According to http://www.energyarts.com/what-qigong:
“Qigong (alternatively spelled chi gung or chi kung) is a form of gentle exercise composed of movements that are repeated a number of times, often stretching the body, increasing fluid movement (blood, synovial and lymph) and building awareness of how the body moves through space.
When you practice and learn a qigong exercise movement, there are both external movements and internal movements. These internal movements or flows in China are called neigongi or “internal power”. These internal neigong movements make qigong a superior health and wellness practice.
The internal movements also differentiate qigong from almost every other form of exercise in the West that often emphasizes prolonged cardiovascular movements (such as in running and biking) or that focus on muscular strength training (weight lifting).”