It’s not all marketing: A running shoe actually can make you faster, if it can strike the delicate balance between weight and comfort. Athletic giant Nike believes that it has perfectly cracked that code, though it took a study in Sports Medicine to convince scientists that its product really was the fastest shoe in the world.
In 2017, Nike released the Zoom VaporFly 4%, a $250 shoe that boasted a specialized foam and somewhat contentious carbon footplate. At the time, Nike claimed that the VaporFly “redefined the feeling of fast,” supporting its claim with a sponsored scientific study showing that it reduced the effort that elite runners exerted by four percent — that’s why it’s called the VaporFly 4.
Grand Valley State University movement sciences professor Kyle Barnes, Ph.D., was one of the reviewers of that Nike-sponsored paper. Though he says it was well-executed, he personally wanted to take a closer look. Importantly, his work, outlined in the new study, is not sponsored by the shoe company.
“If you follow the media on this shoe, there’s a lot of pushback because that original study was funded by the shoe company,” Barnes tells Inverse. “I thought there was a need for independent research.”
Barnes’ study on 24 athletes from the Grand Valley State Track team confirmed the Nike study’s findings. Like the original study, this one also showed that the shoes increased running efficiency by 4.2 percent — lending credence to the idea that it really is the best marathoning shoe around.
Improving on the original study design, he made one change to the protocol that illuminated an unexplored aspect of the VaporFlys. He compared them to track spikes — and even there, they proved superior.
The New Track Spike
“Why couldn’t people who run slightly slower use it for shorter distances as well, like 10K, 5K?” Barnes says. “We have athletes here who wear them for a mile on the track.”
To test whether VaporFlys made his track athletes more efficient, Barnes asked them to do four bouts of running at three pre-determined speeds. Each time, they wore a different pair of sneakers: unweighted VaporFlys, weighted VaporFlys (which is how the Nike study compared them to traditional marathoning shoes), the Adidas Adizero Adios 3 (ADI) (a marathoning shoe), and, importantly, the track spikes. Over the course of his experiment, his runners were about 2.6 percent more efficient when they ran in the VaporFlys than when they ran in the track spikes.
That number means more to a professor of movement sciences than to a collegiate track athlete who has been training in spikes for their entire. “Quite honestly, some of our athletes were skeptical,” he says. “But it’s pretty easy to convince someone when you have scientific data saying you’re six percent more efficient in this shoe than that track spike.”
Though Nike hasn’t outright said that the VaporFlys could replace track spikes altogether, some elite runners — not just marathoners — have already made the switch. For instance, former Olympic triathlete Gwen Jorgenson sported customized VaporFlys modified with a spike plate for the 10K at the US Track and Field Championships. Barnes thinks that the high-speed shoe field is headed in that direction: “I’ve just been surprised I haven’t seen more people doing it,” he says. “I think you’re going to see a shift in the future.”
While Barnes definitely seems sold on the VaporFlys for his track runners, he is still harboring some doubts on how it might impact speed for normal people. Most research on high-caliber running sneakers, he says, has been done on athletes who can run unthinkably fast: The average 5K personal record for the men in his study was 14 minutes and 25 seconds.
His next study will put these high-speed shoes on the feet of recreational runners to see whether we can all benefit from what might actually be the fastest shoe out there.