Of course not! What is the principle? Even if you only practice your arms, you need muscles from other parts of your body to coordinate your movements unless you lie down. Even if it is only a local exercise, it is also exercising the whole body, but the arm accounts for the majority. Thin arms and fat figure will not happen. Even if you only practice your arms during exercise, it's not just your arms that feel tired, is it? But if you really want to lose weight, I suggest you do aerobic exercise, running and the like, which has the best effect and exercises your whole body at the same time.