Once you take a few strides in the Nike Air Zoom Alphafly Next% 2, you’ll never look at your favorite pair of old racing shoes the same way again. A thick, lightweight support system marries the 2 worlds of comfort and speed in holy running matrimony. Enjoy the greatest energy return of all our racing shoes while you chase your personal bests and leave the competition in the dust. Bounce to the Beat - forefoot Zoom Air units and full-length Zoom X foam deliver Nike’s highest energy return cushioning system, adding more bounce into every step. A thin rubber outsole enhances traction and allows for more Zoom X under the Zoom Air cushioning. The additional foam not only adds more bounce, but also helps improve transition from heel to forefoot. Full-length Zoom X foam offers an ultra-lightweight and responsive ride. It’s built for speed but also provides cushioning to stay fresh even in the late miles of a marathon. It offers comfort where you need it.