Meditation Alter Short-Term and Long-Term Breathing
By John M. de Castro, Ph.D.
“By activating the parasympathetic nervous system, meditation healthfully slows down heart rate, breathing rate, blood pressure, sweating, and soothing all other sympathetic nervous system fight or flight functions.” – EOC Institute
In our lives we are confronted with a variety of situations and environments. In order to successfully navigate these differing situations, we must be able to adapt and self-regulate. The Autonomic Nervous System (ANS) is designed to adapt physiologically to the varying demands on us. It is composed of 2 divisions; the sympathetic division underlies activation, including increases in respiration, heart rate, and blood pressure, while the parasympathetic division underlies relaxation, including decreases in respiration, heart rate, and blood pressure.
Mindfulness training has been shown through extensive research to be effective in improving physical and psychological health and particularly with the physical and psychological reactions to stress. These include alterations of the Autonomic Nervous System (ANS) producing physiological relaxation including reductions in breathing rates. But the effects of meditation on breathing has not been well studied.
In today’s Research News article “Breath Rate Variability: A Novel Measure to Study the Meditation Effects.” (See summary below or view the full text of the study at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6329220/), Soni and colleagues recruited experienced meditators and nonmeditators who expressed interest in meditation. They were asked to close their eyes and sit quietly for 15 minutes. During which time they measured for heart rate and respiration.
They found that the meditators had significantly greater mean and median breathing time, standard deviation of the breath to breathe interval, standard deviation of the average breath to breathe interval, root mean square standard deviation of the average breath to breathe interval and significantly lower breath rate. These measures suggest that meditation practice produces short-term changes in breathing when at rest. In addition, heart rate and breath rate variability measures suggested that there was a significant increase in long-term parasympathetic input in the meditators.
These are complex but interesting results that suggest that meditation practice alters respiration over both the short and long term. On the short term, while at rest with eyes closed meditators have better, more relaxed, control of respiration. On the long term, meditator appear to have increased parasympathetic control of respiration. This suggest an overall relaxation of respiration. Meditation would appear to alter the overall balance in the autonomic nervous system toward increased parasympathetic (relaxation) control and decreases sympathetic (activation) control. This may explain some of the benefits of meditation for stress reduction.
So, relax short-term and long-term breathing with meditation
“all forms of meditation studied reduce physiological stress markers in one way or another, and therefore, all forms are likely beneficial in managing stress.” – Michaela Pascoe
CMCS – Center for Mindfulness and Contemplative Studies
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Soni, R., & Muniyandi, M. (2019). Breath Rate Variability: A Novel Measure to Study the Meditation Effects. International journal of yoga, 12(1), 45–54. doi:10.4103/ijoy.IJOY_27_17
Reliable quantitative measure of meditation is still elusive. Although electroencephalogram (EEG) and heart rate variability (HRV) are known as quantitative measures of meditation, effects of meditation on EEG and HRV may well take long time as these measures are involuntarily controlled. Effect of mediation on respiration is well known; however, quantitative measures of respiration during meditation have not been studied.
Breath rate variability (BRV) as an alternate measure of meditation even over a short duration is proposed. The main objective of this study is to test the hypothesis that BRV is a simple measure that differentiates between meditators and nonmeditators.
Settings and Design:
This was a nonrandomized, controlled trial. Volunteers meditate in their natural habitat during signal acquisition.
Subjects and Methods:
We used Photo-Plythysmo-Gram (PPG) signal acquisition system from BIO-PAC and recorded video of chest and abdomen movement due to respiration during a short meditation (15 min) session for 12 individuals (all males) meditating in a relaxed sitting posture. Seven of the 12 individuals had substantial experience in meditation, while others are controls without any experience in meditation. Respiratory signal from PPG signal was derived and matched with that of the video respiratory signal. This derived respiratory signal is used for calculating BRV parameters in time, frequency, nonlinear, and time-frequency domain.
Statistical Analysis Used:
First, breath-to-breath interval (BBI) was calculated from the respiration signal, then time domain parameters such as standard deviation of BBI (SDBB), root mean square value of SDBB (RMSSD), and standard deviation of SDBB (SDSD) were calculated. We performed spectral analysis to calculate frequency domain parameters (power spectral density [PSD], power of each band, peak frequency of each band, and normalized frequency) using Burg, Welch, and Lomb–Scargle (LS) method. We calculated nonlinear parameters (sample entropy, approximate entropy, Poincare plot, and Renyi entropy). We calculated time frequency parameters (global PSD, low frequency-high frequency [LF-HF] ratio, and LF-HF power) by Burg LS and wavelet method.
The results show that the mediated individuals have high value of SDSD (+24%), SDBB (+29%), and RMSSD (+26%). Frequency domain analysis shows substantial increment in LFHF power (+73%) and LFHF ratio (+33%). Nonlinear parameters such as SD1 and SD2 were also more (>20%) for meditated persons.
As compared to HRV, BRV can provide short-term effect on anatomic nervous system meditation, while HRV shows long-term effects. Improved autonomic function is one of the long-term effects of meditation in which an increase in parasympathetic activity and decrease in sympathetic dominance are observed. In future works, BRV could also be used for measuring stress.