 2014). I began with relatively easy simulated climbs where I started the climb at about 5,000 feet and then went to about 17,000 feet. The past few climbs started much higher (12,000 feet) and went all the way up to 20,250 feet. Obviously the degree of difficulty of these climbs changes. What I am looking for in these climbs is a systematic shift upwards of the curves. Last week seems like a setback from my progression from the previous two weeks. I was making great progress but last Saturday I had much lower spO2 values for the same simulated climb. My first guess on why is probably due to a higher intensity. To see if my hunch is correct, I plotted the data for altitude and wattage:
Nope. Looks like I am getting slower at the same altitudes; time to revisit this approach. Sleeping at lower altitudes might not be as effective as I expected. Despite the data, I intend to test out my fitness on Rainier and Aconcagua. My intent is to sleep higher as I go but right now I wanted to remain fresh at night, recover from the increasing workload, and train harder during the day. Obviously, something is not going right with my simulated climbs. I expected to be doing better each week. What the data indicate above is that my weekly simulated climbs are getting harder and harder. The anomalous data from October 3rd came from a simulated climb where I bonked. My comments from that day were "whoa! got off the bike; cut it short after I bonked." Well, that comment speaks volumes.
So where am I now. I remain committed to test out this climb high - sleep low approach for the next few weeks before I take off for Argentina. I wanted to test this approach because sleeping in the tent at high altitude really affects my night's rest. Prior to leaving for Nepal last year, I averaged about 4 hours of good sleep at 20,000 feet. A few months of sleep deprivation (8 hours is my goal) might really affect my cognitive performance. Thus, I wanted to try a different approach. Sleeping low also allows me to continue sleeping in my own bed with my wife - both pluses in my book.
Hope you enjoyed this long post about my current acclimatization routine. Stay tuned for a post about my gear for the three upcoming climbs.