The seventh practice of yoga detailed in Book IV is simple in terms of steps. The only instruction is: ”Let the Zelator breathe as deeply and rapidly as possible.”
There are similarities in this technique to Ujjayi breathing (also called “the ocean breath”), which is common in both Hindu and Taoist yoga practices. In Ujjayi breathing, you breathe as deeply as possible, filling the lower belly, then the rib cage, upper chest, and throat. It is hard to do the ocean breath too rapidly, however.
This practice of yoga has more in common with a technique taught by the Kundalini Yoga taught Yogi Bhajan, called the Breath of Fire. For this practice, breathe very rapidly, pumping the breath in and out with the force of the abdomen. As soon as the lungs fill with air, force it out, and as soon as the lungs are empty, force it back in. Eventually, the rhythm will become almost automatic. You should use force, but not so much that you actually contract the diaphragm.
*Note: My guides to the previous practices of yoga can be found here: