Carbon-plated road racing shoe

technology

From about 2017 a new class of road racing shoe combined a thick, highly resilient foam midsole with a stiff curved plate embedded in it. Independent testing reported running-economy improvements of a few percent, and marathon times at the elite end fell sharply and simultaneously across every fast course, which is the signature of a technology change rather than of a generation of athletes. World Athletics responded on 31 January 2020 with a rule rather than a ban: a road shoe may have a midsole no thicker than 40 mm and no more than one rigid plate, and from 30 April 2020 any shoe worn in competition must have been available at retail for at least four months, which ended the use of one-off prototypes. This matters to any comparison between courses or eras, because it means a time run in 2015 and a time run in 2025 are not measurements of the same thing.

A technology is not a place. Drawing it on a map would assert something about the world that no stored fact supports.