I’m a bit confused regarding the practice of Bhastrika. I always thought it was practiced by breathing forcefully (but not too much) pressing and pulling the stomach in and out. But a teacher I lately met with told to practice this way: “Breathing is done only in the chest, not in the abdomen. It should be shallow and rapid.” He has another practice he calls Bhastrika plus Agnisara looking closer to the way I used to practice Bhastrika. Can you give me your point of view on this practice?
As you have discovered, different traditions practice Bhastrika in different ways. In Ananda Yoga, it’s done with the abdomen, and it’s as follows:
Quickly push the abdomen out, thereby causing an inhalation through the nose. Then quickly squeeze the abdomen inward, causing an exhalation through the nose. Both movements should be smooth and firm—not shallow, but not as deep as possible, either. Your inhalations and exhalations should be of equal duration. Practice at a rate of about one breath per second.
In Ananda Yoga, very few pranayama techniques involve the chest intentionally. Most focus on the abdomen, and although the chest will expand and relax a bit with any breath that is somewhat deep, that movement is incidental to the practice, not intentional.