More of the ongoing exchange between Mr. Zirbel and myself. I asked him, essentially, where he was at in all of this. This is his reply.

byFrom: Tom Zirbel

Obviously, my life has been turned upside down since that day in mid Nov. in which I received the news of my positive ‘A’ sample. But it hasn’t been all bad….it’s been mostly bad not completely. I’ve been overwhelmed by the support. Most of the publications have treated me more than fairly in what they’ve reported. And my friends and family have been a wonderful asset in dealing with this.But this process and situation has been an eye opener for me. Let me preface this by saying that I realize that this isn’t a tragedy. A tragedy is the earthquake in Haiti or growing up in worn torn Afghanistan. My situation is unfortunate, nothing more. However, it still has been very difficult for me and my family to deal with. I’ve said in previous interviews that I could see myself walking away from the sport, but it’s not going to be as simple as I had thought. The last time I raced my bike, I had the best result of my career. For the first time, I believe I’m capable of big things at the highest level. I just don’t think I can give up and quench that fire that is still burning. As hard as this situation is to endure, I have to keep pretending like I see the light at the end of the tunnel.

Another hard thing about this is not knowing how this all happened. I didn’t change anything from my routine leading up to the positive test so I don’t have any strong inclinations as to what caused the positive. I’m still hoping that we’ll figure it out but that’s a scary prospect if we don’t. Both in clearing my name and in assuring that it doesn’t happen to me or someone else again. Once this is all cleared up, I will have plenty to rant about as far as the process and justice of the system in place. And hopefully I will actually do something about it and try to help change what many agree is a very flawed system.

And for those who genuinely love the sport and hate how dopers have affected the integrity, sponsorship, and sustainability of cycling – that is no excuse for damning every positive test outright. We need to treat every case individually and ask intelligent and relevant questions. We tend to treat positive doping tests more absolute than DNA evidence in a criminal trial. Even with DNA evidence motive and criminal history, etc. need to be established as well.

Admittedly, I’m a little biased, but once you start scouring over the facts of my case – you realize that it just doesn’t add up. By saying that I knowingly ‘doped’ with DHEA – you’re essentially saying that I’m a moron. Which is fine if you actually believe that, but if not then there must be some other explanation. It reminds me of the movie “12 Angry Men”. Ask questions. Inform yourself. Be critical. It’s actually sound advice for social issues such as health care reform, foreign wars, political candidates, etc. But usually we’re too busy watching youtube videos, listening to mp3s, and twittering all at the same time to be bothered. Oh, and leaving scathing, anonymous comments on public forums! How’s that for stereotyping modern culture? Condescending, I know. But at least I signed my name to it.

Tom Zirbel

he seems like a good guy, but in all honesty if this is an out of the blue supplement contamination case then what choice does he have other than go hard after the supplement company legally, in whatever court is appropriate.

If this is not his fault, then it has to be someone’s and this needs to be proven I think. I don’t take supplements so I don’t know if there is a contamination disclaimer on the label. If there is, then he needs to be more careful, if there is no disclaimer then the next step seems obvious.

if so many people are claiming contamination by random stuff, why doesn’t anyone get taken to task on it? or maybe i just don’t hear about it over in yurp?

Maybe someone knows. People have said that DHEA is a masking agent. I find this difficult to believe because DHEA is a steroid. I know that I have also read that DHEA is not an effective steroid for athletes. Really I do not know what to think other than there seems to be a cyclist busted every couple of months. What these guys do seems to be superhuman from this fat cubicle bound cyclist’s perspective. On that note is it noon yet?

so what kind of tainted supplements are we talking about here….? cytomax? perpetuem? roctane? accelerade?

or more advanced mixtures that i wouldn’t be familiar with not having ever competed an an elite level….?

just curious….

