You thought you knew what fast meant. Think again. Enter the Vaporfly 4% Flyknit. Nike takes all of its top ingredients, takes them one step further and there's no doubt that this shoe takes the cake. ZoomX: arguably the most energy return you'll get out of any foam, anywhere. Carbon fiber plate: better buckle in because you'll be propelled forward whether you like it or not. Flyknit: be careful because this will disappear on your foot. Everything you need and nothing you don't - we'll see you at the finish line.