A little extra push. The Ultraboost running shoes serve up comfort and responsiveness at every pace and distance. The adidas PRIMEKNIT upper includes foam around the heel to prevent blisters. You'll be riding on a BOOST midsole for endless energy, with a Linear Energy Push system for more responsiveness than ever before. A Continental Rubber outsole grips in wet and dry conditions so you can stride confidently. 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.