Brooks' trusted GuideRails® support system helps reduce excess motion, and the mesh upper provides breathable comfort. GuideRails® support Brooks' innovative GuideRails® technology - shortened to "GTS" for "Go-To-Support" - supports your body in its natural motion path while keeping excess movement in check. Dynamic cushioning Newly added to this version of the Adrenaline, our nitrogen-infused DNA LOFT v3 foam delivers soft, smooth cushioning that adapts to your unique stride for lightweight comfort. Optimized upper The mesh upper provides an ideal balance of breathability, structure, and stretch for a comfortable fit.