I used to beat a big brother who watched aerobics together. Later, I came into contact with the circle of formal wrist competition. After one or two years of exercise and study, I easily killed my former big brother. In fact, wrist wrestling needs an included angle force between the arm and forearm, not the whole strength action of the biceps. Regular arm wrestling is to control the angle between the big arm and the small arm within a right angle, and then rely on the body to drive strength. To put it bluntly, the wrist is the hook of the crane. After you hook something, the angle between the big arm and the small arm is equal to the angle of the mechanical arm of the crane. Then when driving the car body, your hook can hook the mechanical arm and not open when stressed, so you win.