By Ellen Feldman, MD
Altru Health System, Grand Forks, ND
SUMMARY POINTS
- During a COVID-19 lockdown period, participants were randomized into four groups to receive online training in one of four breathing techniques, including two yoga pranayamas (the practice of breath regulation) and two Western mainstream traditional breathing exercises.
- The rate of perceived exertion and breath-holding time were measured before and after training.
- All four interventions were associated with increased breath-holding time (P < 0.000), but only one of the yoga techniques (anulom vilom pranayama) and diaphragmatic breathing were associated with a decrease in rate of perceived exertion, with maximum change associated with anulom vilom pranayama.
SYNOPSIS: In a small prospective study comparing four breathing techniques, the maximum statistically significant effect on reduced perceived exertion during breath-holding is associated with a yoga breathing method called anulom vilom pranayama (alternate nostril breathing).
SOURCE: Shukla M, Chauhan D, Raj R. Breathing exercises and pranayamas to decrease perceived exertion during breath-holding while locked-down due to COVID-19 online randomized study. Complement Ther Clin Pract 2020;41:101248.
A 2020 Harvard health blog proclaimed, “Breath control helps quell errant stress response.”1 Along the same vein, a New York Times article extolls “The Benefits of Controlled Breathing,” while an online John Hopkins page titled “Coronavirus Recovery: Breathing Exercises” reviewed specific breathing patterns.2,3 These and other publications may lead a reader to conclude that breathing exercises and techniques are well-established health interventions, but controlled, well-designed studies uncovering the etiology, risks, limits, and benefits behind this association are lacking, and so the relationship between breathing techniques and health remains unclear.4
We know that humans typically do not require conscious effort for breathing, and we know we can override autonomic control and implement desired changes in breath rhythm and rate. As noted earlier, calming breathing techniques are increasingly recommended anecdotally to help manage anxiety and other related medical conditions, from blood pressure control to headaches.5,6
Shukla et al were interested in adding to the scientific pool of knowledge regarding the efficacy of breathing exercises. The goal was to investigate four different breathing exercises to determine if there was relative superiority of any one technique in increasing breath-holding time at a lower level of perceived exertion during a COVID-19 lockdown period. Breath-holding time is inversely related to rate of breathing. Thus, it is a good measure of rapidity of breathing. Shukla et al noted perceived rate of exertion should be lower in individuals who find a sense of relaxation associated with controlled breathing.
A total of 60 recruited participants were assigned randomly to one of four groups. Instructions on a particular breathing intervention were delivered in a video-based online platform, and participants were asked to practice three repetitions of such interventions twice daily for one week. Breath-holding time and rate of exertion were measured pre- and post-intervention.
The four breathing techniques included two forms of yoga pranayama. Pranayama is integral to the practice of yoga and may be loosely translated from ancient Sanskrit as control of breath (derived from “prana,” or life force, and “ayama,” or extend or draw out.)7 The other interventions involved two other non-yoga techniques.
The interventions are briefly described here:
- Anulum vilom pranayama (AVP): Pinch off one nostril for inhalation and the other for exhalation; repeat in reverse fashion.8
- Kapal bhati pranayama (KBP): Inhale through both nostrils and exhale rapidly by flapping or rapidly moving abdominal muscles in and out. (60 to 120 breaths/minute).8
- Diaphragmatic breathing (DP): Breathe in slowly and deeply via the nose, then exhale deeply by tightening abdominal muscles.9
- Pursed-lip breathing (PLB): Inhale slowly via the nose, then exhale even more slowly via pursed lips.10
Breath-holding time was measured by directing respondents to hold their breath as long as possible following a maximal inhalation. The longest time out of three attempts was recorded. The rating of perceived exertion was documented via Borg’s scale, which is a standard, self-reported method of measuring the intensity of exercise on a scale from 6 to 20.11
RESULTS
Demographic information revealed a degree of homogeneity within the respondent pool, with the mean age per intervention group ranging from 21.47 years to 23.06 years, and the mean body mass index ranging from 20.92 to 22.33. Exclusion criteria for the study included persons with respiratory disorders and smokers. Data on the presence or absence of other medical conditions was not reported.
All four intervention groups demonstrated an increase in breath-holding time from pre- to post-intervention (P < 0.000), with the absolute value of increase being the highest for the DP group. However, for rating of perceived exertion, only participants in the DP and AVP arms reported an overall decrease in this measure.
One-way analysis of variance (ANOVA) is a statistical method used to assess if there is a statistical difference between the means of unrelated groups.12 In this case, one-way ANOVA revealed statistical significance of the differences in the mean drop in rating of perceived exertion among the groups (P = 0.000), with the largest change noted in the AVP participants, followed by the DP participants. The differences in mean breath-holding time pre- and post-intervention among the four arms was short of statistical significance (P = 0.10). Results are further summarized in Table 1.
