"Teacher, please let me take a supplementary lesson..." "After college, change into your gym clothes and come to the gym instructor's office." A physical education class that female student take as a supplementary lesson. The supplementary lesson is swing exercise. A swing is a swinging exercise equipment. However, in today's supplementary lesson, we will train our core to endure without shaking. If the shaking exceeds the standard range, additional supplementary training will be required. That said, the content is something that anyone can do. All you have to do is stay still on the swing. What is a little different is that you are in a standing position and your hands and feet are tied to a swing. That's all. This is a supplementary lesson in which a physical education instructor who wants his female students to graduate safely uses a gentle and sweet whip.