A seat having a backrest and a seat cushion is provided with at least one adjusting element on both sides of the longitudinal center plane of the seat. By alternatingly actuating the adjusting elements in the two halves of the seat, mobilization of the spinal column of a seat user occurs. In order to increase the acceptance of such a mobilization, which requires comparatively long stroke lengths of the adjusting elements to achieve a physiological effectiveness, an accustomization phase occurs before the action phase. During the accustomization phase, the adjusting elements exercise, for example, only about half of the stroke during the action phase. Preferably, a transition phase may be interposed between the accustomization phase and the action phase.
