An exercise apparatus includes a frame for residing on a horizontal surface, a pair of arm-supporting members for supporting the user's arms and a pair of leg-supporting members for supporting the user's legs. A linkage assembly couples the arm-supporting members and leg-supporting members to the frame and moves the arm-supporting members and leg-supporting members in closed paths relative to the frame in response to user forces applied to the arm-supporting members and leg-supporting members. The linkage assembly includes actuators for adjusting dimensions of the closed paths in response to control signal inputs. Sensors mounted on the linkage assembly generate force-indicating signals representing one or more of the user force. A user interface receives and processes the force-indicating signals and supplies the control signal inputs to the actuators, wherein a dimension of at least one of the closed paths is a function of at least one of the forces applied to the leg and arm-supporting members.