Not necessary! We do indeed see a hematocrit rise in most athletes after a month of sleeping in the height tent. However, we do not see this with some athletes. However, these athletes deliver without hematocrit increase also improved performance after a month of Live High, Train Low.
This is very easy to explain since the body will always look for balance in its hematocrit percentage. Hematocrit is the ratio between the red blood cells and the blood plasma. Moreover, where the total volume of red blood cells takes weeks to rise or fall, the blood plasma can rise or fall considerably in just a few hours. This allows you to properly manipulate the hematocrit percentage by, for example, drinking a few liters of water quickly.
Measuring the effect of the height tent by determining the hematocrit is therefore not a smart idea. It is much better toreticulocytesIf this number has risen after four weeks of Live High, Train Low, it is particularly favourable for the performance level at sea level. If this number has risen after 4 weeks of Live High, Train Low, it is particularly favourable for the performance level at sea level. Reticulocytes are the newly formed young red blood cells. These are the most powerful of all red blood cells and also do most of the work in oxygen transport to the muscles and organs.
An independent Finnish study found that no fewer than 82% of athletes who had slept in a height tent for 4 weeks had 10% more reticulocytes afterwards. Their performance level was then also considerably increased.