An all-in-one fitness device that plays music, tracks fitness and offers audio coaching feedback to make running fun through the power of music. Users can run comfortably without carrying a smartphone and they can customize a training program that provides professional guidance. The audio UI gives carefully designed feedback, supporting users in real time when they run. Songs can be automatically selected to suit their heart rate and encourage a faster or slower pace, based on tempo. In an accompanying app, users can set their training goals and enjoy a sense of progress as they attain them, which is fun and encourages ongoing use.