Patent ID: 7914425

Claim:
A hydraulic exercise machine system comprising: one or more hydraulic cylinders; a mechanism coupled to at least one of the hydraulic cylinders, where displacement of the mechanism by a person exercising on the hydraulic exercise machine displaces pistons of the hydraulic cylinders relative to the cylinders; a sensor assembly to measure displacement of a piston relative to its cylinder over time during a workout session; electronic means for analyzing data from the sensor assembly during the workout session, the analysis including calculating user performance data based on mechanical variables of an activity of the person when exercising on the hydraulic exercise machine together with mechanical properties of the hydraulic exercise machine and comparing the user performance data with information stored in a database for the person; a reflector physically coupled to the piston; a radiation source physically coupled to the piston's cylinder; and a radiation detector physically coupled to the piston's cylinder to detect reflected radiation resulting from the reflector reflecting radiation emitted by the radiation source; and a display to provide visual feedback to the person during the workout session based, at least in part, on the analyzed data.