Pumping iron with the Princess

There must, by now, be a million photographs of Diana, Princess of Wales, but there is a single image with which she has become particularly associated. Showing only the back of her head - with, occasionally, a flash of irritated or flirtatious pr ofile - she pushes through the doors in a wall of glass. She is wearing a top bearing the design of the American flag. Although there have been periods when the same image has appeared in newspapers several days running, these are not reprints. Most days , in that same top, the Princess makes this identical journey. Her destination is the Chelsea Harbour Club, her chosen gymnasium and leisure centre.

In an industry in which image is as much to do with the feel of your clientele as the size of your swimming pool, the Princess's very public patronage has provided the vital snob appeal that gives this venue the edge in the market. Currently, there is a six-week waiting list for membership, which costs £2,400, followed by an annual payment of £1,158. There is a wait of several months for the restricted membership, allowing admission only during weekdays, which requires an initial payment of £1,025, with£918 a year to follow. It was on a £15 "guest day ticket" that I recently went undercover to the club.

Having secured entry to the premises, you descend four floors to the basement, where a receptionist hands over two fluffy white towels. On this level are the changing rooms - where the locker keys are hung from a big nappy pin that you attach to your T-shirt - and something called The Clinic. In Andrew Morton's latest book, Diana: Her New Life, he describes the Princess's obsession with New Age therapies and remedies, and it seems likely that it is the noticeboards of the Harbour Club which have drawn many of these techniques to her attention.

Clients are not offered colonic irrigation, which is one of Diana's treatments, according to Morton, but the club can provide aromatherapy, acupuncture, shiatsu, a 5-Vitamin Skin Recovery Programme and something called Seiki, which, until I saw it on thenoticeboard, I thought was the plural for posh watches. Apparently, it is a form of Japanese massage. Among the bottled potions and creams available to patients at The Clinic was the youth-restoring "micronised marine algae''. The recent EL Doctorow novel The Waterworks ends with a terrifying description of late 19th century "immortality clinic'' spas to which rich people were drawn by the promise of eternal life. The Clinic at the Harbour Club is probably the equivalent for a less credulous age. The clients even each receive a little buff folder marked "PATIENT NOTES - CONFIDENTIAL" in which their manicures, massages and mud-baths are recorded.

If you were constructing a time capsule to represent the early Nineties, you would surely include a health club and probably - given its connection with the emblematic Princess Diana - it would be the Harbour Club. In such institutions, two modern socialmovements, health awareness and female self-assertion, come together. They are a product of a general obsession with fitness: a cultural trend so pronounced that there is even a television sitcom about a leisure centre, The Brittas Empire. But, more specifically, the upmarket establishments are a female equivalent of the male club.

Although there is a brisk trade in bankers just after dawn when the place opens, most of the users are women. And the members are as snooty about which premises they frequent as men are about the Garrick. Among leisure centres, the Hurlingham, in Fulham,and the Vanderbilt, in Shepherd's Bush, are preferred - particularly for tennis - but they have punitive waiting lists. The Princess of Wales briefly popularised the LA Fitness Centre in west London, until she discovered that she had been secretly photographed, by a hidden camera in the ceiling, while working out.

In the fitness centre's main workout area, weight-lifting equipment is arranged around the walls, with the centre of the room filled by ranks of exercise bikes and rowing and step machines. This is exercise as science: the machines have liquid-crystal consoles that bleep out miles per hour, difficulty-level, minutes remaining, calories burned. Pulse-rate monitors are also available.

At the front of the room is a bank of television sets, each tuned in to one of the main channels. These are standard fixtures in swish gyms these days - bankers like to keep an eye on the world while they sweat - but, at this club, the screens' presence has another resonance. On several mornings during the recent royal upheavals, the Princess of Wales would be working out in a corner of the room, while, surreally, the television sets all showed her entering the Harbour Club. As her workout coincides with the morning news, her visits to the gym have been, in recent weeks, an imperfect form of distraction.