Tom, cool to see you following up with this. I just want to clarify comments I made a couple of days ago. I want you to know I do think you could be innocent. My main motivation is to let others know, what my understanding of the evidence has found. That being that all of these protein powder/recovery concoctions have not been proven to help. I do understand that when you are knocking on the door of greatness, which I believe you are/were, based on your ride at Nats and Worlds, that you are looking for every edge. It boggles my mind, that knowing of all the positives that supposedly have come from tainted supplements that athletes who are in a testing situation still use them. You said that gatorade is a supplement. That is true but I guarantee nobody has or ever will test postive from that product. You said a friend tested positive for Nandrolene from an electrolyte supplement (electrolyte supplements have been proven to improve performance). I don’t really care who it was, but what was the product? Did he have it tested and did he prove contamination. We need to know this info so this product can be avoided. I really did mean that I hope you come out on top of this ok, whether that is as a bike racer or whatever you decide to do with your life going forward. I am sure you are going through hell right now. I don’t believe that you should be banned for life for this, if you cannot prove your innocence, which by the way I actually hope you do. I will finally end this by saying that I don’t normally participate in intrernet forums/comments etc. and that I did not do it anonymously either I signed my name to my comments too.

Jeff Rasch D.O.

Rasch, good on ya. You have said it well. Better, in fact, than I could. I just want to say, right here for everyone to read, you are a class act.

If tainted supplement is the claim why just Tom Zirbel? Were not his teammates taking the same supplements? Does he not have the information regarding batch/manufacturing date of all his supplements taken on that race day?

Tom you seem like a pretty nice and intelligent guy but here is the way I see things… There are such things as false positive do to statistical variations in lab equipment performance, that is why there is an A and B sample. I am sure that if the A sample is positive there is a 97.7-99.9% chance DHEA is in the sample…. That is a 2.3%-0.1% chance that the machine experiences a statistical variation depending on where in the gaussian they threshold a positive result. If the B sample is positive that machine statistical variance arguement does not go away but the probabilities of such occurrence drop drastically to roughly between 0.0529% and 0.0001%.

Here is the problem…. if the B sample is positive there is at least a 99.9947% (likely a much greater) chance there was DHEA in your urine when the control was taken. I am not saying you are a doper, however you bare responsibility for the result. Part of the responsibility is enduring the wrath of the blogosphere. You are not the first to take it in the chin from the like of us… and certainly not the last.

When I B sample exonerates you I am sure DC and all its commentators will retract any presumptuous proclamations of guilt.

without placing blame on a manufacturer/distributer…

how about a list of the supplements in question?

as a control test… i will gladly comsume said supplements in high dosages and pee under a black light…

One more thing that I just thought of. University student athletes are not allowed to take supplements unless they are given by the athletic training staff. I am talking about everything from the football team to the cross country runners/skiers. I do not doubt the very real possibility of contamination. Knowing this what does a cycling team tell their athletes?

I’m not going to weigh in on innocence vs. guilt, because I don’t know the facts of the case and have no idea. I want to address dafew’s comment’s about the test’s accuracy. Mainly a math correction. As far as my credential’s for making the correction go, I’m a PhD Statistics student.

Using P( … ) for “Probability of …” — also, you can figure out most of this on your own, look up conditional probability and bayes theorem on wikipedia.

What we are trying to estimate is P(Positive | TestB ), I’m using “Positive” for “DHEA in the urine sample”, and “TestB” to mean “The B Test was positive”. The vertical bar “|” means ‘given’, so the idea is, we want to estimate the probability that there really was DHEA in the urine sample, knowing that the B test was positive.

There is a formula for this probability, it’s

P(Positive | TestB ) = P(Positive and TestB) / P(TestB)

To calculate this, we need to know 3 probabilities. I don’t know the true values, so I’m going to make them up. You can make up your own values and put them into the formula.

P(Positive) = 10/1000

This is the probability that a pro cyclist has DHEA in their urine. I just made this number up, you can make up your own number.

P(Test|Positive) = 0.95

This is the probability that one of these tests comes back positive if there really is DHEA in the urine. This number might be available from the literature.

