Which breathing exercises help alleviate stress?

Intuitively most people would agree that breathing exercises can help with stress. The links between the two are many and intimate and in this article, guest writer Anastasis Tzanis – a yoga and breathwork teacher, and a registered nutrition practitioner – will aim to shed some light into the types of breathing that can help us relieve stress and those that do not.

Skip to Key Takeaways

Prior to delving into the breathing techniques, I would like to offer a crash-course on respiratory biochemistry as I expect this will come handy for some readers. Ultimately all types of breathing have an effect in our blood’s biochemistry. There are three gasses in the blood that are affected by the way we breathe: Oxygen, Carbon Dioxide, Nitric Oxide.


  • The primary reason why we breathe
  • Necessary for aerobic respiration
  • To be used in aerobic respiration it needs to be delivered in the mitochondria
  • Oxygen can only be transported in the bloodstream through haemoglobin
  • Haemoglobin stays almost always fully saturated with oxygen1
  • It doesn’t affect the blood’s pH

Carbon Dioxide:

  • Is a by-product of metabolism, which we get rid of through exhalations
  • It has an acidic effect in the blood
  • Due to the Bohr effect, it is needed for oxygen to enter the cells. Low levels of CO2 will trap oxygen in the bloodstream
  • It is the key determinant of our breathing cycle. We feel the urge to breathe in when levels of CO2 reach our tolerance level

Nitric Oxide:

  • It is produced primarily in the upper airway, in the paranasal sinuses
  • It sterilises the air inhaled and acts as a vasodilator
  • It acts as a neurotransmitter and singling molecule of the immune system Which breathing exercises can help with stress?

The breathing exercises I will present are mentioned from easiest to more advanced.

  1. Slow breathing aiming for 6 breaths per minute

Which breathing exercises

Slow breathing is one of the most researched breathing techniques. Even at 12 breaths per minute the Parasympathetic Nervous System can get activated2. It is however at breaths per minute (bpm) that Heart Rate variability appears to pick3.

Note: 60 breaths per minute (bpm) = 1 Hz, 6 bpm = 0.1 Hz

Six breaths per minute have also been shown to reduce the sensitivity to hypercapnia and hypoxia, two common consequences of high stress4.

How to slow down your breath

  • Close your eyes
  • Follow your breath
  • Elongate your breathing cycling while maintaining your body in a calm state
  • Every 3-5 cycles try to prolong the cycle a bit further
  1. Slow breathing with a prolonged exhalation. 1:2 in/out ratio

When different ratios of inhalation to exhalation were tested it was shown that only two were useful5 for dealing with stress (subjects were exposed to a small electroshocks):

  • In : Out = 1 : 1 was effective for dealing with stress that was expected
  • In : Out = 1 : 4 was effective for dealing with stress that was either expected or unexpected

You can watch a review of this study here. A ratio of 1:2 is often accessible to most individuals and in those with a good respiratory capacity can be sustained throughout the day.

How to prolong your exhalation:

  • Close your eyes
  • Follow your breath & slow it down
  • Count in your mind the length of the inhalation and exhalation
  • Try to establish a ratio of 1 to 2. For each count of one on the inhalation exhale for two
  • This exercise can be used to initiate you at breathing with a prolonged exhalation
  1. Light breathing

As the delivery of oxygen to our cells depends on CO2, we need to train our CO2 tolerance in order to enhance our delivery of oxygen to our cells (including the ones of the nervous system). Hyperventilation will deprive our cells of oxygen6.

Light breathing is a gentle way of training our CO2 tolerance. It’s worth remembering that if we increase CO2 by too much, we are likely to cause more stress7 which is why this exercise is more appropriate for those with some experience in breathwork.

How to practice light breathing

  • Close your eyes
  • Follow your breath
  • Reduce the volume of air you inhale and exhale

Which breathing exercises do not help with stress?

While the above breathing techniques can shift the Nervous System in a calm state there are some breathing practices which are likely to offer a temporary relief but are unlikely to have a lasting effect to our nervous system.

  1. Sighing

Sighing is often performed spontaneously but at times it is given as a breathing technique. It is a natural mechanism observed during arousal in infants but it’s also an evolutionary conserved behaviour in other mammals. It is hypothesised to serve as a defence mechanism preventing the alveoli in the lungs from collapsing after shallow breathing8.

In respiratory textbooks & literature, sighing (also referred as sighing dyspnea) is considered a sign of dysfunctional breathing, 50% more often in women9 than men, especially in the more active years of life.

The initial relief often experienced after the first sigh is likely due to the drop to CO2 after the exhalation, which is two to five times the volume of a normal one. Chronic sighing may encourage the reset of end tidal CO2 in the bloodstream at levels lower than optimal10 and chronic involuntary sighing should be considered a red flag as it might be due to chronic inflammation (through Prostaglandin 2 activation)11.

  1. “Deep breathing”

While the idea of breathing deep is good, the way “deep breathing” is often cued makes its practice of limited use. For the purpose of this article I will describe “deep breathing” as follows:

“Take as much air as possible in from the nose – release the air from the mouth.”

