The GEL-DS SKY SPEED 2 is a lightweight trainer for the more efficient runner with a neutral gait and features ASICS’ most advanced upper technologies for an extremely comfortable fit. Foremost among those technologies is an additional Guidance Line technology that decouples the tooling along the line of progression for enhanced gait efficiency, which helps make the most of the Impact Guidance System (IGS) that employs linked componentry that enhances the foot’s natural gait from heel strike to toe-off. The Rearfoot and Forefoot GEL Cushioning System eases the shock experienced during the impact and toe-off phases. Strategically placed stretch Biomorphic Fit material on the upper helps to reduce buckling and the irritation associated with it.