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Is World Athletics about to ban the Nike VaporFly, NEXT% and AlphaFly?

The international athletics body is rumoured to have drafted a new rule limiting the thickness of midsole foam

Amid much speculation about how much of an advantage Nike’s VaporFly, NEXT% and AlphaFly confer and calls for them to be banned, Cathal Dennehy reports in the Irish Independent that World Athletics has drafted a new rule limiting the thickness of a competition shoe’s midsole. Depending on how it is worded, such a rule could make the Nike shoes illegal in competition.

The VaporFly, developed by Nike for its Breaking2 project in 2017, quickly became the subject of intense speculation, and many elite and recreational marathoners embraced the shoe while scientists and journalists studied and debated whether it actually improved running economy, by how much, and how it did so. Was it the carbon fibre plate, or was it the inches of foam in the midsole?

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Media reports about fast marathon finishes were increasingly focused on the shoes, with many observing that the Nike shoes have contributed to a significant drop in marathon times among elites, and winning performances by non-Nike-sponsored athletes increasingly perceived as the rare exception. Meanwhile, several competing shoe companies are scrambling to introduce carbon-plated shoes of their own, and some athletes sponsored by rival brands have been known to wear Nikes, camouflaging them with paint.

The Nike NEXT%

The debate was ratcheted up a notch in October when Eliud Kipchoge wore a new iteration of the shoe with even thicker midsole foam, forefoot pods and three carbon fibre plates to break the two-hour barrier at INEOS 1:59 in Vienna. Named the AlphaFly, the shoe is expected to be released to the shoe-buying public in the late spring of 2020. The Independent claims industry insiders say the new shoe confers a significantly greater advantage than the Vaporfly or NEXT%.

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It says the World Athletics technical committee has been studying the shoes since the release of the Vaporfly, commissioning a working group consisting of two former professional athletes, “alongside experts in science, ethics, footwear, biomechanics and law” and that the new rule setting a maximum thickness for midsole foam is set to come into effect sometime in the new year.

Nike Vaporfly 4%
Nike Vaporfly 4%. Photo: Matt Stetson

The current IAAF rule that shoes may not be constructed “to give athletes any unfair assistance or advantage” and must be “reasonably available to all.”

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At the same time the report was published, Dennehy also published an editorial condemning the Nike shoes and urging World Athletics to ban them. He likens the growth of the Nike shoes to “smuggling a gun to a knife fight,” their effect on international competition to the use of EPO, and rival brands’ quest to produce carbon-plated shoes as an “arms race.” “Almost half of the top 150 marathon times in history occurred since the shoe’s arrival in 2016, and that’s no accident,” Dennehy claims. He believes the proprietary technology in the Nike shoes, which is protected by multiple patents, constitutes a violation of the rule that states that shoes must be available to all athletes.

In targeting midsole thickness, the new rule seems in agreement with some reports that claim the advantage conferred by the Nike shoes results more from the foam than the plate.

Sports scientist Ross Tucker speculates that considering the stack height of both the Vaporfly and the NEXT% is 36 millimetres and that both the male and female world records were run in these shoes, the rule may limit stack height to 36 mm so as not to jeopardize existing world records, rendering the AlphaFly (which is higher) illegal. Like many, Tucker is amazed that Nike’s shoe tech may be about to be reigned in, considering the brand’s dominance in the world of athletics.