A training device capable of converting kinetic energy of an agent into electric energy while applying to the agent a resistance force of a variation behavior appropriate to a motion behavior of the agent. According to the training device, a strength and a direction of a resistance force applied to the agent can be varied via a regenerative braking on a motor according to at least one of a variation behavior of a relative posture between an upper body and a leg of the agent and a temporal variation behavior of the relative posture therebetween.
