The Boston Marathon is a race. But it's also a goal and a training plan and all the days it stays on your mind before the big one. The Adizero Boston 12 Shoes are built for mid- to long-distance running. They bring a race-day feel to training with a propulsive feel that comes from the glass-fiber infused Energyrods 2.0 which limit energy loss underfoot. They're fast but that does not come at the cost of durability — the midsole layers ultra-light Lightstrike Pro cushioning with a new version of durable Lightstrike 2.0 Eva.