James Nestor

“A last word on slow breathing. It goes by another name: prayer. When Buddhist monks chant their most popular mantra, Om Mani Padme Hum, each spoken phrase lasts six seconds, with six seconds to inhale before the chant starts again. The traditional chant of Om, the “sacred sound of the universe” used in Jainism and other traditions, takes six seconds to sing, with a pause of about six seconds to inhale.”
― James Nestor, Breath: The New Science of a Lost Art

“right nostril is a gas pedal. When you’re inhaling primarily through this channel, circulation speeds up, your body gets hotter, and cortisol levels, blood pressure, and heart rate all increase. This happens because breathing through the right side of the nose activates the sympathetic nervous system, the “fight or flight” mechanism that puts the body in a more elevated state of alertness and readiness. Breathing through the right nostril will also feed more blood to the opposite hemisphere of the brain, specifically to the prefrontal cortex, which has been associated with logical decisions, language, and computing. Inhaling through the left nostril has the opposite effect: it works as a kind of brake system to the right nostril’s accelerator. The left nostril is more deeply connected to the parasympathetic nervous system, the rest-and-relax side that lowers blood pressure, cools the body, and reduces anxiety. Left-nostril breathing shifts blood flow to the opposite side of the prefrontal cortex, to the area that influences creative thought and plays a role in the formation of mental abstractions and the production of negative emotions.”
― James Nestor, Breath: The New Science of a Lost Art