Breathing assessment provides a roadmap for training clients to replace dysfunctional breathing with healthy breathing. Correcting breathing fundamentals is critical for heart rate variability biofeedback (HRVB) using paced breathing at the resonance frequency (RF) or 6 breaths per minute. Most clients must learn to rely more on their diaphragm to ventilate the lungs, slow their respiration rate (RR), and breathe consistently to produce robust resonance effects.
This unit addresses V. HRV Biofeedback Strategies: D. How to teach resonance frequency breathing.
Professionals completing this unit will be able to discuss:
A. The characteristics of effortless breathing
B. Core elements of teaching effortless breathing
C. Physiological effects of effortless breathing
D. Medical cautions before teaching effortless breathing
E. Biofeedback modalities used to teach effortless breathing
F. Exercises to complement effortless breathing training
This unit covers Common Breathing Misconceptions, Healthy Breathing Roadmap, Medical Cautions, Breathing Basics, Physiological Effects of Healthy Breathing, Modalities for Teaching Healthy Breathing, Healthy Breathing Training, and Breathing Practice.
Please click on the podcast icon below to hear a full-length lecture.
Appreciation
This unit draws heavily on Dr. Inna Khazan's clinical experience and extensive writing and presentations on healthy breathing.
Evaluate breathing during a psychophysiological assessment, correct breathing fundamentals, and then teach RF breathing to exercise the baroreflex.
If we don’t correct dysfunctional breathing patterns like overbreathing, they could compromise the effectiveness of HRVB training.
For example, overbreathing is associated with RRs far above the RF range of 4.5-7.5 bpm. Also, breathing is irregular--not sinusoidal. Together, these characteristics preclude strong resonance effects.
Before HRVB, respiration and the baroreflex are usually out of phase resulting in weak resonance effects. HRVB brings breathing and the baroreflex into phase. Graphic adapted from Elite Academy.
HRVB training slows breathing to the baroreflex’s rhythm aligning these processes and significantly increasing resonance effects. Graphic adapted from Elite Academy.
Slowing breathing to rates between 4.5-6.5 bpm for adults and 6.5-9.5 bpm for children increases RSA (Lehrer & Gevirtz, 2014). Graphic adapted from Elite Academy.
Increased RSA immediately “exercises” the baroreflex without changing vagal tone or tightening BP regulation. Those changes require weeks of practice. HRVB can increase RSA 4-10 times compared to resting (Lehrer et al., 2020b; Vaschillo et al., 2002).
Caption: The red waveform shows HR oscillations while resting without breathing instructions or feedback. The blue waveform shows HR oscillations with HRV biofeedback and breathing from 4.5-6.5 bpm.
Successful clients learn to breathe near their RF and achieve ocean-like breathing cycles without pacing or feedback.
Effortless breathing could be hazardous if your client suffers from diseases that produce metabolic acidoses like
diabetes and kidney disease. In these cases, overbreathing attempts to compensate for abnormal acid-base
balance, and slow-paced breathing could endanger health.
Clients diagnosed
with low blood pressure should be careful since slow-paced breathing might further lower blood pressure.
Finally, slow-paced breathing might produce a functional overdose if your client takes anti-hypertensive medication, insulin, or a thyroid supplement. If medication adjustment appears
necessary, your client should consult the supervising physician before reducing dosage (Fried & Grimaldi, 1993).
Breathing Basics
Healthy breathing matches metabolic needs, production of CO2, and breath depth and rate. We should maintain optimal breathing chemistry for each activity level and breathing rate.
Although rapid breathing does not always signal overbreathing and slow breathing does not always indicate health, there are correlations (Khazan, 2021).
Breathing should be mindful with focus on the abdomen, effortless, between 5-7 breaths per minute, supported by loose clothing, posture, and ergonomics that promote healthy breathing.
They should breathe at
a comfortable depth (like smelling a flower), exhaling longer than inhaling. Breathing will calm your client when its depth and rate satisfy their resting body’s metabolic needs (Khazan, 2021). Elena Sherengovskaya/Shutterstock.com.
Discourage typical deep breathing, where a client inhales a massive breath and inevitably exhales too quickly because this promotes overbreathing and expels too much CO2 (Khazan, 2021). My colleague Don Moss no longer uses the word "deep" when coaching breathing (Moss, 2022).
