The Endorphin Pro 4 is Saucony's elite race day weapon — built for runners who want every possible advantage on the start line. A full-length carbon fiber plate and PWRRUN PB foam deliver maximum energy return and propulsion, while a featherlight upper minimizes weight without sacrificing fit. Whether you're targeting a marathon PR or racing a shorter distance all-out, the Endorphin Pro 4 is engineered to help you run your fastest.