Kettlebells: the fitness tool that could help you drop a dress size

Kettlebells chime well with the boot camp ethic that has sweated its way through the workout world. Tough, uncompromising and apparently offering miraculous results, it's no wonder they are flying (well, being lugged) off the shelves.

On the face of it, the kettlebell isn't terribly impressive. So, what's the difference between swinging a kettlebell around and hefting barbells or free weights?

Unlike a dumbbell or barbell, the kettlebell's centre of mass is offset from the handle. This means the weight constantly pulls against your hand and requires not only strength and co-ordination, but also the use of the other muscles through your arms, shoulders and your core stabiliser muscles. You use around 600 muscles in a workout and exercise your cardiovascular system, too – it's definitely a total body workout.

And you don't have to be super strong to train with kettlebells. They come in different sizes and weights, starting at 4kg and going right up to a muscle crunching 48kg. Unlike standard weights, which are lifted carefully and slowly, kettlebells are flung around with seemingly gay abandon. You swing them, pump them and pass them from hand to hand. It's a monster workout and some trainers reckon an hour of kettlebells will shed a mammoth 1,500 calories (compared with 300-400 for normal weightlifting or an aerobics class).

Inevitably, there are some risks involved with kettlebells, as there are with any free weights. But these can be minimised by having proper instruction. Once you've learnt good technique, though, the training can actually help prevent injuries. Learning to move and lift properly carries over into daily life.