The compelling thing about holding the breath outside before inhalation is that it shows what death is like, atleast partly. Because we don't breath after we die. So I think it would be wise to slowly get accustomed to this state, as fear grips me what it would be like when the breath finally stops forever, when I'm not even able to make the breath stay outside for a few seconds. As difficult as this holding the breath outside is, it makes me realize how cruel is death by drowning etc compared to death by other means.