Relaxed breathing increases metabolism and the carbon dioxide concentration of arterial blood compared to thoracic breathing. At rest, we only excrete 12-15% of blood CO2. Conserving CO2 lowers blood pH, weakens the bond between hemoglobin and oxygen, and increases oxygen delivery to body tissues. This phenomenon is called the Bohr effect. Check out MEDCRAMvideos YouTube lecture Oxygen Hemoglobin Dissociation Curve Explained Clearly! The breathing chemistry graphics were adapted from Inna Khazan.
Overbreathing
Conversely, low CO2 levels due to overbreathing or hyperventilation raise blood pH and reduce oxygen delivery to body tissues since oxygen remains tightly bound to the hemoglobin molecules (Fox & Rompolski, 2022).
Healthy Breathing
Healthy breathing can increase peripheral blood flow when the RR slows to the resonance frequency (RF) range of 4.6 to 7.5 bpm, and end-tidal CO2 normalizes to 5% or 36 mmHg. Peripheral vasodilation can increase perfusion and delivery of oxygen and glucose to the brain, reduce peripheral resistance, and promote hand-warming. These changes are crucial for executive functioning and treating hypertension, vascular headache, and Raynaud's disease. Breathing in the RF range can slow HR and increase vagal tone and HRV.
Biofeedback Modalities for Teaching Healthy Breathing
The critical modalities for teaching healthy breathing include respirometer biofeedback, accessory muscle SEMG
biofeedback, capnographic (end-tidal CO2) biofeedback, and oximetric (oxygen saturation)
biofeedback.
The HR and breathing waveforms should be synchronous. The phase difference should approach 0 degrees. You can estimate the degree of
synchrony by observing heart rate change with respect to the breathing cycle: 0 degrees = the peaks and valleys are
perfectly aligned, 180 degrees = heart rate increases during exhalation and decreases during inhalation, and 90 degrees
= heart rate increases mid-inhalation and decreases mid-exhalation (Lehrer et al., 2013).
The mean RR is 4.46 on the screen below. Both waveforms are sinusoidal with high amplitude and nearly in-phase (their peaks and valleys almost coincide).
Accessory Muscle SEMG Biofeedback
Down-train accessory SEMG to values below 2 microvolts. This benchmark will vary with equipment, settings,
placement, posture, and amount of adipose tissue.
Capnometric Biofeedback
Train end-tidal CO2 to values between 35 and 45 torr (5% -6%). Values below 33 torr may
indicate overbreathing, and those above 45 torr can be caused by hypoventilation.
A capnometer monitors end-tidal CO2, the percentage of CO2 in exhaled air at the end of exhalation.
A pulse oximeter utilizes a photoplethysmograph (PPG) sensor to measure blood
oxygen saturation from a finger or earlobe. Oximeters compare the red and blue wavelengths in the blood to measure hemoglobin oxygen transport. During overbreathing, oxygen saturation (PaO2) may approach 100%. PaO2 values over 98% signal that less O2 and nitric oxide are available for body tissues (Gilbert, 2019). Train clients to achieve oxygen saturation values between 95% and 98%. A MindMedia oximetry sensor is shown below.
Healthy Breathing Training
You can teach healthy breathing as a component of weekly HRVB training sessions. Provide three or more 3-minute segments (some without feedback and pacing), each followed by coaching. Don’t progress to HRVB until your client has corrected dysfunctional breathing.
The red heart rate and blue respirometer tracings are synchronous with an almost 0-degree phase relationship in the screen below.
Robert Fried (1987)
recommends shifting breathing to the abdomen and slowing its rate. Clients should take normal-sized inhalations and not emphasize breath depth or volume. They should exhale slowly through the nostrils or pursed lips.
Encourage clients to wear nonrestrictive clothing, loosen their clothing to allow the diaphragm to move freely, and assume a comfortable position like reclining. Invite them to place one hand on the abdomen and the other on the chest for feedback (Khazan, 2021).
Some clients may find the image of a balloon helpful in shifting from thoracic to
abdominal breathing and remembering when the stomach should expand and contract.
Inhale -- the stomach expands, inflating the balloon.
Exhale -- the stomach contracts, delating the balloon.
Encourage mindful effortless breathing to prevent larger tidal volumes and faster exhalation that result in overbreathing.
Engage passive volition by using words like "allow," "let,", and "permit," and avoiding "correct," "effort," "try," and "work."
Demonstrate low-and-slow breathing and allow clients several minutes of practice in your clinic.
