Heart Rate Variability and Yoga

‘We had better results with yoga in people with chronic PTSD than any medication that I or anybody else had ever studied,’ he says. ‘That, of course, is pretty interesting and exciting, and not so good news for psychiatry, because psychiatrists are unlikely to transform themselves into yoga instructors. But is yoga helpful? Absolutely.’

– Psychiatrist Bessel Van Der Kolk on ABC Radio. Listen here

An intriguing link to the scientific realm has emerged in the world of yoga and lifestyle medicine, where mind and body intertwine to create an integrated sense of well-being. Recent heart rate variability (HRV) research has uncovered a remarkable connection between yoga practice, the autonomic nervous system (ANS), and overall health. Let us delve into this fascinating exploration, where ancient wisdom meets modern science.

Understanding Heart Rate Variability

At the heart of this journey lies the concept of HRV, a measure of the beat-to-beat variability performed by the heart. The ANS plays a pivotal role in regulating HRV, with the vagus nerve acting as the prime conductor through the parasympathetic nervous system (PNS) (Krygier et al., 2013). HRV is dissected into various frequency ranges, each revealing distinct insights into bodily functions. The frequencies of 0.15-0.4Hz provide insights into respiratory sinus arrhythmia (RSA), an essential process where the heart rate syncs with breathing cycles for efficient gas exchange (Vaschillo et al., 2002). Lower frequencies like 0.05-0.15Hz are tied to blood pressure and baroreflex, while the lowest frequencies of 0.005-0.05Hz reveal information about vascular tone and temperature (Vaschillo et al., 2002). This intricate dance of frequencies unveils cardiovascular health and the potent influence of the ANS on our overall well-being.

HRV and Vagal Tone

The connection between HRV and vagal tone underscores the significance of HRV as an indicator of ANS balance (Ernst, 2017). It serves as a paramount biomarker for understanding our primal stress system. HRV, a reflection of our body’s capacity to adapt to environmental demands and regulate emotions, holds the key to our resilience (Krygier et al., 2013). Reduced HRV has been observed in cardiovascular disease patients, further cementing the link between heart health and ANS balance (Krygier et al., 2013).

Yoga and Meditation’s Impact on HRV

Enter yoga and meditation, ancient practices that have stood the test of time. Meditation has been shown to enhance PNS activity, leading to increased HRV (Nesvold et al., 2012; Phongsuphap et al., 2008; Wu & Lo, 2008). These practices increase HRV and bolster baroreflex sensitivity, improving lung function (Phongsuphap et al., 2008). In the realm of mental health, the significance becomes even more apparent. Depression, often accompanied by decreased HRV, finds solace in the practice of yoga (Karavidas et al., 2007; Khattab et al., 2007; Streeter et al., 2018). The benefits extend to compassionate mind training, which elevates HRV, signifying positive changes in ANS and PNS (Jeffrey J. Kim et al., 2020).

Bessel van der Kolk’s pioneering work ventured into assessing our nervous system’s equilibrium using HRV. To evaluate the state of our nervous system’s well-being, Bessel van der Kolk employed heart rate variability (HRV) to assess the equilibrium between our autonomic nervous system’s two branches: the sympathetic and parasympathetic. Broadly categorised, the sympathetic branch activates with adrenaline, propelling our system into action. In contrast, the parasympathetic branch triggers the release of chemicals facilitating digestion, sleep, and healing.

During inhalation, the sympathetic nervous system comes into play, causing a slight acceleration in heart rate. Conversely, during exhalation, the parasympathetic system takes over, leading to a slight decrease in heart rate. The variance in heart rate between inhalation and exhalation constitutes heart rate variability (HRV). In individuals with good health, a noticeable HRV fluctuation corresponds with breathing patterns. On the other hand, individuals with PTSD exhibit rapid and shallow breathing patterns that show little synchronisation with heart rate. In essence, those with PTSD struggle more to regulate their nervous systems in stimulating and relaxing circumstances.

Van der Kolk delved into investigating the impact of yoga on HRV and made a noteworthy discovery: as short as an eight-week commitment to regular yoga practice contributed to an enhancement in HRV variability. However, Van der Kolk realised that the real significance of yoga transcended its direct effect on HRV; it lay in the heightened bodily awareness it cultivated among practitioners. The series of postures that activated diverse muscle groups, combined with the mindfulness of deep and shallow breathing, enabled practitioners to become more conscious and at ease with the interplay of relaxation and tension inherent in a yoga session.

