Abstract: A device for retrofitting onto or incorporating into a conventional weightlifting machine is provided. The device includes a charge tank and a load tank and a set of hoses for communicating fluid between the tanks. The load tank rests atop a conventional weight stack, while the charge tank rests on the floor proximal to the weightlifting machine. A fluid control means is provided for alternatively filling the load tank with water stored in the charge tank and draining the fluid back into the charge tank from the load tank, as desired. Before an exercise, the load tank is filled with water using the fluid control means. During the exercise, the fluid control means is set to allow water to drain back into the charge tank. The flow rate is set, either manually or through the use of a computer-controller, so that the weight-lifter is lifting his maximum capacity of weight during each repetition.

Abstract: A device for retrofitting onto or incorporating into a conventional weightlifting machine is provided. The device includes a charge tank and a load tank and a set of hoses for communicating fluid between the tanks. The load tank rests atop a conventional weight stack, while the charge tank rests on the floor proximal to the weightlifting machine. A fluid control means is provided for alternatively filling the load tank with water stored in the charge tank and draining the fluid back into the charge tank from the load tank, as desired. Before an exercise, the load tank is filled with water using the fluid control means. During the exercise, the fluid control means is set to allow water to drain back into the charge tank. The flow rate is set, either manually or through the use of a computer-controller, so that the weight-lifter is lifting his maximum capacity of weight during each repetition.