Who goes to Triyoga...

It's an unassuming venue at first glance. Tucked down an alley which appears to house only small industrial units, the building was once the Caterpillar shoe warehouse, and before that a Green Shield Stamp factory. But today, Triyoga in Primrose Hill is Europe's largest dedicated yoga centre. The place hums with activity from dawn till night, and its classes are the regular haunt of the capital's more starry yogis. If you want to catch Geri in a down dog, this is the place to do it.

Fans come for the centre's feel - a breezy combination of tranquillity and cool, well suited to its laid-back postcode. Unlike many of London's yoga centres, this place reeks of chic. There's no mung-bean asceticism here and, while you do have to shuck your shoes at the door, you can still read Vogue in reception (though mobile phones are outlawed - even if you're waiting for a call from your agent).

The slub-silk furnishings, dark wood floor and richly coloured walls were masterminded by designer Matthew Williamson, so there is an opulence that is missing from some of the capital's more frugal yogic establishments. Prada and Gucci are welcome here unlike, say, at Putney's Sivananda Centre where, in leaflets pinned to the back of the loo doors, visitors are exhorted to eschew their worldly goods.

While Triyoga is undoubtedly fashion central, it is also a second home to local grans, the area's kids (yoga classes here start at the age of five), heavily pregnant women who waddle amiably through reception and a large blond retriever by the name of Teddy. 'I guess it was intensely fashionable when we first opened,' says Simon Low, a highly regarded yoga teacher. 'But now the reality is different. Of course, we get our movie stars and famous names, but we also get all sorts of people, from embryos to old ladies, at every level of experience, from every social group. Stars simply roll out their mats alongside the bloke from down the road. Yoga is a great leveller. Very well-known people are happy to come here because there's no fuss. We don't talk about them and they don't get hassled.'

Besides, it's rather uncool to gawp, particularly given that properly executed yoga is meant to be wholly non-competitive. Which is probably why Geri Halliwell enjoys regular classes here, and why mere mortals might well emerge from a series of sun salutations in studio two to discover that they are noseto-butt with Jude Law. Rachel Weisz and Gaby Roslin come for a stretch at Triyoga from time to time, as does Kate Moss - while Jade Jagger has been known to drop by. Sadie Frost finds respite here among the local moneyed and honeyed population who slot in a spot of Phoenix Rising Therapy between their morning frappuccino and their afternoon Brazilian.

If a class crowded with all those super-bods wrapped into elegant pretzel shapes seems offputting, I can report that even the average Ashtanga session at Triyoga is indeed a pretty fashionable event - all pale pink Birkenstocks and Kate Spade bags. As Triyoga regular Lisa Mangan puts it: 'The place is full of irritatingly beautiful women. It's just the way Primrose Hill is. I sometimes feel a bit shabby, particularly if the varnish on my toenails is chipped. But I have been going for years because the tuition is so good. You get the impression that the teachers are trained in both the practice and the principles of yoga. And it's a beautiful space.'

Another habitué agrees that the atmosphere is a big pull. 'Everything has been thought through to make Triyoga warm and welcoming,' she says. 'It's very just so. Each stained-glass window in the studio represents the colour of one of the chakras.'

'It was important to get the balance right,' says Jonathan Sattin, a former lawyer who came up with the Triyoga concept. 'If it is too fashionable, its lifespan is limited.'

Businessman Ford Ennals helped Sattin with the business plan and it was Ennals' wife, journalist Tina Gaudoin, who brought in Matthew Williamson to help with the design.

Sattin balks at the mention of famous Triyogis. 'If they come,' he says, 'it's not to show off, but for the teachers.' One of the reasons for Triyoga's continued cachet is that it boasts the pick of the yoga world's most sought-after names. There's Ashtanga expert John Scott, for instance, who was taught by Gwyneth Paltrow's guru Pattabhi Jois, and who lists Madonna and Sting among his more starry acolytes. Or Baron Baptiste, named by US Vogue as one of 'America's all-star trainers', who has taught his brand of Power Vinyasa Yoga to Elisabeth Shue, Helen Hunt and Raquel Welch. 'It's what gives Triyoga its credibility,' says Low. 'The centre has become a destination point for people who practise yoga.'

Whatever else it is, Triyoga is certainly successful - so much so that nearby residents have in the past complained to the council about noise during the 6.30am self-practice session. If you have never experienced it, yogic breathing can be a little on the loud side. But, as any fan of Triyoga will tell you, it sure beats the city's usual racket of sirens, buses and car alarms.

Triyoga, 6 Erskine Road, NW3 (020 7483 3344)