A New York Times’ study of 500,000 race times, set wearing Vaporflys and other shoes, confirmed Nike’s claims. They found that Vaporflys allowed a runner to run 1% faster than the next-fastest shoe, and 3-4% faster than a similarly skilled runner running in different shoes.
These results, taken from race entries on the app Strava, show that runners were more likely to set a personal record when wearing Vaporflys (though not quite as likely as those wearing Nike Streak shoes). Runners were also more likely to run faster when switching to Vaporflys and complained of less leg fatigue.
So, what’s so great about these shoes? Carbon fibres. Each sneaker features a carbon fibre plate in the midsole which absorbs and releases energy, throwing the runner forward with every step.
Since the shoes don’t contain any springs or elastics, they’re not likely to be banned from future sports competitions. But given their $250 price tag, don’t expect to see me wearing them anytime soon.