Eliud Kipchoge captured the imagination and admiration of millions when he broke the mythical two-hour barrier for the marathon distance in Vienna last October.
For 26 miles and 385 yards, the Kenyan ran faster than most can sprint, crossing the line in 1 hour 59 minutes 40.2 seconds. Broadcast live on mainstream TV, it was a piece of sporting theater enjoyed by millions.
The shoes are thick-heeled with spring-like carbon fiber plates in the midsoles which help to push energy back into an athlete’s stride. The new version is said to be even more beneficial to a runner than the 2016 Nike “Vaporfly” shoe which has seen official men’s and women’s marathon records tumble.
Kipchoge, speaking only a few weeks after his sub-two-hour marathon, defended the shoes.
“I respect technology. I respect innovation,” he said. “The world is moving, and you can’t stop. We are moving with the world, and the world is changing.”
Closer to home, British athlete Laura Muir took five seconds off a 31-year-old British indoor mile record in February last year. The shoes appeared similar to Kipchoge’s and the new record was briefly called into question.
Her coach denied their impact, claiming Muir could “run in high heels” and it wouldn’t make a difference.
Nike Chief Executive John Donahoe has also rejected the idea that the technology gives athletes an unfair advantage.
“It’s simply using the same materials that go into a shoe and putting them together in an innovative way that allows the athlete to do their very best in a safe way,” Donahoe told CNBC last week.
But others aren’t so sure. Robert Johnson, who edits the running site LetsRun.com, went so far as to say those who have benefited from the shoes in previous competitive races have been guilty of “mechanical doping.”
And non-Nike athletes have petitioned World Athletics as to their fairness. Responding at the beginning of February, the sports body has set a maximum sole thickness of 40mm on trainers for the first time ever.