COHERENCE®   & The New Science of Breath®




                                                                                                                                                     April 29, 2009

The Science: also see the discussion of the valsalva wave

COHERENCE(TM) represents a formative “New Science of Breath(TM)". This new science is based on a breakthrough in the understanding of autonomic nervous system balance and its relationship to subtle heart and breathing rhythms.

"Coherence", refers to amplitude, frequency, and phase regularity of the intrinsic autonomic nervous system rhythm as reflected in the variability of the heart rhythm (HRV). Amplitude and frequency characteristics of this rhythm have been shown to be indicative of both physiological and psychological status. Amplitude of this rhythm is primarily a function of breathing frequency/depth whereas coherence of this rhythm is primarily a function of breathing "synchrony", for without synchronous breathing, although relative, coherence is not possible.


Maximal amplitude and coherence result when heart rate variability (HRV) and breathing rhythms are synchronized. This synchrony both results-in, and is a result-of, balance between sympathetic and parasympathetic functions as well as a synergistic harmony between autonomic and somatic branches of the central nervous system. (The autonomic nervous system consists principally of two antagonistic divisions, the sympathetic division - responsible for "activating" functions, and the parasympathetic division - responsible for "deactivating" functions. Working together, sympathetic and parasympathetic divisions "autonomously" strive to establish and maintain homeostasis.)

         FIGURE 1: Breathing Rate vs. Autonomic Nervous System Emphasis                              ("Mild", "moderate", and "severe" divisions are arbitrary.)

For adults in the state of rest or semi-activity, optimal synchrony between HRV and breathing rhythms occurs at a specific frequency, this being 1 cycle in ~12 seconds, or 5 cycles in ~1 minute. When operating at this pace, cardiopulmonary efficiency and effectiveness are maximized and in keeping with the fundamental underlying autonomic nervous system rhythm. Cardiopulmonary operation at this rhythm is characterized by relatively low average heartbeat rate, maximized heart rate variability amplitude, and maximized heart rate variability coherence.

There is growing acceptance within the broad medical community that HRV amplitude is a key indicator of health status, adequate amplitude being indicative of sound health and inadequate amplitude being indicative of health risk. Furthermore, HRV "coherence" is emerging as a key indicator of autonomic nervous system balance, this balance or lack thereof manifesting in overall emotional and physiological status - coherence being strongly indicative of psychological/ physiological harmony and incoherence being equally indicative of its opposite.(7)

Referring to FIGURE 1, when in the state of rest or semi-activity, the autonomic nervous system takes its cue from the breathing frequency. Breathing at a relatively rapid pace, even while seated and otherwise relaxed, results in an autonomic shift toward sympathetic emphasis, sympathetic emphasis often being characterized as the “fight or flight” response. The degree of emphasis varies directly with the rate of breathing. Sympathetic emphasis is characterized by relatively faster average heartbeat rate, reduced heart rate variability, increased heart duty cycle, and reduced heart rate variability coherence, as well as other physiological and psychological changes.

There is an emerging understanding within the medical community that sympathetic dominance underlies many modern day maladies including anxiety and hypertension. What is not understood is the root cause of sympathetic dominance. COHERENCE(TM) asserts the theory that the root cause of sympathetic dominance is in fact suboptimal breathing. Breathing at the The Fundamental Quiescent Rhythm(TM), brings about autonomic nervous system balance, correcting the state of sympathetic over activity and parasympathetic under activity and its consequences including internal tension, anxiety, and potentially the myriad of other psycho-physiological challenges to health and well being resulting from this imbalance. By adopting the breathing rate of 1 cycle in ~12 seconds or 5 cycles in ~1 minute as one’s “normal” resting breathing rate, autonomic balance can be realized and sympathetic dominance and its myriad affects averted. No Specific claims are made regarding health benefits.

Why 1 cycle in ~12 seconds? For adults in the state of rest or semi-activity, if the breathing cycle is synchronized with the heart rate variability cycle, the resulting center frequency and primary component of the heart rate variability frequency spectrum is .085 cycles per second or 1 cycle in ~12 seconds. Because this is the "natural frequency" at which the cardiopulmonary system inclusive of nervous system aspects resonates, at this frequency, heart rate variability and coherence are maximal. You can experience this rhythm in an instructive format by clicking here (~500K). (Requires RealPlayer)

In summary, COHERENCE(TM) asserts the following principles:

  1. While at rest, the adult cardiopulmonary system inclusive of central nervous system aspects, resonates at a specific frequency, 1 cycle in ~12 seconds – the Fundamental Quiescent Rhythm(TM), this frequency being essentially the same for all adults.
  2. Human cardiopulmonary functions are organized to work most effectively and efficiently when in harmony with this rhythm.
  3. Operation at this rhythm is indicative of autonomic nervous system balance.
  4. Optimal autonomic balance - with optimal coherence, is a result of synchrony between the breathing cycle and this Fundamental Quiescent Rhythm(TM).
  5. Rapid breathing while at rest results in autonomic nervous system imbalance,specifically a shift toward sympathetic emphasis. Increased heartbeat rate and decreased HRV amplitude are evidence of this shift.
  6. In a “healthy” individual, HRV amplitude is a function of breathing frequency and depth. Consequently, in a “healthy” individual, low HRV is indicative of suboptimal breathing.
  7. Because, while at rest, the average adult breathes at a rate of 10-20 breaths per minute, they exist in a state of persistent sympathetic emphasis.
  8. By breathing at the frequency at which the cardiopulmonary system (inclusive of central nervous system aspects) naturally resonates, one can achieve optimal autonomic balance and avert sympathetic dominance.
  9. It is desirable to achieve and maintain autonomic balance on an ongoing basis as life circumstances permit. This is the premise of COHERENCE(TM), the company.

COHERENCE(TM) provides Breathing Pacemaker(TM) products for the purpose of synchronizing the breathing cycle with an external reference signal operating at the Fundamental Quiescent Rhythm(TM) of ~12 seconds, resulting in Coherent Breathing(TM) and optimal autonomic nervous system balance.

For those that are interested, much of this author's focus has been on the function of autonomic balance and coherence in the practice of yoga and meditation. These insights are shared in the evolving page, Yoga & Meditation.

To view "The Science" section in its entirety click here. This page is large. Depending on your connection speed it may take a few minutes to download. Thank you for your patience.



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COHERENCE, The New Science of Breath, and What Was Lost Is Not A Chord But A Rhythm are trademarks of COHERENCE L.L.C.
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