The Controversy Behind The Nike Vaporfly Running Shoes

“The introduction of the Vapor Fly to the running community really has changed what we think of as possible for running, particularly in the marathon.”

“These shoes certainly are game-changing and transformative.”

“This is a very sizeable seismic shift.”

Critics say the sneakers provide an unfair advantage to those who race in them and that their revolutionary design threatens the very integrity of the sport itself.

So, does the technology inside them given an unfair advantage? And should they be banned from competition?


With the Tokyo Olympics around the corner, these are the questions facing the world of competitive running.

On October 12th, 2019, elite marathoner Eliud Kipshoge ran 26.2 miles in less than 2 hours breaking one of sport’s greatest barriers.

The next day, fellow Kenyan Bridgette Kosgei shattered the woman’s marathon record in Chicago.

What both runners had in common was what was on their feet. Both athletes were wearing versions of Nike’s Vapor Fly racing shoes, which according to the company allow runners to improve their times by up to 4.2%.


If recent records are any indication, those claims may actually be true. Since the Vapor Fly was released, male runners in the Nike shoes have run five of the top ten fastest marathon times ever recorded.

And it’s not just the elites that have embraced the Vapor Fly. If you visit the starting lines of any road race in the United States today from a major marathon to a local 5k, chances are you’ll come across the distinctive neon sneakers.

But Nike’s success hasn’t come without controversy. Ever since the shoes were introduced in 2017, they’ve ignited a fierce debate about whether the Vapor Fly should be banned from competition.

Until now, tracks international governing body world athletics has provided only a loose guideline on sneaker tech.

“Such shoes, however, must not be constructed so as to give athletes unfair assistance or advantage.

In a statement to The Wall Street Journal, Nike said “We respect world athletics and the spirit of their rules and we do not create any running shoes that return more energy than the runner expends.”

With the Tokyo Olympics around the corner, World Athletics launched an investigation into the Vapor Fly, the results of which are expected before the end of the month.

Update: The Vapor Fly won’t be banned from the Olympics.

Peter Thompson, professional running coach and former IAAF official says “A person in the street could say well why would you not use them because they give you an advantage.


The same people might say well why don’t you allow doping because that can be accessible to everybody. And if it doesn’t harm them, then why can’t they just do doping. Some people have suggested that the shoe issue right now is a form of mechanical doping.”

Peter Thompson has spent his career coaching professional distance runners all over the world. Like many in the running community, he thinks the Vapor Fly should be banned from competition to protect the integrity of the sport.

He continues “The definition of cheating is doing something to deliberately gain an unfair advantage.

Why are we doing our sport? Are we doing it purely for performance? Or, is it for the competition of person against person? If it’s about competition person against person, then the need for a level playing field is exemplified.”

The University of Michigan’s orthopedic research laboratory cut open a pair of Nike Vapor Fly Next% to see what’s inside.

Dr. Kenneth Kozloff says “This shoe has different features that I’d like to point out to you. First, the shoe has a new type of foam called Pebax, which Nike calls Zoom X”


This is a foam found in airplane insulation that is squishier, bouncier, and lighter than the foams typically found in running shoes.

“Second, there’s a full-length carbon fiber plate and this carbon fiber plate adds a lot of stiffness and stability to the shoe, as well.”

The science behind how the Vapor Fly foam plate system works still isn’t entirely clear.

Jeff Burns is a professional ultra runner and a University of Michigan doctoral candidate in biomechanics.

Last year, Burns co-authored a paper in which he argued for a compromise between those who would like to see the shoes banned from competition and those who see the Vapor Fly as the next step in the sports technological innovation.

Burns and his co-author recommended that they simply regulate the midsole thickness of the shoe. The idea is limit the thickness of the midsole.

Now, moving forward we have a definition that shoes are 40 millimeters, or shoes are 35 millimeters, or shoes are 45 millimeters or less.

We have that space in which to innovate.

Until the Vapor Fly came along, marathon racing shoes mostly relied on thin rubber soles. The big idea was the lighter the shoes, the faster you run.

For years, shoe companies have offered products to improve performance, but at least for running, no one product eclipsed the competition in the same way the Vapor Fly has today.

In distance running, there hasn’t been a profound technological advancement in the past 40 to 50 years.

The Vapor Fly represents the first time that we’ve seen a distinct seismic shift in something that benefits performance.

Burns’ proposal allows for shoes like the Vapor Fly to remain in competition, but with clear limits on how the technology can be developed going forward.

This middle-ground approach in sport isn’t without precedent.

Michael Phelps said, “I am wearing the fastest suit in the world and that’s a fact.” During the 2008 Olympics in Beijing, every swimmer who could get one was wearing Speedos Laser bodysuit.

Developed with help from NASA, the Laser was a technological breakthrough in swimwear design that cut down on the body’s friction and water by mimicking shark skin. And world records just crashed.

FINA, the world governing body of swimming, banned the suit after an unprecedented number of swimmers broke world records in it.

But FINA’s policy, like Burns’ proposal, was a compromise. Although full-length suits were banned, the Laser’s revolutionary material is still permitted in competition swimwear.


Burns recruited a fellow competitive marathoner.

To compare the Vapor Fly with a conventional shoe like the Adidas Adios Boost, he ran two miles on the treadmill.

The plan was to have him run a mile in his training shoes, Adidas Adios Boost because it’s the shoe that the previous marathon world record was set in. Then a mile in the Vapor Fly.

He said, “I haven’t had a shoe that’s like it and the energy return you get is fabulous. You can hear the bouncing on the treadmill when you’re running in these. Interacting in the ground in these, you just feel everything way more. You feel like you’re on a nice pillow.”

With the Olympic Trials approaching, qualifiers are waiting for World Athletics’ is guidance on what they’ll be allowed to lace up on race day.


About Eric Barber

Eric Barber is a happy father of two little angels, a husband, and a runner. He eats, sleeps, and dreams anything foot related: running shoes, walking shoes, sneakers, you name it. It all started when Eric was a shoe store specialist watching and fitting people's feet day in and day out.

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