Are these sports shoes designed for indoor use?
Because cardio fitness is mostly done in the gym and/or at home, our shoe has been designed for indoor use. For example, its 'softer' rubber is specifically designed for indoor use, and will wear out prematurely if it comes into repeated contact with tar. The grip of our soles has been tested on indoor surfaces. And speaking of soles, they don't leave marks on the floor! Clever, isn't it?