An adjustable supine cycling machine is an apparatus that efficiently exercises and strengthens abdominal muscles. The apparatus targets the all of the abdominal muscles from all angles. As the user pedals, the user may retract or extend his or her legs and tilt his or her legs in order to activate all the muscles of the abdominal region. The apparatus includes a leg-exercising device, a support base, a lifting arm, and a linear actuator. A spherical bearing allows the tilt of the leg-exercising device. The leg-exercising device is preferably a cycling machine. The lifting arm pivots the leg-exercising device about the support base and is controlled by the linear actuator. The apparatus preferably applies resistance to the rotary movement of the leg-exercising device in order to strengthen the abdominal muscles. The resistance is adjusted by a control unit.
