ANY exercise craze that promises a quick-fire way to achieve a toned physique to rival that of Elle MacPherson is always worth a look at.

So I jumped at the chance to try out Bosu Training classes, a new style of exercise that has taken America by storm and is fast growing in popularity over here.

The class I was invited to is run by Julie Burfoot and her partner Mark Brown, who are both qualified Bosu trainers. If ever there was an advert for the benefits of the Bosu, this pair are it. Fuelled with unbounding energy and boasting bodies that are toned to within an inch of their lives, the couple were bitten by the Bosu bug two years ago and are unstinting in their enthusiasm which makes for a great class.

When I arrive for my first session, Julie, 29, and Mark, 27, are busily handing out a Bosu to each member of the class. Bosu stands for 'both sides up' and refers to the large air-filled dome with a plastic base that is the main focal point of the exercise. It is a daunting piece of apparatus to look at but once you have got the hang of it, it is rather fun a word not normally synonymous with the painful gruel of keeping fit.

The idea of using the Bosu is to work every muscle group in the body at the same time through a combination of work-outs that involve anything from standing and jumping to lying on the inflatable dome.

Julie explains: "Bosu is a challenging work-out as it uses all the stabilising muscles, rather than working on one set of muscle groups at a time, so you get toned much faster than you would in a normal keep fit class."

The 'stabilising' really is the key to the class as you are required to jog, squat and leap on and off of the Bosu, an activity that demands a good deal of concentration and muscle tension and is also a great source of hilarity. In my first class, I spent most of my time falling off the Bosu than staying on it.

"The classes are great fun because it is so different to anything else on the market. Every time you step onto a Bosu, it makes people smile," says Julie.

But it is not just about having a laugh. Despite enjoying a good giggle with the rest of my fellow class members as we struggled to get our balance while executing a lunge and then a stretch in one seamless move, Julie made us sweat for our money. And it was my abdominals that suffered the most. As well as bouncing about on top of the inflatable dome, the Bosu is capable of other types of torture when it is turned upside down hence the name 'both sides up'. One exercise involved us lying on the floor with our feet placed firmly on the flat side of the upturned Bosu. We then had to raise our pelvis slowly up off the ground and back down a manoeuvre made all the harder by the fact we were constantly struggling to keep our feet balanced. My aching stomach muscles the next morning were proof that this does indeed increase the effectiveness of the exercise. But it is not just the abdominals that benefit from a spot of Bosu.

"The balance training in Bosu classes improves body awareness, the cardiovascular training improves your heart and lung efficiency and fitness level which, in turn, burns fat and the muscle strength and endurance helps to strengthen the muscles and give the muscle definition," explains Julie, who claims that her strength has improved ten-fold since she began Bosu training.

"You really will see the difference in six to eight weeks," she assures me.

Julie is so confident in the rewards of Bosu training that she has even persuaded a friend to come along to classes to get in shape for her wedding and if a bride-to-be can put her faith in the Bosu, anyone can.

Bosu Integrated Balance Training Classes take place at Tylers Green Village Hall every Tuesday from 8pm to 9pm and at various times in the private home studio Julie and Mark run from their business Innovative Fitness. For August and September classes will be £3 (usual price is £7.50) For more information, visit www.innovative-fitness.co.uk.