The Instinct started it all and is back with a new look, softer upper, and more responsive ride! The Instinct & Intuition 3.5 retains its lightweight, flexible design and innovative technology that put Altra on the map. The FootShape toe box allows your foot to relax and spread out naturally and keeps the big toe straight for more power. FootPod outsole technology maps the bones and tendons of your foot for natural flexibility and more responsiveness. A top layer of our A-Bound energy return compound puts a spring into each step. Lace up into this update and upgrade your run with the new Instinct & Intuition 3.5.