The controversy surrounding Nike's Vaporfly Next% shoe could carry into multisport.

Nearly all triathletes have heard about the famed Nike Next% shoe, which won critical acclaim with their claim that, in most cases, it makes the wearer 4% more efficient. 

The big “trick” on the Next% line is a carbon plate sandwiched between cushioning foam that is meant to create increased greater efficiency (so, easier at a certain pace) via some level of energy return. In fact, a few other brands—like Hoka, Adidas, and others—have already released something similar in the last year.

While the Next% was initially designed with elite marathoners in mind, it didn’t take long for the shoe to become a favorite of pro and amateur triathletes alike. 

Anne Haug and Lucy Charles-Barclay, who finished first- and second-place, respectively, at Kona in 2019 both wore the Nike Next%. Ben Hoffman, who finished fourth-place in Kona, also sported the lime green speed shoes. 

Skye Moench, a pro triathlete who clocked the fastest run split of the day at 70.3 Santa Cruz in 2019 while wearing the famous Nike shoes, is still not sure the shoes alone are responsible for great athletics performances. 

“At the end of the day, I’m a firm believer that the athlete has to perform,” said Moench, who comes from a running background. “I never see any gear and think ‘I need that,’ because I believe so much in my own ability.”

But, Moench, conceded, having the best gear (in swim, bike, or run), will only help enhance one’s performance.

However, this neon unicorn of a shoe is facing new scrutiny by World Athletics, the governing body of road and trail running, as well as track and field. As World Athletics is planning to roll out new running shoe guidelines soon, many speculate that the Next% may face new regulations, or even a ban, at IAAF-certified events. 

The origin of this speculation stems from current rules by World Athletics, which state that a shoe “must not be constructed so as to give athletes any unfair assistance or advantage.” 

Many critics of the shoe also argue that the Next% crosses the line of what is high-tech and what is mechanical doping in road running.

So, will the Nike Next% be banned in triathlon? The waters are a bit murkier.

Triathletes who wear the Next% have spent the past couple weeks speculating if USAT and/or Ironman will follow suit with a Next% ban should World Athletics enforce one for IAAF-sanctioned events. 

“USA Triathlon is aware of the issue as well as the consideration of any rules changes by other organizations, including potentially World Athletics, regarding running shoes that feature new technologies,” USAT noted.

And yet a statement from USAT noted that there are currently no limitations on running shoes in USAT-sanctioned races: 

“While USA Triathlon has regulations for wetsuits, helmets and bikes, it does not prohibit the use of any running shoe models currently available on the market.” 

Basically, USAT is monitoring the situation, but does not currently have plans to ban the Next%. However, triathlon’s governing body will continue to work closely with the International Triathlon Union (ITU) to determine if eventual updates to current equipment rules are needed.

Although Ironman didn’t have a comment to offer on the subject at this time, the ITU say they’re prepared to enforce IAAF rules.

“At the moment, ITU doesn’t have any rules about shoes. And where we have no specific rules (for running), IAAF rules apply” the ITU said in a statement. “It would not be [ITU’s] own ban since we don’t have rules on this matter, it would be—if the case arrives—us following IAAF rules.”

For now, all is status quo. Wear those bright, speedy shoes to your heart’s content. But, should the IAAF enforce a ban or limitation on when and where the Next%s can be worn, be ready for those changes to impact your shoe choice in triathlon. If anything, this is motivation to get 4% faster all on your own.