Do aerobic exercise once a day, or run at the same speed for 40 minutes. You will lose a lot of fat in the first month and the second month of diving. In the third month, you can gradually reduce the frequency and quantity to maintain it. I think three months is enough, because you are not fat, but you are not satisfied with your body. So I think three months is enough for your course. But a word of caution, you must jump for more than two months or you will rebound. Stick to it, and you will have a healthy body and a quite harmonious and beautiful figure. Because aerobics is divided into pilates, belly dancing, progressive, aerobic aerobics and so on. Each of its courses has modifications and fat reduction for each part. So I think these two methods are the fastest.