Since its introduction to the running scene, the Saucony Endorphin Speed has earned the reputation of being a fantastic lightweight and fast running shoe that dedicated runners love to lace up on both speed days and longer efforts. Starting with the midsole, the Endorphin Speed 3 features the same wonderfully soft and responsive PWRRUN PB cushioning that encases a redesigned winged nylon plate. These two elements work with the SPEEDROLL geometry to deliver a highly energetic and efficient underfoot experience. The winged plate adds torsional rigidity in the midfoot and heel while maintaining flexibility through the forefoot. This offers the stability runners need for cornering and making tight turns while simultaneously propelling the foot forward. Meanwhile, the PWRRUN PB offers an ultra-bouncy ride that makes track workouts a blast while delivering the protection needed to tackle long runs with ease. In the outsole, the lattice designed rubber layout offers fantastic traction in the forefoot that also has the durability to put this shoe through the ringer. Despite the durable outsole and high stack of cushioning in the midsole, this shoe remains very lightweight, and helping with the weight is the engineered mesh upper that strikes the perfect balance between being minimal yet secure. The integrated tongue not only helps with lock down, but it is so comfortable that you'll forget it's there. Overall, the Endorphin Speed 4 carries the legacy of its predecessors while adding a bit of flare that elevates it to be a shoe that helps runners push the pace during their hardest training efforts.