LONDON (Reuters) – Nike said the Alphafly shoe worn by Eliud Kipchoge that breaks the two-hour marathon barrier is legal under the new rules of World Athletics and widespread reports of its shoes that contain triple carbon plates are not correct.
Kenya's Eliud Kipchoge, the marathon world record holder, crosses the finish line in Nike Vaporfly shoes when he wanted to run a marathon in Vienna in less than two hours on October 12, 2019. REUTERS / Lisi Niesner / File Photo
On Wednesday, Nike Inc launched a new version of the shoe that complies with the rules introduced by the association last week to limit the use of carbon plates and sole thickness for elite races, as technological developments have an unnatural advantage for runners procured.
The latest incarnation of the shoe is the Air Zoom Alphafly Next% with a curved carbon plate, an insole thickness of 39.5 mm and additional air pockets. The new rules – the first of the WA for running shoes – stipulate that street shoes may contain insoles with a thickness of no more than 40 mm and no more than a rigid, embedded carbon fiber plate.
"We are pleased that the Nike Zoom Vaporfly series and Nike Zoom Alphafly NEXT% are still legal," said the US company. "We will continue our dialogue with World Athletics and industry about new standards."
Nike said Thursday that the shoes used by Kipchoge for its unofficial two-hour marathon in Vienna last October were still legal under the new rules.
"We're not making three-plate running shoes," a Nike spokesman told Reuters, adding that the thickness of the midsole is also within the new parameters. Industry speculation that Kipchoges shoes are triple coated was based on the Nike patent for 2018 for a shoe with triple coated plates.
WA President Sebastian Coe, who was a 38-year ambassador for Nike until he stepped down in 2015, said last week after most Nike vaporflys were considered legal, “We don't think we can rule out shoes that do Periods of time are widely available for a significant portion of the population ".
Another change that WA introduced last week is that as of April 30th, any future version of a shoe will have to be available to the public for four months before it can enter the Elite competition. Alphafly's new shoes will be available in limited quantities starting this month to ensure they are approved for this year's Tokyo Olympics.
At the unofficial Vienna Marathon, Kipchoge wore a prototype that appeared to contradict the rule applicable to races approved by world athletics, according to which every shoe should be "reasonably available", although this rule was not applied by the governing body regarding various prototypes of the shoe, which was launched in 2016 as Vaporfly.
The shoe has since contributed to a multitude of records and great race victories and is extremely popular with recreational runners who suddenly shorten their best times. WA decided last week that most models in the range would remain legal, much to the frustration of many observers who view the shoes as "mechanical doping."
Former British elite marathon runner Tam Yamauchi said WA "gave the green light to performance-enhancing shoes," and others predicted that they will set a legal Sub-2 record, possibly at this year's London Marathon in April, when Kipchoge's current is owner, goes head to head with Kenenisa Bekele.
After the launch of the new Alphafly version on Wednesday, Nike boss John Donahoe denied that the technology gave the athletes a mechanical advantage.
"It simply uses the same materials that are in a shoe and put together in an innovative way so that the athlete can safely do his best," Donahoe said in an interview with CNBC.
Reporting by Mitch Phillips; Additional reporting from Rohith Nair; Edited by Pravin Char and Christopher Cushing