Iron vest is an internal practice sometimes trained along with iron palm that is designed to help the body absorb damage from strikes. In iron vest training, the student performs certain movements for repetition increase the qi and, over time, allow it to withstand harder and harder strikes from an opponent.
Iron vest also typically involves some standing meditation in addition to preset movements.
This type of training differs from iron body because iron body involves striking the body (usually with iron body bags), but iron vest is only a series of breathing, moving, and qigong exercises. It is purely internal. The twisting and turning and various postures involved in iron vest are thought to toughen the body, fascia, and are thought to allow the qi to support and protect the body.
Some versions of this program also require a special herbal tonic or pill to be taken during the first 100 days.
Progress usually takes a while; sometimes 3 years is said to mark the end of the beginning phase, and by 10 years the student may have developed some considerable skill.
Iron vest advanced training program and should be practiced only under the guidance of a qualified instructor, as incorrect practice can potentially cause damage to the qi flow and internal organs.