Great vid! You guys were really huffing and puffing. BUT… according to Tim Noakes' running bible "The Lore of Running", reviewing the literature shows that the benefits of high-altitude training are not exactly well-supported.
Some people show an increase in EPO and RBC concentration, but most people don't see an increase in RBC simply by training for a short time at altitude. And it takes weeks for even the limited number of RBC-responders to acclimate and get over the fatigue and reduced distance/exertion before they see any benefit (which they often don't), which is lost training time probably better used training strongly at low altitude. VO2 max also hasn't been shown to increase in "train high" strategies either, although VO2 by itself is prob not a very good measure of performance, since the amount of oxygen delivered to the muscles is (according to Noakes) limited by the heart's ability to feed itself oxygen, not the blood's ability to hold it.
What does seem to work is "live high, train low", where you spend long enough (like months, or years) at altitude /not/ training to get over initial fatigue, you are more likely to get a real, sustained increase RBC, and you get increased blood vessel growth to the heart so it can sustain a higher level of activity. Then you train at competition speeds at low altitude, with a higher RBC conc and a heart that can pump harder before it gets hypoxic itself. The muscles get more oxygen, but it's because the heart is pumping better and able to work harder. Most of the "train high" stuff traces back to the 1968 Olympics and our misunderstanding of what makes E. African runners so good.
I could go on and on, but read Noakes book! I should say I only know any of this because I'm running a marathon next week for an episode on my channel, I've been studying.