A rotary torso comprises: a frame with a base, several supporting columns vertically installed on the base, a U shape railing installed a little bit above the supporting columns, and a U shape handle installed at the top of the supporting columns; a hollow box shape rotating arm, with one rotatable end pivot installed by a shaft bearing at the central bottom of a fixed shaft; a rotating plate, with a rotatable central hub, supported at the rotating shaft at the free end of the rotating arm; and ...