The main problem with this breathing technique is the heavy exhalation. When we are exhaling more air than normal we are having an excessive reduction of CO2. Lower levels of CO2 though means oxygen gets “trapped” in the bloodstream and cannot enter freely into the cells (due to the Bohr effect12).

Oxygen is a key component of aerobic respiration, taking place in the inner membrane of our mitochondria. With oxygen not entering the cells, our mitochondria are also deprived of oxygen: energy production is compromised, and the cellular metabolism is shifted towards a more anaerobic state. This can aggravate fatigue and stress.

It is worth pointing out that “deep breathing” is often cued alongside diaphragmatic breathing which is beneficial both in times of stress as well as everyday life. Ideally though “deep breathing” should not be accompanied with mouth exhalations13. Healthy levels of 13 CO2 and diaphragmatic breathing go hand in hand14.

Key Takeaways

  • With the exception of our thoughts there is no faster way of altering the state of our nervous system than our breath
  • Breathing soft, slowly, consciously, diaphragmatically, will allow as to stay calm in the most stressful situations
  • To get the benefits though of any breathing technique we need to be familiar with it
  • Slow breathing is one of the most researched breathing techniques. Even at 12 breaths per minute the Parasympathetic Nervous System can get activated.
  • Oxygen is a key component of aerobic respiration, taking place in the inner membrane of our mitochondria

Many thanks to Anastasis for his blog. If you have questions regarding the topics that have been raised, or any other health matters, please do contact Amanda by phone or email at any time.
01684 310099

Amanda Williams and the Cytoplan Editorial Team


1With the exception of some pathogenic conditions such as pneumonia, during certain breathing exercises and when arriving in a high altitude.

2Driscoll, D., & DiCicco, G. (2000). The effects of metronome breathing on the variability of autonomic activity measurements. Journal of manipulative and physiological therapeutics, 23(9), 610-614.

3Bernardi, L., Porta, C., Gabutti, A., Spicuzza, L., & Sleight, P. (2001). Modulatory effects of respiration. Autonomic neuroscience, 90(1-2), 47-56.

4Bernardi, L., Gabutti, A., Porta, C., & Spicuzza, L. (2001). Slow breathing reduces chemoreflex response to hypoxia and hypercapnia and increases baroreflex sensitivity. Journal of hypertension, 19(12), 2221-2229.

5Cappo, B. M., & Holmes, D. S. (1984). The utility of prolonged respiratory exhalation for reducing physiological and psychological arousal in non-threatening and threatening situations. Journal of Psychosomatic Research, 28(4), 265-273.

6Litchfield, P. M. (2003). A brief overview of the chemistry of respiration and the breathing heart wave. California Biofeedback, 19(1), 1-11.

7Houtveen, J. H., Rietveld, S., & de Geus, E. J. (2003). Exaggerated perception of normal physiological responses to stress and hypercapnia in young women with numerous functional somatic symptoms. Journal of psychosomatic research, 55(6), 481-490.

8Li, P., & Yackle, K. (2017). Sighing. Current Biology, 27(3), R88-R89.

9Maytum, C. K. (1938). Sighing dyspnea: A clinical syndrome. Journal of Allergy, 10(1), 50-55.

10Gilbert, C. (1998). Hyperventilation and the body. Journal of Bodywork and Movement Therapies, 2(3), 184-191.

11Forsberg, D., Horn, Z., Tserga, E., Smedler, E., Silberberg, G., Shvarev, Y., … & Herlenius, E. (2016). CO2-evoked release of PGE2 modulates sighs and inspiration as demonstrated in brainstem organotypic culture. Elife, 5, e14170.

12Bohr, C., Hasselbalch, K., & Krogh, A. (1904). Über einen in biologischer Beziehung wichtigen Einfluss, den die Kohlensäurespannung des Blutes auf dessen Sauerstoffbindung übt. Acta Physiologica, 16(2), 402-412.

13Ma, X., Yue, Z. Q., Gong, Z. Q., Zhang, H., Duan, N. Y., Shi, Y. T., … & Li, Y. F. (2017). The effect of diaphragmatic breathing on attention, negative affect and stress in healthy adults. Frontiers in psychology, 8, 874.

14Bradley, H., & Esformes, J. D. (2014). Breathing pattern disorders and functional movement. International journal of sports physical therapy, 9(1), 28.

Last updated on 23rd February 2021 by cytoffice


6 thoughts on “Which breathing exercises help alleviate stress?

  1. Very useful article. Simple techniques that would be easy to teach to clients. It reminded me about how important breath work is and that I need to remind my clients!

    Many thanks.

  2. Thank you, I find all your blogs very interesting and helpful. Funnily enough I only yesterday spoke to my husband about breathing deeply from the diaphragm!

  3. Another excellent article from Cytoplan. Breathing is a much neglected aspect of creating well being and over coming stress and needs more publicity. It surprises me that GPs do not seem to talk to their patients about breathing techniques.

  4. As a Health Coach breath work is one of the disciplines we are taught … very important for mindset and relaxation .. fab article

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