Not one to slow down, Mahony flew from the US to Hong Kong to visit friends. By chance, she accompanied a friend to a qi gong class conducted by Mak Chung-man, a Chinese herbalist and qi gong master from Cheung Chau who is regarded as an ambassador for both traditional practices - and she hasn't looked back.

According to the Chinese, 'qi' is the body's vital life energy, which should ideally circulate freely and easily. When it becomes blocked and stagnant, illness or fatigue occurs. Get it to flow smoothly again - which is where qi gong ('gong' means exercise) comes in - and the cause of illness will go. The better the qi flows on a daily basis, the stronger the vital organs and immune system will be.

'Master Mak changed my life by teaching me about qi and self-healing through qi gong exercises,' Mahony says. 'Not long after I started classes, my husband was transferred from Boston to Hong Kong so I was able to see Master Mak every day. It was fate. Someone up there was watching out for me.'

About a year later, Mahony went back to her American doctors for tests. They were, as she puts it, 'flummoxed'. Not only had she arrested the disease, she had managed to reverse it. In her opinion, she had rebalanced her qi so her brain could give her body the right messages and her bones had been able to grow back. As Mahony grew more familiar with qi gong, she started to adapt the various exercises for use while she was out and about, developing them to fit her lifestyle.

'We all have qi but we don't all have the time to set aside a couple of hours a day, which is what some masters insist on,' she explains. 'They make a big deal about the breathing, about the mystique of it, about having to come to them at a particular time . . . that's nonsense. Master Mak believes it isn't a secret art and that you shouldn't be reliant on your master. He taught me specifically so I could go away and exercise myself.

'Qi gong used to be like going to a tennis lesson - you'd set aside a particular hour to go to a class - but you can use all your spare pockets of time to get your qi flowing. I do qi gong on the plane - and don't get jetlag anymore - in a supermarket queue . . . I'm even doing qi gong now.'

Without getting up from her seat, Mahony demonstrates how, by placing her feet shoulder-width apart, arms away from her sides (so as not to trap the qi), elbows open, and resting her hands with fingers spread (to allow toxins to escape) palms down on the table, she is increasing her mental alertness. There is nothing weird or wonderful about her posture; she isn't breathing any differently or squirming around. But then she shows me her fingertips: they look red, a sure sign that her qi is moving.

'Pictures of Chinese emperors always show them sitting on thrones in this position - they were doing qi gong to keep themselves alert,' she says. 'It's a fantastic exercise to do at your desk or in a meeting. The most important thing is to hold your head as though it is being suspended by a piece of string or supporting a pile of books and keep your arms away from your sides.'

This and many other quick and easy qi gong exercises can be found in her new book, Indispensable Qi Gong For People On The Go (Rhino Press, $98).The guide features illustrations of various qi gong exercises accompanied by easy-to-follow explanations on performing each stance and its benefits. An anecdote or handy hint (such as doing the stance to relieve constipation only when you're near a bathroom) rounds off each page. There are exercises you can do while watching television (to strengthen your lower back and calves), doing the housework (to ease tension) and waiting to tee off on a golf course (good for circulation), as well as sickness-busters, depression-fighters and even a hangover cure, for which Mahony's husband was the guinea pig.

'I tried to make it as simple and as fun as possible, taking the mystery out of qi gong,' Mahony explains. But in case you can't get the hang of it, the book comes with a CD-Rom featuring Mak demonstrating the exercises.

Although the book has already proved a hit in Malaysia, Mahony is keen to stress she's not just another self-help author out to make money, nor is she a qi gong master. 'I believe in the powers of qi with a passion - if I had been lackadaisical it wouldn't have worked - but I'd never presume to call myself a qi gong master,' she says. 'I wrote the book to tell others about the benefits of qi gong and Hong Kong is where it all happened, which is why I wanted to launch it here before Europe and the United States. I would like it to be published there because I think a lot of Westerners are turning to traditional Asian healing methods these days. I'd also like to have it translated into other languages and write a book for kids. But that will have to wait until I've written my racy blockbuster.'

Joan Foo Mahony will be signing copies of her book from 5.30pm this Wednesday at Dymocks, 2/F, IFC Building, Exchange Square, Central. For further details, call Franki Ng on 2688 5773.

1. When you're hungover

a) Stand on your left leg. Bend your right leg and with your right foot off the ground, make a circular motion with it.

b) Ensure that your left leg is slightly bent and your hands are at your sides but away from your body. Your arms should be slightly bent with palms facing downward, and fingers spread.

c) Don't forget - you should use your arms to help you balance.

d) Change sides and draw circles with your other leg.

2. Back pain and joint ache

a) With your knees slightly bent, stand about 60 centimetres away from a ledge with your legs shoulder-width apart.

b) Using the ledge or counter for support (it should be no higher than your chest) rest your arms on it and spread your elbows, and - palms inwards - lightly cup but don't touch your hands. Spread your fingers and make sure your thumbs face the sky.

c) Keeping your knees bent, lean forward at a steep angle and hold that position. You should feel the weight in your elbows.

3. Relieving headaches

a) Stand with your knees bent and feet apart.

b) Bend your elbows and put your hands next to your ears with fingers spread and palms downwards.

c) Now tilt your body backwards at a 45-degree angle.