The Ultraboost isn't our first performance running shoe to hold appeal in the realm of fashion. It's just one of the most beloved. The simplicity of the design shines a spotlight on the pattern of the adidas PRIMEKNIT. And because comfort's a non-negotiable, run or no run, BOOST offers incredible energy return in every step. This shoe's upper is made with a high-performance yarn which contains at least 50% Parley Ocean Plastic — reimagined plastic waste, intercepted on remote islands, beaches, coastal communities and shorelines, preventing it from polluting our ocean. The other 50% of the yarn is recycled polyester.