If you show your abdominal muscles and other muscles because you are thin, it can only show that your body fat is low, which is completely different from the muscles that have been exposed through exercise. They are different in nature, just like the fat man's big breasts and the bodybuilder's chest muscles can't be compared; If you can't make a dragon flag or a human flag with the muscles displayed after exercise, it means that your core strength and arm strength are not enough. If you use the flag, you should have enough back strength, mainly latissimus dorsi, and you should continue to practice. If you are satisfied, give it an adoption.