Abstract: An isotonic body gym system that provides constant resistance for exercising includes a plurality of isotonic bars, a plurality of power bands, and a plurality of band manipulators. Each of the plurality of isotonic bars includes a mount bar that supports a plurality of hooks to which the plurality of power bands can be attached. Each of the plurality of power bands has an elastic band with a cross-sectional area and a resistance value, wherein the resistance value of the elastic band is determined by the cross-sectional area of the elastic band. The resistance value is the effective maximum weight that can be applied to the elastic band. Each of the plurality of band manipulators is designed for working different body parts and is attached to the elastic band opposite the mount bar, such that a user can manipulate the direction in which the elastic band is stretched.

Abstract: The body building apparatus of the present invention has two cylindrical bars, the bars having a gripping surface and optionally being enclosed within a cushioned tubular pad, the bars being releasably connected at opposing ends by two flexible, elastically extendible side members of equal length so that the cylindrical bars and the side members define a rectangle. In an alternative embodiment, a pair of ceiling hooks replace one of the cylindrical bars, the elastically extendible side members being suspended from the ceiling hooks at one end and supporting a cylindrical bar at the other end, the ceiling, the cylindrical bar, and the side members defining a rectangle. In both embodiments, the side members extend to a maximum length under tension between about 20% to 30% greater than their length at rest.