The Sanskrit word Yoga योग means to yoke/harness/join. It originated in ancient India and entails physical, mental and spiritual practices that promote awakening and recognition of the ultimate union of body/mind with Consciousness. As yoga travelled to the West the accessible and adaptable physical aspects made it one of the most popular fitness routines for people of all ages. This article explores the science behind yoga from a physiological point of view.
It all starts with the fact that growing scientific evidence reveals what any long-term yoga practitioner will know from their own experience: Body, mind and spirit are intrinsically interconnected and interrelated and as such yoga benefits your wellbeing by improving physical and mental health.
Yoga is said to be a 5,000 year old science that investigates human consciousness through the body. At the heart of this exploration stands the age-old question: What inhabits this body? For their investigation ancient scientists had to rely on the only tool available for measurement: the body and the mind in the present moment. In order to gain reliable results they realised that it would take deep commitment and dedication to a regular practice.
It is thought that yoga was initially a sitting practice and movement was added along the way. The results of the emerging experiential knowledge is the wisdom that has been passed down from guru to disciple from generation to generation. One of the most detailed and thorough expositions on the subject are the Yoga Sutras of Patanjali (thought to be written 400 BCE) that define yoga as “the cessation of the fluctuations of the mind”.
From a physiological perspective, yoga works through our nervous system that extends throughout the body and keeps in constant interchange with our brain. When we think about ourselves it is easy to forget that our brain and nervous system once started out in the womb as the ectoderm, which later develops into the skin, and folds inward to form the neural tube, which later becomes the spinal chord (Pansky, 2013). I find it fascinating to watch the ancient wisdom beginning to be evidenced by cutting-edge science that allows us to measure our mind (to certain degrees) through fMRI-scanners and other high-tech tools. Researchers from various disciplines such as neuroscience, physics and psychology partake in this exciting quest.
A Stressed Generation
Finding better ways of dealing with stress is another way of looking at yoga from both a psychological and physiological perspective. We live in a fast paced culture that is dominated by thinking and doing. Just trying to keep up with life whilst juggling work, home, social commitments and finances can be stress provoking. When our body perceives stress it reacts with the fight/flight survival mechanism, that is by activating the sympathetic nervous system.
It goes like this: The brain perceives stress and sends a signal to the hypothalamus that sends, in turn, a hormone-signal to the pituitary gland, which sits just underneath the brain. The pituitary gland then sends a hormone-signal to the adrenal glands. They sit roughly on top of the kidneys and send off a number of chemical compounds into our bloodstream: epiphrine (formerly adrenaline), norepiphrine (formerly noradrenaline) and cortisol. Their immediate distribution has high impact on the body. Your heart starts beating faster, you start to sweat and your muscles get ready for action and movement (NIH, 2002). At the same time blood is withdrawn from your digestive and immune system.
Now, if this is a fire alarm that activated your sympathetic nervous system, run! However, what happens to many of us is that our sympathetic nervous system gets stuck in a feedback loop whereby adrenalin and cortisol are picked up by the hypothalamus that triggers the cycle again and again putting the system on chronic overdrive. Over time this can have negative effects on both mental and physical health such as depression, insomnia, heart disease, skin disorders and headaches.
Imagine one of those days where you maybe feel already tense and tight because of all that awaits you. One thing goes wrong and then another and suddenly things start to pile up. This is added to by an argument at home and that sets you up for a bad night sleep and another day starts off like the previous. When this continues for weeks and years we can wind up running on constant overload. So how do we learn to switch off?
Learning to Switch Off
Similar to Mindfulness, Yoga offers a break because it helps to stimulate the parasympathetic nervous system. This branch of your autonomic nervous system is active in rest, relaxation and digestion. It has the opposite effect to the sympathetic nervous system allowing the body to wind down and re-balance. When the parasympathetic nervous system is stimulated muscles are encouraged to relax, the heart rate slows down and the blood pressure lowers. Breathing returns to a normal rate and our digestive system is ready to function. At the same time your immune system is ready to produce new white blood cells. (Carroll, 2001)
You will know from your own experience that taking a few deep breaths and making your exhale slightly longer than your inhale has a calming effect. Dr. Stephen Porges (1995) explains the science behind it in that deep breathing stimulates the myelinated vagus nerve that down-regulates the sympathetic branch (fight/flight) as well as activates the parasympathetic branch (rest/digest). As such yoga movements can inhibit and reduce the effects of stress, anxiety and depression to name but a few benefits.
To sum it up, yoga can help us experience life more fully and freely. By using our body (asana), focussing our mind (meditation) and working with our breath (pranayama) we learn about ourselves and our relationship with life. What we experience and explore on the mat directly reflects our approach and attitude towards ourselves and others. We get to see our sincere wish to improve, our laziness, our control, our generosity, our self-compassion…. – whatever is there in us will show up; pleasant and unpleasant.
We can learn to use this information with a wise and kind heart towards ourselves and, in turn, learn how to deal more efficiently with challenges and difficulties that we encounter in life. It can enable us to transform unhealthy habits and find more freedom. As such, I like to think about yoga as a practice that keeps the body healthy and the mind and spirit in good working order, that is healthy and happy.
About the Author:
Veronika is an accredited YAP Senior Yoga Teacher & Teacher Trainer, an experienced Mindfulness facilitator, and a BACP registered counsellor & therapist with a business background and extensive life and self-development experience.
Carroll, R. (2001) The Autonomic Nervous System: Barometer of Emotional Intensity and Internal Conflict [Online] available from http://www.thinkbody.co.uk/papers/autonomic-nervous-system.htm [Accessed on January 28, 2014]
NIH, National Institutes of Health (2002) Stress System Malfunction Could Lead to Serious, Life Threatening Disease. [Online] available from http://www.nih.gov/news/pr/sep2002/nichd-09.htm [Accessed on June 16, 2011]
Panksy, B. (2013) Germ Layers and Their Derivatives, Review of Medical Embryology in LifeMap Discovery: the embryonic development, stem cells, and regenerative medicine research portal. [Online] available from http://discovery.lifemapsc.com/library/review-of-medical-embryology/chapter-25- germ-layers-and-their-derivatives [Accessed on February 18, 2015]
Porges, S. (1995) Orienting in a defensive world: Mammalian modifications of our evolutionary heritage. A Polyvagal theory. Psychophysiology, 32, 301-318.