Nature | News: Explainer
Why great Olympic feats raise suspicions
'Performance profiling' could help to dispel doubts.
Ewen Callaway
01 August 2012 Corrected:
03 August 2012
Chinese swimmer Ye Shiwen broke the world record for the women's 400-metre individual medley event at the Olympic Games on 28 July.
L. Neal /AFP / Getty Images
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See also Editors’ note | Letter from Lai Jiang | Editors’ note (continued)
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 2011. 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.
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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 (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 ysed 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.”
EDITORS’ NOTE (updated 6 August 2012)
This article has drawn an extraordinary level of outraged response. The volume of comments has been so great that our online commenting system is unable to cope: it deletes earlier posts as new ones arrive. We much regret this ongoing problem. The disappearance of some cogent responses to the story has fuelled suspicions that Nature is deliberately censoring the strongest criticis. This is absolutely not the case: Nature welcomes critically minded discussion of our content. (We intentionally removed only a few comments that violated our Community Guidelines by being abusive or defamatory, including several that offensively stereotyped the many Chinese readers who commented on the story.)
[UPDATE 8 August 2012: The technical problem has now been resolved and all of the posts that were inadvertently hidden have now been restored. In order to keep this problem from recurring, we have closed the story to further comments.]
Many of the commenters have questioned why we changed the original subtitle of the story from “‘Performance profiling’ could help catch sports cheats” to “‘Performance profiling’ could help dispel doubts”. The original version of the title was unfair to the swimmer Ye Shiwen and did not reflect the substance of the story. We regret that the original appeared in the first place. We also regret that the original story included an error about the improvement in Ye’s time for the 400-metre individual medley: she improved by 7 seconds since July 2011, not July 2012. We have corrected the error.
We apologize to our readers for these errors, and for the unintended removal of comments because of technical issues with our commenting system. Below we reproduce one of the most thorough and thoughtful of the hundreds of responses we received. Beneath it, we continue with our response
为什么奥运会上的卓越表现引发怀疑
尤恩·卡拉韦
在奥运会上，“太快了”是多快？这个问题在中国的女子游泳运动员叶诗文于星期六打破了400米女子个人混合泳世界纪录后一直困扰着她。对于那场比****，一些游泳砖家怀疑她是不是用了能够提高成绩的**才得以获胜。她在任何已知的禁药测试中都没有被查出使用**，并且国际奥委会星期二也宣布她的****后尿检是合格的。这就使得现在的争论充满了种族主义和政治色彩，而脱离了科学的本质。《自然》将在此讨论如何利用一名运动员的过往表现的记录和人体生理学极限来抓出者。
叶的成绩异常吗？
是的。她在400米混合泳中的成绩比她在六月份在另一重大****事的同一比****项目中的成绩快出整整7秒.但是真正让人疑神疑鬼的是她在最后50米中的表现，在那过程中，她甚至比美国男子游泳运动员罗切特在星期六赢得金牌时的最后50米还要快，而他的成绩是历史第二快的成绩了
（译注：最后这个历史第二快指的是全程哦）
在****事中的药检合格就能排除的可能性了吗？
否，南非开普敦大学的运动生理学家Ross Tucker表示，运动员更倾向于在训练中使用药物，于是使得药检变得不那么可靠。“人人都能通过奥运会的药检，几乎没人是在奥运期间被查出的。”Tucker说。
****事之外的检测通常更容易抓到的运动员，他说，但是全年都对所有的顶尖运动员进行药检是不现实的。监测运动员在不同时期的表现并且标记出表现异常的时期可以让反管理机构的资源更加合理的分配。德国弗赖堡大学的运动生理学家Yorck Olaf Schumacher提出了以上的观点。Yorck Olaf Schumacher是2009年《建议在反中把“表现监测”作为工具》的论文的作者之一。他说“我认为这是一种既便宜又有效的方法，可以迅速在大量运动员中锁定可疑人群，因为不管怎么说，用药总是为了提高成绩的。”
“生物护照”，是指对运动员的血液成分进行分析来寻找的生理证据，正发挥着和“表现监测”类似的功用。在这种方法在2008年被引入后，自行车运动管理机构在西班牙车手Antonio Colom的血液中发现了异常成分，并且对他进行了有针对性的药检，并发现了使用禁药EPO的证据。
“表现检测”如何帮助抓住者呢？
Schumache表示，反机构需要一种更好的方法来寻找异常表现或表征。为了做到这一点，运动科学家们需要建立数据库——根据运动类型和比****项目进行分类——来记录运动员的表现如何随着年龄和经验的增长而变得更好。对于运动员表现的纵向记录将被用于建立统计模型，依此，对照他们过去的表现记录和人类生理的极限，可以判断一个运动员是否有“跑得太快了”或“游的太快了”的可能性。
在奥运冬季两项中（冬季两项是一项冬奥项目，包括越野滑雪和射击）已经开始使用“表现检测”的手段了。在一个实验性的计划中，位于奥地利萨尔茨堡的国际冬季两项联合会的科学家们和意大利费拉拉大学的科学家们开发了一个软件，该软件可以对180名运动员在过去6年中的血检和表现情况来判断谁更像磕过药。国际冬季两项联合会现在已经开始使用这一软件来寻找需要额外做药检的运动员了。
运动员是否会仅仅是因为过于优异的表现而被处分？
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。”
[ 此帖被myuniv在2012-09-07 11:28重新编辑 ]
