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.