Training the muscles is something that any motivated person can do. Specifically training with an emphasis on strengthening the nervous system while training the muscles is an elite exercise program, and Qigong is one of the most powerful ways to do it.
"Qi/Chi" is the life force that animates the body, and "Gong/Kung" is to cultivate through training. By transferring one's awareness internally within the body while practicing Qigong, the nervous system responds at a much higher level.
Certain energetic pathways can be focused on while doing specific deep breathing techniques and flowing body movements. The result is that electrical current of the nervous system increases in intensity, and practitioners begin to feel a very pleasureful sensation of vibrational energy traveling through their limbs.
As a rational, sequential exercise program, Chi Kung offers exercises even the most injured and out of shape people can participate in as part of an elite training program from the moment they begin their training. For the more serious athlete, there are incredibly challenging Chi Kung exercises available to push their athletic abilities to the next level by further honing of the nervous system.
In affecting the nervous system this way, all of the other body systems, i.e. digestive, respiratory, nervous, endocrine, lymphatic, et. respond at an accelerated level, and the body's health increases dramatically.
IN THE HIERARCHY OF THE BODY, THE NERVOUS SYSTEM IS AT THE TOP AND IS IN CONTROL OF ALL OF THE OTHER BODY SYSTEMS.
The central nervous system flows into the peripheral nervous system, which innervates the muscular system. How is it that elite Asian Martial Art Masters are able to hit with so much power despite lacking muscular bulk? "Recruitment" of existing muscle is more important than muscle size:
When a motor neuron is activated, all of the muscle fibers innervated by the motor neuron are stimulated and contract. The activation of one motor neuron will result in a weak but distributed muscle contraction. The activation of more motor neurons will result in more muscle fibers being activated, and therefore a stronger muscle contraction. Motor unit recruitment is a measure of how many motor neurons are activated in a particular muscle, and therefore is a measure of how many muscle fibers of that muscle are activated. The higher the recruitment the stronger the muscle contraction will be.-Wikipedia, "Motor Unit Recruitment"
Therefore, to strengthen muscular contractions within an under performing limb, one can use Qigong in a clinical setting to correct asymmetries within body. In fact, Qigong can be used to increase the overall potential of power for the entire body. It is a perfect foundation exercise for any sport.
Qigong is usually practiced by people studying Tai Chi or Kung Fu to improve chi flow and increase power. The principles are very much the same for movement and focus, just differing in the complexity of the movement, i.e. Tai Chi and Kung Fu are more difficult to execute movement-wise than Qigong.
One core Tai Chi principle unites all Yogas, whether Tibetan, Indian, Chinese, Buddhist, Taoist, Hindu, Martial Art, etc:
The Shen ("spirit/mind entity") points the Yi (awareness) which advances the Chi (energy or life-force) which infuses the Li (physical body).
-Zhang SanFeng, "Tai Chi Classics"
There is so much to this diagram that the casual observer cannot understand.
It is a very simple formula, but one that is problematic for modern humans. The mind is so overwhelmed with daily details that separating one's awareness from the continuous problem solving and multi-tasking of modern existence and redirecting it at the inner-constructs of the body is a Herculean task that takes real discipline.
In China, Qigong is used as a medical tool in conjunction with acupuncture to accelerate the healing process and reduce downtime for people fighting all types of diseases and healing structural issues. The thought is that if the nervous system can be strengthened, the body's own innate healing capacity will do the rest.
There is no safer and more effective exercise for healing injuries than Qigong. It is typically far safer than doing Hatha Yoga asanas for healing injuries. In fact, the best Hatha Yoga exercises for healing, the "Anti-Rheumatics", more resemble Qigong exercises than Hatha Yoga asanas.
In the context of prehabilitation, Qigong exercises can be used to enhance the nerve conduction throughout the body. It is a powerful tool that provides the most injured people with a safe and constructive program that will do no harm and the most powerful athletes a means to improve performance and dramatically extend their ability to participate in their favored activities long beyond the norm.