Impulse current can be used to trigger contractions in innervated muscles. This application can partially preserve muscle function when the patient is unable or not permitted to contract the muscle voluntarily, and—when used as a supplement to active training—can help accelerate the improvement of certain functions. Today, we know that this is not merely a simple, local muscle contraction, but that local, segmental, and central neurological changes can also be demonstrated. The following discusses applications in the context of conventional strength and endurance training, muscle stimulation for incontinence, and stimulation of denervated musculature. Stimulation with low- and medium-frequency impulse current is addressed.