About Vagus nerve and its fundamental role in our sense of safety and why deep breaths do work on feeling less anxious.

“The breath can be used as a gas pedal and as our brakes,” says Arielle Schwartz, PhD, a clinical psychologist and certified yoga instructor. “If I’m feeling shut down and need more alertness, I can bring in some breath of fire; or if I’m feeling anxious and panicky and I want to tap the brakes, I’ll emphasize long, slow exhales and deep belly breathing.”

https://www.mindful.org/why-your-breath-is-connected-to-your-well-being/