Fast and light with industry-leading support. Brooks has shifted their focus beyond the feet to the most injury-prone part of a runner’s body: the knees. GuideRails keep you moving comfortably by keeping excess movement in check. BioMoGo DNA midsole cushioning and rebounding rubber deliver comfort without adding extra weight, perfect for days when you're working on your speed. The Midfoot Transition Zone is shaped to go from heel to toe quickly. The lightweight, single-layer mesh upper improves comfort and fit.