To provide an apparatus which can properly assist the pedaling motion of a bicycle by an agent from the viewpoint of the reduction of the physical load or the like of the agent.

By this exercise assisting apparatus 1, a target value x0 of a motion state variable x is properly set while considering the change of the activation situation of the physical load or the physical functions of the agent according to a measured value of a running state variable, such as the tilting degree of the running surface of the bicycle 2 pedaled by the agent or an air resistance value received by the agent under consideration. In addition, a measured value of the motion state variable x which is properly defined from the viewpoints characterizing the motion of the pedaling of the bicycle 2, such as the hip joint angle H of the agent or the rotational speed of the pedal, and the target value x0 are used as the bases for the motion control of an actuator 12.