The Programmable Force Generator can be incorporated into existing microgravity exercise equipment such as the Advance Resistive Exercise Device (ARED) or in future exercise equipment to generate resistive forces. The PFG increases the flexibility of exercise equipment because the force can be controlled independently throughout the exercise motion. The PFG will increase the time that is spent exercising relative to the time spent configuring equipment because the generated force can be adjusted automatically throughout the range of motion. The PFG uses minimum power through the application of a regenerative braking system that harvests power during the pull stroke and applies that power to generate the motive force during the return stroke. NASA has made significant investments into the development of the Advance Resistance Exercise Device which has proven to be an excellent countermeasure for astronauts' health. During Phase I we will work together with NASA to develop the required interfaces to incorporate the PFG into the ARED. Incorporation of the PFG will improve the effectiveness of the ARED and decrease the amount of time that is spent configuring the equipment relative to the time spent exercising. We will develop both the mechanical interfaces and the interfaces with the control software that is currently part of ARED. By utilizing this approach, NASA will achieve tangible benefits from the proposed research in a short timeframe. The exercise equipment market is a multi-billion market that is receptive to innovative changes. Electronic interfaces are becoming more prevalent in all aspects of life and cardiovascular training equipment has followed this trend. Strength training, however, still relies mainly on weights. The PFG can advance strength training equipment to the modern age. Another potential application is for physical therapy. Rehabilitation patients are susceptible to additional injury and therefore great care must be taken during the exercise programs. For this reason, there are specific exercise methods to aid in the recovery from specific injuries. With the implementation of the Programmable Force Generator into rehabilitation equipment, precise load profiles can be programmed to increase speed of recovery from an injury. Another application of the PFG is to reduce the loads on a patient's legs during rehabilitation. Currently, underwater treadmills are used to decrease the load on the legs and hips during rehabilitation. An alternative approach is to place a harness on the user and attach them to a cable from a PFG which is attached overhead. The load of the PFG can then be set to a fraction of the bodyweight of the patient to reduce the stress on the leg and hip muscles. In this manner the patient still has full mobility and can move freely, but the loads on the legs and hips are decreased.