Some shoes aren't just good, they're too good—which has World Athletics seeking a response to Nike's Vaporfly sneakers, Quartz reports. The governing body of track and field knows these shoes are helping runners set marathon records, but what to do? The Times of London reports a ban is coming, while the Guardian says World Athletics is more likely to limit future upgrades, especially to the amount of foam in the midsole. That would make the current model, Vaporfly Next%, OK to use, but ban a commercially unavailable version that Eliud Kipchoge wore to break the 2-hour marathon last October. The Kenyan ran 26.2 miles in Vienna in just an hour and 59 minutes and 40 seconds, the New York Times reported last year.
So what force did Nike tap into? The Vaporfly's foam-packed, carbon-fiber plate captures "more of the energy in each footfall and propel the runner forward with every step," says Quartz, while the New York Times points to the 36-millimeter insole, which is 5 millimeters higher than a limit proposed by marathoner Geoffrey Burns. Meanwhile, the shoe is understandably popular—over 84% of runners wore the Next% at a race in Japan earlier this month. And with performance shoes a mere fraction of Nike's $39 billion business, the company will likely shrug off any future ban. Nike might even market it, like it did when the NBA banned Michael Jordan's original sneakers for failing to match his Chicago Bulls jersey. (More shoes stories.)