Originally Posted by Carbonfiberboy

There's a third thing that enables both those other things: the body's ability to move oxygen, i.e. RBC count. Which is what they're trying to increase through various legal means. High hematocrit is the key to increased performance.

The skaters who got down to <91% for 30" were only at 1000 meters, their home altitude. That's not high altitude. At 10,000', I can get my oxygenation down to 93% without too much stress, so that does work of course. Never tried long anaerobic efforts at altitude. But I don't think that's quite what was going on for the 1000 meter skaters.

One of the interesting things in this study was the failure of simple hypoxic exposure to increase RBCs. Recently researchers have been saying that the whole "sleep high, exercise low" strategy actually does't seem to produce results. Your $10,000 hyperbaric tent maybe was a waste of money.

So I'm going with the "not strong enough" idea. Can't use the oxygen fast enough. Or maybe can't transfer the oxygen fast enough. Need stronger legs, be able to make stronger anaerobic efforts, then need more RBCs to move that oxygen into the muscles. Kind of a chicken and the egg thing. They don't say what distance these skaters specialized in . . .

So this all takes us back to looking at results rather than theories, which says that 4 X 8' worked best for polarized trainees, for whatever reason.