How chi gong achieves healing effects is not fully understood, though several mechanisms of action have been proposed. From the standpoint of traditional Chinese medicine, chi gong energizes the body's vital forces, balances yin and yang, strengthens blood circulation, and improves the patient's emotional and mental states. From the viewpoint of Western medicine, chi gong increases the absorption and utilization of oxygen from the blood, as does yoga. Nobel Prize-winner Otto Warburg found that oxygen deficiency is typical of cancer cells and that when the body is rich in oxygen, cancer cells die. Practicing chi gong exercises has a positive effect on certain enzymes that play key roles in the body's maintenance of health and in phospho~rylation, a basic biochemical process that supplies the energy necessary for cell work.12 Phosphorylation is central to oxygen provision for all of the body's cells and is vitally important to immune response.

Exercise can mobilize the body's natural killer cells, which seek out and destroy cancer cells and cells infected by viruses. An increased oxygen uptake from the blood can also neutralize free radicals. The slow, deep breathing and moderate body motion of chi gong (or yoga) can cause the newly available oxygen to bind with free radicals, rendering them harmless.13 Research in China indicates that after a chi gong exercise lasting about forty minutes, the body's internal regional blood volume increases by 30 percent, which greatly improves the supply of oxygen available to the cells.14

Through intensive practice of chi gong, "a whole set of beneficial psychological and spiritual conditions emerge," observes Paul Dong in his book Chi Gong: The Ancient Chinese Way to Health. Besides promoting emotional well-being, chi gong exercises build patients' confidence and steel their will to defeat cancer. Dong, who has practiced chi gong since 1980, notes that positive attitude plays a role in curing disease. He likens chi gong's apparent immune-boosting effects to Western mind-body healing approaches such as the new field of psychoneuroimmunology.

In addition to internal chi gong, the manipulation of energy flow within one's own body, there is also external chi gong, the reputed ability to project one's internal chi toward another body. In external chi therapy, widely accepted in China for the treatment of many disorders, no physical contact is required. The advanced chi gong expert simply projects his or her chi energy through the fingers or palm toward the patient, thereby purportedly killing cancer cells. External chi gong practitioners in China claim that through this technique, they can destroy bacteria and transmit health-promoting energies. They believe they have proven the existence of chi as a physical reality evident in psychokinetic (mind-over-matter) powers, clairvoyance, and healing effects. To skeptics, these assertions spring from self-deception and heightened suggestibility.

Paul Dong tells of a Japanese cancer victim, with a tumor the size of an egg deeply imbedded in his nasal cavity, who made a trip to a Beijing hospital to undergo external chi therapy. After twelve days of treatment, the man's tumor had shrunk and his pain had considerably eased.15 Dr. Feng Li-da, professor of immunology at Beijing College of Traditional Chinese Medicine, has done many experiments on external chi transmission and claims that a chi gong expert can destroy uterine cancer cells, gastric cancer cells, flu virus, and colon and dysentery bacilli with varying degrees of success. In The Scientific Basis of Chi Gong, Professor Xie Huan-zhang of Beijing Industrial College states that chi effects detected with scientific instruments include magnetic fields, infrared radiation, infrasound, and ion streams of visible light and superfaint luminescence.16