An exerciser structure includes a fixed unit and a movable unit. The movable unit includes a pair of ring sections. One of the ring sections is fixed with a torque generating portion. The fixed unit is disposed with a fixing board on which an inner guide wheel and several outer guide wheels are rotatably disposed. The inner and outer guide wheels tightly contact with the ring section, so that the ring section can be stably rotated. The exerciser structure can be easily folded with strength saved. In addition, the stress exerted onto the pivot section of the exerciser structure is evenly distributed. The exerciser structure can be alternatively folded by an electric folding measure as necessary.