BOOST midsole Imported Bring power and exceptional comfort for your feet with the adidas Ultraboost 22 Running Shoes. Linear Energy Push system enhances forefoot and midfoot stiffness to provide you with more responsive stride. adidas PRIMEKNIT textile upper. The Ultraboost 22 gives you a responsive ride, no matter your training level or distance. The comfort comes from the foot-hugging adidas PRIMEKNIT upper and the incredible energy return of BOOST. There's also the Linear Energy Push system, which increases forefoot and midfoot stability for more responsiveness than ever before.