Abstract: In a process for supporting fitness training by playing music, in which the exercising person repeats movement cycles periodically, the motivating effect of the music in enhanced in that the music is synchronized by and with the movement cycles and uses a rhythm or a rhythmic beat at a predetermined point within the movement cycle of at least one part of the body of the exercising person. A device for implementing this process includes a pulse generator arranged to correspond to the movement phases of the exercising person during a movement cycle, a synchronization unit which further processes the pulses of the pulse generator, and a device for playing music controlled by the synchronization unit.