Science confirms the physical benefits of yoga, but the mental risks are considerable. The waistline contracts, but the critical sensibility may wither. The blood pressure falls, but the Downward Dog may lead to prostration before gurus. I should know. Ten years ago, two sessions of yoga cured two decades of back pain. Since then, I have tried, as the yogis say, to make yoga ‘part of my daily practice’, like gin and tonic, but I remain stuck on the lower rungs of consciousness.

The Goddess Pose is about someone who ascended to global celebrity via yoga’s blend of PE and fraud. Indra Devi’s life and travels spanned the 20th century. Her biography is the history of how affluent Westerners came to say ‘Om’ and how, as the Christian brand lost its share of the spiritual market, the mind-rotting power of yoga fused with the West’s fetish for youth to produce the sweaty religion of self-improvement.

Eugenia Petersen was born in Riga in 1899. Her father, a Swedish banker, absconded soon after her birth and her aristocratic mother left with a touring theatre company. In 1915, Eugenia read Fourteen Lessons in Yogi Philosophy and Oriental Occultism by Yogi Ramacharaka, who was really William Walker Atkinson, the Chicago-based author of Thought-Force in Business and Everyday Life. His blend of Hindu mysticism and Occidental horse sense became invaluable when the Russian Revolution stripped Eugenia’s family of its titles and wealth, and derailed her ambitions as an actress.

Trained by Theodore Komisarjevsky in creating ‘stylized’ characters, Petersen improvised for survival. In Moscow, Michelle Goldberg implies, she may have prostituted herself for food. She danced in White Russian cabarets at Kiev and was arrested by the Cheka in Tiflis. Eventually, she slipped into Poland with an actors’ troupe, then landed in ‘madly festive’ Berlin. Working in an avant-garde cabaret, Der Blaue Vogel, she resumed her spiritual enquiries under the posthumous influence of an earlier Russian aristocrat, Madame Blavatsky. In 1926, after travelling to Holland to hear Krishnamurti, Eugenia became a Theosophist.

By the following year ‘Jane’ Petersen was at the Theosophical Society’s headquarters in Madras, where she was ‘happy beyond measure’ to be part of the menagerie. The Theosophists supplied Jane with souls to admire and names to drop, even after Krishnamurti denounced Theosophy as ‘rot’. She met Tagore, whose verse collection Gitanjali she had read in Russia; Nehru, who had dropped his teenage Theosophy but retained, we learn, his ‘melting brown eyes’; and Gandhi, another juvenile Blavatskyite, whose vow of silence prevented him from replying to Petersen’s greetings.

Still dancing and acting – as ‘Indira Devi’, she starred in a silent Hindi movie, The Arabian Nights – Petersen married a Czech diplomat. Panic attacks brought her to yoga – not the ‘classical’ yoga of self-abnegation, but the modern yoga of self-actualisation. Hindu nationalists had adopted Western physical culture to toughen their minds for the struggle. Petersen’s first teacher, Swami Kuvalayananda, was influenced by the American bodybuilder Bernarr Macfadden and by Rajratna Manikrao, a revolutionary who devised mass calisthenics for Indian youth. The vinyasa yoga of her second teacher, Krishnamacharya, incorporated moves from the Danish trainer Niels Bukh, used in British Army training. She complained that her third teacher, B K S Iyengar, was more interested in bowel movements than in ‘mystic or occult training’.

In December 1939, her husband moved to China. In Shanghai, she started teaching yoga. Her husband bought a noodle factory and prospered as the city starved. She left him when the war ended and sailed for California with $6,000. Finally unknown, she reinvented herself as Indra Devi and began marketing the ‘secular magic’ of yoga in Hollywood. Before long, Elizabeth Arden had hired her to teach at her splendidly named Maine Chance spas. In Forever Young, Forever Healthy (1953), Devi urged women to stand naked in front of a mirror and measure the consequences of food, drink and tobacco. Yoga, she promised, restored ‘vital cosmic energy’, tightened wrinkled skin and improved the sex life. She bigamously married Stravinsky’s quack doctor, Siegrid Knauer, who diagnosed using a pendulum, injected patients with ground-up dinosaur fossils to treat ‘radiation poisoning’ and advocated ‘rejuvenation by the ingestion of minced fetuses’. The couple became an ‘alternative medicine power couple’, and Devi the ‘First Lady of Yoga’.

Devi missed the chance to teach yoga to John F Kennedy, but she capitalised on the Sixties’ drug-addled spirituality craze. Announcing a Manichaean ‘divine quest’ called the ‘Crusade for Light in Darkness’, she built a Tower of Light on her Mexican ranch, recorded an LP and decided to carry a ‘fire of peace and solidarity’ to India. Prevented from carrying her torch onto the plane, she transferred the flame to a series of cigarettes, which she kept puffing until she reached Delhi, where she relit the torch and presented it to Indira Gandhi.

The Sixties marked the second coming of Theosophy. Devi schmoozed with the Dalai Lama and the Maharishi, while also backing Sai Baba, the Paul Daniels of Hindu mysticism. She and 30,000 fans prayed in a stadium as Baba vomited a selection of stone lingams (ritual phalluses). He believed that he was divine; she agreed, and recruited for him among acid casualties high and low. To her credit, she addressed John Lennon as ‘Mr Lemon’ throughout his visit. She did not know that Baba was also performing hand tricks on some of his young male followers. When she discovered his pederasty, she remained an admirer and continued to work for him.

Devi believed in watermelon fasts, coffee enemas, and ‘detachment and love’, though this meant principally detachment from responsibility and love of fame. Her next guru, Swami Premananda, was convicted of raping and imprisoning orphaned young girls and plotting the murder of an estranged disciple. She lived long enough to witness yoga’s global triumph, dying in 2002 aged 102.

Michelle Goldberg, who took up yoga while backpacking in India, agrees with Orwell’s criticism of Gandhi – ‘non-attachment’ is escapism from responsibility to others – but Devi’s dramatic potential gets the better of her. Devi was as substantial as a watermelon diet and, even posthumously, she remains as irresistible as a coffee enema. As ever, yoga trumps mortality and morality.