- Kenyan runner Eliud Kipchoge won gold at the Tokyo Olympics marathon.
- Some runners and researchers claim that the Nike Vaporfly shoes Kipchoge wears give an unfair advantage.
- But he emphatically told Insider that it’s the runner, not the shoe, that determines performance.
Eliud Kipchoge is today the best male marathoner in the world.
The Kenyan runner won gold at the Tokyo Olympics and Rio Games in 2016. In 2018, he broke the world marathon record, finishing the Berlin race in two hours, one minute and 39 seconds, or more than a minute faster than the previous one. save.
But some researchers and competitors argue that Kipchoge’s success stems in part from his shoes. Kipchoge was sponsored by Nike for almost two decades. But its impressive feats have worsened over the past five years, following the debut of Nike’s Vaporfly shoe technology.
Athletes wearing Nike Vaporfly, who made their debut in the 2016 Olympics, dominated the marathon that year and in all major long-distance road races thereafter. Studies have shown that the Vaporfly’s carbon fiber and foam combination provides around 4% more fuel efficiency, allowing long-distance runners of Kipchoge’s caliber to save three minutes or more over their marathon times. .
But when asked about critics who say Vaporfly technology confers an unfair advantage, Kipchoge replied unequivocally: It’s the runner, not the shoe, that determines performance, he said.
âEven if the shoes are on and you’re not fit enough to run, you can’t play,â Kipchoge told Insider. “A lot, a lot of people rate the shoes, but they still work the same way. So the bottom line is that they need to train more than they currently train if they are underperforming.”
Nike tech helped Kipchoge run a less than 2 hour marathon
Kipchoge is the only person in history to have run a marathon of less than two hours.
A new documentary, “Kipchoge: The Last Milestone”, explores how he did this. The event, called Ineos 1:59 Challenge marathon, was designed to help him achieve the feat in October 2019. Kipchoge had a phalanx of leaders throughout the marathon, which took place on a flat course at Vienna, as well as a paying team. irreproachable attention to its food. He wore a Vaporfly prototype called the Alphafly, which incorporated two air cushions under the sole of the shoe for extra energy return per step.
Kipchoge finished in one hour, 59 minutes and 40 seconds. But that, he said, was due to the specialized conditions.
âWithout all the things around me I don’t think I would have run fast,â he said.
World Athletics, which governs most international athletics events, did not call the feat a world record because of the advantages that distinguish Kipchoge’s race from traditional marathons.
âIs it the technology or the athletes? “
A 2017 study who analyzed the first Vaporfly models predicted Kipchoge’s accomplishment: “With these shoes, the best athletes could run much faster and achieve the first marathon under 2 hours,” the researchers wrote.
The key is the shoe’s lightweight carbon fiber and foam sole, which minimizes energy loss per step. Vaporflys foam, which Nike named ZoomX, is based on a material called polyether block amide, or Pebax. When crushed, the resilient foam returns to its original shape, restoring 85% of the energy used by the runner to compress it. In comparison, the ethylene foam of old running shoe soles gives back 60 to 70%. The addition of the carbon fiber plate helps the foam to compress and expand quickly.
âThe runner runs the race, but the shoe allows him to run it faster for the same effort or ability,â University of Michigan kinesiology researcher Geoff Burns told Insider of Vaporflys. “So for two athletes of equal skill on race day, the one with the shoes will beat the one without the shoes.”
Kipchoge said the shoe also helped him recover. ZoomX is softer than its predecessors, providing athletes with more comfort because it is compressed.
âThe shoe absorbs a lot of pressure from the asphalt,â he said in the documentary.
For this and other reasons, Kipchoge believes new technologies should be adopted.
âBeing a strong advocate for change and innovationâ is part of his recipe for success, he said, as is âworking hard, respecting sport and taking every day as a challengeâ.
At a press conference ahead of the 2020 London Marathon, Kipchoge said Nike’s Vaporfly technology was “absolutely” right, The Guardian reported.
âDevelopment goes hand in hand with technology,â he said. “The shoe is good. We’re doing a press conference virtually, right the technology? We should embrace the technology and marry the technology.”
But of course not everyone agrees.
“It’s hard to know what we’re actually seeing in some ways – is it the technology or the athletes?” Kyle Barnes, a movement scientist at Grand Valley State University who published a study on Vaporfly shoes, previously told Insider. “I know it takes an exceptional human being to come close to these achievements, but the leaps we are seeing are technology.”