Quotes of the Day

The truth hits me as the first full day at the Complete Retreat limps to an aching close: the other guests have succumbed to Stockholm syndrome. That's the phenomenon in which hostages fall in love with their captors. Some of these people have already endured the iron regime of Lisa Jeans—and have returned, of their own free will.

Complete it may be, but the very name "retreat" is a misnomer. This isn't a refuge but a bracing course of exercise combined with a raw food diet, all designed by naturopath Jeans. Stern stuff, yet my fellow captives gaze cow-eyed at the honey-haired Jeans as she maps out the program for the week: yoga at 7 a.m.; a minuscule protein shake at 8:15 along with a vat of celery and cucumber juice that morphs from bland to blah with each mouthful; an 8:30 hike involving prolonged uphill slogs; at 11:15 more juice and a wheatgrass chaser (imagine a concentrate of freshly cut weeds mixed with nail-polish remover). Then there's more yoga, lunch and time for a treatment, perhaps from Antonin Zemlicka, a Czech-born therapist who punctuates his savagely deep massages with epigrammatic statements. "A little torture is good," he says. "A lot of torture is better."

That could easily serve as the retreat's motto. The matutinal cycle of torment repeats in the afternoon, and every day, a treadmill of yoga and yomps. Jeans herself describes the retreat as "a health boot camp." "The most effective kick start comes from a combination of diet and exercise," she explains. She runs her camp for 12 weeks a year in the Spanish hilltop village of Gaucín in Andalucia. But it's a movable raw-food feast, with two additional weeks planned in Cornwall, England, this year, and in 2007, for the first time, a long-haul retreat on St. Barts in the French West Indies. Accommodation in all locations is plush, and no more than 10 participants are accepted at one time.

So why did my husband and I consign ourselves to this exclusive penitentiary? An old friend and retreat veteran bamboozled us into joining her by making it sound like a spa. "It's lovely. Lovely walks, lovely yoga, lovely massages," she said. In retrospect, her eyes were suspiciously bright as she added: "And you'll love Lisa."

Love is a many-splendored thing. Day 3 and my husband has a new refrain: "If you really loved me, you'd take me away from this." Jeans avers that guests often feel "a little low on the third day. I tell them the pain will be forgotten by Saturday when they will look fabulous and feel full of energy. It's tough love, really." As it happens, I'm getting into the swing after shaking off a caffeine-withdrawal headache. Only one person in the retreat's four-year history has ever quit. And the yoga is wonderful, a dynamic mix of ashtanga and hatha techniques, taught with exquisite clarity by the retreat's regular instructor, Wendy Wardell.

The grub's not half bad, either. Meals might be a rabbit's fantasy of haute cuisine, but Henry Cumming, a top-flight chef from Britain, knows how to coax out the inner bunny. Plus it's not all salad. There's hummus and guacamole and soups—gazpacho and an unctuous white cream of almonds and garlic.

The menu is vegan, barring the odd egg, and the diet is supposed to make our bodies less acidic (bones leach calcium and other minerals if the body strays too far from its naturally alkaline pH of 7.4, says Jeans). It also tames blood-sugar swings. I'm never hungry, despite petite portions and epic helpings of exercise. On our final morning, out come the scales and most retreaters prove to be shadows of their former selves. Our friend is the biggest loser—4.5 kg lighter. My weight has barely dipped, but I realize I may have lost something else: my mind. Despite the punishing regimen, I'm sad to leave. But my husband assures me we'll be back. thecompleteretreat.com

• Catherine Mayer
• Forget lounging about— all that gets laid down on this yoga break are tough rules