Abstract: The invention relates to a vibration unit with a grip or a contact surface, to be mounted detachably on exercise machines or on a body part. The vibration unit comprises a vibration generating element (1, 2) and a mounting device (4). According to some embodiments of the invention, the mounting device is adapted for application around or inside a handle of an exercise machine. According to other embodiments of the invention, the mounting device is adapted for application on a frame of an exercise machine or on a body part, by means of various devices. According to other embodiments of the invention, the vibration unit is provided as a separate unit for mounting to a rigid support.