"Bone marrow nei kung is a system to cultivate internal power through absorbing cosmic energy into the bones. The bone marrow is revitalized, the blood replenished, and the life force within nourished. These methods are said to make the body impervious to illness and disease. In ancient times, the steel bodyâ€™â€™ attained through this practice was a coveted asset in the fields of Chinese medicine and martial arts. Taoist methods of regrowing the bone marrow are crucial to rejuvenating body"