P(Test|Negative) = 0.01

This is the probability that one of these tests comes back positive if there isn’t DHEA in the urine. This number might also be available from the literature. Note that it is not necessary that P(Test|Positive) + P(Test|Negative) = 1, because in the first probability we know that there was DHEA and in the second probability we know that there wasn’t.

Once we have found/fixed/know these three probabilities, we can calculate the probability we are really interested in.

P(Positive and TestB) = P(Test|Positive) ^ 2 * P(Positive)

My numbers give approx 0.009025

P(TestB) = P(Test|Positive)^2 * P(Positive) + P(Test|Negative)^2 * (1 – P(Positive)

My numbers give approx 0.009124

The P(Test|Positive) and P(Test|Negative) are squared because you need BOTH the A and the B tests to come back positive.

Now we can calculate the real probability we care about.

P(Positive|TestB) = P(Positive and TestB) / P(TestB)

My numbers give approx 0.9891495

This means (if you believe my original probabilites I made up) that there is a 1.1% chance that there never was DHEA in the urine sample. You can make up your own numbers and put them in. But I’m pretty sure that the result is significantly lower than “99.9947%” dafew came up with. Honestly, I bet the number is low enough, that given how much cyclists get tested, that it wouldn’t be surprising to find that every year or two there is a completely innocent pro cyclist who has A and B samples come back positive.

Leif Johnson

Minneapolis, MN.

Addendum: In my calculation, I assumed that the two tests (A and B) were independent of each other. Importantly, that the probability of a false negative on the B test is the same as the probability of a false negative on the A test. This is probably not true, I’d bet the probability of a false negative on the B test is much higher, as there is likely some reason that the sample had a false negative in the first place, and this makes a second false negative more likely. I don’t know the science of how the testing works, so I have no way of working it into my calculations. So I made this (poor) assumption just to keep the math simpler. This number probably isn’t in the literature.

Doped to the gills…..

Tom,

You’re OK in my book. No one will ever know the truth 100% except you, and frankly, I’m tired of being jaded and pissed. I am making the CHOICE to believe you based simply off of the fact that you have actually entered into an intelligent conversation to defend yourself against the faceless horde of “Kill ‘em all, and let God sort them out” crowd and rather than be bitter about it, you are using this conversation to try and inform. The vibe I get from your posts has been enough for me. I think it was a mistake, and I’ll be there to cheer you on when you come back.

-Bianchi

@leif I will yied to your statistical superiority.

My perspective was from my experience as a pure water chemist where prior to each analysis the process was verified with known samples that fell within 2 sigma for both a blank and known (calibration) sample.

My point was not so much numerical accuracy but rather that the erroneous P(a|b) was the product of two low probabilities.

I would contend that maintaining conditional independence (e.g. independent analysis of B samples) erroneous B samples should have the same probability for error as A samples.

I think we agree. If the number is 17 errors in 1000 as you contend perhaps a C sample is in order…. I am curious positive A result always yield excuses like “tainted supplement” or “Jack Daniels” (Landis) or “unborn aborted Twins” (Hamilton) prior to the B sample result.

I will be the first to say congrats… if Zirbel’s is exonerated but I think have been down this road before.

Tom who?

And where do I get some of this super-duper performance-enhancing crap? I’m stuck with beer for now, and I see no noticeable improvement.

It seems we rid the world of another doper as Tom has retired as of today per Velo news . Coward . Self denial . Come clean and be the next Manzano …………………We know the shit show at DC .

Yes Tom, give us some names of the goodies you were throwing on board? You can’t be afraid of negative ramifications from sponsors are you? What outside of normal food and drink were you doing?

According to Velonews Zirbel just retired http://velonews.competitor.com/2010/02/news/tom-zirbel-retires-says-he-wants-to-move-on_106267

outstanding piece of writing here at http://drunkcyclist.com/2010/02/26/pessimism-and-the-power-of-a-website-continued/ . Thiking to translating your writing into japanese for our readers. Will let you know after I talk to our writers. many thanks.