The so-called reading to cultivate vital energy means cultivating the energy of heaven and earth, and the highest realm is the unity of heaven and man.
This is very similar to certain natural cultivation schools of Taoism.
Buangfu Xian was no match for a Grandmaster in cultivation, but he refused to yield, using his last breath to hold onto the energy of heaven and earth, preventing its righteous spirit from scattering.
Chapter 182