Breathing Exercises for Vagus Nerve Stimulation
Now continue with the four-count on the inhalation, but on the exhalation, count to six: Inhale for one, two, three, four, and exhale for one, two, three, four, five, six. Continue breathing, inhaling for the four count and exhaling for the six count.
Now we’re increasing our inhalation to a seven count. An example would be inhale for one, two, three, four, and exhale for one, two, three, four, five, six, seven. Continue breathing, inhaling for the four count and exhaling for the seven count.
https://www.mindful.org/a-12-minute-breathing-practice-to-activate-your-vagus-nerve/