The invention provides a fitness
machine. The fitness
machine comprises bearing rods and a plurality of counter weight irons and further comprises a connection and separation mechanism, a selection mechanism, a self-
locking mechanism, a positioning rod, an elastic member and an actuating and control mechanism, wherein the connection and separation mechanism comprises locking pieces which are rotatably arranged on the counter weight irons for clamping or separating the bearing rods, the selection mechanism comprises guide rails and a moving block which is arranged on the guide rails and can push the locking pieces to rotate one by one, the self-
locking mechanism comprises a self-locking frame, the self-locking frame is arranged on a sliding member, moves with the sliding member, is provided with a self-locking clamping groove and can rotate around the guide rails, the positioning rod is provided with a plurality of positioning grooves capable of matching with the self-locking clamping groove, the elastic member is used for connecting the sliding member and the self-locking frame, and the actuating and control mechanism is used for driving the moving block to move on the guide rails and controlling the movement direction and distance. According to the fitness
machine, the connection and separation mechanism, the selection mechanism, the self-
locking mechanism and the actuating and control mechanism are arranged for automatically changing the number of the counter weight irons, so that a user can omit operations such as pulling out, alignment and
insertion, and the operation process for selecting the number of the counter weight irons is simplified significantly.