Breathing exercises and their benefits

Highlights:

• Breathing exercises exists in many forms – from deep diaphragmatic breathing to more complex interval techniques
• Controlled breathing has shown benefits as a tool for self-regulation in case of stress or anxiety
• Usage of breathing techniques may improve the pulmonary condition, especially in elderly patients
• There is a lack of studies on physiological details of breathing exercises’ influence, and different techniques are frequently mixed in the existing studies
  
  

Introduction‍

Breathing is the most crucial and instinctive life-sustaining activity. While a person can survive for some time without eating or drinking, the longest record in history for holding breath was 24 minutes 37 seconds. And though breathing is so essential, or maybe precisely because of it, we tend not to pay attention to how exactly we breathe. Research shows that breathing exercises may be a beneficial intervention for various health conditions, as well as an easy technique to improve one’s subjective well-being.

Types of breathing

Multiple normal and pathological modes of breathing were described, most well-known among them are (1,2):

• Eupnea, or quiet breathing – a type of non-conscious breathing that occurs during rests and includes contraction of the diaphragm and external intercostal muscles (small muscles, located between each rib);
• Diaphragmatic, or deep breathing – a type of breathing that emphasizes diaphragm contractions, while the intercostal muscles do minimal work;
• Costal, or shallow breathing – a type of breathing that results from the contraction of the intercostal muscles;
• Hyperpnea, or forced breathing, occurs during physical exercises or activities requiring active breathing manipulations, such as singing.

The exercises, based on each category, can be divided into inhale- or exhale-focused, interval-based, employing slow or fast breathing, purely physiotherapeutic, or combined with elements of mindfulness. 

Breathing techniques in physiotherapy

Based on the abovementioned classification, several types of breathing exercises are widely used in physiotherapy (3). Among the most popular and well-known is intentional deep breathing. Another technique is glossopharyngeal, or “frog” breathing – a method using muscles of the mouth and the pharynx to push air into the lungs forcefully. Pursed lip breathing is a technique that includes inhaling through the nose and exhaling through the tightly pursed lips. If some particular lung part needs attention, then segmental breathing (or costal expansion exercise) can be employed, where a patient breathes with intended increased expansion of a specific area.

Interval breathing techniques (4-6), though predominantly used for relaxation and pain treatment, are also widely employed and include techniques such as box breathing (4 seconds inhale – 4 seconds hold – 4 seconds exhale), techniques based on physiological sigh, 4-7-8 (4 seconds inhale – 7 seconds hold – 8 seconds exhale), and its variation 2-3-4 breathing.

In addition to the abovementioned classification, there are a variety of techniques (7), including Pranayama (slow and fast breathing techniques derived from yoga), Qigong breathing, etc. 

Benefits for mental health

The breathing exercises are a widely recommended intervention to reduce perceived depression, anxiety, and stress levels. The randomized control trial of students’ well-being (8) demonstrated that semester-long participation in a program combining yoga, breathing, and meditation led to an improvement of six subjective parameters characterizing depression, stress, mental health, positive affect, mindfulness, and social connectedness. Another study combined a questionnaire with biofeedback data showed a significant decrease in anxiety levels for patients who practiced deep breathing for eight weeks (9). The usage of the breathing techniques was also correlated with improved emotional control and psychological well-being in healthy participants (10) and improved cognitive function such as enhanced attention (11).

Some studies reported an improvement of sleep in people who practiced breathing exercises and thus suggested that self-regulation of breathing may be used as an additional treatment for insomnia (12). The researchers hypothesized that the major mechanism behind insomnia is hyper-arousal accompanied by parasympathetic hypoactivation, and breathing exercises may work as a “switch” between sympathetic and parasympathetic nervous systems. Combination of mindfulness meditation techniques and breathing exercises was also shown to be beneficial in reducing anxiety and stress levels (13).

Some studies also indicated positive effects of Pranayama on post-traumatic stress disorder patients (14) and deep breathing on nicotine withdrawal (15).

