The shoes feature a stiff sole plate and an air pocket under the ball of the foot, as well as using a new kind of foam which is softer, returns more energy and is very lightweight, said Geoff Burns, a sports scientist at the University of Michigan.
“That combination has been really transformative,” Burns told CNN on Friday.
First seen in road running shoes a few years ago, the technology has since made its way into track shoes, too.
Its introduction drove down road running race times significantly, and while its effect on the track is less pronounced, it still gives an estimated 1% to 2% advantage for middle- and long-distance runners, said Burns.
“How much that moves the dial in a sprint event, that’s a big unknown right now,” he said.
While there is no data on the effects of the spikes in shorter races, 400 meter champion Warholm criticized the Nike shoes worn by rival Rai Benjamin and raised concerns about their potential impact on the sport.
“He had his…