Legend has it that 4000 years ago in Ancient China, the Yellow Emperor invented a system of breathing and movement to vitalize body and mind.  According to ancient Chinese thought, Qi is the fundamental substance constituting the universe.  All phenomena are produced by the changes and movement of this vital energy.  Qigong literally means practice and exercise of Qi.  It is a way of promoting harmonious exchange of energy between all parts of the body and mind and the environment.  Qi is not a theoretical concept.  It is easily felt and directly experienced by practicing Qigong.