"Pigu" originated from "not eating grains" in Taoist health preservation, and it was a common way of health preservation in ancient times. It originated in the pre-Qin period and was popular in the Tang Dynasty. Also known as "Valley Valley", "Valley Valley Valley", "Valley Valley", "Valley Valley" and "Hugh Valley". The earliest record about Bigu originated from Zhuangzi Xiaoyao Tour: "Since ancient times, there have been immortals living in the hills. If the skin is like ice and snow, it is like a virgin, not eating grains, sucking wind and drinking dew, traveling around the world by flying clouds and dragons ... "As a health rule to prolong life, Pigu is also recorded in many ancient books.

Traditional ways of breaking grain are mainly divided into two kinds: taking medicine and taking medicine. Persuaded to break the grain mainly through hunger strike and breath adjustment (breathing), but its effectiveness lacks scientific basis at present; Taking medicine to avoid cereal is to adjust the body function by taking other complementary foods (nuts, Chinese herbal medicines, etc.). ) instead of eating the staple food (grain).

"Carnivores are brave, food eaters are clever, gas eaters are born, and those who don't eat are born." It is the earliest theoretical basis of the art of crossing the valley. There is a similar record in Huainanzi Terrain Training.