Assemblies, systems, devices, and methods for attaching a pull up and cross pull up bars to a clamp assembly which is equally clamped to both sides of a door frame above a doorway, with or without additional straps and cords supporting a suspended bar for the performance of exercises; and stand-alone racks with straps and cords supporting a suspended bar used for the performance of exercises; and existing bars or structural members with straps and cords supporting a suspended bar used for the performance of exercises.