An exercise device that allows users to exercise in a manner that strengthens their core and improve their balance with respect to rotation. The device includes a base for placing on the ground and a board on which the user stands, and includes a pivot between the base and board. The exercise device has a neutral position and also provides a restoring force when the user rotates the board. The restoring force is determined by the shape of the pivot and the supporting elements on the board and/or base.