Abstract: Balancing board device formed of a roller, a treadle board normally resting on the roller and a connector releasably interconnecting the board and roller, the connector including a first part on the board and a second part on the roller, the parts being substantially rigid and inflexible and normally arranged in coactive connection at a location completely within the roller outline for maintaining the roller substantially perpendicular to the longitudinal axis of the board and permitting limited relative longitudinal movement between the board and roller and rocking movement of the board on the roller while preventing separation of the roller from the board, and a release mechanism permitting disconnection of the parts for separation of the roller from the board.