The Glycerin GTS 22 takes everything runners love about the Glycerin — plush DNA LOFT v3 cushioning, a smooth ride, and premium comfort — and adds Brooks' GuideRails support system for runners who need a little extra stability. GuideRails work holistically to keep your body in its natural motion path, reducing excess movement without restricting your stride. The result is a premium cushioning daily trainer that's as supportive as it is comfortable.