Breathing and pulmonary function

One of the traditional uses of breathing exercises is the rehabilitation of patients with pulmonary conditions. A pilot study of a deep breathing technique based on free diving breathing, which includes the ability to hold breath for a comparatively long amount of time, has shown a decrease in levels of anxiety and discomfort of patients with chronic obstructive pulmonary disease (COPD) (16). Pursed lip technique also showed a significant improvement in exercise tolerance for patients with COPD (17). In asthmatic patients, the use of diaphragmatic breathing exercises resulted in improvement in breathing kinematic (interval, depth, and magnitude of a breath), oxygen consumption, and pulmonary function (18,19). The study in elderly patients shows that using breathing techniques combined with elastic band exercise effectively increases indicators of pulmonary function, such as forced expiratory volume (20). 

Recently, it was also shown that breathing exercises are effective in the respiratory rehabilitation of elderly patients after COVID-19 (21). After a six-week course, the patients showed a significant improvement in respiratory function and a decrease in anxiety.

Moreover, proper breathing is as important in healthy individuals. Controlled breathing was shown (22) to effectively maximize heart rate variability (HRV), which is variation in time between heartbeats, and preserve autonomic function (i.e., cardiac regulation, vasomotor activity, control of breathing). Both of these parameters were linked to the decreased mortality and promote longevity in the general population (23-25). 

Physiological mechanisms 

Though there are a variety of studies on breathing exercises, there is a lack of unified explanation of the exact mechanisms behind the effect. In their meta-analysis, Zaccaro et al. (10) analyzed a range of articles on slow breathing techniques. The majority of the research points towards the connection between breathing exercises and the parasympathetic nervous system. Slow breathing techniques increase heart rate variability (HRV), which indicates their influence on the cardio-respiratory system (26). Higher HRV is associated with better cardiovascular health and higher stress resilience. The same dependency is observed for high-rate breathing (27), which correlates with the improvements in blood pressure metrics of hypertension patients who practiced yoga breath (28). However, the detailed studies of breathing influence on HRV yielded contradictory results, with some studies observing an increase in high frequency (HF) peak compared to control (29,30), other studies registering no changes in HF (31,32) or its decrease (33). HF peak is one of the main parameters determining the healthy HRV, thus the contradiction in these results does not allow for an interpretation of long-term cardiovascular risks and benefits connected with the breathing exercise.

Recommendations‍

Breathing exercises vary in their difficulty, and it is recommended to start from the easier ones for the limited time and increase complexity and exercise duration with the practice. For many techniques, in-person training is recommended, and you can direct your client/patient to a certified physiotherapist with experience in breathing exercise training. While recommending this intervention, you should remember that the evidence for these techniques is incomplete and limited. If your client/patient wants to attempt the breathing exercises, you can recommend them the following (34):

• Start with simple focused breathing with counting focusing on diaphragmatic breathing;
• Depending on the purpose continue with more complex techniques, such as pursed lip breathing, initially under the supervision of a specialist;
• Intense breathing focused on the exhaling (such as kapalabhati exercise (28) from yoga breath) can be dangerous to unprepared clients/patients (35) and can be recommended only for healthy people under supervision;
• During the exercise, client/patient should not experience intense discomfort, headaches, and/or dizziness (36);
• If patient/client experiences dizziness during exercises, it is recommended to decrease the level of difficulty

As any intervention, intense breathing exercises have their general contraindications similar to those for testing lung function (37), among them intense pain and recent surgery.

Conclusions 

More research is required to estimate the full potential, benefits, and contraindications for the existing breathing techniques. At the moment, there are a few comprehensive studies or meta-analyses, and breathing techniques are often either not specified by researchers or mixed with other interventions. Altogether, it weakens the evidence base for the breathing exercises. However, some beneficial effects (i.e., anxiety reduction, improvement of pulmonary conditions) have been consistently observed, thus breathing exercises still are a valuable addition to the intervention toolbox. The breathing exercises can be employed as an accessible and safe self-regulation and anti-anxiety technique by your clients if properly practiced.

DISCLAIMER: This article is based on incomplete scientific research. The methods presented lack robust evidence.

