The GEL-Kayano 21 is built for the serious runner who experiences mild to moderate over-pronation. Maintaining its trademark comfort, support and gait efficiency, this season sees the addition of an upgraded Fluid Ride midsole with increased bounce back for superior cushioning. Overall protection has been enhanced through the combination of a more supportive Guidance Trusstic under the midfoot and a stronger Heel Counter in the rearfoot. Furthermore, a new rearfoot set up slows the speed of pronation, resulting in a decrease in soft tissue stress while a new forefoot construction allows for much greater flexibility, improving running efficiency. Every year the GEL-Kayano raises the bar and this installment is no exception, showcasing the latest and greatest in running footwear technology.