You'll feel a difference after your first workout. As your body releases endorphins and as most major muscle groups in your body have been activated, you will experience increased physical awareness, resulting in an improved posture. After a day or two, you'll feel some muscle stiffness, which is normal and is indicative of your body's recovery process. Within a period of about 4 weeks, you'll feel stronger and different muscles will improve to coordinate movements more effectively. After roughly 6 to 8 sessions (6 to 8 weeks) you will not only feel, but also see a visible difference from the training in the form of gradually increased muscle formation and a possible reduction in body fat (depending on your diet). As with conventional training, EMS training should be done regularly to ensure and maintain optimal results.