With a tradition of excellence in the sport of running, the AdiZero Boston 7 running shoes are back with updates to this well-known racing staple. This competition-ready racing shoe features an ultra-lightweight, breathable air mesh upper material with a Microfit system that provides a secure feel and midfoot during the run. Despite its sleek design, the Boston 7 features a responsive Boost cushioning as part of midsole for and energized running experience. Upper: A lightweight, air mesh upper provides breathable flexibility and improved fit. A more snug fit is perfect for racing performance. Recommended to size up by a half size. Midsole: Midfoot TORSION® SYSTEM provides stability and propulsion throughout the midfoot phase of the gait cycle. A midsole of 55% Boost™ provides unmatched energy return and superior cushioning. Outsole: Continental Rubber on the forefoot outsole delivers 21% more traction in dry conditions and 23% more traction in wet conditions. Features a flexible, STRETCHWEB outsole that flexes more naturally.