ASANA vs EXERCISE - the neuroscience of yoga postures

Contemporary research underscores the myriad benefits of yoga, but isolating the specific effects of the physical practice is challenging since asana is often instructed in combination with some type of breathing and or meditation technique. Nevertheless, the impact of asana on cognition, mood, and self-regulation becomes evident when comparing it to conventional exercise.

ASANA (if practised traditionally) vs EXERCISE 

• Done with the intention of spiritual evolution

• Develops a sense of calmness and stillness 

• Practised slow and consciously, with intentional focus on breath, bandhas, and body awareness

• Low impact movements, submaximal joint load, mainly isometric contraction 

• Goal is for the movement to feel stable, yet light and effortless

• With continued practice, body’s physiology is altered so that there is a reduced respiratory rate, heart rate and pulse rate (reduced O2 consumption) 

Here, I will showcase only some of the many scientific theories underlying how asana can influence how we feel and think.

1) Increased parasympathetic activation - rest & relax

Extending from the throat to the base of the spine, the vagus nerve communicates signals from the majority of the body to the brain, playing a crucial role in self-regulation (Berthoud and Neuhuber, 2000). It is the main nerves of the parasympathetic nervous system, that allows for the body to rest, recover & digest.

Slow and rhythmic breathing (often cued in asana classes) is theorised to stimulate the vagus nerve (Sovik, 2000). Moreover, backbends and forward folds, typical yogic postures, expand and contract the rib cage, increasing the depth of the breath which further promotes vagal tone. Engaging the major bandhas: throat, abdominal and root lock may also stimulate the vagus nerve that innervates those regions. 

2) Embodiment

Another feature of yoga asana, especially emphasised in styles like Hatha, Iyengar, Yin, is that the asana is held for an extended period of time (e.g., 3-5 minutes). To understand how this can influence psychological states, we need to explore the concept of embodiment. Remarkably, as a society, our linguistic evolution already reflects an internalisation of this concept. Originally, the term "attitude" denoted physical posture; and “position” today, refers to one’s evaluation of an object or issue. 

Indeed, attitudes are deeply embodied, and intricately linked to postures and bodily responses. Specific postures can elicit specific psychophysiological effects, affecting pain tolerance, neuroendocrine levels and even risk propensity (Bohns and Wiltermuth 2012). "Power poses",postures exuding "high-power" and "confidence", have been correlated with reduced cortisol levels, increased testosterone levels, and heightened feelings of psychological power (Carney et al. in 2010). Conversely, assuming a slumped posture may contribute to a heightened sense of perceived helplessness (Riskind and Gotay, 1982). 

Specifically, yogic asanas often emphasise the spine - part of the central nervous system and where the major endocrine organs are located, forming the neuroendocrine system that is responsible for communication and maintaining homeostasis throughout the mind-body complex. Backbends, forward folds and twists promote blood flow to these regions, rejuvenating them and allowing for improved functioning. A study (though almost 20 years ago) reported that backbends were linked to greater increases in positive mood compared to forward folds or standing poses (Shapiro and Cline, 2004). However, this is only preliminary evidence, more research is definitely needed to add confidence to this finding. 

3) Improved cognition

With precise alignment cues, asanas emphasise the cultivation of interoception, proprioceptive and body awareness - internal processes that are crucial for self-regulation. On a neurobiological level, these functions, along with motor coordination and procedural learning are supported by the Basal Ganglia (BG), a set of neurons that are also implicated in higher-order cognitive functioning (Arsalidou et al. 2013). 

As the adage goes, "neurons that fire together wire together", a regular asana can strengthen the neural pathways within the BG, inadvertently improving one’s cognition too. Neuroimaging studies further bolster this theory, showing greater functional connectivity in these circuits in expert yoga practitioners when compared to novices (Gard et al. 2015). 

This exploration merely scratches the surface of the theories underlying the benefits of asana; for a deeper dive, stay tuned for future workshops and courses.