The term qigong as currently used was promoted in the late 1940s through the 1950s to refer to a broad range of Chinese self-cultivation exercises, and to emphasize health and scientific approaches, while de-emphasizing spiritual practices, mysticism, and elite lineages. The two words are combined to describe systems to cultivate and balance life energy, especially for health and wellbeing. Gong (or kung) is often translated as cultivation or work, and definitions include practice, skill, mastery, merit, achievement, service, result, or accomplishment, and is often used to mean gongfu (kung fu) in the traditional sense of achievement through great effort. Qi is the central underlying principle in traditional Chinese medicine and martial arts. Qi primarily means air, gas or breath but is often translated as a metaphysical concept of 'vital energy', referring to a supposed energy circulating through the body though a more general definition is universal energy, including heat, light, and electromagnetic energy and definitions often involve breath, air, gas, or the relationship between matter, energy, and spirit. Qigong ( Pinyin), ch'i kung ( Wade-Giles), and chi gung ( Yale) are romanizations of two Chinese words ' qì' and ' gōng' ( 功).
Main articles: qi and Chinese martial arts