Friday, June 15, 2012

Science Friday: Inspired by Lance Armstrong

Remember, he's a marathoner too!
He said it was the "hardest physical thing" he's done.
This week’s re-emergence of the never-ending case against Lance Armstrong made me want to do an EPO inspired post. Perfectly, an article came out just last week examining the effects of EPO in the brain. EPO is erythropoietin, a growth factor your body produces to increase red blood cell production. Endurance athletes take a recombinant (artificial) version because it greatly increases performance and endurance. In one study, a group of normal volunteers (not professional athletes) increased their time to exhaustion on a cycling test by 50% with EPO treatment. That's huge. Most of the actions are thought to be through increasing the blood's ability to transport oxygen. The recent findings from a group in Switzerland suggest that it can also have an effect on the brain. They used three groups of mice: (1) normal mice, (2) mice that have EPO only in the brain (not the blood), and (3) mice that were injected just once with EPO. They looked at things EPO normally affects in the blood, like blood volume and levels of hemoglobin, the protein in red blood cells that carries oxygen. Since one group of mice had EPO only in the brain, and another group only got EPO once and was examined soon afterwards (before there would have been an effect), they saw no effects of EPO in the blood. Interestingly, they found that mice with EPO still had increased VO2max and could exercise (run on a treadmill) for longer before becoming exhausted. Since this was independent of changes in the blood, the improvements must have been from EPO in the brain. Perhaps EPO improves endurance and reduces time to fatigue by acting on your brain, rather than just oxygenating your muscles. The paper mentioned another group that had found opposite results, that EPO has no role in the brain, and suggested the different doses used by the two groups matters. My question is which dose is similar to the ones used by professional athletes?

I did some more research on EPO to brush up on my doping knowledge. How is it that cyclists can get away with this for years or even decades? Why do some samples have to be thrown out? (Apparently just training at altitude makes your sample ineligible. A lot of people train at altitude for many reasons, do we have to start being suspicious?) An easy to read summary and more technical review were helpful, although rather disheartening. The drug cheats have always been ahead of the science, and probably will continue to be. EPO is incredibly hard to detect because your body makes its own, so it comes down to differentiating between the recombinant EPO and the normal EPO everyone has. Apparently our tests don't differentiate those two very well. Furthermore, you can keep the injection frequency pretty low and still experience enormous gains. (Which makes me wonder if it would have an effect on the brain, as suggested above.) The review includes a schematic about how a cyclist could have pulled it off without getting caught; it takes a lot of out of season injections. Fortunately, out of season testing is getting more routine. The newest (and perhaps most promising) ideas are “blood passports” and “athlete biological passports.” These are individual profiles of each athlete and contain all data gathered over time.  Because of enormous variation between athletes, particularly on the measures EPO tests examine (hemoglobin concentration and hematocrit, the percentage of red blood cells in the blood), it may be more useful to compare the athlete to himself/herself rather than others. Over time and after enough data is collected, outlying data points can be investigated further. This method still has a ways to go; studies so far have been mixed, with some getting false positives and others missing up to half of the volunteer dopers. You can understand how people manage to pull this off and get away with it, but it’s incredibly discouraging for people who want sports to be clean and honest. 

As for Lance: after reading some of his interviews, I’m doubting his innocence and beginning to think he's kind of a jerk. (Of course, he may have some excuses given the circumstances.) But I wanted to remember all the struggles he's overcome and the inspiration he’s been, so I'm finally reading his autobiography before his reputation is completely ruined. Can he fend off this most recent accusation, or is he to be added to the list of role models gone terribly wrong? (I’m looking at you Marion Jones.)

In case you're interested: A story about a marathoner accused of using EPO (who eventually confessed) is here.

Dream big and stay clean,
Teal

2 comments :

  1. brush up on my doping knowledge. You are a spectacular athlete AND writer.

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  2. I share your mixed feelings about Lance.

    I have slowly/reluctantly drifted more toward the view that he must have doped in some way. There are too many rumors, especially coming from folks who worked on his team (and in one case a wife of a teammate) and they just won't go away. If true (and if we'll ever know for sure), it is a sad twist on what is otherwise an amazing story -- a man coming back from cancer to win what may be the toughest contest in sport seven times!

    Indirect evidence came up last year, during the Tour de France when the New York Times published a report comparing/analyzing the mountain climbing times of the 2011 cyclists -- most/all of which were much slower than they'd been over the last 15 years or so. The author argued it was a sign the Tour was a cleaner race in 2011 -- otherwise, what was holding the racers back? The comparison also suggested that many/most of the riders were doping during the last 15 or more years. The whole pack of 2011 was slower vs. the packs of previous years, if I remember the details correctly.

    So, if we can muster any sympathy for Lance as a doper, we can consider what might have been his choice when he returned to the Tour after the cancer bout: Use chemistry/EPO/whatever to stick with the peloton, or try to beat them w/o it? If he did the latter, his achievement is even more of the charts, as we know that several of his rivals have been proven to be dopers. Was he beating them by matching their doping behavior and out-biking them, or was he so much better he could defeat them clean while they were dirty?

    His story has always been borderline incredible, but maybe the "I am clean and I beat all the dirty guys" is just plain incredible.

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