The term "hay gong" can be "hei gung" with a literal meaning of "air or breath work," which applies basically with breathing exercises. The term "hei" is used in Chinese, which means courage, backbone or determination. Hei in Cantonese or "chi" in Mandarin bears the same Chinese character meaning "air." The other interpretation of "hei" or "chi" is a term used in Sha Chi (Mandarin) or Saat Hei (Cantonese) that means "death air" or a "killing aura." This conforms to "qi gong" or the praying mantis in kung fu martial arts. Hay gong or "hei gung" may imply an exercise involving hard, dynamic tension or combining breathing with controlled tension.
"Chi gong" or "qi gong" is a technique that deals with the flow of human energy. When the technique is applied, it employs the human body as meridians through which the energy flows. In connection with Chinese medicine, various illnesses are due to blockages on these channels. With the use of internal human energy and possible energy from earth and the universe, chi gong can be utilized to relieve pain, improve intelligence, strengthen the body and prolong life. Chi gong is accepted widely as an exercise that can promote vitality and prevent sickness. Chi gong works from inside the body outward. It connects the human body and the spirit. This is done by concentrating and focusing on breathing, as well as by physical movement.
"Hay" is said to be a typographical error for the word "hei." "Hei" is a Cantonese word for "qi" or "chi" that means "life force." The word "chi" is defined in Chinese philosophy as "circulating life energy" that is inherent in all things. In traditional Chinese medicine, it is believed that the balance of positive and negative forms found in the body is essential for good health.
The difference of "hay gong" and "chi gong" lies in the utilization of the human body in providing physical well-being. Hay gong uses the breathing as a means to exercise, while chi gong makes use of the human body as a channel where the energy can flow. In hay gong, it takes hard and dynamic tension to execute the exercise for the body to benefit. Chi gong, on the other hand, simply permits the flow of energy throughout the body by concentration, focus and physical movement.