My dr recently sent me for blood letting with a hematocrit level of 56. I think i may have an idea where he may be going with this. After some thought look at Floyd Landis. He lost his TDF title because they said he was doping. His claim was an atmospheric chamber that tricked his body into thinking he was at a higher elevation. When one does this, your body will create more red blood cells to deal with the depleted oxygen levels. Why else do you think that the US Olympic training facility is in Denver, the Mile High City? This prompts our Olympic athletes' bodies to produce more red blood cells which in turn allows for better cardiovascular endurance at lower altitudes and more easily sustainable high O2 saturations. If they are doing it and it is ok then why is it bad for us? Is that what you are getting at?