A supine cycling exercise machine includes a frame attached to a horizontal base and a rotation driving assembly supported by the frame. The driving assembly includes a rotatable crankshaft and two crankarms with proximal ends thereof attached to opposite ends of the crankshaft, with two pedals attached to distal ends of the crankarms. One or more crankarm includes a redirection connection mechanism at the proximal end thereof, and such a crankarm is adapted to be repositioned by an exerciser between an opposing and a parallel orientation relative to the other crankarm. The exercise machine can be used for two different cycling exercises, with either a reciprocating motion or a parallel motion of the exerciser's feet.