The Optimized BOOST in the UB19 features 20% more BOOST in the midsole compared to the first-gen Ultraboost, while the Torsion Spring sees an overhaul too. It wouldn’t be an Ultraboost with that Primeknit upper! For the UB19 adidas deploy a 360 knit – that feels like a second skin, combining pure comfort with lightweight performance. Finally, adidas turn their attention to the heel cage which boats an Updated 3D Heel Frame – a stripped-back design cradles the heel, bringing the perfect mix of adaptability and support.