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The Explainer: Will the biological passport catch micro-dosers?

  • By Charles Pelkey
  • Published Apr. 7, 2011
  • Updated Apr. 18, 2011 at 11:08 AM EST

Q.Dear Explainer,
As a follow-up to your answer to an earlier question on the biological passport, I’m curious whether there is any science out there on the relative benefits of micro-dosing EPO and other methods designed to avoid detection in doping controls as compared to more traditional and easily catchable doping methods.

Stated another way, what I’m asking is this: even if there are ways to circumvent the current system, is there any evidence that the current system at least reduces the advantage that dopers might gain and therefore makes the playing field “more” level rather than perfectly level? It is probably naïve to think we’ll ever eliminate doping entirely, but I’d like to hope that detection methods have at least some effect.
– Quentin

A.Dear Quentin,
I am not entirely certain as to what scientific studies have been conducted on the benefits of “micro-dosing” EPO or other red-blood-cell enhancers. Given the limitations imposed by the UCI’s biological passport system, the benefits would pretty much be limited to the ability to maintain a relatively constant hematocrit over the course of a heavy racing schedule, particularly a grand tour.

While micro-dosing EPO doesn’t fully circumvent testers’ ability to detect the use of recombinant erythropoietin, it does limit the window of opportunity in which such detection can occur.

The current EPO test can distinguish recombinant erythropoietin from its natural counterpart because the recombinant hormone has a unique glycosylation pattern. That produces EPO isoforms with a different electrical charge and that allows testers to use an isoelectric focusing technique to distinguish the two. That’s a nifty test, but those isoforms generally last for only a few days, while the benefits of EPO last much longer.

Micro-dosing reduces the presence of EPO isoforms from, say three days, to several hours. The net result is that regular micro-dosing can generally go undetected.

In a sense, that’s disheartening because it seems that some riders — especially those with access to expert medical advice — are getting away with something. That’s true, but we are a long, long way from the early days of EPO, when riders reportedly jacked up their hematocrit levels to insane levels. There was a reason that Bjarne Riss’ nickname in the peloton during the mid-1990s was “Mr. 60 percent” and it had nothing to do with the returns on his investment portfolio. You might also recall that when Marco Pantani was transported to the hospital after breaking his leg in the 1995 edition of Milan-Turin. Doctors reportedly found his hematocrit was in the range of 61 or 62 percent.

Back in 1997, the UCI imposed the old “50 percent rule,” which required riders whose hematocrit was above that level to take a two-week “rest” or have a sound medical explanation for why it was that high. The number was based on the mean hematocrit for normal adult males, plus two times the standard statistical deviation. That would cover about 95 percent of the population, with about one half of the other five percent producing hematocrit levels above that limit and the rest turning in relatively low numbers.

The statistical model was generally pretty accurate, as data shows that about 2.5 percent of the peloton was naturally above 50 and those riders were able to receive a medical certificate confirming their higher-than-usual hematocrit levels. For example, the press room at the 1999 Tour de France was abuzz with rumor and speculation on the eve of the race when it was reported that three of the 190 riders had tested above 50. As it turned out, though, all three of them had already provided substantial medical evidence that their numbers were normal for them. That fit well within the expected number of riders producing higher-than-normal red-blood-cell counts.

That rule did, at least, impose an “upper limit” on the abuse. The problem was, of course, that riders were all producing hematocrit counts in the high 40s, bumping just up against the limit of 50. At the 2004 Tour of Romandie, for example, Tyler Hamilton — whose normal hematocrit was around 41 or 42 — submitted a sample that showed it to be above 49 percent. He was, of course, later suspended for homologous blood doping when a new test found he had a “secondary population” of cells — someone else’s blood — in his system.

The introduction of the aforementioned EPO test in 2000 also resulted in some riders being caught. Riders with more sophisticated medical advice took to micro-dosing their levels up to that 50-percent level, avoiding the test.

But the new biological passport makes even that latter approach risky, since the reviewers look at a whole range of parameters now. Chief among those is the relationship between new red blood cells (reticulocytes) and mature cells. As I mentioned in that column on the biological passport, one reason riders continue to use EPO is to raise the level of reticulocytes in their blood to offset the skewing of that ratio caused by the reinjection of stored blood red blood cells.

It’s a delicate dance and unusual fluctuations in any of those numbers would raise a red flag with testers.

Yes, I know that it was a long answer to a short question, but the bottom line is that the development of new technologies, the application of new and existing tests and greater scrutiny will not entirely eliminate doping in the sport, but it can — and likely will — limit the benefits that cheaters can derive from it.
– Charles

Q.Dear Charles,
The recent Giro del Friuli here in Italy saw many riders abandon after an early break went down the road and the main bunch wasn’t making any real headway toward catching them.

It was admittedly a cold, wet, and miserable day which likely played a part in each rider’s decision not to finish, but I suspect that’s an oversimplification. I can appreciate slippery roads and risk of breaking limbs being a concern, as well as being miserable on the bike, but can you shed some light on what training and other factors are considered (both by rider and team) when deciding to pull riders out of an early-season race like this one?

Doesn’t it jeopardize riding into form and that schedule? What are the trade-offs?
Thanks,
– Bill

A.Dear Bill,
We noticed that one, too. On that cold and wet day, there were 163 riders who lined up for the 2011 Giro del Friuli. With rain and strong winds, the peloton was cut to about 30 riders by the 50km mark and that’s about all that finished. The final results of the race included just 28 finishers and 135 others had abandoned along the way.

You pretty much hit the nail on the head, Bill. Slippery roads, risk of injury and downright miserable conditions prompted the vast majority of these riders from turning this into a long training ride.

When I first saw your question, I happened to be talking to Jonathan Vaughters, the manager of the Garmin-Cervélo squad. I ran it by him and while he didn’t – as they say – have a dog in that fight, he said he could “come up with any number of reasons why.”

“It really doesn’t make a lot of sense to keep a rider out there when, one, there is no chance of winning, with a break of 30 up the road and, two, the risks of an accident or illness are that high.”

Bottom line, it’s the old “live to fight another day” argument. It makes no sense for a guy to ruin part – or all – of his season competing in a race for 29th place in a one-day event.

Sure, when I was racing as a ne’er-do-well amateur, I used to always swear I would “never quit,” imagining it as some sort of moral imperative. Of course, my 20 or 30 races a year pale in comparison to the number of racing days a pro’ gets thrown into. At that point, it’s all a matter of cost/benefit analysis … and there’s really no benefit to be derived when riding with 130 of your closest friends on a cold, slippery, crappy day.

If you’re looking for that never-say-die inspiration, though, there’s still plenty of it out there. It just happens to be in stage racing, where the cost of quitting is huge. Just think back to the famed “day the big men cried” when Andy Hampsten rode into the maglia rosa on the strength of his ride across the Gavia in a snow storm. Stage racing offers plenty of that. One-day events?

Well, sometimes it just makes no sense to ride.
– Charles


“The Explainer” is a regular feature on VeloNews.com. If you have a question feel free to send your query to CPelkey@CompetitorGroup.com and we’ll take a stab at answering. Not all letters will be published and some questions may be combined with those of other readers. Please include your full name and hometown.

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