If you are interested in martial arts, you may wish to practice long boxing after your basic skills reach the standard. There is a video I said on the internet, so take your time to learn. If you want to have a good waist, you need to run every morning. After running 3 kilometers, do 100 sit-ups immediately. I'm sure your abdominal muscles will be like a piece of iron in a year. What do you think will happen to your waist strength?