My assailant looms over me on the gym mats. He’s not quite as ugly as Zao, the balding henchman in the Bond movie Die Another Day, but he’s easily as tall, and certainly as mean. He strikes out, sending a fist perilously close to my lipstick and hairdo. But I counter with a move that might impress Bond himself.

It’s not often that kneeing a man in the groin counts as exercise, but keeping fit has recently taken an unusual twist in California. It has become rather violent. In fact, gyms that don’t serve up a helping of adrenalin with their treadmills and StairMasters these days are looking decidedly lame, rather like my assailant after I’ve finished with him. Although, perhaps, I am flattering myself. I’m training to be a Bond girl and, frankly, I think I’m more deskbound Moneypenny material than Pussy Galore.

Spy School is the latest exercise hit from the land where only showbusiness tops keeping fit as a preoccupation. It’s a thirty-hour course spread over eight weeks, which promises, at its conclusion, a “Bond-girl body and a butt- kicking attitude”. At $1,500 (£820), it’s pricey but it’s what all the stars are doing and the waiting list to sign up has as many names as Miss Moneypenny’s Rolodex. Each week there is a different class: ice-climbing, abseiling, aerial arts (taught by an instructor from Cirque du Soleil), surfing, gymnastics, weapons training, belly dancing. Just about anything that’s terrifying and dangerous is included, as well as a few courses designed to exercise the funny bones such as erotic dancing and how to change your look with wigs and make-up.

The most crucial component of it all, however, is the assailant-defence class. “Once you’ve fought off five guys, it allows you to go into the office the next morning and ask your boss for a raise without even thinking,” says Sascha Ferguson, a Pilates instructor and entrepreneur, who set up Spy School at the Absolution gym, in West Hollywood. “This course gives women confidence in themselves. We have been doing this since last October and the feedback I have had from women who have been to Spy School is that it has changed their lives.”

Besides raising a fist for girl power, the underlying premise behind this course, and others like it, is to breathe life into the dull routine of exercise. Ferguson will not name the A-listers who are devoted fans of her course, but she says the stars love it because it is so much more fun that anything they are used to. “Going to the gym is so boring,” says Ferguson. “Human beings are not hamsters designed to run on a treadmill in front of a TV. Getting fit is meant to be fun. And one of the best parts about being fit is being able to do the things you want to do, such as ice-climb a mountain.

“I started this course because I knew so many women who would watch the girls in movies such as Charlie’s Angels or the Bond films, and get depressed because they felt they couldn’t live up to those women. But the truth is, they can. This course is all about teaching people to do things they never thought they could do. We have the best instructors for each of the different aspects of Spy School and anyone can do it.

“It’s also addictive. We are going after adrenalin whores. When you are training in the adrenalin state, your body is really working. You just get into the moment and it makes your muscles work hard. The aim is to come out of the course with incredible flat abs but also feeling very sexy and very powerful.” I’m not sure that I feel either, as my assailant — a male instructor dressed up in a large padded suit — pushes his face right up next to mine, shouts profanities and aggressively aims his punch.

I have been taught the Ready Stance: hands up by the face in a defensive pose, feet slightly apart. I’ve been taught how to block his punch, where to aim a knee, how to yell “no” and how to overcome the common “freeze response”, which is what many women do when assaulted.

But this is a scary moment. I’m more of your knitting-and- a-nice-cup-of-cocoa kind of girl. I read Good Housekeeping, for heaven’s sake. This evening was clearly a mistake. I’m not the type who meets assailants . . . And it’s while I’m explaining this, and finding other excuses to sit out the exercise, that a female instructor tells me that one woman in three is likely to experience some kind of sexual assault during her lifetime, according to statistics. That’s a lot of women. She tells me I can drink as much cocoa as I like and still meet a real-life assailant in a supermarket car park.

And so I stay — and I surprise even myself. My assailant was doubled up on the floor by the time I’d finished with him. I’m doing abseiling next; not to mention asking for a pay rise.

THE GYM IS NOT ENOUGH

Sascha Ferguson, founder of Spy School, on how to spy-up your exercise routine:

1 Get out of the gym; we are not meant to be hamsters on a treadmill
2 Join a gymnastics class
3 Do a self-defence class
4 Gather a group of friends together and hire a belly dancer to teach you the moves
5 Take up rock climbing
6 Seek out and take part in all the adrenalin-fuelled activities you can
7 Take the bus to an area of town you’ve never been to before and walk home

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