The Saucony Endorphin Speed 4 - where speed and versatility meets innovation. The Speed 4 is designed with PWRRUN PB cushioning, giving you responsive energy return for a ride that's both lightweight and responsive. Although engineered predominately for uptempo running, the Speed 4 is versatile enough to double as your daily trainer. Additional torsional rigidity while maintaining some flexibility at toe-off is achieved with the winged nylon plate, giving you a balance of stability and speed Saucony also features their new Super Responsive Sockliner (SRS) which provides added underfoot bounce. The Endorphin Speed 4 features zonal engineered mesh that's not only breathable but more durable, paired with an integrated tongue for a secure, connected fit. Whether you're gearing up for tempo runs or logging everyday miles, the Endorphin Speed 4 is here to help you reach new speeds in confidence.