World Athletics, the sport of running’s international governing body, set limits on midsole design and construction that would ban some versions of Nike’s Vaporfly franchise from elite competition. The new rules limit the overall thickness of soles to 40mm, and limit the use of plates or blades in the midsole construction to a single, rigid plate, or multiple plates within the same plane. Nike’s prototype AlphaFly shoes worn by Eliud Kipchoge when he broke the two-hour barrier for a marathon distance closed course have three carbon plates and would not be allowed in competition. The Vaporfly available for purchase has ... Log in to view full article.