A reformer exercise apparatus comprises a rectangular frame, a movable carriage mounted on the frame for supporting a user, and an elongated elastic member extending between the frame and the movable carriage for biasing the carriage toward the one end of the frame. The telescopic rectangular frame has a first frame section and a second frame section that each includes two spaced apart parallel tubular rail members. One set of rail members is telescopically received in the other set of rail members so that the frame is selectively movable between a first storage position and an extended operating position.