The test subjects trained their upper body during one workout and took care of their lower body the following training day. Changing the number of repetitions probably stimulates other types of muscle fibers, so that you train your muscles more fully. The principle works better than making the same number of repetitions each time. It even works better than changing the number of repetitions per week according to a schedule. And do you know what is the best? Experienced strength athletes also respond well. It is therefore an excellent way to break through your plateau.