Yoga is much more than just impressive poses. It’s a complete philosophy, as highlighted by the insightful article written by Dr. Carolina Estevao published here on Inspire the Mind.
But do you ever wonder what is going on inside the brains of the 300 million worldwide yoga practitioners? Let's find out!
I’m a research & development engineer working on brain-computer interfaces for a tech company. But during my off-hours, you'll catch me practicing headstands and feeling fantastic afterward. My interest in yoga started during the COVID-19 period as it was easily accessible to practice at home thanks to cool YouTube channels like Breathe and Flow or Yoga with Adriene. Now, I finally have the opportunity to connect with the vibrant yoga community in person. But after each session, I can’t help but wonder where all these positive feelings are coming from.
Connecting the Dots: Getting the Full Picture
In the world of brain research, there are two important non-invasive methods to study the brain: electroencephalography (EEG) and magnetic resonance imaging (MRI). EEG is like a quick camera that captures brain activity in real-time, but it's not so good at seeing deep inside the brain. On the other hand, MRI is like a detailed map that can show us different brain areas, but it's not as good at showing the brain's fast responses to things. Luckily, we can look at studies using either EEG or MRI and try to piece together the full picture of what is going on in all the brains of yoga practitioners.
EEG – The Dance of the Brainwaves
EEG is a method to see how the brain's electrical activity works. We use small sensors placed on a cap over the participant’s head. These sensors measure the brain’s electrical signals in a completely non-invasive manner. The signals come from lots of brain cells working together. We can find patterns in these signals, which we call brainwaves. There are four main brainwave patterns, each with a different speed: delta (very slow), theta (slow), alpha (medium), and beta (fast). These brainwaves help us understand what the brain is doing at different times. We can relate the activity of a certain brainwave to a mood or a state somebody is in – for example, if you’re feeling relaxed and calm that means your brain’s alpha waves, the medium waves, are more active.
Let’s see what’s happening with those brainwaves when you decide to do yoga.
To illustrate this, I will briefly summarize the results from an insightful systematic review, which is a synthesis of the existing scientific studies in the topic. First, you sit down and take a couple of deep breaths. Your mind is still a bit noisy – this means that your beta (fast) brainwaves are dominating. They will continue to dominate as you’re listening to the instructor’s cues and doing different poses. But as you’re approaching the end of the session and you become more and more relaxed, your slower brainwaves start to become more active – the alpha and theta waves. Delta has the slowest speed and it’s usually very minimal in an awake state. However, after an intense yoga practice that has an emphasis on meditation (such as yin yoga), some individuals might experience increased delta waves, contributing to feelings of rejuvenation and restoration.
And it doesn’t stop there – experienced yogis reap the benefits of the practice even outside of the yoga practice in their daily lives. Regular yoga practice has been associated with reduced stress and anxiety levels. EEG studies have indicated that experienced yogis may exhibit higher levels of delta brainwaves and lower levels of stress-related brainwave patterns, such as beta waves, even when confronted with stressful situations in their daily lives.
MRI – Cell Bodies and Their Connections
Coming back to MRI, this is a special way to take detailed pictures of the brain using a strong magnet, radio waves, and a computer. It's like taking a super-detailed photograph of your brain's insides.
The brain has two important types of tissues: white matter, which is like the cables connecting different brain cells, and grey matter, which are the cell bodies responsible for learning, memory, muscle control, and self-awareness. More gray matter in certain areas means better brain performance overall.
The MRI scans of people who regularly practice yoga have shown something very intriguing. Doing yoga, with its postures, breathing, and meditation, increases the grey matter in parts of the brain called the frontal cerebral cortex, which is a part of the brain located in the area of your forehead. Moreover, the grey matter increases in the hippocampus, a structure deep inside the brain. These areas are responsible for focus, concentration, emotional control, and understanding rewards and consequences. Even more interestingly, grey matter usually shrinks as we age, but older people who practice yoga tend to have less of this shrinkage. So, it seems that yoga could be helping to keep your brain young and healthy!
And the Full Picture?
According to EEG studies, regular yoga practice can increase activity in the slower brain waves, leading to a sense of calm and a better response to stressful situations. Additionally, MRI research suggests that certain brain areas show more cell bodies after consistent yoga practice, which may improve concentration and emotional control. Moreover, there's evidence that yoga may even play a protective role against age-related brain shrinkage.
While research on yoga's impact on the brain and body continues, weaving together these fragments to form a comprehensive picture represents a positive step. Ultimately, it helps us move towards a better understanding of the complete philosophy behind yoga.