I've heard about people that basically do this constantly everyday essentially making their diaphragms stronger . I feel like I need to go to class to learn thi

I've heard about people that basically do this constantly everyday essentially making their diaphragms stronger . I feel like I need to go to class to learn this . I just to the basics which is slow breathing through the nose and fill air specifically in the stomach region . Hold . Exhale through the mouth slowly . Repeat