Energy of breathing: Khi Cong
The basic technique of energy-developing exercises (that sometimes is called by a Chinese term "hard (battle, fighting) chi-gun") is breathing. The "Inhale-Hold-Exhale" cycle is combined with specific exercises, each having a special effect.
Vietnamese Wing Chun Kung Fu uses "loud breathing" - that is a clearly audible powerful inhalation and a concentrated exhalation. During the initial stages of training it is necessary so that the student will feel his breathing and would learn how to control it. When the breath is held the energy moves to the part of body which the exercise is designed for or stays in the main energy center of the body - a spot in the center of the stomach (dan dien).
The breathing exercises of Khi Cong start during the warm up. Loud breathing during the warm up is obligatory. Eventually the inhalation and exhalation will synchronize with the movements of the body. The better the student will learn the breathing cycle, the more effective would the warm up and, in turn, the whole training be.
Most of Khi Cong exercises strengthen the entire body, improve the reaction, stamina and overall health. However, some exercises are very specific.
By focusing on the breathing cycle and simultaneous movements of the body, the energy moves into the needed part of the body and concentrates there. That is how masters of Khi Cong can break chains and endure the mightiest of strikes with hard objects into unprotected parts of the body. By reaching the highest levels of control Patriarch Huynh Ngoc An can move his heart, decrease the volume of his lungs fivefold and make his muscles hard "like stone" which makes it impossible to grab the skin and allows him to block very strong attacks. And this is only a few of the effects resulting from Khi Cong exercises.
Contemporary Vietnamese Wing Chun Kung Fu(Article by Grandmaster Huynh Ngoc An)