- Jul 27, 2010
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The Hitch said:It was a theory, I've seen, been mentioned here a few years ago, that epo benefits those of greater physical build. Don't know what evidence there was to back it up.
RR was pushing this idea here about a year ago. The theory is that "densely-muscled" riders have a larger reservoir of tissue that can make better use of the increased oxygen transport with EPO. Supposedly, Armstrong, Ullrich and Pantani were all outstanding examples of this kind of build.
But RR never provided any evidence for this other than some insiders he talked to supposedly claimed so. There is no evidence for it in the literature that I know of, and just a consideration of physiology suggests it wouldn't be the case. RR didn't even provide any evidence that the riders he named had this kind of build, let alone that it mattered if they did.
That said, we do know that there are at least two ways in which some athletes can respond better to EPO than others. First, a given dose of EPO may have a greater effect on HT in some individuals than in others. Studies have demonstrated this, though we have no way of identifying which riders might have been better responders in this sense. This effect would be particularly important after a test for EPO was developed, and riders micro-dosed. When the amount of EPO you dare take is limited, the advantage goes to those who get the most effect from a given dose.
Second, a lower natural HT can be raised to a higher % than a higher HT. This was important before there was a test for EPO and you could take all you wanted, but it became particularly significant after the 50% limit was imposed. A rider with a natural HT of 40 could raise it 25% under these conditions, while a rider with a natural HT of 45 only about 10%. Armstrong was known to have a fairly low natural HT, though I'm not sure it was low enough to provide an advantage over most other riders. RR claims it was in the high 30s, but in the biopassport data that were published for 2009/2010, it's listed in the low 40s, hardly lower than the mean for males, which is around 43-44. Jan and Marco supposedly also had low natural HTs, but it's hard to find references to their precise values.
