Nei Gong (內功), or Internal Power, is the development of the inner muscles and organs. The purpose of Nei Gong training is to relax while not using muscles, this is usually done in a subconscious manner, which can be static, repetitious, or both. The eight mother palms of Ba Gua are an example of Nei Gong and can be found in the postures that twist in place while walking the circle and holding the postures. The fundamental purpose of this process is to develop a high level of coordination, concentration and technical skill.
Nei Gong practice is normally associated with the so called "soft style", "internal" or nèijiā (內家) Chinese martial arts, as opposed to the category known as Wai Gong (外功) or "external skill" which is historically associated with Shaolin Monastery martial arts or the so called "hard style", "external" or wàijiā (外家) Chinese martial arts.