Breathing', specifically modifying one's pattern of breathing in order to trigger psychological, psychological, emotional, and spiritual effects, is a Connection Technique.
List of Connection Techniques
Connection Technique > Bornless Ritual, Breathing, Caloric Reduction, Connection Affirmation, Connection Visualization, Dance, Deprivation, Detachment, Drumming, Fasting, Graduation Invocation, Holotropic Breathwork, Hypnotism, Hypoventilation, Intent, Japam, Meditation, Mindfulness, Mysticism of the Historical Event, Poetry, Power Quest, Receptive Seeking, Relaxation, Spirit Canoe, The Method of the Lamp, The Way of the Hollow Bone, Thought Control, Vajra Breath, Vision Quest, Writing, Yoga, Zazen
"The true man of old slept without dreaming and awoke without anxiety. He ate without tasting, breathing deeply, incredibly deeply. The true man breathes from his feet up, while ordinary people just breathe from the throat. The words of broken people come forth like vomit. Wallowing in lust and desire, they are but shallow in the ways of Heaven."
- Palmer, Martin, trans. The Book of Chuang Tzu. New York: Penguin Books, 2006. Chapter 6, Paragraph 4