The Physiological Sigh

Most-effective protocol to reduce stress in real-time without having to disengage from stress-inducing activity!

Man covered in notes Sign me up, of course! This sounds WAY too good to be true, but I wouldn’t steer you wrong.  For those of you not aware of this exciting medical finding, Dr. Andrew Huberman conducted an extensive study to compare breathing strategies for stress reduction and the findings revealed:

Physiological sighing for 5 minutes significantly outperformed meditation & 3 other breathing protocols executed for the same duration to reduce stress and improve mood ‘around the clock’ for a 24-hour period!


In the discussion below you will not only learn how to perform the physiological sigh and its health benefits, but also see the details of the study to prove its effectiveness.

A picture of Dr. Huberman sitting down

But first, let me more properly introduce the man behind this critically practical & profound information! Dr. Huberman is an American neuroscientist and tenured associate professor in the Department of Neurobiology and Psychiatry and Behavioral Sciences at Stanford University School of Medicine. He has made major contributions to the fields of brain development, brain plasticity and neural regeneration and repair. 

The logo for Huberman Lab

Luckily for us, in 2021 he launched the “Huberman Lab” podcast with the goal of translating neuroscience into valuable applications for everyday life.  Throughout his podcast episode, “How to Breathe Correctly for Optimal Health, Mood, Learning & Performance,” he discusses the findings of what his laboratory found as the most effective intervention for not only immediate stress reduction, but for the entire day! The podcast link is noted below so you can watch it in its entirety.  You can imagine how much I enjoy the ‘deep dives’ into anatomy and physiology, but I know it’s not for everyone.  I’ll give you the bare bones summary as these results speak for themselves.


The Basis of the Study

Published earlier this year in Cell Reports Medicine, Dr. Huberman, Dr. David Spiegel & team compared three different types of deep breathing with mindfulness meditation.  The goal was to see whether a breathing technique might be as effective as mediation in reducing stress. Researchers sorted 114 people into four groups and asked them to practice mindful meditation or one breathing exercise listed below for 5 minutes a day for 28 days.

A chart of benefits from physiological sighing

Cyclic sighing, box breathing and cyclic hyperventilation were compared to mindful meditation to determine which protocols would best promote effective and efficient stress management.

To perform a cyclic (physiological) sigh, you inhale through the nose to fully inflate the lungs, then quickly inhale again, followed by a long exhalation (fully deflating the lungs).

Box breathing involves equal bouts of inhalation, breath hold, exhalation, breath hold, with volume determined by your carbon dioxide tolerance.

Finally, cyclic hyperventilation involves up to 30 long, forceful inhalation/short exhalation cycles followed by a 15-second breath hold.

By analyzing wearable data sensors (including heart rate variability and other physical parameters) it was determined that breathwork, and more specifically cyclic sighing, was more effective than meditation for stress management.  And the best part is that it takes less than FIVE MINUTES of practice per day to achieve a better state of well-being. 

Now don’t get me wrong.  Mindful meditation is extremely beneficial.  It is well-documented that 10-plus minutes of meditation per day helps to improve focus, memory, cognition and learning.  But five minutes of breath work per day led to greater reductions in stress than five minutes of meditation!

Keep in mind, there is ZERO cost needed to improve stress management and well-being.  Simply adjusting normal breathing patterns at rest can help to regulate anxiety, nighttime sleep and hyperactivity of the brain


Instructions for Physiological Sighing


History & Medical Benefits of Physiological Sigh

Initially studied in the 1930’s, sighing was observed as an involuntary breathing pattern that occurs most often before we are about to fall asleep, during sleep, and when we cry.  It re-emerged in the 2010’s based upon research of UCLA neurobiologist Jack Feldman and Stanford biochemist Mark Kransow.

As you will hear in the full version of the podcast, there are many body systems that work in parallel to achieve specific functions.  Let’s focus now on just one aspect of how this additional ‘second, short, nasal inhale’ makes all the difference in the body’s ability to achieve long-lasting stress reduction and mood change.

A chart showing gas exchange in the lungs

The lungs themselves do not move on their own.  Like bellows, they expand and compress from the skeletal muscle around them, mainly the diaphragm and the intercostal muscles.  One important fact is that the lungs have little sacs at the bottom of them where oxygen exchange occurs with the blood supply.  Due to most people having inefficient breathing strategies, the lungs are left with a lot of ‘dead space,’ meaning the lungs are not fully utilized.  That intense inhalation helps to “pop” the alveoli to undo the “collapse,” and therefore, maximizes the surface area for balancing oxygen and carbon dioxide exchange in the blood.  (Fun fact: If you laid out all the alveoli from one person, they would cover an entire tennis court!)

A chart of physiological sigh instructions

There are tremendous health benefits associated with this “sigh.”  In short, but very importantly, you are switching from your sympathetic to your parasympathetic nervous system, which slows heart rate, decreases blood pressure, improves digestion, lowers anxiety & improves mood, just to name a few!  

We need to be able to freely and deliberately switch gears and pass between sympathetic and parasympathetic states. Acute stress can be beneficial in reactionary situations, like that quick inhale when you are afraid or in danger, which triggers your fight or flight response.  But we must be able to turn it off and recover as we are not meant to constantly live there.

House MD giving two thumbs up

In this day & age, there are so many hacks and gimmicks out there, it can get overwhelming for sure.  The physiological sigh is not a hack but an involuntary response to our body’s needs to regulate gas levels in the blood, but we can also voluntarily sigh to produce immediate and long-lasting improvements to our stress and mood.

 “People think taking a deep breath is the way to ease stress, but it turns out that exhaling slowly is a better way to calm yourself,” Dr. David Spiegel highlights.   The physiological sigh uses the body to control the mind, rather than trying to use the mind to control the mind.  I mean, it doesn’t get any easier than that! I do it when I get in the car every morning, what about you?


YouTube Videos

3 min version : 

Full Podcast:

  • Bonus information for watching:
    • He provides an absolute hiccup solution (around minute marker 1:45)
    • He describes how a ‘side stitch’ is not a cramp but more so ‘referred pain’ from the liver as the diaphragm sits on it and affects its position/mobility during breathing (around 1:36 min)

For reference, this is the study the podcast & article are noting:

Brief structured respiration practices enhance mood and reduce physiological arousal