The Shala Daily

A 2018 study from the Rotterdam Study followed more than 15,000 participants over time, with a subset of 3,742 undergoing repeated brain MRIs alongside questionnaires about their meditation and yoga practice.

The finding: practitioners showed smaller right amygdala volume—and that volume continued to decrease over time. The right amygdala processes fear and aversion to unpleasant stimuli. Less volume, less reactivity.

Meanwhile, 90.7% of practitioners reported that their practice helped them cope with stress. Science confirming what the body already knew.

🧠 The Direction of Change

What strikes me most is the direction of change. We usually frame growth as accumulation—more strength, more flexibility, more knowledge. But here the benefit appears as reduction. The practice is paring something away.

This fits the Ashtanga model. We don’t add poses to feel better. We return to the same sequence, and through repetition, something unnecessary falls off. The nervous system learns it doesn’t need to grip so hard.

In the Yoga Sutras, Patanjali introduces a complementary pair: abhyasa and vairagya—devoted practice and non-attachment. We show up consistently (abhyasa), and through that showing up, we learn to let go (vairagya). The brain imaging study captures this teaching in three-dimensional tissue: the letting go becomes literal.

“Yoga is the cessation of the fluctuations of the mind.”
— Patanjali, Yoga Sutra 1.2

⏳ Time as Ingredient

The study also reminds us that time is an ingredient. These structural changes emerged over years of sustained practice, not a weekend intensive. The daily return matters.

This is tapas in action—not the dramatic heat of a breakthrough moment, but the steady flame that burns when no one is watching. The thousandth sun salutation. The breath we return to again and again.

The amygdala doesn’t care about intensity. It responds to consistency. To the message, repeated across months and years: we are safe enough to soften.

🕊️ What Falls Away

The right amygdala specializes in dvesha—aversion to unpleasant stimuli. It’s one of the kleshas, the obstacles that cloud clear seeing. When we practice, we don’t fight dvesha directly. We create conditions where it naturally diminishes.

Perhaps this is why the yogis speak less of acquiring peace and more of uncovering it. Santosha—contentment—isn’t something we build. It’s what remains when we stop generating so much unnecessary reactivity.

The researchers measured cubic millimeters of neural tissue. The practitioners described coping with stress. Both point to the same truth: the practice makes space by taking something away.

🧘 The Practice Off the Mat

I read studies like this and I’m reminded that the ancient teachings weren’t guessing. The eight limbs describe a systematic unwinding—ethical restraints that reduce external friction, breath practices that calm the nervous system, sensory withdrawal that lessens input, concentration that narrows the field until what remains is clear.

Less volume. Less reactivity. More space.

The brain scans don’t prove yoga works—practitioners already know. But they do offer a kind of translation: what feels like softening is softening, all the way down to the tissue.