"Yin still meditation can strengthen the mind (i.e., the EMF of the Qi), and can build up the Qi to a higher level. The still meditation of Taiji Qigong can open the paths of the Conception Vessel (Yin) and Governing Vessel (Yang), and increase the Qi stored in them. When the Qi in these two vessels is abundant, the Qi circulating in the twelve primary channels will be abundant, and therefore your physical body will be able to function more efficiently. Developing the Yi and Qi through still meditation is the root of physical power. Remember: only when the Qi is strong can the power manifested by the physical body be strong. Qi is the Yin side of power, while the physical manifestation is the Yang side.
"According to this theory, moving meditation is considered Yang because it manifests the Yi and Qi stored by Yin still meditation through the actions of the physical body.
"The correct way of martial Taiji training is to practice both Yin still meditation and Yang moving physical manifestation equally. Many Taiji practitioners today ignore the Yin still meditation and practice only the external moving manifestation. They do not realize that building up the Yi and Qi is the key to effective Qigong and martial power (Jin) training.
"Still Meditation and moving meditation can also be divided into Yin and Yang:" *