A twist machine for whole body exercise comprises a base (10), a rotary post (20) rotatably mounted on the base, a seat (30) provided on the top of the rotary post, a handle (60) operatively associated with the rotary post for rotation about the rotary post, and a reverse rotator (50, 70, 72) for causing the rotary post and the handle to turn in an opposite direction with each other when one of the rotary post and the handle is subjected to forcible rotation. The reverse rotator is provided with a sun gear (70) affixed to the rotary post, a plurality of planetary gears (72) rotatably mounted to the base in a meshing engagement with the sun gear and a ring gear (50) fixedly secured to the handle in a meshing engagement with the planetary gears.