Every few months the same study is proposed as "New Study".
This is an old study, that can't demonstrate anything, if referred to the best athletes in the world.
1) The subjects were well far from being "elite"
2) The subjects didn't try to run at their max possibility, nor in the test before EPO administration, nor after the administration
3) "Well trained" doesn't mean anything, comparing their training with the training of the top Kenyan athletes. No one of the authors has some knowledge about the real training.
4) Nobody denied that, with "average people", and also "average athletes", EPO can produce improvement. The real goal is to see if EPO can improve the performances of top athletes, already with proper training in altitude (that is the reason of their performances, of course together with the personal talent).
So, at the end of the study we had the confirmation that EPO can help everybody (included Kenyan and Ethiopian SLOW athletes), who trains at volume and intensity FAR from what they need for the maximal evolution of their performance.
I repeat again : if ALL THE ATHLETE subjects of the study, during the same period of one month, instead taking EPO in the described way, had a methodological increase in their training, the improvement of their performances was BY FAR better than what they achieved taking EPO.
Can EPO increase the performances of the best athletes, when already they are in the maximal training ?
There is no research about this question. We know there are athletes of top level that took EPO (Rita Jeptoo, Jemima Sumgong, Mathew Kisorio, Wilson Erupe, maybe Asbel Kiprop also if his case is very strange), but we don't know when they started to dope, and the idea they started from the beginning of their career is pure speculation, without any basic proof. My opinion (I was the coach of Rita till 2007 and I well know the incredible level of training she was able to do already that period, when was of sure completely clean) is that they started to dope not for running faster, but for having a "shortcut" in order to recover in short time the level of Aerobic Power, lost for deifferent reasons (in the case of Rita, 3 months without training after a car accident).
Two of these athletes came back after their period of ban, were controlled with continuity (so we have to suppose they were clean in their career after the ban), and improved their PB, compared with the period of supposed doping :
Wilson Erupe ran (before the ban) in 2:05:37 in 2012, and after the ban in 2:05:13 in 2016, in the same marathon
Mathew Kisorio ran (before the ban) in 2:10:58 in 2011, and after the ban had his best marathons : 2:06:33 in 2015, 2:07:32 in 2017, 2:06:36 and 2:04:53 in 2018, with a big improvement.
Looking at these two cases, it seems difficult to suppose that EPO can give real advantages, especially in the long distances.
I repeat again : I'm for banning, for long time, all the athletes taking EPO (and generally doped), but this has nothing to do with the REAL improvement in their performances.
They MUST be banned, because their will is to cheat and to take advantage compared with clean competitors, and we have to put at the top of our goals the ethic values, that are at the base of a social education. But, also, they MUST be banned because are IDIOTS risking their career for NOT HAVING ANY ADVANTAGE, and we have to clean athletics from all the idiots who look for cheating and think to have big illegal helps taking doping.
The most part of the doped athletes have the brain of a hen : if you see at the ridiculous attempts to justify the EPO found in her urine, made by Jemima Sumgong, you understand that the level of education is very low, and again who want to be too smart at the end acts like an idiot.
In all this, could really be interesting a research ON THE EFFECTS OF TRAINING (the real training, not the generic training of "well trained athletes", which is absolutely ridiculous as volume and intensity).
All the physiologists who speak about the effects of blood manipulation in long distance runners don't have any clue about the REAL training of the top athletes, and at the end, in my opinion, with their "estimes" of the advantages, become the best testimonial for doping.
The fact is that in all the activity where the muscle strength is the main quality, from 1988 there was not improvement, so it's clear that the fight against steroids had a good percentage of success.
Instead, in all the activity of endurance, we continue to see improvement in both men and women, in spite of Biological Passport , better systems of analysis, and the increased number of tests.
Possible that the 99% of African runners are so smart to bypass all the tests, if really doped ?
In top 100 sprinters all time, 42 were sanctioned for doping (some of them for 3 months only, in any case indicators of a mentality looking at every kind of support for improving their performances).
In top 100 marathon runners all time, only Goumri (n. 67 in the world with 2:05:30) was banned, for the Biological Passport, and in the top 100 half-marathon runners (inside 59'35") only Mathew Kisorio was banned.
These are facts, the other are SPECULATIONS and SUPPOSITIONS. And we have to look at facts, not at what we suppose could happen, without any evidence.