在奥林匹克运动中，多快就太快了呢？
上周六，在16岁的中国选手叶诗文打破女子400米个人混合泳的世界纪录。此后，她一直为这种质疑深深困扰。那场比赛之后，一些游泳砖家怀疑她的胜利是服用了兴奋剂的结果。然而她的药物检验无一阳性。国际奥委会周二宣布，她赛后的测试是干净的。叶诗文是清白的！由此引发的辩论一直被渲染着种族和政治的色彩，但是自然杂志的小科学项目更愿意就此讨论一下如何参照运动员的以往表现和人体生理学极限来科学质疑兴奋剂选手。
叶诗文的表现超常？
是的。她400米个人混合泳成绩比七月的另一项赛事足足快了7秒。而且更让人瞠目结舌的是，她的最后50米，比刚刚赢得男子400米混合泳冠军的罗切特还要快。
赛中的兴奋剂检真能完全奏效吗？
没这说法……南非开普敦大学的运动生理学家塔克说，运动员更倾向于训练而不是比赛时使用兴奋剂。这使得赛中的药物测显得比较宽松。“人人都将通过奥运(专题)会药检。几乎没人在赛中药物检验中落网“塔克说。
赛外药检其实更容易奏效，他说。但是要常年定期测试所有的精英运动员又不太现实。德国弗赖堡医学大学的运动生理学家舒马赫，在其与塔克2009年共同撰的一篇文章中提出，追踪运动员的成绩记录，以发现超常表现来缩小兴奋剂检验范围，可以节约检测资源，成为反兴奋剂的有力手段1。“我认为这是一个很好且廉价的方式，来缩小范围，找到可疑的运动员。因为毕竟，任何兴奋剂都是为了提高成绩”舒马赫说。
一种类似的方法所谓“生物护照”，它追踪记录运动员的各项血液指标，以其异常波动来检测兴奋剂的使用。自2008年此法推出后，仅过一年就收获战果一枚：西班牙自行车选手安东尼奥・科洛姆，在2009年被发现血液指标异常，从而进行了针对性的药物检验，结果促红细胞生成素（一种血液激素，简称EPO，被用作兴奋剂）阳性。
如何以成绩波动找到兴奋剂服用者？
舒马赫说，反兴奋剂管理者需要一个更好的方式来标记异常成绩。要做到这一点，运动科学家需要建立数据库 ― 逐一追踪每场比赛―来发现运动员如何随着年龄增加和经验的积累而正常的提高成绩。运动员的成绩记录要输入统计模型，参照他们以往的成绩和人类生理极限，来质疑他们跑得或游得太快。冬奥会项目冬季两项（一个结合了越野滑雪和步枪射击的追逐项目，源于北欧鬼子野蛮的雪地狩猎）已纳入统计分析。在这个试点项目中，来自奥地利萨尔茨堡国际冬季两项联盟，和意大利费拉拉大学的科学家们，开发软件，统计分析了六年里180个冬季两项运动员的血液指标，以确定那些最有可能服用兴奋剂的运动员。冬季两项联合会现在已使用该软件，来进行有针对性的兴奋剂检验。（多少大众项目可供研究啊，为啥非要做个冬季两项呢？很有代表性吗？很受广大群众关心吗？再说射击也不怎么需要兴奋剂吧……真心搞不懂这些鬼子的独特采样理念）
Tucker说“那可就太不公平了，最终处罚决定将根据药检结果做出，并且也只能是依据药检结果作出的。”近几年，自行车运动管理机构已经成功的对血检异常但是没有发现例如RPO这样的禁药的运动员提起了控告。但是，运动员的表现和禁药的关系太过间接，而且可以影响运动员表现的外部因素实在是太多了，因此不能仅仅凭借运动员的优异表现就给他们定罪。Tucker 说“当我们审视这个打破了世界纪录的中国小姑娘的时候，他的成绩优异不能说明任何问题，最多就是让人有一两个问题想问而已。”（译言 翻译）
Why great Olympic feats raise suspicions
'Performance profiling' could help to catch cheaters in sport.
Ewen Callaway
At the Olympics, how fast is too fast? That question has dogged Chinese swimmer Ye Shiwen after the 16-year-old shattered the world record in the women's 400-metre individual medley (400 IM) on Saturday. In the wake of that race, some swimming experts wondered whether Ye’s win was aided by performance-enhancing drugs. She has never tested positive for a banned substance and the International Olympic Committee on Tuesday declared that her post-race test was clean. The resulting debate has been tinged with racial and political undertones, but little science. Nature examines whether and how an athlete's performance history and the limits of human physiology could be used to catch dopers.
Was Ye’s performance anomalous?
Yes. Her time in the 400 IM was more than 7 seconds faster than her time in the same event at a major meet in July. But what really raised eyebrows was her showing in the last 50 metres, which she swam faster than US swimmer Ryan Lochte did when he won gold in the men’s 400 IM on Saturday, with the second-fastest time ever for that event.
Doesn't a clean drug test during competition rule out the possibility of doping?
No, says Ross Tucker, an exercise physiologist at the University of Cape Town in South Africa. Athletes are much more likely to dope while in training, when drug testing tends to be less rigorous. “Everyone will pass at the Olympic games. Hardly anyone fails in competition testing,” Tucker says.Out-of-competition tests are more likely to catch dopers, he says, but it is not feasible to test every elite athlete regularly year-round. Tracking an athlete over time and flagging anomalous performances would help anti-doping authorities to make better use of resources, says Yorck Olaf Schumacher, an exercise physiologist at the Medical University of Freiburg in Germany, who co-authored a 2009 paper proposing that performance profiling be used as an anti-doping tool1. “I think it’s a good way and a cheap way to narrow down a large group of athletes to suspicious ones, because after all, the result of any doping is higher performance,” Schumacher says.
The ‘biological passport’, which measures characteristics of an athlete’s blood to look for physiological evidence of doping, works in a similar way to performance profiling (see 'Racing just to keep up'). After it was introduced in 2008, cycling authorities flagged irregularities in the blood characteristics of Antonio Colom, a Spanish cyclist, and targeted drug tests turned up evidence of the banned blood-boosting hormone erythropoietin (EPO) in 2009.
How would performance be used to nab dopers?
Anti-doping authorities need a better way of flagging anomalous performances or patterns of results, says Schumacher. To do this, sports scientists need to create databases that ― sport by sport and event by event ― record how athletes improve with age and experience. Longitudinal records of athletes’ performances would then be fed into statistical models to determine the likelihood that they ran or swam too fast, given their past results and the limits of human physiology.
The Olympic biathlon, a winter sport that combines cross-country skiing and target shooting, has dabbled in performance profiling. In a pilot project, scientists at the International Biathlon Union in Salzburg, Austria, and the University of Ferrara in Italy, developed a software program that retroactively analysed blood and performance data from 180 biathletes over six years to identify those most likely to have doped2. The biathlon federation now uses the software to target its athletes for drug testing.
Could an athlete then be disciplined simply for performing too well?
“That would be unfair,” says Tucker. “The final verdict is only ever going to be reached by testing. It has to be.” In recent years, cycling authorities have successfully prosecuted athletes for having anomalous blood profiles, even when banned substances such as EPO could not be found. But performance is too far removed from taking a banned substance and influenced by too many outside factors to convict someone of doping, Tucker says. “When we look at this young swimmer from China who breaks a world record, that’s not proof of anything. It asks a question or two.”
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