The princess works out mainly on two weight machines, which are identified by signs such as Total Body and Total Hip. The first involves assuming the crucifixion position, then raising your bodyweight against a variable pressure. The second is like doingthe can-can with a bag of rocks tied to each thigh. No one approaches or speaks to her while she works out. This is not the result of instructions, but, as one member says: "You get this sense that everybody prides themselves on knowing how to behave inher presence.'' Another observer says that she has reached the level of fitness at which she no longer sweats.

She is, though, easily rich enough to install a Total Body and Total Hip machine at Kensington Palace, so there must be another reason for her regular attendance. Perhaps it is the chance to check up up on the latest wacky therapies on the noticeboard. But I suspect the reason is that membership of a health club - the ambience and exclusivity and rules - is in itself a New Age therapy, and to take the machines or trainers home would miss the point.

In the matter of exclusivity, it should be pointed out that, although colloquially referred to as "Chelsea Harbour Club'', and legally registered as The Harbour Club - and Chelsea's harbour is the only one nearby - the place isn't in Chelsea at all. Its high walls protect it from a rather rough part of Fulham, where the pubs contain men who have led very colourful lives. Chelsea, though, sounds better on the phone and looks better on the brochure. Perhaps, for the people who go there, Chelsea is less a place than a state of mind, and so, even in the midst of Fulham, they are in Chelsea.

Certainly, the literature seems aimed at the more exclusive postal codes. Members are sent a four-page booklet called: A Guide For Nannies - To TheAcceptable Behaviour of Children. Carers will get their wrists slapped if they fail to "ask themselves whether their children are being considerate to others and whether they are doing anything that a reasonable person would find inconvenient or disturbing''. Nappies shall not be worn in the swimming pool and "crayons should not be used in the Clubroom and television area since they cause damage to the leather sofas''.

The 25-page Rule Book For Members includes the curious warning: "No Member or Member's Guest shall attempt to induce any employee of the Club or the Company to leave his employment or to act in any way contrary to the interests of the Company.'' This legalistic phrasing is believed to cover attempts by rich women to persuade trainers to come and work with them personally at home: apparently a regular hazard at such centres. There are no specific rules outlining procedure if you should find yourself pump ing iron next to the Princess of Wales, although staff contracts are openly paranoid about the company's greatest asset, directly forbidding contact with journalists.

I did 10 miles on one of the stationary bikes, then had a shower: "It sounds a lot of fun. I'll put it to the board next week,'' boomed a voice from a cloud of steam in the corner. Then I slugged down a £2 bottle from the Evian slot-machine, and went to the hair salon, the only one of The Clinic's activities open to day guest members. A simple trim cost £30: prices are so high at the Harbour Club that pulse-rate monitors would be useful in the salons and restaurants as well as the gym.

I stopped for coffee in the restaurant lounge, where, according to A Guide For Nannies, "some spilling of food is inevitable, but throwing it or deliberately dropping it on the floor is unacceptable''.

Groups of women gleaming from the shower were chatting over cafetieres of decaf. Diana is driven back to Kensington Palace immediately after exercising - to avoid any possibility of changing-room or shower nude shots from a peephole ceiling camera - but the other members bathe, blow-dry their hair and socialise, shining with aerobic after-glow in their designer tracksuits. The clientele divides between diplomatic wives and ex-pats - particularly Americans, for whom such clubs are a kind of human right -and grown-up Sloanes like Diana.

"That trainer's fine,'' said one. "But I'm not over-fond of the Australian sense of humour.''

"I've just sold my restaurant - and I'm about to open another one,'' boasted another.

"You mean you've never been there?'' asked a third. "It's the best pick-up place in Pimlico.''

"I had sex with a Frenchman once - never again,'' confided a fourth.

"She wasn't in this morning,'' said a fifth, and the sixth replied: "No. Although she's definitely in London. There was a picture of her in the Times.''

There was only one person "She'' could be. Perhaps, then, this is the future for the monarchy: as national exemplars of fitness. There was once a television workout expert called the "Green Goddess". Diana could become the "Green Queen", and the "Chelsea'' Harbour Club her palace.