治身：天門，謂鼻孔開，謂喘息闔，謂呼吸也1
Cultivating the body: the Heavenly Door, called opening the nostrils, called closing gasping and resting2, which is called exhaling and inhaling3.
天門亢，擤鼻，旡
The Heavenly Door is haughty, blowing one’s nose, to choke4.
Iron training and its main breathing technique, empty breathing, are exercises less and less witnessed in internal practices. They target the capacity to tense all and any part of the body while relaxing and stretching. They use an old type of respiration, sometimes linked to Taoist practices, which consist of taking a long exhalation to empty as much as possible, not only the lungs but the stomach and the whole trunk for the least, and keep at all costs this state while inhaling.
