Taoist culture in China attaches great importance to the tradition of light body. Taoism's pursuit of intellectual man fit is mainly the pursuit of life experience of flying in the sky, which is called intellectual man fit or weightlifting in ancient books. One of the main ways to realize the "light lifting" life state is the valley.

The so-called skinning, also called deboning, means not eating whole grains, but using other methods to lose weight. Bigu's weight loss method has some similarities with modern weight loss.

Zhuangzi. "Happy Travel" records: "There are many gods and people living in the snow valley." Skin is like ice and snow, more like a virgin. They don't eat whole grains, suck the wind and dew, ride dragons and travel around the world. "This story is about a man of god on the mountain. He often practices the skills of cereal and doesn't eat whole grains. He just sucks the wind and drinks dew to keep healthy. So he is as light as a swallow and can control clouds. Bigu is very mysterious and is often associated with Taoist art of inspiration and guidance. Ge Hong of the Eastern Jin Dynasty recorded a very interesting story in the third volume of Bao Pu Zi. It is said that a man named Zhang Guangding had to hide his four-year-old daughter in an ancient tomb with vertical holes at the entrance to the village in order to avoid the war. He only gave her dry food and water for a few months.

Three years later, the father came back to collect his daughter's bones. I didn't know she was alive. After eating, my daughter was very hungry at first because she had nothing to eat. Later, she found a turtle in the grave with its neck stretched out and swallowed it in one breath. So she craned her neck like a turtle and swallowed it, but she was not hungry. So he and the tortoise stayed in the grave for three years. Later, the father rescued his daughter from the grave and gave her food. After the daughter ate it, her stomach ached and she vomited. Later, she began to chew slowly again. The ancients thought that eating gas was also a way to live longer, so there was a saying in the Book of Rites of Taiyi life's core monuments that eating gas was the birthday girl. The legend above is just a legend, but celebrities in history have also practiced digging valleys.

According to Historical Records, Sean said: "Learn to open the valley, and there is light in the road. When the emperor collapsed and Lv Hou left the Marquis, he was forced to eat. He said, "Life is like a white dog in the world. How can you stand so much suffering? "You must stay at the Marquis's house, listen to people and eat people." The "guiding sound" here refers to guiding, mainly imitating the inhalation action of animals. Sean's mind is relaxed because he practices digging valleys. Lv Hou advised him not to dig valleys or eat. Why does he find it difficult? So Sean had to eat again.