Taking a deep breath when you're stressed is solid advice, but how you take that breath is what really counts.

People in high-stakes environments (that’s you) often use box breathing: four in, hold for four, four out, hold for four. It works, but is it the most effective way to calm the nervous system, allowing you to stay clear-headed and take action?

Probably not.

Across all cohorts of the UnBurnable course, we’ve taught a range of downregulation techniques, and breath consistently stands out as the most universally effective. It’s fast, accessible, and doesn’t require prep or special knowledge.

It's also one of the most potent ways to get out of the red line.

The Red Line ​ When under pressure, the sympathetic nervous system often revs too high and takes you into the figurative red line, where thinking becomes white noise or vision tunnels. ​ Targeted breathing techniques can reduce sympathetic arousal and restore clarity. ​ The idea isn't to create a gelatinized, blissful state; it's to get you just enough below the red line so you can think, function, and get moving again.

The Recipe

There are four key ingredients that help downregulate the nervous system through breath:

• Inhale through the nose (exhale through either the nose or pursed lips).
• Breathe low - deeply into the pelvis/feel your belly expand, not the upper chest.
• Keep the pace slow (fewer than 10 breaths per minute).
• Use a 1:2 inhale-to-exhale ratio, which has been shown to trigger a stronger parasympathetic response than the 1:1 rhythm used in box breathing.

The Nose and Nitric Oxide

Nasal breathing gives you access to nitric oxide, which is continually produced in the nasal mucosa. With inhalation, nitric oxide reaches the lungs, promoting pulmonary vasodilation, lowering arterial pressure, and improving oxygenation. These physiological changes support a shift toward parasympathetic activity.

Nasal airflow also stimulates the trigeminal nerve, further increasing parasympathetic tone and decreasing sympathetic drive.

Rate and Ratio

Breathing through the nose at a rate of fewer than 10 breaths per minute, with attention to diaphragmatic expansion (belly breathing), has been shown to optimally induce parasympathetic activation.
​
A 1:2 inhalation-to-exhalation ratio enhances this effect more than a 1:1 equal-duration breathing ratio. While 1:1 breathing (as in box breathing) is functional, 1:2 consistently produces a stronger vagal response.

I opt for a 3:6 breathing count as it gets me under the 10 breaths per minute threshold, maintains the 1:2 ratio, and doesn't feel so slow that I'm getting air hunger.

What About Apnea and Breath Holds?

Adding a brief pause after inhalation or exhalation, as used in box breathing, has not been shown to significantly increase parasympathetic activity. I found this surprising in my research, as an apneic pause has been part of my toolbox for years.

What’s the Goal?

When you're amped up and need to either perform or respond without overreacting, parasympathetic breathing helps turn down the inner tachometer just enough to regain control.

Inhale through the nose, breathe low and slow at a 1:2 ratio.

Keep on rocking,

Robbie O

P.S., Something in here hit home? Hit reply. I read every message and try to respond to as many as I can.

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References

Nasal Nitric Oxide

1. Törnberg DC, Marteus H, Schedin U, et al. Nasal and oral contribution to inhaled and exhaled nitric oxide: a study in tracheotomized patients. Eur Respir J. 2002;19(5):859-864.
2. Sánchez Crespo A, Hallberg J, Lundberg JO, et al. Nasal nitric oxide and regulation of human pulmonary blood flow in the upright position. J Appl Physiol (1985). 2010;108(1):181-188.
3. Lundberg JO. Nitric oxide and the paranasal sinuses. Anat Rec (Hoboken). 2008;291(11):1479-1484.
4. Yu S, Wang D, Guo Y, Shen S, Wang J. Numerical study on the distribution of nitric oxide concentration in the nasal cavity of healthy people during breathing. Nitric Oxide. 2023;130:12-21.
5. Holden WE, Sippel JM, Nelson B, Giraud GD. Greater nasal nitric oxide output during inhalation: effects on air temperature and water content. Respir Physiol Neurobiol. 2009;165(1):22-27.

Nasal Breathing and Parasympathetics

1. Watso JC, Cuba JN, Boutwell SL, et al. Acute nasal breathing lowers diastolic blood pressure and increases parasympathetic contributions to heart rate variability in young adults. Am J Physiol Regul Integr Comp Physiol. 2023;325(6):R797-R808.
2. Fan WH, Ko JH, Lee MJ, Xu G, Lee GS. Response of nasal airway and heart rate variability to controlled nasal breathing. Eur Arch Otorhinolaryngol. 2011;268(4):547-553.
3. Baraniuk JN, Merck SJ. Neuroregulation of human nasal mucosa. Ann N Y Acad Sci. 2009;1170:604-609.
4. Ulusoy S, Bayar Muluk N, Scadding GK, et al. The intranasal trigeminal system: roles in rhinitis (allergic and non-allergic). Eur Rev Med Pharmacol Sci. 2022;26(2 Suppl):25-37.

Breathing Rate and Type of Breathing

1. Zaccaro A, Piarulli A, Laurino M, et al. How breath-control can change your life: a systematic review on psycho-physiological correlates of slow breathing. Front Hum Neurosci. 2018;12:353.
2. Sevoz-Couche C, Laborde S. Heart rate variability and slow-paced breathing: when coherence meets resonance. Neurosci Biobehav Rev. 2022;135:104576.
3. Gerritsen RJS, Band GPH. Breath of life: the respiratory vagal stimulation model of contemplative activity. Front Hum Neurosci. 2018;12:397. doi:10.3389/fnhum.2018.00397
4. Fan WH, Ko JH, Lee MJ, Xu G, Lee GS. Response of nasal airway and heart rate variability to controlled nasal breathing. Eur Arch Otorhinolaryngol. 2011;268(4):547-553.

Prolonged Exhalation is More Potent than Equal Inhalation–Exhalation

1. Bae D, Matthews JJL, Chen JJ, Mah L. Increased exhalation to inhalation ratio during breathing enhances high-frequency heart rate variability in healthy adults. Psychophysiology. 2021;58(11):e13905.
2. Van Diest I, Verstappen K, Aubert AE, et al. Inhalation/exhalation ratio modulates the effect of slow breathing on heart rate variability and relaxation. Appl Psychophysiol Biofeedback. 2014;39(3-4):171-180.