Yoga’s Impact Beyond HRV

Through this, they understood that sensations were transient and could tolerate them. Such heightened awareness extended to recognising the tension and relaxation woven into their everyday lives. Many participants discovered a greater attunement to their bodies, making it simpler to discern their moment-to-moment needs. One of the invaluable insights from yoga was that apprehension of certain emotions and sensations (like anger, shame, or sadness) usually proved more detrimental than the feelings themselves. Yoga illustrates that emotions crest and then recede, much like yoga postures. The unease surrounding these emotions often proved more destabilising than the emotions per se.

Bridging Wisdom and Science

Yoga essentially utilises the body as a conduit to teach these fundamental lessons, constituting an experiential approach to learning that surpasses reading, discussion, or visual media. It underscores the necessity of experiential engagement to truly internalise these insights. As yoga teachers and students, the connection between HRV research and yoga practice becomes clear. Through conscious breathing, mindful movement, and the interplay of the ANS, yoga becomes a bridge between ancient wisdom and cutting-edge science, guiding us toward equilibrium and integrative health.

Here is a list of evidence-based practices from the realms of yoga, pranayama (breath control), and meditation that have been shown to improve heart rate variability (HRV):

• Mindfulness Meditation: Mindfulness meditation involves focusing one’s attention on the present moment without judgement. This practice has been linked to increased HRV, likely due to its ability to engage the parasympathetic nervous system and reduce stress (Krygier et al., 2013).
• Breathing: Controlled deep breathing techniques, often integrated within yoga practices, promote parasympathetic activity, enhancing HRV. Techniques like diaphragmatic breathing and coherent breathing (equal duration of inhalation and exhalation) have been effective (Lehrer et al., 2013).
• Vagus Nerve Stimulation Yoga (VNSY): A specific form of yoga, VNSY emphasises postures, movements, and breathing patterns that stimulate the vagus nerve, leading to increased parasympathetic activity and improved HRV (Sharma et al., 2020).
• Yogic Breathing Practices (Pranayama): Pranayama techniques, such as alternate nostril breathing (Nadi Shodhana) and extended exhalation (Ujjayi Pranayama), have demonstrated positive effects on HRV by enhancing vagal tone and balancing the autonomic nervous system (Vasudev et al., 2018).
• Loving-Kindness Meditation (Metta): Metta meditation involves cultivating feelings of compassion and kindness towards oneself and others. This practice has been associated with increased HRV and positive emotional states (Kok et al., 2013).
• Transcendental Meditation (TM): TM is a form of meditation that involves the repetition of a mantra. Studies have shown that TM practitioners experience improved HRV and increased coherence between heart rate and breathing patterns (Rainforth et al., 2007).
• Yoga Nidra: Also known as yogic sleep, Yoga Nidra is a guided relaxation technique that promotes deep relaxation while maintaining awareness. This practice has been linked to increased HRV and reduced stress (Saraswathi et al., 2014).
• Sudarshan Kriya Yoga (SKY): SKY is a rhythmic breathing technique taught in the Art of Living courses. Practitioners of SKY have exhibited enhanced HRV and reduced stress levels (Zope & Zope, 2013).
• Compassion Meditation: Compassion-focused meditation practices, such as loving-kindness meditation and compassion meditation, foster positive emotions and social connectedness, leading to improvements in HRV (Kok et al., 2013; Jeffrey et al. et al., 2020).
• Metta Bhavana: Metta Bhavana, or the cultivation of loving-kindness, is a Buddhist meditation practice that involves generating feelings of goodwill and compassion towards oneself and others. This practice has been associated with increased HRV and reduced stress (Condon et al., 2013).

These practices showcase the powerful potential of mind-body interventions like yoga, pranayama, and meditation in enhancing HRV and promoting overall well-being. However, it’s important to remember that individual responses may vary, and consistent practice over time is key to experiencing the benefits. Always consult with a registered yoga instructor or healthcare professional before beginning any new practice, especially if you have pre-existing health conditions.

About the Author

Celia Roberts introduces us to deeper dimensions of Yoga, Meditation & Lifestyle Medicine. Celia runs the BioMedical Institute of Yoga & Meditation in the foothills of Brisbane, Australia, and reaches a global online audience with Yoga and Meditation Teacher Training. She invites people from all walks of life to merge science and spirituality for betterment of their health and well-being, to ultimately have deeper insight and know true compassion within. 

References

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