Originally Posted by
Carbonfiberboy
Well, either we don't know what we're doing or the folks in the study were a little different:
(EIH: Exercise Induced Hypoxaemia)
Maybe it takes some really incredible legs!
Or those finger oximeters aren't accurate at measuring what we want measured. Mine measured HR accurately most of the time. In the study, they used a forehead sensor rather than finger. Beats me. On my best 3' interval, I was panting hard for 1.5 minutes, with the last minute spent accelerating hard, right at my limit. The ox said 98%, dropping to 97% for a few seconds after the interval. Nowhere near the <91% described in the study. My HR was 6-8 beats over LTHR, maybe 6 beats below absolute max.
Once I figured a way to tie the ox onto my finger, I didn't have any trouble on the rollers. Felt kinda good to play at being the kilo man again.
OTOH, I've always figured that VO2max intervals do their work by stimulating RBC production and 3' intervals are the standard for that. So . . .
Or, maybe a third possibility:
VO2Max is restrained by two criteria: 1) The body's ability to take in oxygen. 2) The body's ability to utilize that oxygen.
The test was restricting the athlete's ability to take in O2 by subjecting them to high altitude and forced a hypoxic state much the way a person with COPD or pneumonia becomes hypoxic -- they simply can't take in the oxygen (in their case because it just wasn't there to take in...).
Conversely, you may have hit the limit on your body's ability to utilize the O2 it had taken in (rather than its ability to take in O2) and thus your O2 saturation remained steady....
In the study, it sounds to me like they were actually trying to replicate the conditions whereby those starved for O2 by things such as COPD generate additional levels of endogenous EPO...