The gym has a high muscle density and a particularly good figure, but most people who practice martial arts don't have that kind of explosive muscles. The muscles exercised in the gym are not explosive, but they have strong endurance and good explosive power in practicing martial arts. For example, when we are practicing Taekwondo, the coach specializes in practicing the explosive power of our legs and running back and forth for a short distance. I went to the gym again these years. I feel that the muscles in the gym are big, but the explosive power is not very good. This is my personal opinion.