Every material, seam, and stitch of the Saucony Endorphin Speed 4 was obsessed over and maticulously engineered so you can focus on pushing the pace, daily. The Saucony Endorphin Speed 4 is best for tempo runs, and can even be used on race day or as an everyday trainer for runners with an efficient gait. Smooth Speedroll technology provides effortless speed and an addictive forward motion feel. Energy efficient PWRRUN PB is paired with a re-engineered winged nylon plate for enhanced energy return as well as additional torsional stability for a snappier toe off. An all-new zonal engineered mesh and integrated tongue offers a secure and connected fit.