Abstract: This invention relates to an improved reformer apparatus comprising a pair of parallel rails supported by a supporting structure, a carriage mounted between and over the rails and biased towards the top end of the reformer apparatus, cords attached to the carriage and brought through pulleys and connected to straps which are returned back towards the carriage to permit a user to pull the carriage along the rails against the bias, adjustable posts to support and adjust the height of the pulleys, a longitudinal C-shaped opening formed in the rails which are derived from an extrusion having upper and lower flanges and a web, a rectangular supporting structure for the carriage including depending lugs, wheels to run within the C-shaped openings mounted on axles set in the lugs, and bushings set within the lugs of one side of the carriage for slidably receiving the axles of one set of wheels which run along the respective C-shaped opening of one of the parallel rails so that as the carriage is pulled along the rai