Nano X3 Unisex Shoes If2554Believe it or not, there's a training shoe you can actually run in. Meet the Nano X3 training shoes with the all new Lift and Run Chassis system. A dome shaped heel piece compresses under load when lifting to create a stable platform, then softens when you push off to run. It all rides on award winning Floatride Energy Foam that gives you lightweight cushioning to make that run the easiest part of the workout.