The body's adaptation to high altitude helps significantly but doesn't fully compensate for the lack of oxygen.There is a drop in VO2 max of 2% for every 300 m elevation above 1500 m even after allowing for full acclimatization.I know that this is a difficult concept to believe because so many programs have touted the benefits of high altitude training.To fully appreciate this realize that there aren't any world record times at high altitudes.altitude training associatesThink about this a moment. The air density is much lower,thus wind resistance is much lower.Wind resistance is the cyclists biggest barrier to speed.If all other factors were equal, then there must be faster times at higher altitudes.Because there aren't,means that something else must have decreased.That something is the engine -- the human engine.There is some more recent evidence to suggest that a"train-low,sleep high"approach may confer some advantages.In this scenario,training is carried out at low altitude -- to push anaerobic threshold,altitude training equipment and VO2 max --but sleeping is done at high altitude so that the hypoxic stress increases red cell mass.Certainly a creative approach and one which might yield excellent results,because it may give the athlete the "best of both worlds".In a practical sense it may be difficult to construct,but if you are lucky enough to live in a situation that allows this type of training,it is worthy of consideration.Furthermore,while adaptation to high altitude makes you better at high altitude it hasn't proved useful for making you faster at sea level.There is a lot of mysticism that surrounds the belief of enhanced sea-level performance after altitude training altitude training mask 2.0,but the current scientific evidence is lacking.The reason is that some of the adaptive responses at high altitude are actually a hindrance at lower altitude.As more research is done then perhaps a training regimen that shows definitive improvement will emerge.The best advice as of 1994 is that high-altitude training is like"magic shoes"-- If it works for you then wear them.