The subject of Stake Standing and it's value come up a lot in discussions of Internal Martial Arts. And it is hard to write about with real clarity because it is by nature experiential. More body knowledge than intellectual knowledge. So I almost hesitate to write anything at all but since I have this blog I feel obligated to try!
Of course there are many forms of standing but for the purposes of Xingyi the most important is Santi Shi, or three pattern standing. I talk about this elsewhere on my site and there is a good examination of it by Mao Mingchun concerning his own experiences. I have read elsewhere some longtime (at least they said they were "longtime") practitioners of Internal Arts say that they stood for many years, up to an hour a day, and achieved very little if anything. I believe them.
Master Li said that many times standing practice leads only to physical pain and mental and spiritual frustration. (I feel the same thing when I think about Donald Trump) This is because they are standing without any idea of what they are looking for, in a sense. They are just trying to be still and maintain form and hoping that something magical will happen. Often this just leads to excess muscular tension in the body. After a while they may overcome the pain but the result can easily be an overly firm body without any "springy" quality.
I did not see the value in standing for a long time. I stood but gained very little. It was many years into my practice before I learned that standing was not a static practice. Song Zhiyong said that in the beginning of his studies with Master Li he was told to stand and look for the Jin (energy). I was puzzled about what that really meant for a long time.
The first thing I ultimately had to learn to do was actually simple. If I felt pain, lightly shake the body. Then later when I saw Song's own students practicing standing I observed many kinds of movement, shaking, vibrating, twisting, waves, etc. and some students were very still but with subtle internal movements. Song explained that while standing it is necessary to use the mind to observe the body internally. When you do that it is possible for Original Energy to arise. This can cause many forms of movement to happen. For instance after a long time the body might begin to vibrate deep inside as if a bell were struck and one might have a sense of the whole body breathing. (I think all of this is part of the neuromuscular changes that can happen in the body including the development of the fascia). The mind is also used to relax the outer body and remove any excess tonos while maintaining the form. All of this helps to remove stagnations of blood and Qi in the body in the same way that a bear in hibernation will shudder and shake unconsciously to keep the blood from pooling in the body. This vibrating and unconscious shaking of the body is also essentially Fa Li. Once the body can do it on its own, so to speak, you can learn to do Fa Li consciously. This practice along with Si Ba develops an outer supple body and an inner springy elastic body. It also develops awareness and instinct.
Master Li said that Standing is not static but is a movement exercise. Even though the body is still on the outside the inside is always moving. Once I began to understand this I began to really progress in my Xingyi practice