The adidas UltraBoost 21 ‘Cloud White’ offers a blank-slate colorway of the performance running shoe that packs more Boost and energy return than its predecessor. The sneaker’s breathable knit upper, partially made with recycled Primeblue materials that include Parley Ocean Plastic, sits on a full-length Boost midsole built with 6% more Boost capsules than the UltraBoost 20. Underfoot, a new Torsion system dubbed Linear Energy Push increases forefoot bending stiffness by 15%, yielding a more responsive ride.