After all this debate, we are left only with natural HT as a solid basis on which to make a case for differential response to doping. Prior to the biopassport, a rider with a low HT could, by raising it to the 50% level, get more of a relative benefit than a rider with a higher HT.
It seems to me, then, that we should be trying to find out the natural HT of various riders. I'm going to start with LA's, because there is quite a lot of info publicly available, but I encourage others to report what they know about Ulle's, and other riders, particularly light climbers who some think were made unemployed by the EPO era.
This
article lists seven values obtained after he announced his comeback, but before he rode any Pro Tour races. The mean
+ SD of these values is 42.14
+ 2.31.
Similar values were published later in 2009, during or between the two GTs he rode then. All of these values were above 40, except for one value of 38.2 at the end of the Giro, when a lower than natural HT is expected because of plasma expansion.
The mean HT value for LA is close to the average, which is in the range of 42-44. For example, in
this study, which I referred to before in this thread, EPO was used to raise the natural HT of twenty male subjects. Before administration of the drug, the mean HT was 42.7%, with a SD of 1.6%.
The key question we are addressing, though, is how much benefit could a rider get from blood boosting pre-passport, when the effective limit was 50%. The linked study above provides one good estimate of this. In this study, EPO administration raised the HT of the subjects to an average of 50.8%, or almost 20% the natural value. The same study found that the (relative) V02 max of these subjects increased 7%, from about 63 to 68 ml/min-kg.
The 7% V02 increase reported in this study seems a reasonable estimate of the maximum performance enhancement LA could have obtained from blood doping. Since this is a mean value with significant variation, it could be greater or it could be less, but in the absence of any information allowing us to rationalize a differential response, I argue that this 7% value is the best indicator of maximum performance enhancement that we have. In fact, there are a lot of studies suggesting that elite riders benefit less from PES than non-elite, which would suggest the 7% value might be an overestimate.
How much advantage would this enhancement give him over other riders in the peloton? In Coyle’s study, a value of 81 is reported once during the racing season, but somewhat lower values, 70-75, in the offseason. This could be due to training, but also due to doping. Following cancer treatment but before he returned to competition, he recorded a value of 66.
Suppose we just conclude that his natural relative V02 max was somewhere in the range of 70-80. With the 7% improvement from blood doping estimated above, this value would be raised about 5 ml/l-kg. extending the range to 75-85. The upper end of this range would put him close to the highest values for cyclists I have seen, 92 for LeMond, and 88 for Indurain.
OTOH, to get to this value, he would have to start from a value of 80, which would already suggest he could be a pretty good climber. Yet he clearly wasn't prior to the late 90s. So one might argue that his natural V02 was in the range 70-75, and he raised it to 75-80. This would certainly be expected to improve his climbing ability, but not, I think, put him in the company of the elite, even clean.
Moreover, keep in mind that the peloton was not clean. If other climbers were blood boosting, even to a lesser degree than LA, their advantage over him might be reduced, but it would still be substantial.
To summarize, I have made the following assumptions about LA:
1) his natural HT, as reported in various media, is in the range 41-42
2) by raising it to 50%, he would increase his V02 max about 7%
3) given the most favorable estimate of his natural V02, this increase would probably allow him to become one of the best climbers, but only if the traditionally best climbers were clean.
4) If the climbers were doping, as many if not most certainly were, LA’s relative advantage would be reduced. I thus find it hard to explain, simply through an increased HT, how he could transform himself from a relatively poor climber to the best one.
I emphasize that I have made certain assumptions here, but I think they are the best ones possible under the circumstances. One can always increase the estimate of performance benefit by assuming:
1) his natural HT was somewhat lower. But even then, the best estimate of the V02 max increase is only improved a few ml/min-kg.
2) his V02 max responded exceptionally well to a HT increase, better than most other riders’. But then we are presuming he was just lucky. AFAIK, we have no evidence that he could benefit in this manner. It might be out there somewhere, but it hasn’t been made public.
3) Perhaps most important, there are performance measurements, such as time to exhaustion, which may be increased more than V02, and which might provide a better indication of a rider's benefits during an actual race. Science of Sport had a good analysis of this a few years ago. A larger benefit suggests the possibility of a larger relative benefit, though again, we no reason to believe that LA was a high responder without evidence.