I don’t intend to get into all the details. But it seems as though something was in Contador’s blood that should not have been.
However, I do plan to hypothesis the source of the positive test, because many in the cycling media seem to be unable to make this connection. But first, here is a grab bag of quotes from Contador’s defenders:
(1) The amount was so small that it could not possibly have a benefit.
(2) Taking such a drug at such a late stage in the race could not possibly have a benefit.
(3) The drug was not present in any other samples during the race. This must be an anomaly.
(4) Why would I take a drug that is so easily detected?
I believe that Contador did not take the drug during the race. But he almost certainly popped a couple of blood bags into his arm on one or two occasions.
That is the most likely source of these trace amounts.
As a bit of history, when Floyd Landis was charged with doping testosterone in the 2006 Tour de France. His defenders made these exact claims. Testosterone is the sort of drug you take in training to boost muscle growth, you don’t take it midway through a race. I have since read that Landis, although admitting to doping throughout his career, still claims to have no idea what caused his testosterone positive during the 2006 race.
Since the positive test is irrefutable, because Landis’ sample contained what is undoubtedly synthetic testosterone. Landis is right to ask “where did it come from?”, the impolite response is “Blood doping, fool!”
Blood doping with your own blood is virtually undetectable. It is probably the safest way to dope these days. But you must be organised, because you need to build up a stockpile of blood for your use in the future. I am sure that people who are smart and have good advice, ensure that there blood bags are nice and clean. But, if a few of your bags go sour, you might need to grab some from an older batch, when perhaps you were not as careful.
Contador has ridden for a number of teams where blood doping was commonplace (Liberty Seguros, Discovery, Astana). I am willing to accept that the contaminated meat theory might be true, but I think contaminated blood bags is far more likely.
Thomas the Think Engine 
Poor old Bjarne Riis, he doesn’t know to be happy or sad!
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so how does blood doping work? Do you take blood when you are at high altitude and then inject it back during the race?
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Basically yes, but not necessarily at high altitude. Take blood out in the off season, pop it back in mid race. This sort of doping is illegal, but there is no official test for it.
You can also dope with another person’s blood, but that can be detected (ask Tyler Hamilton). There are some tests which can ‘imply’ that a person has doped with their own blood, basically because the body stops replacing blood cells at the normal rate, they get an abnormal ratio of mature red blood cells to young cells. But there is too much natural variation in individual’s ratios for an effective test at this stage.
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Is it about adding “more blood”, or “better blood”?
i imagine that you could thrash yourself into the dirt in training to build up red blood cells, take your blood out, then taper off for recovery before a race, safe in the knowledge you can squirt your “super blood” back in when you hit the bergs.
Or is 10 litres just better than 9?
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