Yannis Pitsiladis is my friend, and we discussed, few months ago, about the level of intervention of EPO on the performance.
At first, we have to say that the research his group of scientists did with Kenyan and Scottish boys can't demonstrate anything else that "EPO can work with EVERY not trained person, in every part of the World".
I never said EPO doesn't work with Kenyans. There is a big mistake considering the subjects of my statement "Kenyans" : the subjects are "top athletes, born, living and training in altitude AT THEIR TOP LEVEL OF PROPER TRAINING".
In the case of the research of Yannis, there are different subjects, and the situation is totally different : average in 3000m for Kenyans of 9'30" and for Scottish of 11', and NO INFO ABOUT THEIR TRAINING.
I repeat again : with athletes, the effect of training can strongly vary according to different training (training structure, volume, intensity, proper recovery).
In all the researches, NEVER TRAINING IS CONSIDERED.
For example, in the case of the research of Yannis' group, we have to ask some questions :
a) Which type of training the selected runners had BEFORE the test ?
b) Which type of training they had DURING THE PERIOD OF EPO ADMINISTRATION ?
c) Which type of training they had AFTER the period of EPO administration?
If they, for example, didn't have any serious training, and the system was the same before, during and after, we can say that ALL THE IMPROVEMENT is due to the EPO assumption.
But if they, during the period of assumption, increased their little training (nothing to do with REAL training), the improvement is due to two different elements : EPO and training itself. Which percentage of the improvement can we give to each of the two elements ? It depends on the increase of volume and intensity of the training. How much is the DIRECT INFLUENCE of EPO on the performance ? If training really improved seriously, the percentage is ZERO, because moving in one month not trained boys (I don't consider a Kenyan running 9'30" or a Scottish running 11' a trained person) from 9'30" to 9', and from 11' to 10'30", with proper training, it's very easy for every coach of medium level.
The problem is that, if we want to see the effect of EPO, we must do exactly the same training (maybe nothing, or 40' easy run every day, or very tough training) before, during and after the administration, AND WE HAVE TO CERTIFICATE THIS TRAINING IN CLEAR WAY (in all the researches physiologists speak generally of "well trained athletes", of course without having any idea about what the real training of the best athletes is).
So, that research doesn't give absolutely any new information, apart the fact EPO can work for not trained people. If it works DIRECTLY, increasing the performance of low level, of NOT DIRECTLY, supporting the ability to have more training (which produces the improvement), is something that the research doesn't explain.
And, at the end of all the story, also if Yannis is my friend, that research was totally useless, and didn't demonstrate anything, if we look at the effects on top performances, achieved by athletes with well different level of training and of talent.