The Boston Marathon is a race. But it's also a goal, and the reason you train and always have it on your mind before the big day. The Adizero Boston 12 are designed for medium and long-distance runs. They put you in race mode during every training session thanks to the glass fiber-reinforced Energyrods 2.0 that provide propulsion and reduce energy loss. They are fast and durable. The midsole combines ultra-lightweight Lightstrike Pro cushioning with the renewed durable Lightstrike 2.0 EVA.