Poser: My Life in 23 Yoga Poses

In the 1970s, the Buddhist teacher Chögyam Trungpa coined the phrase "spiritual materialism" to describe the pervasive western habit of consuming far-flung religious practices as lifestyle accessories rather than techniques for cutting the ego down to size, as was generally intended. The practice hasn't exactly abated since his death. Thanks to the gleeful cultural appropriation of celebrities, we are all familiar with Kabbalah bracelets and the weight-loss benefits of Ashtanga yoga, if not the real purpose of these exotic rites.

One of the drivers of this trend, Madonna aside, is the memoir of spiritual awakening, in which a woman, possibly after a divorce or job loss, goes on a quest for peace and self-acceptance that ends triumphantly after a month or two of meditation in some glamorously distant location. The classic of the genre is the monumentally self-indulgent Eat, Pray, Love (2006) by Elizabeth Gilbert; as such, Gilbert's cover description of Claire Dederer's yoga memoir as "the book we all need" does not exactly inspire confidence.

Fortunately, Poser is very different. Dederer, a freelance journalist from Seattle, began her affair with yoga in the late 1990s after damaging her back while breastfeeding her "pleasingly substantial" baby daughter. From the off, she confesses to being deeply wary of the whole business. "I had a number of preconceptions about yoga," she writes. "I thought [it] was done by self-indulgent middle-aged ladies with a lot of time on their hands, or by skinny fanatical 22-year-old vegetarian former gymnasts. I was also unsettled by the notion of white people seeking transformation through the customs of brown-skinned people - basically, to my mind, a suspect dynamic."

This self-appointed outsider's viewpoint can be very funny. At her first class, the teacher sashays in, all blonde bob and well-maintained eyebrows. "She looked as though she had been a step-aerobics teacher until about five minutes ago. She looked like her name was Jennifer. 'I am Atosa,' she said. Like hell you are, sister." Dederer also squeezes much gentle comedy from the right-on Seattle social scene that she is a semi-willing part of, where co-sleeping is de rigueur and giving your kids non-organic soda pop is akin to child abuse.

The wry, self-deprecating tone is a wise choice. It punctures pretension, and makes Dederer's periodic forays into seriousness all the more convincing. Even so, it quickly becomes clear that this is a more ambitious book than might be expected, and that its ambition lies, refreshingly, in the very domesticity of its scope. Rather than describe a peak experience thousands of miles from home, Dederer has chronicled the ups and downs of a regular, long-term practice that is rooted in ordinary life. The physical contortions she gradually persuades her unwilling body through act as mirrors for the equally demanding compromises she must make as a wife, mother and daughter, let alone as a woman with ambitions and desires of her own.

The parallels between life in and out of the yoga studio are emphasised by the book's structure. Each chapter is assigned a different pose, and illuminates an aspect of working motherhood and family life on the cusp of the 21st century. Dederer is particularly good at unpicking the differences between her mother's generation and her own, returning five times to the Child Pose to work through the contours of her fractured childhood.

Her mother left her father to run away with a handsome, Porsche-driving hippie eight years her junior when Dederer and her brother were young, part of "a rondo of departures: women fleeing in cutoff jeans, in business suits, in dashikis and Mexican wedding gowns and halter tops". She is deft at surveying the effect this tidal wave of liberation had on the small, defiantly conservative children caught in its backwash - "We would be good, all the time. We would stay married, no matter what, and drink organic milk" - and at analysing how constricting their reactionary stance soon proved to be.

Miraculously - which is to say, slowly and painfully - Dederer's yoga practice becomes a way out of this desire for perfection, and into a way of feeling more at ease with her ordinary, messy, decidedly imperfect self. One of the more infuriating tenets of New Age thought is the equation of physical flexibility with spiritual development, as if being able to touch your toes or wrap your feet behind your neck automatically made you wiser and more compassionate than your stiff-jointed fellows. In reality, the two are not necessarily related, but there is little doubt that, in mastering Downward Dog, Dederer has also discovered a rich store of what Chögyam Trungpa would have called spiritual wealth. Summed up in a sentence, this sounds cheap. Carried out over the course of a decade, it's anything but.

Poser: My Life in 23 Yoga Poses
Claire Dederer
Bloomsbury, 352pp, £12.99

Olivia Laing's book "To the River: a Journey Beneath the Surface" will be published by Canongate in May