Yoga has gone from a niche enterprise practiced by a select few to a multi-billion industry. Tens of millions Americans engage in the 5,000-year-old practice. And while most of us are well-aware of the benefits yoga promises—including increased flexibility, mental clarity, and improved muscle tone—it’s all too easy to brush it off as another fitness craze.

And yet, here’s the thing: While droves of people engross themselves in the practice—and yoga communities have popped up everywhere from Honolulu to Houston—at its core yoga is a profoundly personal venture that not only improves our ability to accept change but also initiates it.

Yoga and I go way back. I started taking yoga classes at the YMCA when I was sixteen, having been lured into the ancient endeavor by a friend who was a seeker of things with a deeper meaning. The yoga teacher we found epitomized the gentleness at the crux of the practice: She had a soft, enchanting voice and a beautiful demeanor. (She also didn’t charge us for classes because she was so happy that we were coming to her class.) She solidified a love for yoga in me, and I practiced it on and off throughout college and naturopathic medical school—primarily the forms of Hatha, which is not only the foundation of all Western yoga but also a practice of breathing, meditation, and introductory postures, and Iyengar, a style of yoga that places tremendous attention on anatomical details and alignment. I always felt a yearning to make yoga a predominant factor in my life but between college, naturopathic medical school and then building a practice, I barely had enough time to sleep.

It wasn’t until years later that the teachings of yoga genuinely landed. The year was 2016, and I had spent the last decade wholly focused on my work as a physician, business owner, public speaker, and author. Days started early and ended late, and yoga, alas, fell to the wayside. But when my Sunday swimming buddy suggested I throw myself back into the practice through a teacher training in Iyengar, I jumped at the chance to re-immerse myself.

Throw I did. The first class was a weekend-long undertaking in which I learned that Iyengar, like many forms of yoga, had evolved significantly since the last time I rolled out a mat. Downward-Facing Dog, for one, no longer asked practitioners to press their sit bones (quite literally the bones under the flesh of your butt) towards the sky, which creates a lordosis (or sway back) in the lumbar spine. Rather, we were told to flatten our backs and pull them down towards our heels. The other postural changes, combined with the fact that all of the poses were taught in Sanskrit, underscored my absence. Where had I been—and where was I going?

Towards something I couldn’t have imagined. Yes, that weekend left me sore, but I also felt fantastic. Yoga operates with the body’s meridians—pathways within our “subtle body” that help keep the current of energy flowing freely. (These are the same meridians that are concentrated on in acupuncture.) According to yogic theory and Traditional Chinese Medicine, if this internal, unseen network is disrupted due to energy blockages, the body will not function properly, and one may experience everything from physical imbalances to under-performing organs to a dysregulated nervous system. That weekend of Iyengar training—the first in a two-year-long program—awakened my meridians. I had never felt more alive or ready.

My friend eventually opted out of the teacher training but I remained—not necessarily because I wanted to teach (at least not right away) but because of the differences yoga was making. The hip pain that had haunted me on and off for years disappeared. The ache in my lower back—pain stuck in my left sacroiliac joint that I had tried to treat with a chiropractor—evaporated. I found myself sitting up straighter, smiling more, and thinking better. I even found myself standing erect and pinning my hips in, like in mountain pose, while pumping gas instead of unconsciously thrusting my hip out to the side. Yoga was re-aligning my entire body.

It was also realigning my perspective. I come from a long line of diligent Germans for whom work isn’t just a priority—it’s one’s life. Given that I didn’t escape this DNA, I always thought that running a successful naturopathic practice meant running myself to the ground, my own health and pleasure be damned. (Yes, I see the irony.) Without fail, I worked from 9am to 7pm five or more days a week, often from a place of deep exhaustion. During my Iyengar training, I began leaving the office early twice a week to attend yoga classes. This was unprecedented for me; a colossal change in lifestyle. And yet, it also felt true, right, and necessary. I thought I was taking care of myself by becoming a leading physician in the community and obtaining financial stability. But the very things I was asking of my patients—to treat their health holistically, to discover wholesome coping strategies, and to take time to savor the beauty of simply living—were lost on me. I was burning the candle at both ends, and trapped in the trance of work, work, and more work.

This isn’t to say that yoga doesn’t make her own demands, particularly Iyengar. Iyengar stresses precision, focus, respect, consistency, and abhyasa (or practice/discipline).

Teachers of Iyengar follow these principles religiously. Training to become a certified instructor is serious—and rigorous—business, entailing a 250 hours course, three years of practice, and a daily personal practice in order to be recommended for certification. The certification exam consists of a demonstration of 74 asanas (or physical postures), a pranayama test (pranayama is a style of yoga breathing), a written test, and a practicum to showcase one’s teaching skills. The Iyengar teachers I’ve followed are not only utterly devoted to the tenets set forth by its founder, B.K.S. Iyengar, but also huge proponents of teaching to the individual, utilizing props to enable anyone of any age to do the postures, and building a safe place for students to practice. Step into their studio and your outside identity vanishes. You are no longer a doctor, a wife, a mother, a brother, or a CEO; age 55 or 22 or 80. You are simply a student of yoga, and stripped down to your elements of breath, body, and spirit. Your only job is to unlock your heart and let the yoga do its quiet, inner magic.

The science is there to show yoga’s values, including helping to relieve neck pain, fibromyalgia symptoms, sore feet, Parkinson’s, atrial fibrillation, improve stroke recovery, sleep problems, strengthen bones and more. A study at Universidade Federal de São Paulo on the effects of yoga on postmenopausal symptoms showed that those in the yoga group reported far less severity of insomnia (31%), depression (27%) and stress (36%), and they reported a 27% increase in their quality of life, while there was little difference in the control group and only slight improvement in the group that was stretched by a physical therapist. And I’m just getting started on yoga’s health benefits!

It’s also no secret, science or not, that yoga creates strength, on and off the mat. Staying in postures for a good, long while naturally translates to greater mental resilience. It’s no secret either that yoga facilitates ease, allowing dedicated practitioners to accept life’s inevitable changes. But one of the biggest draws for me and the patients to whom I’ve prescribed it is that it sparks change—and from the inside out to boot. It’s like self-Rolfing—a form of bodywork that reorganizes connective tissue in the name of enhanced balance—just as it is a form of meditation in motion. It works on metaphorical levels that are less frequently analyzed by Western scientists. In practice, you may be aligning your back foot with the heel of your front foot, but you’re also aligning your actions with your values. You may be concentrating on opening your spine but you’re actually opening your mind. You might be finding space between your vertebrae but you’re really discovering room to grow. Those I have recommended it to have not only resolved many of their immediate health issues but have also found that it affects every major domain of their life. They eat better, sleep better, work better, exercise more, and love deeper. And some, as in my case, are at long last practicing what they preach. “Yoga does not change the way we see things,” Iyengar once said. “It transforms the person who sees.”

Click here to buy Dr. Laurie Steelsmith’s books, Natural Choices for Women’s Health, Great Sex, Naturally and Growing Younger Every Day: The Three Essential Steps for Creating Youthful Hormone Balance at Any Age.