Reverse Breathing

Reverse breathing is a kind of forced expiration in which the abdominal wall is pulled in, or deflated, during the inhalation and is actively pushed out, or inflated, to expand in the exhalation. It is called the practice “reverse breathing” because during the inhalation the abdomen is pulled in (as opposed to pushing out in natural breathing) and during the exhalation it is pushed out to power movement and effort (as opposed to pulling in on the exhale in natural breathing). 

Doing this reverse breathing during the Zhan Zhuang practice will relieve the pressure that the hiatus can place on the vagus nerve. When you inhale the chest will be expanded and the stomach will go up and diaphragm down. Then in exhalation the diaphragm will go up and and the stomach down by pushing your abs. This opposite direction movements will massage and relieve the vagus nerve.