02 December 2021 - Article
On 31 January 2020, World Athletics updated its technical footwear rules. Contrary to expectations (see our previous article Why banning Nike’s ZoomX Vaporfly Next% would be a mistake), the ban on Nike’s Vaporfly Next% running shoes did not materialise. Instead, World Athletics introduced an immediate freeze (until further notice) on the use of shoes:
1. containing more than one rigid plate (whether carbon fibre or another material with similar properties); and
2. with a sole thickness of more than 40mm.
Although tighter regulation was predicted, the rules are less restrictive than initially expected. In effect, World Athletics chose to (i) give the ‘green-light’ for Nike’s controversial ZoomX Vaporfly Next% shoes to be used in competition (they have a sole thickness of exactly 40mm and just one carbon fibre plate), and (ii) curb further development via the use of multiple rigid plates and even thicker soles.
Whilst the decision to endorse technology developed under the old rules is sensible – not least because a contrary decision would have led to a whole new category of world records – the direction of regulation is not. The new rules focus on the technical elements of sole construction, rather than an allowable level of energy return – which remains unregulated.
World Athletics’ approach will inevitably leave the regulator one-step behind innovators, who will simply find new ways of increasing energy return by combining a 40mm sole and one rigid plate with new technologies.
Nike are, for instance, about to launch their new Alphafly Next% shoe (based on the sub-2 hour marathon shoe worn by Kipchoge in October 2019) which achieves an even greater energy return by the addition of two “Zoom Air pods”. As the new rules do not regulate “Air pods” (or other forms of achieving energy return), records will continue to tumble and controversy is set to continue.