Abstract: A programmable adaptive resistance exercise system and method. New type of resistance allows a user to maximize amount of muscle growth benefit while minimizing the effort to attain that level. Resistance level may be controlled by computer based on position or any derivate thereof with respect to time. Resistance is adaptive since force level used throughout exercise range is based on current and past performance data. Level of effort and force versus time profile combinations are unlimited. Rest calculated based on the current and past performance data. May utilize hardware having a motor, an exercise interface (such as an bar or handle for example), a position sensor, digital input device to identify someone, computer configured to control the motor and exercise interface using current and past personal training data, calculate an exercise program based on preference and a time for subsequent workout, optionally alert a user when time to workout.

Abstract: A method and apparatus for rapidly measuring chemical properties of a solution using a plurality of devices having relatively long thermal time constants selectively coupled to a control means. Current I.sub.d flows through only one device at a time. A timing logic control circuit controls the timing of the drain switch and, if present, the reference switch. The output of the multiplexing circuit is sampled a precise amount of time after each device begins conducting current. The temperature at the sample time is a constant. The characteristics of the solution in which the device is immersed is the only variable in the operation of the device (i.e., I.sub.d, and V.sub.ds are held constant). By sampling the output a predetermined amount of time after the device has been turned on, the temperature rise is controlled.