References

1.         Betts G, Young K, Wise J, Johnson E, Poe B, Kruse D, et al. The Process of Breathing. In: Anatomy and Physiology [Internet]. OpenStax; 1st edition; 2013. Available from: https://opentextbc.ca/anatomyandphysiologyopenstax/

2.         Whited L, Graham DD. Abnormal Respirations. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited 2022 Jan 31]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK470309/

3.         Solomen S, Aaron P. Breathing techniques-a review. Int J Phys Educ Sports Health. 2015;2:237–41. 

4.         Biber D, Stoepker P, Heidorn B. Techniques to Promote Healthy Self-Regulation in Physical Education: Column Editor: Anthony Parish. Strategies. 2019 Mar 4;32(2):56–60. 

5.         Ahmed A, Gayatri Devi R, Jothi Priya A. Effect of Box Breathing Technique on Lung Function Test. 2021; 

6.         Vlemincx E, Abelson JL, Lehrer PM, Davenport PW, Van Diest I, Van den Bergh O. Respiratory variability and sighing: A psychophysiological reset model. Biol Psychol. 2013 Apr;93(1):24–32. 

7.         Bellissimo G, Leslie E, Maestas V, Zuhl M. The effects of fast and slow yoga breathing on cerebral and central hemodynamics. Int J Yoga. 2020;13(3):207. 

8.         Seppälä EM, Bradley C, Moeller J, Harouni L, Nandamudi D, Brackett MA. Promoting Mental Health and Psychological Thriving in University Students: A Randomized Controlled Trial of Three Well-Being Interventions. Front Psychiatry. 2020 Jul 15;11:590. 

9.         Chen Y-F, Huang X-Y, Chien C-H, Cheng J-F. The Effectiveness of Diaphragmatic Breathing Relaxation Training for Reducing Anxiety: The effectiveness of diaphragmatic breathing relaxation training for reducing anxiety. Perspect Psychiatr Care. 2017 Oct;53(4):329–36. 

10.       Zaccaro A, Piarulli A, Laurino M, Garbella E, Menicucci D, Neri B, et al. How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing. Front Hum Neurosci. 2018 Sep 7;12:353. 

11.       Melnychuk MC, Dockree PM, O’Connell RG, Murphy PR, Balsters JH, Robertson IH. Coupling of respiration and attention via the locus coeruleus: Effects of meditation and pranayama. Psychophysiology. 2018 Sep;55(9):e13091. 

12.       Jerath R, Beveridge C, Barnes VA. Self-Regulation of Breathing as an Adjunctive Treatment of Insomnia. Front Psychiatry. 2019 Jan 29;9:780. 

13.       Krisanaprakornkit T, Sriraj W, Piyavhatkul N, Laopaiboon M. Meditation therapy for anxiety disorders. Cochrane Common Mental Disorders Group, editor. Cochrane Database Syst Rev [Internet]. 2006 Jan 25 [cited 2022 Jan 31]; Available from: https://doi.wiley.com/10.1002/14651858.CD004998.pub2

14.       Descilo T, Vedamurtachar A, Gerbarg PL, Nagaraja D, Gangadhar BN, Damodaran B, et al. Effects of a yoga breath intervention alone and in combination with an exposure therapy for post-traumatic stress disorder and depression in survivors of the 2004 South-East Asia tsunami. Acta Psychiatr Scand. 2010 Apr;121(4):289–300. 

15.       McClernon FJ, Westman EC, Rose JE. The effects of controlled deep breathing on smoking withdrawal symptoms in dependent smokers. Addict Behav. 2004 Jun;29(4):765–72. 

16.       Borg M, Thastrup T, Larsen KL, Overgaard K, Hilberg O, Løkke A. Free diving-inspired breathing techniques for COPD patients: A pilot study. Chron Respir Dis. 2021 Jan;18:147997312110386. 

17.       Cabral LF, D’Elia TDC, Marins DDS, Zin WA, Guimarães FS. Pursed lip breathing improves exercise tolerance in COPD: a randomized crossover study. Eur J Phys Rehabil Med. 2015 Feb;51(1):79–88. 

18.       Shaw BS, Shaw I. Pulmonary Function and Abdominal and Thoracic Kinematic Changes Following Aerobic and Inspiratory Resistive Diaphragmatic Breathing Training in Asthmatics. Lung. 2011 Apr;189(2):131–9. 

19.       Shaw I, Shaw BS, Brown GA. Role of diaphragmatic breathing and aerobic exercise in improving pulmonary function and maximal oxygen consumption in asthmatics. Sci Sports. 2010 Jul;25(3):139–45. 

