The shoe's soles have a fusion of foam and carbon-fiber plates designed to help runners get the
Adidas ZX 850 Mujer most forward push for each stride. A February study done by researchers
Nike Air Max 90 Damen unaffiliated with Nike found that the shoes improved runners'
Nike Air Max 270 Dames energy efficiency by 4% (hence the moniker) compared with other sneakers.Over marathon-length distances, 4% can mean a lot — it'd cut about nine minutes off a 3 1/2-hour
Nike Air Max 270 Femme marathon time.Another study, from November 2017, looked at early
Adidas ZX 700 Femme Vaporfly models
www.aadkruiswijk.nl and reached the same conclusion: "The prototype shoes lowered the energetic cost of running by 4% on average," the researchers wrote.They added: "We predict that with
Adidas NMD Femme these shoes, top athletes could run substantially
Adidas Superstar Femme faster and achieve the first sub-2-hour marathon." Two years later, that prediction came true.
In October, Kipchoge completed the Ineos 1:59 Challenge marathon in Vienna — an event arranged specifically for him to attempt a sub-two-hour marathon
Nike Internationalist Womens — in 1 hour, 59 minutes, 40 seconds.Kipchoge was wearing a prototype
Nike Air Max 95 Femme of the Nike Vaporfly that haven't hit the market yet.Shoes aside, Kipchoge's Vienna achievement doesn't count as a world record because the runner had a rotating phalanx of pacesetters — who were also wearing Nike Vaporflys —
Adidas Superstar Mujer that kept him on pace and broke the wind. That's against the regulations set by the International Association of Athletics Federations (IAAF).Kipchoge already holds the
Nike Air Max 90 Mens world record marathon time: 2 hours, 1 minute, 39 seconds. He clocked that in
Adidas Superstar Womens the Berlin marathon last year, where he also wore Vaporflys.
Nike Air Max 270 DonneIn fact, according to The New York Times, the five fastest marathon times ever recorded were all achieved by male runners wearing Nike Vaporfly shoes.Last year, ahead of his second New York City Marathon, Kamworor was asked whether he
Nike Air Max 97 Femme thought the Nike Vaporfly 4% shoes confer an advantage."I don't think that the shoe is a factor. Provided that you are prepared, that you are training hard, you can run with any kind of shoe. So the shoe is not a disadvantage to other people," Kamworor said in a press conference.Not all runners agree
Nike Air Vapormax Femme about that, though.The IAAF, which governs most international track and field events, has yet to make any move to ban or regulate the sneakers.