The highest state of internal work is called "knowing the body", which means "the body itself knows the movement of Qi". To put it more bluntly, it is called "opening the second pulse of Ren Du". This statement is not unreasonable. People who study Chinese medicine have all studied acupoints, and there is a formula about the sequence and time of qi and blood running in human body. Which viscera to run at noon, which viscera to run at noon ... one day 12 hours so run all over the body. This is a Sunday (congenital big Sunday). This week was born to keep running. It takes an hour for a person who practices internal skills to control the internal forces to run quickly in the body to complete the operation that should be completed in one day. Can he still be like a normal person? And this Sunday (Sunday the day after tomorrow) is divided into two kinds, one is a big Sunday and the other is a small Sunday. Small Sunday means that the control of qi and blood only bypasses Ren Du (starting at Baihui point on the top of the head and ending at Yin Hui point on the crotch). The middle line in front of the body is ren meridian, and the middle line behind it is du meridian), and the long work is fast and slow. Big Sunday refers to controlling qi and blood to bypass all meridians of the whole body, fast and slow. This level of internal cultivation can only be achieved by people who know the body.

People who achieve "body knowledge" really give people an unfathomable feeling. There was a famous Taiji master (deceased) who was over 1.6 meters tall. Before his death (when he was over 80 years old), a strong man with a height of 1.9 meters pressed his arm with both hands and pressed him with all his strength. The old man just gave a cry and ejected the strong man more than 2 meters with internal force. This is the power of knowing the body.

In addition, there is also an internal skill that is not used to hit people. Wu Tangmen has a kind of kung fu called "Cold and Summer Iron Cloth Kung Fu", which was founded by Zhang Sanfeng. Practicing this kind of kung fu can make people not afraid of cold and heat, and they can travel around the world in four seasons with only their clothes on. This kind of internal strength involves not only the theory mentioned above, but also the unique world outlook and health preservation theory of Taoism. I won't repeat it here. But again, there is a limit to internal strength. Like I am in Changchun now, it often snows and the weather is cold, but I still only wear shirts and coats, not sweaters and down jackets. Iron shirts are tougher than me in hot and cold weather, but it is impossible to explore the South Pole with only a pair of shorts.