Elite is a word that can have different means, depending on the goal of the research.
For many researchers, who had more than 160,000 data of marathon runners with PB till 6 hours, elite were runners able to run under 2:40. For these runners, the generic explanation "well trained" meant people running 3 times per week about 1 hour.
If we want to see the effects of this type of training compared with the effects of NO training, this research is ok, and runners under 2:40 can be considered elite.
But, if I want to face the idea that ALL THE WR ARE DOPED, I need to investigate the subjects AROUND this level. So, for me, in this case, Elite means athletes who are in the World Lists in top 5 all-time (and already, this list includes many athletes who, in my mind, are not functional with the final goal of the research).
Which are the limits of the top 50 all time, at the moment ?
We indicate the time for the number 50, and also for the number 100 :
800m : 1'43"22 - 1'43"82
1500m : 3'30"83 - 3'31"96
5000m : 12'55"52 - 13'00"60
10000m : 26'58"38 - 27'13"94
3000m SC : 8'08"14 - 8'12"04
HM : 59'22" - 59'43"
Marathon : 2:05:30 - 2:06:22
For your information, an athlete running 10000m in 28'27" at the moment is number 1720 in the all-time list, so it's difficult to consider him "elite", with any system we want to use.
About the validity of the research, I can say that not only doesn't follow any scientific parameter, but some data is a total bullshit. I bet ANY REAL PHYSIOLOGIST to find only ONE PERSON (also not athlete) LIVING IN ALTITUDE than, going to sea level, in 2 days can lose two points of Hct.
You want to show me some research, instead you showed me a RUBBISH, written only for having one page in some specific magazine, without any control. Of course, if you give credit to idiotic works like this one, you have to think that EPO can have these wonderful effects.