Abstract: An apparatus for measuring and monitoring the torque exerted by a cyclist during pedalling of a human-powered machine, as for example a bicycle, includes a cartridge or the like which is adapted, in use, to be releasably retained within a hollow spindle (101) of the machine, and one or more sensor elements (110, 120, 130) for progressively sensing and generating signals, during rotation of a crankshaft of the machine, which are indicative of the angular position of the or each crank arm (63) of the machine and/or the torque applied thereto. The apparatus allows for measuring and monitoring both in the direction of, and against the direction of, pedalling of the cyclist.