Table 1. Results of One-way Analysis of Variance Comparing Mean Values Between the Four Study Groups
|
|
Anulom Vilom Pranayama
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Kapal Bhati Pranayama
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Diaphragmatic Breathing
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Pursed-Lip Breathing
|
P Value
|
|
Difference in seconds in mean breath-holding time (pre- to post-intervention)
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8.45 ± 2.8
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10.53 ± 2.7
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14.06 ± 7.5
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7.8 ± 9.5
|
P = 0.10
|
|
Change in rating of perceived exertion (self- report using the Borg scale)
|
1.40 ± 0.50
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0.27 ± 1.39
|
1.06 ± 0.05
|
0.2 ± 1.08
|
P = 0.000
|
COMMENTARY
This small, short-term, randomized study conducted during a lockdown period in the midst of the COVID-19 pandemic gives us limited but potentially valuable information regarding interventions designed to address health and wellness during times of high stress. Months into a global pandemic, with vaccines still on the horizon, Shukla et al seem to have anticipated the need for individuals to develop methods of self-regulation, then designed a study to investigate relative efficacy of selected exercises.
Specifically, this study focused on four breathing interventions. With only 15 relatively homogenous participants and only one week of intervention for each group, it is difficult to generalize results. Additionally, without a control group, the effect of the interventions (vs. time, for example) are unclear. A lengthier time period for follow-up, more participants, a more diverse pool of respondents, and a control arm all will be useful to include in future investigations.
The relationship between increase in breath-holding time, reduction of perceived exertion and health is an area needing more data and research. A 2018 systemic review looked at studies investigating a mechanism and evidence of physiologic and/or psychologic change induced by slow breathing techniques in healthy subjects.
The authors concluded that methodologic weaknesses and inconsistency between studies made conclusions difficult to generalize and recommended more robust future investigations. However, they did note that many of the studies pointed to a link between slow breathing and both increased parasympathetic activity (leading to decreased arousal) and central nervous system changes associated with feelings of well-being (documented via electroencephalography).4
Another recent study involving 60 participants used three groups — a control group with no intervention and two placebo groups. One placebo arm received sham oxygen, and the other received sham carbon dioxide. Verbal cues were delivered to the sham oxygen group suggesting breathing would become easier. An increase in breath-holding time and a positive change in some physiologic measures was documented in the sham oxygen group, suggesting that psychological factors may play an important role in this field.13
It does appear that, in the Shukla et al work, one technique (DP) suggested superiority in association with increased breath-holding time, and even more significant separation from the other techniques was shown in reduction of perceived exertion by AVP. Perhaps, most significantly, all the interventions seemed to be associated with longer breath-holding time post-intervention. However, with no placebo arm in the investigation, it is especially difficult to attribute causality. It still is interesting to note that, at the least, instruction to pay attention to breathing was associated with increased breath-holding time.
Although the conclusion of Shukla et al seems premature (“… a combination of AVP and DP may be best during lockdown to increase the pulmonary reserve and decrease anxiety …”), this investigation adds potentially clinically relevant information to a growing database of studies linking control of breathing to health benefits.
While more studies are indicated to delineate any connection between breath-holding time, reduction of perceived exertion, and health, the work of Shukla et al may prompt a provider to inform patients about specific techniques that are designed to help with slowing and controlling breathing. This relatively simple study, comparing breathing exercises taught via online delivery, helps reinforce the concept of the importance of self-care and self-monitoring and emphasizes that attention to wellness does not need to be “locked down” even while the world engages in such measures.
REFERENCES
- [No authors listed]. Relaxation techniques: Breath control helps quell errant stress response. Harvard Health Publishing. Published July 6, 2020. https://www.health.harvard.edu/mind-and-mood/relaxation-techniques-breath-control-helps-quell-errant-stress-response
- Alderman L. Breathe. Exhale. Repeat: the Benefits of Controlled Breathing. The New York Times. Published Nov. 9, 2016. https://www.nytimes.com/2016/11/09/well/mind/breathe-exhale-repeat-the-benefits-of-controlled-breathing.html
- Lien P. Coronavirus recovery: Breathing exercises. Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/coronavirus-recovery-breathing-exercises
- 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.
- National Health Service. Breathing exercises for stress. Updated Sept. 18, 2018. https://www.nhs.uk/mental-health/self-help/guides-tools-and-activities/breathing-exercises-for-stress/
- André C. Proper breathing brings better health. Scientific American. Published Jan. 15, 2019. https://www.scientificamerican.com/article/proper-breathing-brings-better-health/
- Sengupta P. Health impacts of yoga and pranayama: A state-of-the-art review. Int J Prev Med 2012;3:444-458.
- Saoji AA, Raghavendra BR, Manjunath NK. Effects of yogic breath regulation: A narrative review of scientific evidence. J Ayurveda Integr Med 2019;10:50-58.
- Cleveland Clinic. Diaphragmatic breathing. Updated Sept. 14, 2018. https://my.clevelandclinic.org/health/articles/9445-diaphragmatic-breathing
- Nguyen JD, Duong H. Pursed-lip breathing. In: StatPearls [Internet]. StatPearls Publishing; 2022.
- Centers for Disease Control and Prevention. Perceived exertion (Borg Rating of Perceived Exertion scale). Updated Sept. 17, 2020. https://www.cdc.gov/physicalactivity/basics/measuring/exertion.htm
- Laerd Statistics. One-way ANOVA. https://statistics.laerd.com/statistical-guides/one-way-anova-statistical-guide.php
- Piedimonte A, Barbiani D, Benedetti F, et al. The placebo effect in breath holding: A preliminary behavioral investigation. Neurosci Lett 2020;739:135434.
