Lie on your back or straighten your back, keep your abdomen slightly adducted and take a deep breath, but don't let your abdomen swell. Don't dilate your abdomen, just suck air into your chest. In chest breathing, the chest area is enlarged and the abdomen should be kept flat. The deeper you inhale, the abdomen will face the spine inward and the ribs will face outward. Feel the expansion of the whole chest, then exhale, and the ribs will go down and inward.