I like to share knowledge to help Yoga practice and one’s Thai massage for healing purposes. Here are some wise words from the hatha yoga pradipika
Khumbhaka in Yoga is retention of breath. There are eight kumbhakas; suryabhedana, ujjayi, sitkari, sitali, bhastrika, bhramari, murccha and plavini.
At the end of an inhalation (puraka) one should do jalandhara bandha the chin lock; and at the end of Kumbhaka and the beginning of exhalation (rechaka) uddiyana bandha should be done.
These are wise words from the Hatha yoga Pradipika