If you want to "cheat" and skip to the end, here is what he says.
I have practiced boxing arts since my youth. I had heard every teacher say that these boxing arts are Daoist arts. I was doubtful whenever I heard this until I had progressed to training the hidden energy. Hardness and softness had merged into one, movement felt miraculous, and it became spontaneous and natural.
Discussing it with my fellow students, we each knew something about it. However, once I had moved on to training the neutral energy, the quality of discussion about my new internal condition had changed. Those who understood the experience were often less willing to talk about it, and those who knew nothing about it would not stop talking about it. For that reason, I have put pen to paper in order to reveal it to my fellows. For those of you who have passed through to such a condition, by sharing with each other we can mutually achieve perfection.
When I trained to develop the neutral energy, at the finish of each day’s practice of postures I would stand straight and think of my spirit and energy settling. Each time, I felt something down in my root chakra (also called the Yin Jiao acupoint). [Yin Jiao means “where the passive energy is quickened”. This is again still the same place as Hui Yin, meaning similarly “where the passive energy gathers”. There are three names for the same place because of three traditions: in Chinese medicine it is called Hui Yin (“Gathering Place of the Passive”), Daoists named it Yin Jiao (“Passive Quickened”), and Buddhists named it Hai Di (“Under the Sea”).] It was like a plant sprouting, and in the beginning I did not pay it much attention.
In my daily practice, there were times when the sensation would be there, other times when I felt nothing at all. In the course of time, there were occasions when the sensation lasted very long, as well as other times in which there was again no sensation. Gradually, once in the finishing posture and thinking on settling, it seemed like it was there but on the verge of going away. I thought of what the Elixir Book says about seated meditation: “Your true active aspect activates.” I made use of this idea, which to elixirists is a matter of movement within stillness.
Among those who practice seated meditation, there are a great many who understand the idea of seeking movement within stillness. In the case of boxing arts, what is sought is stillness within movement, but I am not sure how that can be communicated. I also thought upon this phrase from the Boxing Classics: “Always the exercise is to be maintained and never allowed to slip away.” I trained every day, never skipping a day.
Eventually in the training, from the moment I was in the finishing posture my whole body went into a condition of emptiness. My true active aspect would also activate, but would be on the verge of going away. Such a state is what Liu Huayang meant by “returning to a sense of the true primordial state”. I became aware of my body’s smallest movement, and I dared not to move at all, for if I moved it would go away.
I thought if I returned to the method in the boxing, it would adjust the situation. My intention within was of sinking naturalness down to my elixir field, while underneath also using an intention of naturalness to lift up my rectum. The idea inside and out was now just like when practicing the boxing. Then the moment my intention focused on my elixir field, the active aspect promptly shrank in upward and resprouted there. My whole body was now pleasantly warm and stayed so continuously. [In short, what Sun had discovered here is the simple but crucial principle that if you are sticking your butt out, your energy will seem to leak away, but if you slightly tuck your tailbone in, you will feel full of power.]
I did not yet know about the principle of rotating the dharma wheel, but it was all going on there within my elixir field, like two things in a state of competing with each other. [A dharma wheel rotation is the active energy moving up the Du meridian in the back and the passive energy moving down the Ren meridian in front, and the elixir field is where the exchange of passive and active takes place.] Then after four or five hours like that, finally they were at peace.
It seemed to me that the cause of such stillness was that from when I was practicing the boxing, the essential breath had remained in my elixir field. Even when I was not practicing, despite even the breathing of conversation, the true breath within was not hindered at all. Indeed I was not trying to deliberately cause such an effect, but there was no moment when it was not so. Zhuangzi said [Zhuangzi, chapter 6]: “An authentic man breathes with his heels.” This is essentially the idea, and this engine of there being breath without my mind being on the breath drove the activity of the active aspect to be absorbed and to smoothly reach to every part of my body.
I thereafter repeated the process as before, again rousing my elixir field, again going through my practice routine of boxing postures. With my inside and outside always a single continuum, I slowly and leisurely practiced, not allowing the slightest bit of unevenness anywhere. As I practiced, within and to my extremities it was harmonious, a continuous emptiness, and then the situation once I was standing in the finishing posture was no different from before.
There were times when I would go through my practice routine and then feel nothing, times when I would go through my routine twice and still feel nothing. But subsequently when there was something happening, I would again lift it to my elixir field and then use the boxing art’s internal breathing to rotate the dharma wheel, my intention focusing on my elixir field.
Breathing mindfully, I rotated the wheel along its course from my tailbone, to my spine, to my head, to my headtop, and then back down, same as in seated meditation practice, back down to my elixir field. At times I could do only two or three rotations and then the feeling would stop, at times only three or four rotations and then the feeling would stop. The degree of my intent was matched in both cases, the amount of rotations I could manage and the amount of boxing practice I had put in.
Later when I was not practicing, whether I was just sitting, standing, or walking, inside I was still using the breathing of the boxing practice. My body while walking could still process it. Later on it happened even when I was sleeping deeply. There would be a sudden stirring within, which immediately woke me. I again used the breathing from practicing the boxing to absorb it. I then slept soundly, and inside there was no movement. Inside and out, my whole body to its extremities suddenly felt like a void. My whole body was as harmoniously contented as if I was taking a bath.
Sometimes when this situation happened in my sleep, I was able in my dream to mindfully breathe and thereby absorb it. After I woke up, I was aware that it had happened and had been dealt with in my dream.
After practicing the boxing, I slept soundly and there was stillness within. Eventually I only had to fall asleep for my inside and out to suddenly slip into a period of emptiness. During the day, whether walking, standing, sitting, or lying down, my limbs also experienced periods of such emptiness, and the sensation within my body was extraordinarily comfortable. Every evening, I practiced the boxing, and then while I was asleep in the night, my body often slipped into a state of emptiness. Although if I did not practice in the evening, the emptiness during sleep would occur less regularly.
Later on I understood that elixirism has an energy which dispels ailments. My own personal experiences and observations of internal and external conditions were that typical human problems become inconsequential, all illnesses are cast off, and vitality is increased. After doing seated meditation in this way and practicing the boxing in this way, I finally understood that boxing arts and elixirism share the same principles.
This has been my personal experience, internal and external, of practicing boxing arts. I have written it down for the purpose of further clarifying for my comrades.