US Patent 8007418 Portable resistance training device

A portable resistance training apparatus for use in exercise routines is described in this patent application. According to the principles of the embodiments of the present invention, a portable resistance training device comprising: an integral elongated cylindrical unit capable of accepting a piston for doing work on a compressible fluid where the force to drive the piston is supplied from without; an elongated rod whose movement is controlled by adduction or abduction exercise routines; valve means for controlling the flow of air from the internal volume of the cylindrical unit thereby controlling the amount of force supplied by the user, and monitoring means for safe training.