Breathing Rate Variability

The Physiology of Breathing Rate Variability (BRV)

Breathing is both spontaneous and voluntary. It is the only physiological parameter that we can consciously control. Meanwhile, breathing influences a plethora of physiological and psychological functions.
We do not control spontaneous breathing, and the main source of this phenomenon originates from certain areas of our brain, such as the (Pre-)Bötzinger complex. The spontaneous act of breathing arises from the biochemical processes of blood carbon dioxide accumulation, pH decrease, and optimal oxygen delivery to the tissues. This is called the Bohr effect, which can be understood as the body’s natural response to maintain a balance of gases in the blood.

The vagus nerve, the longest and most widely distributed nerve in the body, is a testament to the intricate and interconnected nature of our body’s systems. It plays a crucial role in controlling the heart, lungs, and digestive systems, demonstrating the awe-inspiring complexity of our physiological functions.

Our breathing rate, when we are calm and at rest, tends to be quite regular, with small fluctuations. However, when we are aroused by our environment or internal stimuli, the pace tends to rise and fluctuates more. This increase in breathing rate and/or variability can significantly impact our physiological balance and, consequently, our well-being, underscoring the importance of managing our breath for overall health.

There is growing evidence that emotional processes influence dynamic respiratory regulation in ways that are reflected in breathing variability measures, and advancing theory and methodology is now bringing more focused attention to these measures.

^{Vlemincx et al. (2013). Respiratory variability and sighing: A psychophysiological reset model. Biological Psychology, 93(1), 24–32.}

Some of the most significant influences on our breathing stability are emotional and cognitive attention (thinking). Everyone has experienced this effect when frustration or anger arises: we breathe faster, and sometimes we even stop breathing for a while, followed by rapid air intake. This increases our heart rate and blood pressure, and decreases the Bohr effect efficiency, leading to a decrease of oxygen absorption. Similarly, when we focus too much on a task, our attention increases, and our breathing rhythm becomes irregular. On the contrary, when we are in a relaxed environment, conducive to manifesting a state of contemplation, our mental activities are reduced and our breathing rate decreases as well as its variability.

Breathing Exercises in Ancient Times

As I have introduced above, we can control our breathing patterns, both in pace and fluctuations. Yogi masters, who had understood this for a long time, understood this well. They formalized this breathing practice into what is known as Prana-Yama (work of Prana, which is the vital force believed to permeate all of life in Indian traditions).

*“Breath is the king of mind.” – B.K.S. Iyengar*

Breath work was performed by ancient Eastern traditions from India, China, Japan, and Tibet, but also from European countries, mostly performed by monks during prayer recitations. For example, breath work is implemented in Neigong, China, and Prana is called Qi (pronounced Chi). In Greece, Prana is called Pneuma, which means spirit or soul. Breathing exercises were practiced after the primary sport using different rhythms to relax and accelerate recovery.

Variability in Practices and in Natural Phenomena

The regimen of Prana exercises is often very systemic and regular, making them a routine and then a habit. This procedure is, however, prone to unnecessary repetitions that may lead the practitioner to boredom and laziness while practicing almost unconsciously.

However, using random variations in the exercise may increase the degree of alertness and concentration, allowing for a more enjoyable session and leading to new insights into the practice and its benefits. Variations are everywhere in nature and, especially in biological systems, as they are the means to produce new patterns that are more suited for life. This is the adaptability that leads to creativity and evolution.

Breathing Guidance and Biofeedback

Breathwork in these ancient traditions mainly had three purposes: 1) prolong our life span, 2) maintain good health, and 3) spiritual realization. Pranayama is implemented according to the level of practice and one of these three goals. There are, in fact, hundreds of different Pranayama that can be classified into these three categories. The technique was taught by a master who guided the student in avoiding pitfalls when practicing these exercises. Later, when ready, the student could perform the exercises by himself, while from time to time, he was instructed or corrected by the master.

Vitalab App snapshot while in a ***Breathe*** sound guided biofeedback session showing the Breathing Score in real time as a biofeedback cue

Breathing exercises have been revived for a few decades thanks to the renewed understanding of their vital role and efficiency in restoring our body and mind balance. Modern technologies are helping in this endeavor by offering many guided breathing platforms, from the most complex ones used in clinics to the simplest ones using mobile Apps. Guidance can be implemented in many forms, such as sound/music, videos, vibrations, and light.
While guidance is efficient, the most efficient way is using biofeedback. In ancient traditions, the master corrected the student in his practice, which was the most crucial element in the training.

The master was critical of the feedback. Biofeedback can be implemented via different sensing devices that capture physiological signals such as breathing and cardiac rhythms. The practitioner can sense the body’s response to breathing with the sensors’ signals and correct his practice for optimal effect. The practitioner can even set a specific goal for his training. For example, if the goal is to calm the mind, the student can set the goal to lower breathing variability and pace. Another example is boosting energy and arousing the mind by imposing a faster pace and/or variability.

Elemental Breathing and BRV

In previous posts (Part I, Part II, and Part III), I have introduced the concepts of the five elements and how they pervade our mind, body, and the entire universe. Breathing is no exception and is linked essentially to the wind element but also to the other four, as explained in one of my essays.

The four components of the breathing cycle: inhale, hold, exhale, and hold, can be assigned to specific elements’ qualities, such as creation, movement, spaciousness, stabilization, diffusion, and transformation. When performing breathwork, we consciously or unconsciously activate these functions. Therefore, we can aim to activate one specific element and its functions.

Furthermore, the introduction of a time-varying breathing rate, and thus variability, can significantly enhance the elemental qualities. For instance, when aiming to calm the mind, it can be challenging for beginners to start with slow breathing immediately. This can sometimes lead to stress and frustration. Therefore, the use of a faster breathing rate at the beginning of the session, gradually decreasing its frequency, is a reassuring approach that ensures better success and a more fulfilling journey in breathwork.

SATHeart BRV

Unfortunately, breathing rate variability is often overlooked in scientific and clinical studies, and its quantification is a rarity in breathing biofeedback platforms. However, SATHeart has been a pioneer in this field, introducing BRV from the start in its metrics.

The BRV is a key feature of the soon-to-be-released Vitalab App, allowing users to visualize it in real-time. This feature not only provides further insights into their emotional, cognitive, and mental states but also keeps them engaged and connected to their health.

Vitalab App snapshot while in a ***Minilab*** session showing five metrics in real time among which is the BRV (cycle per minute, cpm)

The BRV can also be used for sleep studies, as its value is related to the sleep state and directly reflects the consciousness state.

SATHeart uses photoplethysmographs to quantify the neuro-cardiovascular and respiratory systems and extract vital signs, including the BRV.

SATHeart