How Breathing Can support Stress Management and how to use Biofeedback

Many breath work practitioners use breathing to relax the body or calm the mind, but how to unlock this pathway and benefit from breathing for relaxation can be explain by the science. An indicator of stress used by many practioners is the measure of Heart Rate Variablity (HRV). HRV is a glimpse into the central nervous system with a focus on how our Autonomic Nervous System (ANS) is funcitoning. Two main branches of the ANS is the Sympathetic (SNS) fight or flight and the Parasympatheic (PSNS) rest & digest tones. These branches regulate certain functions within the body such as blood pressure, heart rate, dilation of arteries and so on. These two branches are always in operation and having and strong balance between the two indicates a resilient ANS (1).

Many people are more Sympathetic in their tone due to chronic stress on the body and mind. Through breathing we can tap into the hearts frequency and breathing rate to stimulate the X cranial nerve know as the Vagal Nerve. This nerve runs from brain to stomach and once activated elicits a more parasympathetic tone. 

Through a slower breathing rate of 5-7 breaths per minute we are able to activate the Vagus Nerve and transition into a stronger parasympathetic tone which may cause an increase in HRV (2). Breathing that has the correct Resonance Frequency (RF) with the heart and respiratory system is the key to this pathway (3,4). 

A 1:1 ratio can be used such as a 5 second nasal inhale followed by a 5 second nasal exhale hits the 6 breath per minute mark. We can also play around with ratios such as a 1:1.5 changing us to 4 second nasal inhale followed by a 6 second nasal exhale. 

A 1:1.5 ratio is a little more difficult to follow as the increase in carbon dioxide can create an increased air hunger but research suggest that it is the exhale that can really help support and elicit the parasympathetic tone. 

Biofeedback is an interactive process where individuals can directly learn how to change their physiological activity during a breathing practicing. It is possible to view in real time the influence of breathing on heart rate variability and how slower breathing rates impact on your individual physiology. Although 5-7 breaths per minute is a guideline, each individual has their own resonance frequency and the use of biofeedback enables the individual to precisely measure and monitor what breathing rate has the greatest positive impact on themselves (5). 

Many different tools are available to measure HRV and train using biofeedback but the use of but a tool that limits the amount of error or artifcats gives a more accurate a precise reading. 

In a paper by Steffens et al, 2017 the process of identifying individual Resonance Frequncy (RF) is to have the person breathe at 4.5, 5.0, 5.5, 6.0, 6.5 and 7.0 breaths per minute during EKG recording (heart rate belt polar H10 works well). HRV frequency and time domain measures are then evaluated to find which breathing rate results in the largest changes in HRV. A common approach is to examine the low frequency (LF) range (0.05–0.14) of the HRV spectrum to find the largest frequency spike, which usually occurs at about 0.1 Hz. As people slow their breathing down and approach RF, HRV amplitude increases significantly. When a person breathes at their identified RF breathing rate, heart rate and breathing become synchronized and the highest levels of HRV are typically obtained.

The recommendation here is to start at a ratio of 1:1 and get comfortable breathing at 6 breaths per minute. Move onto a 1:1.5 ratio and then graduate into using biofeedback to really master the technique. 

1. Shaffer F, Ginsberg JP. An Overview of Heart Rate Variability Metrics and Norms. Front Public Health. 2017;5:258. Published 2017 Sep 28. doi:10.3389/fpubh.2017.00258

2. Lin IM, Tai LY, Fan SY. Breathing at a rate of 5.5 breaths per minute with equal inhalation-to-exhalation ratio increases heart rate variability. Int J Psychophysiol. 2014 Mar;91(3):206-11. doi: 10.1016/j.ijpsycho.2013.12.006. Epub 2013 Dec 28. PMID: 24380741.

3. Pal GK, Velkumary S, Madanmohan. Effect of short-term practice of breathing exercises on autonomic functions in normal human volunteers. Indian J Med Res. 2004 Aug;120(2):115-21. PMID: 15347862.

4. Steffen PR, Austin T, DeBarros A, Brown T. The Impact of Resonance Frequency Breathing on Measures of Heart Rate Variability, Blood Pressure, and Mood. Front Public Health. 2017;5:222. Published 2017 Aug 25. doi:10.3389/fpubh.2017.00222

5. Lehrer PM, Woolfolk RL, Sime WE. Principles and Practice of Stress Management. New York: Guilford Press; (2007).