The word qigong is modern. The practices it covers, breath regulation, guided movement, and the long tradition of nourishing life, are old and were known by other names, but the compound term came into general use in China in the 1950s, when the new state was looking for a secular, national and inexpensive approach to public health. Presenting the material as exercise rather than as religion was part of what made it acceptable.
That framing worked, and then it slipped. Through the 1980s a mass enthusiasm developed that went far beyond health exercise: masters attracted large followings, extraordinary powers were claimed and reported in the press, research institutes were founded to study external qi, and organisations grew to a scale the state had not anticipated. Some were straightforwardly commercial, some were religious in all but name.
The state's response after 1999 was to suppress the movements it regarded as a threat and to retain the health practice, and the distinction between approved exercise and prohibited organisation has been enforced since. Qigong in its medical form remains widely taught in Chinese hospitals and parks.
The claims divide accordingly. That slow coordinated movement with attention to breath benefits balance, flexibility and mood in older adults is supported by trials of reasonable quality. That a practitioner can direct qi outward to affect another person or an object has been tested and not demonstrated.