Whats the point of training at altitude if its just going to make you a one-trick pony who can only perform well in zone 2, but folds like a cheap tent in any other intensity. Does anyone actually know how altitude training affects zone 2 efficiency, or are we all just drinking the Kool-Aid and assuming its some kind of magic bullet.
Im not looking for some vague, anecdotal nonsense about how altitude training is hard, but its worth it. I want to know the actual, quantifiable effects of altitude training on zone 2 efficiency. Is it a real, measurable improvement, or is it just a placebo effect.
And whats the optimal altitude, anyway. Is it 5,000 feet, 8,000 feet, or do you need to be all the way up at 10,000 feet to see any real benefits. And how long do you need to stay at altitude to see any real improvements in zone 2 efficiency. Is it a week, a month, or do you need to be a full-time resident of Boulder to see any real benefits.
And what about the trade-offs. Does altitude training improve zone 2 efficiency at the expense of other intensities. Do you become a zone 2 specialist, but struggle to keep up with the pack in a sprint or a hill climb.
Im not buying the hype until someone can give me some real, data-driven answers. So, lets hear it. Whats the science behind altitude training and zone 2 efficiency.