A ski or a snowboard in the form of a board-type gliding device has by reference to the board body width, at least one slot in its middle portion extending in the depth direction from the board body top face towards the running surface facing and in its longitudinal direction essentially parallel with the board body longitudinal direction to cause a cross-sectional weakening and reduce the stiffness of the board body transversely to its longitudinal direction. At least one geometry-influencing device produces a cross-sectional board body shape or contour which is variable manually or as a function of load. The slot is then faced with a bridging element which is elastically stretchable or expandable, at least transversely to the longitudinal extension of the slot to prevent snow from being transferred or getting inside the slot from the running surface facing towards the top face of the gliding board body.