This is my HR (red), altitude (green), and time (x-axis) data from the sportive in the Pyrenees. You may notice that everything seems nice and familiar until about 7 minutes into the climb up Tourmalet when the HR data hits the floor (around 20bpm) which obviously isn’t right. I remember the moment. I caught a group of good cyclists at the base of the climb and even felt good enough to think I could continue passing them… as I pulled to the left a sudden malaise came over me and I immediately knew that within 2 pedal strokes I’d be going a very different speed. Windows has their “Blue Screen” but I’d actually equate it more to Macintosh OS X crash where things pause for 1 second, then the screen slowly turns to black from top to bottom, then you get a nice message in Chinese, English, and German that basically, this game is over.
I managed to pull back all efforts and arrive at the top, crushed and dejected. Even a 20 minute descent wasn’t enough to get a reading on my HR which was still producing strange readings (205-220bpm) but it actually was accurate. At some point during the flat section on the way to Col d’Aspin, things turned back to normal, if you consider riding mountains for the past 90 minutes without cellular oxygen “normal”.
You can re-live the action here: https://waywardcyclist.wordpress.com/2011/07/16/video-from-the-pyrenees/
[Note: This was a draft that was written over a year ago, never published, but might as well]