日期: 来源:比比西英语网

Science & technology


Sports equipment


Getting a leg up


New running shoes could help smash a string of Olympic records


Platform shoes are back in fashion, at least in athletics. Many of the long-distance runners at the Tokyo Olympics, which begin on July 23rd, will arrive at the starting line sporting footwear with a distinctive chunky-looking heel. It will be more than just a fashion statement. The new shoes offer such a big performance advantage that critics have described them as "technological doping".


Running-shoe makers have long tried to boost athletic performance, observes Geoff Burns, a biomechanics expert at the University of Michigan. In olden days, a 1% improvement in "running economy"—the energy taken to travel a given distance—would have impressed. But in 2016 Nike released the first version of its "Vaporfly" model, which improved running economy by 4%.


If that percentage were to translate directly into performance, it would knock about five minutes off an elite male's marathon time. In practice, as Dr Burns observes, it wouldn't quite do that. A marathon improvement of around 90 seconds would be a more realistic expectation. But Vaporfly and its successors have helped athletes smash a string of records. On June 6th Sifan Hassan, a Dutch runner, completed a women's 10,000 metres race in 29 minutes and 6.82 seconds, beating a record set in 2016. Two days later she was overtaken by Letesenbet Gidey, an Ethiopian, who clocked 29 minutes and 1.03 seconds. In 2019 Eliod Kipchoge, a Kenyan, became the first to run, albeit in an unofficial event, a marathon's distance of 42.195km in undertwo hours. The same weekend Brigid Kosgei, another Kenyan, broke a women's marathon record that had stood for 16 years.

如果将该百分比直接转化为成绩,那么一位优秀男运动员的马拉松时间将减少5分钟左右。然而,正如伯恩斯博士所观察到的,在实践中它并不能完全实现这一点。在马拉松比赛中提高90秒左右是比较现实的期望。而Vaporfly及其系列鞋已经帮助运动员打破了一系列记录。6月6日,荷兰选手斯凡·哈桑以29分6.82秒的成绩完成了女子10000米的比赛,打破了2016年创下的纪录。两天后,埃塞俄比亚选手Letesenbet Gidey以29分1.03秒的成绩超越了她。2019年,肯尼亚人埃利奥德·基普乔格在两小时内跑完42.195公里的马拉松,成为第一个跑完全程的人,尽管这是一项非官方赛事。就在同一个周末,另一名肯尼亚人布里吉德·科斯盖打破了保持了16年的女子马拉松纪录。

Scientists are still puzzling over exactly how the shoes work. The soles are made of a new type of foam that offers an unprecedented mix of resilience and squidginess, according to Dr Burns. This returns around 80% of the energy from each strike of a runner's foot. The carbon-fibre plate may help by stiffening the midsole, and possibly by altering a runner's gait. By cushioning a runner's bones, muscles and ligaments from repetitive impacts, the shoes may even help athletes train harder than they otherwise could.


All that is great news for Nike, which sells the Vaporfly and its successors for around $250 each. (Rival manufacturers now offer similar shoes of their own.) Whether it is good for the sport is another question. Different sports have different tolerances for technological assistance. Running tends towards the conservative end of the spectrum.


In January 2020 World Athletics, the governing body of international athletics, passed new rules limiting the thickness of a road shoe's sole to 40mm. Meanwhile, Nike appears to have shelved plans to deploy high tech shoes designed for sprinters at the Tokyo games, possibly because they did not comply with regulations either. But if they, or a rival manufacturer, have worked out a way around that problem, there could be fireworks in the sprints, too.