World Athletics bans prototype Nike Vaporfly

LONDON, ENGLAND - APRIL 17: The new Nike Zoom Vaporfly Elite Flyprint running shoe at the launch of the Nike Zoom Vaporfly Elite Flyprint in London in London at The Institute of Contemporary Arts on April 17, 2018 in London, England. (Photo by Patrik Lundin/Getty Images for Nike)

World Athletics has banned certain variants of Nike's Vaporfly running shoes for elite competition and announced significant changes to its rules on shoe technology