I found this in my notes for my Yoga Chi Gung theory, it really resonated with me.
It's from the translation of the 'Dao-yin' made by sinologist Joesph Needham in "Sicence and Civilization in China"
When it (the qi) goes down it becomes quiet. When it becomes qiuet it will solidify. When i becomes solidified it will begin to sprout. After it has sprouted it will grow. As it grows it will be pulled back again (to the upper regions). When it has been pulled back it will reach the crown of the head. Above, it will press against the crown of the head. Below it will press downwards.
Whoever follows this will live; whoever acts contrary to it will die.