July 29, 2006
Floyd Landis, doping, and the Tour de France
What a dramatic Tour this year -- and it still isn't over.
There appears to be a widespread presumption of guilt here, and given the history of doping in professional cycling, that's not surprising. But being of a contrarian mind, I hesitate to jump to any conclusions about Landis. Especially since the one positive test report doesn't make much sense: the test is designed to detect the use of steroids, but you don't dose yourself with steroids for a quick pick-me-up -- they are for building muscle over the long term. And since Landis passed the same test after every other race stage, if he did take steroids, he took them in a way sure to get himself in trouble and equally sure not to have any performance benefit.
The other thing I keep looking for in the news coverage is an estimate of the test's false-positive rate. This abstract (with link to full article) describes a study that found a false-positive rate of 4%, using a urinary testosterone to epitestosterone ratio of greater than or equal to six to define a positive result. Yet even though there is evidence that some male athletes naturally have a T/E ratio approaching or even exceeding six, the Tour's anti-doping agency has now lowered the threshold to four -- likely increasing the false-positive rate substantially.
I probably won't be adding much more on this topic, but Out of True appears to be following the story quite closely.
UPDATE: The NY Times is reporting that a carbon isotope ratio test has been run on the A sample -- and the results don't look good for Landis. There remains the question of why the T/E ratio was over limits on only one of the several tests run on Landis during the course of the race. Some authorities claim that while steroids' main benefit is in building muscle over the long term, they can also help in short-term recovery after intense exercise. There does not appear to be a consensus on this, however -- and placebo effects are not to be discounted, either (that would be ironic, if Landis ended up disqualifying himself for taking a substance whose only benefit was psychological). I imagine much of this could be cleared up if the remainder of Landis's urine samples were also subjected to carbon isotope testing. There are a number of possible explanations for the one failed T/E test, but things would get much, much more interesting if anomalies turned up in the carbon isotope tests. Three main possibilities then, as I see it:
1. All samples test positive for steroid use. Landis is disgraced, professional cycling takes another huge hit.
2. All samples up until the one with the skewed T/E ratio are clean, that and those after aren't. Landis is stripped of his title and suspended. Possibility of Landis recovering at least some of his good name, especially if it comes out that someone else such as a team doctor was responsible for dosing him.
3. All samples except the one with the skewed T/E ratio test clean, including samples taken afterwards. Near-conclusive evidence of malicious tampering: Landis vindicated, but a scandal for the Tour perhaps worse yet than doping!
UPDATE: More on carbon isotope testing at Corante; lots of comments, too.
Posted by David on July 29, 2006 3:28 PM
...Floyd's A sample has a T/E ratio of 11... don't talk about false-positives here...
Posted by: Charles Hodson on July 29, 2006 4:41 PM
Mr. Hodson, where did you obtain that figure of 11:1? I don't doubt that this figure could be correct, however, the only figure I was able to find said 5:1. I suspect that the actual figure hasn't been released yet, since most press releases use the quote "unusual level", without quoting any actual ratios. My guess is any actual ratios quoted are speculation, or bad reporting at this point.
I tend to agree with the original post. T/E testing is known by the cycling union to have a high rate of false positives as well as false negatives. It is for that reason, that they are supposed to wait until after the second test has been completed before going public.
I am amazed how quickly people are willing to condemn Landis based only on preliminary data, when only a few days ago, the same people were praising him. I put much more faith in what Landis has to say that what some French cycling agency (that has been known to Lie in the past) claims.
Posted by: Brad on July 31, 2006 8:14 PM
brad, the comment "some french agency that has been known to lie ion the past" is just the same sort of untestable crap that you are complainng about yourself. you don't have any evidence that L'Equipe did lie, do you? just your desire to see armstrong carry his good name into the future...
are you an american too? blinded by the patriotic light of jingoism? 'methinks he doth protest too much.'
anyway, they don't have to wait for the B sample test before going public. the B sample test is there for the rider to claim if he or she feels that it is necessary, not as a prerequisite for any accusation. anyway, the carbon isotope test will trip him up more than a urine T/E test will.
Posted by: harry on August 4, 2006 2:59 AM
OK Brad, please excuse the venom i was having a bad day.
but the isotope ratio test did reveal the presence of exogenous testosterone, and the high T/E ratio was confirmed in the B sample.
so, you cannot misread an isotope test: it is like looking in your sock drawer and finding a large iguana. it is an iguana, there's no getting around it. the question may now revolve around who put it there.
if he did it himself ony on the night before, that is weird: why do it for one day only? testosterone does not work well that way, but there is a small increased rate recovery from exercise.
matybe he was always using it but stuffed up his masking agent. like, forgetting to take the epiteste as well. (that way you keep the ratio correct). screening only looks first at the TE ratio as it is easy and direct to do, if you want the isotope ratio it take more sophisticated equipment and lots more effort, so you only do it if you already have found a T/E problem.
if he had been doping for a while, the testosterone should have been elevated for ages before, and after. why is he not claiming that people should test him now? if there was only one high rading, it would mean the stuff had been added to his sample later. a single test error woud be possible in the lab, but not in both A and B samples. if he has the same ratio now then he was perhaps justified in claiming his innocence. if it is different now, then he is still stuffed.
thre is one other place the extra artificial testosterone could have come from: a malicious spiking of his pee tube, like a quick wipe down with a swab. i hope he used a sterile-wrapped container. i know i would insist on one, and i don't have the enemies he has.
but the most likely explanation is that he stuffed up and forgot something in his doping procedure, or made an error, and drew atention to himself by actually winning. L'Equipe has absolutely stuff all to do with it.
Ps yes, i am a pharmacologist and a long-time cyclist. (ie slow) ;-)
Posted by: harry on August 21, 2006 7:30 AM
cronaca.com