Originally posted by gntlmn
I'm wondering if a rider who builds up his red blood cell count and O2 uptake with EPO will have a permanent, positive increase in performance. How long does it take before the drug wears off and the blood counts go back down, if they do?
Originally posted by gntlmn
I'm wondering if a rider who builds up his red blood cell count and O2 uptake with EPO will have a permanent, positive increase in performance. How long does it take before the drug wears off and the blood counts go back down, if they do?
Originally posted by mitosis
Due to wear and tear, the average red cell lasts about 90 days in humans. If you stopped taking EPO, the high red cell count would gradually taper off over that period.
Originally posted by mitosis
Or by blood doping - taking some of your own blood several months before a big event then reinjecting it shortly before the race.
Originally posted by steve007
Its very difficult to catch someone. Its also possible to increase your red blood cell count through high altitude training.
Originally posted by limerickman
And this type of cheating has now come back in to vogue because
EPO is now detectable.
In the 1970's - blood transfusions were the vogue (it wasn't illegal at the time).
Lasse Viren the Finnish long distance rider was alleged to have
had quantities of blood transfused out of his body - and the same
blood was stored and then transfused back in to him just before
major competition.
This type of activity is largely undectable - where as performance
enhancers which are chemical based, may well leave a trace.
Originally posted by Ted B
Detecting EPO use is anything but a cut and dry matter and requires several tests to confirm a positive result.
The synthetic EPO peptide differs only very slightly from natural EPO. While the synthetic markers can be detected in the blood, the test is only reliable if the injection occurred in the previous 6-12 hours. Obviously, this test is of very limited value, especially in that the positive benefits of EPO are greatest some 3 weeks after the injection. This renders David Millar's alleged use timed to fit perfectly into the mountain stages of the TDF.
Since EPO raises one's hematocrit, an initial positive test for EPO use is flagged with a hematocrit of >50 and a reticulocyte count of >2.4. An initial positive is confirmed with a very sensitive urine test that assays for certain markers of synthetic EPO.
Originally posted by Ted B
If the EPO injection did what you wanted it to do three weeks down the road, you will have elevated hematocrit levels, which are easy enough to detect (if they trip the legal threshold) followed by a confirmation via the sensitive urine assay.
Originally posted by gntlmn
Ahh. So you are saying that the blood test is only reliable at the 6 to 12 hour mark for synthetic markers, but the urine test will still be reliable at the 3 week mark?
How is it then that they can still cheat it? I suppose the riders are particularly concerned with making sure their hematocrit levels are not elevated above the acceptable levels so that they can continue to deny EPO use.
Originally posted by Ted B
AFAIK, yes...however I believe the urine test (slower + expensive) is only used as a followup to an abnormally high hematocrit (quick and easy).
Originally posted by steve007
Actual EPO is detectable for around 72 hours. Its the effect of EPO which is detectable in a blood sample, generally by presence of young red blood cells.
Originally posted by gntlmn
Oh. Now the picture gets clearer. These young red blood cells appear immediately under the influence of the additional enzyme that EPO provides, and they don't reach full size until the 3 week mark, at which point the effects are maximized. That's the part I didn't understand above about the red blood cells having to grow. Is that what's happenning?
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