Iconic training shoes redesigned for optimal comfort Happy Nanoversary! To celebrate the 15th anniversary of the iconic training shoe, Reebok set out to make the most comfortable version yet. These unisex shoes have a dual-density midsole with firmer foam in the heel for stability and more responsive foam in the forefoot for comfort while running and jumping. A plush collar keeps the foot locked down and eliminates distractions. A decoupled, Metasplit outsole enhances runnability.