Abstract: An exercise machine for strengthening the upper torso of a user. An overhead support structure supports a wheel assembly that attaches to a rotatable handlebar assembly and a mass. The handlebar assembly is supported by the overhead support structure in a manner that allows it to rotate substantially without friction. The handlebar structure is further situated so that a user can grasp the handlebar assembly with one or both hands and twist his upper torso around his centerline. When the user twists his upper torso, it causes the wheel assembly to cooperatively rotate the mass. In the preferred embodiment, the wheel assembly has two gear wheels with interlocking teeth. One of the wheels rotates with the handle bar assembly and the other wheel rotates with the mass. In an alternative embodiment a continuous belt interconnects the two wheels. The mass can be a conventional removable and interchangeable exercise weight.