A wrist exercise includes a casing composed of upper and lower casing members mating each other to form a hollow sphere, a retention ring fixed between the upper and lower casing members, a rotor rotatably supported inside the casing by the retention ring. Cavities are formed in opposite sides of the rotor and are each divided into chambers by partitions fixed in the cavities. Holes are defined in an outside surface of the rotor and are in communication with the chambers, whereby, in operation of the wrist exerciser, the rotor is rotated and high-speed airflows are caused between the holes and the chambers due to centrifugal forces induced by the rotation of the rotor, which airflows generate sounds, thereby effecting sound generation of the wrist exerciser.