Longer Exhalations Are an Easy Way to Hack Your Vagus Nerve

Longer Exhalations Are an Easy Way to Hack Your Vagus Nerve

Christopher Bergland

This post is a follow-up to "Diaphragmatic Breathing Exercises and Your Vagus Nerve," from that earlier series of posts. I'm excited to update what was primarily speculation a few years ago with some new scientific literature (Gerritsen & Band, 2018 and De Couck et al., 2019). These studies corroborate that longer exhalations are an easy way to hack the vagus nerve, combat fight-or-flight stress responses, and improve HRV.

What is HRV? Heart rate variability represents the healthy fluctuation in beat-to-beat intervals of a human or animal's heart rate. During the inhalation phase of a breathing cycle, the sympathetic nervous system (SNS) facilitates a brief acceleration of heart rate; during exhalation, the vagus nerve secretes a transmitter substance (ACh) which causes deceleration within beat-to-beat intervals via the parasympathetic nervous system (PNS).

HRV is used to index the robustness of someone's vagus nerve responses and vagal tone (VT). Higher HRV is associated with stronger vagus nerve function, lower chronic stress levels, better overall health, and improved cognition.