Several years back, interest developed in a different model... live high - train low in which people resided at higher elevations but came down to lower elevation to train. The data on this has been mixed with one study out of Utah showing a benefit and another nicely done randomized trial in Europe showing no benefit. The one kicker from the study in Utah is that in order to derive a benefit the athletes had to spend a lot of time living at altitude each day (> 20 hours) and it needed to be done for a while.