Click on the Read More button for sample instructions from Inna Khazan.
"Let's practice low-and-slow breathing. Allow your breath to shift lower towards your abdomen and to slow down gently . To help guide your breath lower, imagine that there is a balloon in your belly. What color is it? …. Now, with every inhalation, imagine that you are gently inflating the balloon and with every exhalation, you are allowing the balloon to deflate."
"Do not push your stomach out, do not pull it back in. In fact, do not apply any effort at all.
Provide your body with some guidance, and then let your body breathe for you.
This is all about letting your breathing happen as opposed to making it happen."
"Keep in mind that your body knows exactly how to breathe low and slow. When you were a baby and a young child, you were breathing this way all the time. You have a few years of practice. This is kind of like riding a bike; you don’t forget how to do it. You just need to let your body do what it knows how to do. Watch me doing this first, and then join in whenever you are ready.”
"Let’s shift the breath down from the chest to the belly, take a normal-sized comfortable breath in, and exhale slowly, perhaps blowing air out through pursed lips, as if you are blowing out a candle.
Allow yourself to exhale fully, do not rush the next inhalation
Again, take a normal-sized comfortable breath in, exhale slowly and fully."
Repeat for 5 or 6 breaths (Khazan, 2021).
Help Clients Recover Their Breathing Reflex
The Breathing Reflex
The breathing reflex is a physiological drive to inhale in response to rising CO2 levels. Clients may override the breathing reflex during overbreathing. They inhale too early before CO2 levels rise to the level that triggers the next breath, lowering blood CO2 levels.
This “hijacking” of the breathing reflex may represent an attempt to catch one’s breath due to fear of insufficient oxygen or to reduce anxiety (Khazan, 2021).
Several "red flags" can signal effortful breathing. First, accessory muscle (e.g., trapezius and scalene) SEMG increases. A trapezius-scalene placement is sensitive to breathing effort.
A
BioGraph ®
Infiniti accessory muscle training screen used to correct clavicular breathing is shown below.
Third, the respirometer waveform may lose its smoothness when clients try harder.
Breathing Practice
Breathing practice can help generalize breathing skills to everyday life. Clients may benefit from breathing apps and pacers. Encourage them to practice an exercise 20 minutes daily, log the activity, and discuss it at the start of the next training session. Also, encourage mindful low-and-slow breathing.
Invite your client to observe their breathing several times a day in different settings. When they find themselves overbreathing, they can remind themselves to breathe with less effort.
Encourage Practice with Breathing Apps and Breathing Pacers
You may use a computer, pad, and smartphone apps that provide auditory or visual pacing. Try them out to find the apps that offer the adjustability and ease of use best for your clients. Click on the Read More button for computer software and smartphone breathing apps, and breathing pacers.
Consider
Coherence Coach and EZ-Air Plus for computers.
Popular apps are available for both Android and Apple platforms.
Assign practice with breathing pacers and then gradually fade them. Click on the Alliant link to download these free tracks.
Healthy Breathing Tips
Erik Peper (1994) and Inna Khazan (2021) have proposed several invaluable breathing suggestions.
The BioGraph ® Infiniti display below shows healthy inhalation and exhalation in which the abdomen gradually
expands and contracts.
The BioTrace+/NeXus-10 training screen below was designed to teach effortless breathing. The balloon's inflation and deflation mirror the respiration sensor's rhythmic expansion and contraction.
Mary's client wants to breathe deeply during her HRV biofeedback training since she's
read that this breathing pattern is healthy. How should Mary respond?
Mary could explain that deep breathing will reduce her HRV. She might invite her client to perform a simple
experiment where she observes the peak-to-trough difference in heart rate during both breathing patterns. Deep
breathing will produce a smaller difference than healthy breathing.
Glossary
accessory muscles: the sternocleidomastoid, pectoralis minor, scalene, and
trapezius muscles, which are used during forceful breathing, as well as during clavicular and thoracic
breathing.
apnea: breath suspension.
bicarbonates: the salts of carbonic acid that contain HC03.
capnometer: an instrument that monitors the carbon dioxide (CO2) concentration in
an air sample (end-tidal CO2) by measuring the absorption of infrared light.
clavicular breathing: a breathing pattern that primarily relies on the external
intercostals and the accessory muscles to inflate the lungs, resulting in a more rapid RR, excessive
energy consumption, and incomplete ventilation of the lungs.
