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Biofeedback : A primer

It was a great week learning all about Biofeedback after interviewing Dr. Debbie Miller for my podcast One thing. I have put together some information on Biofeedback to share with you all. This is an introduction biofeedback, heart rate variability, and polyvagal theory. Its intended to inform you but also to give you a feel for why we all need to learn how to manage our vagal tone! I expect everybody to be so chilled out after reading it that you will have a great day!

Biofeedback : An Introduction​

An introduction to biofeedback, heart rate variability, the Vagus nerve, polyvagal theory.

Biofeedback is a term that broadly defines getting a signal from some biophysical process (i.e. Heart rate, Temperature, Respiratory rate) and then using that interpretation to make cognitive, behavioral, or physiologic moves to improve regulation.

In this article I am going to tell you about biofeedback and the more common types of biofeedback like heart rate variability training. I will mention why we should all care about it and give you a feel of what it’s like to use biofeedback for your health. In part 2 of this article we will dive deeper into the technology.

Biofeedback continues to find its way into conventional medicine after being a mainstay in integrative and alternative medicine fields. Non drug treatments for stress related disorders are greatly needed. Reliance on pharmaceuticals for stress related disorders like insomnia, anxiety, and post-traumatic stress disorder can lead to other problems like addiction and withdrawal effects. More, a great need exists for therapies that address the mind and body as one. Biofeedback is one of the unique tools that does this. Where counseling can also help with cognitive and behavioral understanding of stress related illness, biofeedback can help with learning how to modify one’s own physiology when triggered. Biofeedback has made its way into the do it yourself, biohacking community with the availability of biofeedback wearable technology.

What is the need for biofeedback and who does it help?

On an individual level, if you are like most of us and have been at some point advised to learn how to manage your stress then the options are vast with yoga, meditation, exercise, and mindfulness. For some , transition and training in the modalities is fluent an intuitive. For others who’s learning style is more kinesthetic, a biofeedback element can help understand how these modalities actually work.

On a more meta-level, there is need for non-drug options to improve clinical outcomes and quality of life of those suffering from stress related condition. The research on biofeedback is extensive however some core needs for it exist because conventional therapies are not addressing stress-related disorders completely. (SATTAR & VALDIYA, 1999)

Here are some examples:

Alternative to Benzodiazepines

Benzodiazepines have been show less effective then non drug therapies in minor presentations of psychological disorder. Addiction potential, withdrawal are all factors to steer us toward non-drug treatments(SATTAR & VALDIYA, 1999)

Stress and Anxiety Reduction

Meta-analysis of 24 studies totaling 484 participants who received HRV biofeedback training for stress and anxiety. HRV biofeedback training associated with a large reduction in self-reported stress and anxiety (Goessl, Curtiss, & Hofmann, 2017)

Biofeedback for Mild Hypertension

11.0 mm Hg systolic and 8.8 mm Hg diastolic), persisting eight months after the training, suggests that relaxation-based behavioral methods might be offered as a first-time treatment to patients with mild hypertension or prehypertension (Lin et al., 2012)

Biofeedback for fitness and conditioning: in the wearable market there has been an increased demand and benefit in using Heart rate variability (HRV) biofeedback as a tool to help with training and exercise management.

It is important to know there are other forms of biofeedback being used in medicine especially in gastroenterology in the area of idiopathic constipation. This beyond the scope of discussion for this current article.

About Heart Rate Variability: (HRV biofeedback)

A great deal of emphasis is being placed on HRV biofeedback which was originated from the work of Dr. Stephen Porges Published studies have found that HRV biofeedback helps people with a variety of disorders, including anxiety , depression , hypertension, chronic pain , and other disorders, particularly when they have functional components .

In lay terms: Heart Rate Variability is a measurement which indicates the variation in your heartbeats within a specific timeframe. It is measured in units of milliseconds. If the intervals between your hearts beats are rather constant then your HRV is low. If the interval between your heart beat varies then HRV is high.

A high heart rate variability is an indicator of good vagal tone. What is good vagal tone? Good vagal tone is an indicator that the parasympathetic nervous system is acting in good co-ordinance with the sympathetic nervous system. The parasympathetic response from the posterior (dorsal branch of the Vagus nerve allows us to “Freeze”. While the sympathetic nervous system allows us to “Fight or Flight”. When the “Freeze” part of our nervous system is not “toned” then we remain in arousal.

Good heart rate variability is an indication is indication that the body is adapting to stress responses.

When this takes place according to the Poly Vagal Theory (Porges) then we are able to have more social engagement as the anterior (ventral) branch of the Vagus nerve is more tone and we can come from a place of connectedness, mindfulness, and curiosity. We are part of the world and others instead of disconnected or fleeing. My patients hear me talk about approaching life and health from a place of curiosity instead of fear and avoidance all the time. This explains the mechanism!

To unpack this a little further lets look at the three branches of the Vagus nerve as described by (Walker, 2019).

Each branch has distinct functions and roles upon activation.

The Sympathetic Nervous System branch of the Vagus nerve:


  • Blood pressure

  • Heart Rate

  • Respiratory Rate

  • Fuel Mobilization (glucose and fat)

  • Bronchodilation


  • Insulin

  • Digestion

  • Immune response

  • Salivation

This is largely termed as the fight or flight response.

The parasympathetic branch of the Vagus Nerve is divided into Posterior (Dorsal) Vagus and Anterior (ventral) divisions.

The Posterior (Dorsal) Vagus Nerve

Increases the following responses:

  • Avoidance in the face of fear

  • Insulin activity and Fuel storage

  • Endorphin release to help with pain threshold

Decreases the following responses:

  • Metabolism

  • Heart Rate

  • Blood pressure

  • Temperature

  • Muscle Tone

  • Social behavior (many aspects)

  • Depth of Breath

it is largely termed as the "freeze" response.

The Dorsal Branch of the Vagus Nerve


  • Digestion

  • Motility

  • Resistance to infection

  • Immune response

  • Movement in eyes and head turning

  • Circulation

  • Oxytocin

  • Breathing function


  • Defensiveness

  • Increases what we call the "Flow State"

​This is called the social engagement response.

So we can see that this training can help some core biologic processes in the body . Once you are aware of the systems that are driving the lack of stress resilience then you can do something about it! Particularly learning biofeedback can help bring forward the Dorsal Branch of The Vagus Nerve. There are some simple things that can help to like signing and gargling that can help that I will delve into in Part 2 of this article. Also in part 2 of this article, I will discuss the different ways HRV variability are measured and some of the commercial devices that are available to you. For more information listen to Dr. Millers interview.


Wearables for Neurofeedback and Biofeedback

Smart Apps for Neurofeedback and Biofeedback


Altini, M. (2019, 03 06). heart-rate-variability-a-primer. From

heart-rate-variability-basics. (2019, 03 06). From

Walker, R. (2019, 02 21). Poly Vagal Theory. From

Goessl, V. C., Curtiss, J. E., & Hofmann, S. G. (2017). The effect of heart rate variability biofeedback training on stress and anxiety: A meta-analysis. Psychological Medicine, 47(15), 2578–2586.

Lin, G., Xiang, Q., Fu, X., Wang, S., Wang, S., Chen, S., … Wang, T. (2012). Heart Rate Variability Biofeedback Decreases Blood Pressure in Prehypertensive Subjects by Improving Autonomic Function and Baroreflex. The Journal of Alternative and Complementary Medicine, 18(2), 143–152.

SATTAR, F., & VALDIYA, P. (1999). Biofeedback in Medical Practice. Medical Journal Armed Forces India, 55(1), 51–54.

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