The Endorphin Shift combines a lofty bed of PWRRUN cushioning with finely-tuned stability to create a truly effortless ride. The secret is in its thicker midsole, which results in a stiffer forefoot and delivers speed roll's feeling of continuous momentum without the need for a race-day plate. And with supportive details from the heel forward, you get faster, feel-good runs for every day of the week.