diaphragm: the dome-shaped muscle whose contraction enlarges the vertical diameter
of the chest cavity and accounts for about 75% of air movement into the lungs during relaxed breathing.
effortless breathing: Erik Peper’s relaxed breathing method in
which the client uses about 70% of maximum effort, attention settles below the waist, and the volume of air moving through
the lungs increases. The subjective experience is that "my body breathes itself."
end-tidal CO2: the percentage of CO2
in exhaled air at the end of exhalation.
hyperventilation syndrome (HVS): a respiratory disorder that has been increasingly
reconceptualized as a behavioral breathlessness syndromein which hyperventilation is the consequence and not the cause of the
disorder. The traditional model that hyperventilation results in reduced arterial CO2 levels
has been challenged by the finding that many HVS patients have normal arterial CO2 levels
during attacks.
metabolic acidosis: a pH imbalance in which the body has accumulated excessive acid and has
insufficient bicarbonate to neutralize its effects. In diabetes and kidney disease, hyperventilation attempts to compensate for abnormal acid-base balance. Slower breathing could endanger health.
overbreathing: subtle breathing behaviors like sighs and yawns reduce
end-tidal CO2 below 5%, exceeding the body's need to eliminate CO2.
pulse oximeter: a device that measures dissolved oxygen in the bloodstream using a photoplethysmograph
sensor placed against a finger or earlobe.
respiratory amplitude: the excursion of an abdominal strain gauge.
resonance frequency (RF): the frequency at which a system, like the cardiovascular
system, can be activated or stimulated.
reverse breathing: the abdomen expands during exhalation and contracts during
inhalation, often resulting in incomplete ventilation of the lungs.
thoracic breathing: a breathing pattern that primarily relies on the external
intercostals to inflate the lungs, resulting in a more rapid RR, excessive energy consumption, and insufficient ventilation of the lungs.
torr: the unit of atmospheric pressure, named after Torricelli, which equals 1 millimeter of mercury
(mmHg) and is used to measure end-tidal CO2.
trapezius-scalene placement: active SEMG electrodes are located on the upper trapezius and scalene
muscles to measure respiratory effort.
Test Yourself
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REVIEW FLASHCARDS ON QUIZLET
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Visit the BioSource Software Website
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For Biofeedback, BioSource Software offers Human Physiology to satisfy BCIA's Human Anatomy & Physiology requirement. For Neurofeedback, BioSource provides Physiological Psychology to satisfy BCIA's Physiological Psychology requirement.
BCIA has accredited each course, and they combine affordable pricing ($150) with industry-leading content.
Assignment
The screens below show breathing with a hand on the abdomen and then a book. Which produced the best results? Why?
Inspect the blue respirometer tracings. The bottom tracing is more sinusoidal. Examine the red heart rate tracings.
The bottom tracing is also more sinusoidal. Finally, check for synchrony. The bottom tracing shows a closer alignment
of the peaks and valleys for both signals. For this client, the book on the abdomen method was more effective.
Which breathing problem is illustrated by the screen below? How did this problem affect the distribution of HRV
power?
The 12-second pause after the second breath is consistent with apnea. Note the low LF amplitude and dominant
frequency in the VLF range due to disordered breathing. Finally, observe the absence of a sinusoidal waveform in
the red heart rate tracing and the absence of synchrony between both the heart rate and respirometer signals.
These recordings are from chronic pain patients who received treatment in an interdisciplinary chronic pain program.
References
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[Abstract]. Applied Psychophysiology and Biofeedback, 32(1), 52.
Fried, R. (1987). The hyperventilation syndrome: Research and clinical
treatment. John Hopkins University Press.
Fried, R., & Grimaldi, J. (1993). The psychology and physiology of breathing. Springer.
Gevirtz, R. N. (2005). Heart rate variability biofeedback in clinical
practice. AAPB Fall workshop.
Gilbert, C. (2019).
A guide to monitoring respiration. Biofeedback, 47(1), 6-11. https://doi.org/10.5298/1081-5937-47.1.02
Kabins, A., Goedde, J., Layne, B., & Grant, J. (2008). Brief coaching increases inhalation volume [Abstract]. Applied
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Khazan, I. (2019). Biofeedback and mindfulness in everyday life: Practical solutions for improving your health and performance. W. W. Norton & Company.
Khazan, I. (2021). Respiratory anatomy and physiology. BCIA HRV Biofeedback Certificate of Completion Didactic workshop.
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