It has been known for thousands of years that breathing is key to health, performance, and longevity. We are just beginning to understand why − breathing has much to do with “circulation,” both quantity and quality. Typically, when we are at rest, blood in the body circulates once each minute; when we are exercising this can increase to six times per minute (Medical Physiology, Guyton & Hall, 2002).
The Thoracic Pump
While we have yet to quantify it, blood flow during Coherent Breathing, even though we may be resting or semi-active, is somewhere in between. This increase in blood flow is principally a function of the “thoracic pump” which is powered by the “diaphragm”, the large sheath of muscle separating the lungs and heart from the digestive organs. The thoracic pump draws blood from the extremities on inhalation and sends blood throughout the body on exhalation. This wave like action, known as “the respiratory arterial pressure wave” is visible in the fingers, where (using the right instrument) we can see the fingers filling with blood during exhalation and emptying of blood during inhalation.
Circulation, Gas Exchange, and Nervous System Governance
Possibly more importantly, the work performed by the diaphragm, a large strong muscle, off-loads the work performed by the heart and vascular system, moving more blood, and at the same time giving the heart much needed rest! Of course, over and above circulation, breathing is about “gas exchange”, the intake of oxygen and the output of carbon dioxide. Respiration and circulation are the mechanisms by which gas exchange occurs. Better breathing and better circulation result in better gas exchange. Ultimately circulation and blood flow are a function of the central nervous system which carefully monitors our biological status. When we are breathing “coherently”, the nervous system “relaxes”, and when it does both body and mind follow. This can be observed using instruments that measure electrical activity in the brain, the muscles, and the skin.
Respiratory Sinus Arrhythmia – Breathing Induced Heart Rate Variability
When we inhale, our heart rate tends to increase – when we exhale it tends to decrease. This phenomenon is known as “respiratory sinus arrthythmia”. I dislike this term because it makes it sound as though this variation in heart rate as a consequence of breathing is pathological, when in fact the opposite is true – the lack of this variation is pathological. To avoid this misunderstanding, I prefer the term “respiratory sinus rhythmia” or “breathing induced heart rate variability”.
The accepted physiological mechanism for breathing induced variation in heart rate is variation in the respiratory arterial pressure wave. When the respiratory arterial pressure wave rises in the arterial circulation, heart rate falls. When the respiratory arterial pressure wave falls in the arterial circulation, heart rate rises. Referring to the graph, heart rate is blue and the respiratory arterial pressure wave (the “Valsalva Wave”) is red. We can see that they tend to be 180 degrees out of phase, specifically, when we are breathing “coherently” (i.e., at resonance).
Valsalva Wave Pro Depicting Heart Rate And Respiratory Arterial Pressure Wave
We measure the variation in heart rate in “beats”. For example, when we inhale, the heart beat rate may increase to 100 beats per minute (BPM); when we exhale it may slow down to 60 BPM. The difference is 40 beats. If we monitor this change in heart rate with an instrument, for example Valsalva Wave Pro, we can see the tendency for the heart rate to vary with each cycle of respiration. If we employ 40-60% of diaphragm range, AND we relax, the variation in heart rate will tend to be in the 20-30 beat range. This is a goal of the Coherent Breathing method, to cultivate a heart rate variability of 20-30 beats. The current understanding is that this correlates with changes in respiratory arterial pressure wave of ~2% as measured at the upper extremities (e.g., finger, ear lobe, etc).
The important thing to understand is that the heart rate is a very good indicator of autonomic status and activity. Decreasing heart rate indicates increasing parasympathetic emphasis. Increasing heart rate indicates decreasing parasympathetic emphasis, with a net sympathetic effect. So, by breathing “coherently”, we can consciously modify the status of our autonomic nervous system. The result is that each time we inhale, the entire body/mind tends to flex; each time we exhale the entire body/mind tends to relax. The net effect is “balance.”
Benefits of Breathing “Coherently”
Central nervous system balance yields many psychological and physiological changes including mental and physical comfort, better communication, better performance, better sleep, etc. The typical adult breathes erratically, using about 10% of available diaphragm range. This breathing pattern yields enough gas exchange and blood flow for us to “survive” but not to “thrive.” Our goal is to learn to employ 40-60% of diaphragm range in a rhythmic fashion.
Coherent Breathing – The Method
The Coherent Breathing method is very simple, yet specific. I summarize it as, “Breathe, then relax.” It sounds simple, and it is. At the same time, there are a few things to know. With heart rate variability (HRV) amplitude as the measure, I see that clients fall into two general categories: those that respond promptly and dramatically to breathing alone, and those that do not (where the goal is 20-30 beats of difference between peak and valley heart rates). Certainly there is a gray zone, but for purposes of keeping it simple lets think of clients as being in one of these two groups. Then the question is, “Why do some respond promptly and others not?” While there is clearly an age component to it, I’ve come to see the issue primarily as one of entrainment. In other words, the longer one has been breathing “short and shallow” and the longer one’s been living with the autonomic consequence, i.e. sympathetic bias, the more likely it is to take time for them to “unwind” this pattern.
Breathe – Then Relax
“Breathe, then relax.” “Relax, then breathe,” does not work. Why not? Because the autonomic nervous system will not allow relaxation while our breathing is rapid and shallow. Try as you might, but without correcting breathing frequency and depth, little progress will be made. Instead, try having your clients simply breathe coherently for 8-12 minutes. Usually, depending on severity, the autonomic nervous system will begin to shift, and as it does small muscle motor units throughout the body will begin to relax. We can usually feel this in face first where all at once we become aware that the facial muscles are tense. Hand temperature is another simple low cost indicator that blood flow is increasing; however, I find that the face is the clearest initial indicator. At this point, we can begin progressive relaxation, first focusing on the face, then the hands, then the pelvic floor, then the feet. [In total there are 10 points that I refer to as “bridges”, but they can be generalized to 6 and ultimately to these 4.] With this as the basic 20 minute practice, and the incorporation of Coherent Breathing into daily life, the autonomic nervous system begins to loosen its defensive posture. With this comes increased mental and physical comfort, increased flexibility, better communication, easier sleep, etc. Maybe most importantly, once we’ve retrained our breathing and “flushed” the tension from the system we’ve increased our immunity to all forms of stress.
Stephen Elliott is President of COHERENCE – The New Science of Breath and is the principal author of The New Science of Breath and Coherent Breathing – The Definitive Method. You can find out more about Stephen and Coherent Breathing at www.coherence.com. Coherent Breathing is a registered trademark of Coherence LLC, Allen, Texas.