Abstract: An exercise apparatus resistance unit includes flex members to bend to provide a resistance, a first end piece, a second end piece provided another end of the flex members to secure the flex members to rotate and translate within the body according to a bending motion of the flex members, a main pulley, and auxiliary pulleys rotatably provided on the first end piece. The resistance unit may provide a variable resistance.

Abstract: A tubular structural member that provides adjustable directional resistance to a device. When orientated in a certain manner with respect to the direction of use, the tubular structural member will provide a different stiffness to the device it is affixed. The tubular structural member may be integrated with these devices so that these devices can have adjustable resistance and stiffness.

Abstract: A transmission line is established between two distant points utilizing a pair of pipelines, one of which is insertable within the other. The outer or larger diameter pipeline is first installed or laid between the two distant points and the pipe is filled with a suitable high density lubricating liquid. The other pipeline which carries and houses the transmssion line is initially filled with an inert gas and in this condition the pipeline and transmission line are "floated" into and through the outer pipeline. After both the inner pipeline and transmission line are in place inside the outer pipeline, the high density lubricating liquid between the pipes may be removed and substituted with a high thermal-conducting non-polluting fluid. The inert gas within the inner pipeline is also replaced with a standard electrical grade insulating oil.