20.       Kim K, Han JW, Kim YM. Effects of elastic band resistance exercises with breathing techniques on pulmonary function in female seniors. J Exerc Rehabil. 2019 Jun 26;15(3):419–23. 

21.       Liu K, Zhang W, Yang Y, Zhang J, Li Y, Chen Y. Respiratory rehabilitation in elderly patients with COVID-19: A randomized controlled study. Complement Ther Clin Pract. 2020 May;39:101166. 

22.       Russo MA, Santarelli DM, O’Rourke D. The physiological effects of slow breathing in the healthy human. Breathe. 2017 Dec;13(4):298–309. 

23.       Aeschbacher S, Bossard M, Ruperti Repilado FJ, Good N, Schoen T, Zimny M, et al. Healthy lifestyle and heart rate variability in young adults. Eur J Prev Cardiol. 2016 Jul;23(10):1037–44. 

24.       Zulfiqar U, Jurivich DA, Gao W, Singer DH. Relation of High Heart Rate Variability to Healthy Longevity. Am J Cardiol. 2010 Apr;105(8):1181–5. 

25.       Kemp AH, Quintana DS. The relationship between mental and physical health: Insights from the study of heart rate variability. Int J Psychophysiol. 2013 Sep;89(3):288–96. 

26.       Bernardi L, Spadacini G, Bellwon J, Hajric R, Roskamm H, Frey AW. Effect of breathing rate on oxygen saturation and exercise performance in chronic heart failure. The Lancet. 1998 May;351(9112):1308–11. 

27.       Perry S, Khovanova NA, Khovanov IA. Control of heart rate through guided high-rate breathing. Sci Rep. 2019 Dec;9(1):1545. 

28.       Misra S, Smith J, Wareg N, Hodges K, Gandhi M, McElroy JA. Take a deep breath: A randomized control trial of Pranayama breathing on uncontrolled hypertension. Adv Integr Med. 2019 May;6(2):66–72. 

29.       Park Y-J, Park Y-B. Clinical utility of paced breathing as a concentration meditation practice. Complement Ther Med. 2012 Dec;20(6):393–9. 

30.       Stark R, Schienle A, Walter B, Vaitl D. Effects of paced respiration on heart period and heart period variability. Psychophysiology. 2000 May;37(3):302–9. 

31.       Siepmann M, Aykac V, Unterdörfer J, Petrowski K, Mueck-Weymann M. A Pilot Study on the Effects of Heart Rate Variability Biofeedback in Patients with Depression and in Healthy Subjects. Appl Psychophysiol Biofeedback. 2008 Dec;33(4):195–201. 

32.       Lin IM, Tai LY, Fan SY. Breathing at a rate of 5.5breaths per minute with equal inhalation-to-exhalation ratio increases heart rate variability. Int J Psychophysiol. 2014 Mar;91(3):206–11. 

33.       Lehrer PM, Vaschillo E, Vaschillo B, Lu S-E, Eckberg DL, Edelberg R, et al. Heart Rate Variability Biofeedback Increases Baroreflex Gain and Peak Expiratory Flow. Psychosom Med. 2003 Sep;65(5):796–805. 

34.       Bott J, Blumenthal S, Buxton M, Ellum S, Falconer C, Garrod R, et al. Guidelines for the physiotherapy management of the adult, medical, spontaneously breathing patient. Thorax. 2009 May 1;64(Suppl 1):i1–52. 

35.       Johnson DB, Tierney MJ, Sadighi PJ. Kapalabhati Pranayama: Breath of Fire or Cause of Pneumothorax? Chest. 2004 May;125(5):1951–2. 

36.       Tabor A, Wilson C, Bateman S. Designing to support uncomfortable breathing exercises: ethical considerations. In: Adjunct Proceedings of the 2019 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2019 ACM International Symposium on Wearable Computers [Internet]. London United Kingdom: ACM; 2019 [cited 2022 Jan 31]. p. 1087–9. Available from: https://dl.acm.org/doi/10.1145/3341162.3354058

37.       Cooper BG. Republished review: An update on contraindications for lung function testing. Postgrad Med J. 2011 Oct 1;87(1032):724–33.