Joseph Pilates was a walking advertisement for his own product. No need for sandwich boards or complicated PR campaigns to convince the world of the benefit of his series of exercises. Just look at the results.

A sickly child, suffering from asthma, rickets and rheumatic fever since his birth in Duesseldorf in 1880, Pilates began - during his teenage years - to devise the “method” which now bears his name. The sickly baby went on to become a boxer and circus gymnast.

There’s nothing mystical about Pilates; the exercises are precise and rooted in scientific principles. And since its founder’s death in 1967, the Pilates method has been continually adapted as physiologists have learned more about the human body.

The basics, however, remain unchanged. Pilates promotes correct posture and improved co-ordination by aligning the body’s basic structures and strengthening important muscles. The aim is to combine strength and mobility, to tone and lengthen muscles rather than to bulk them up. The key, apparently, is the transversus abdominus muscles. Identified by Joseph Pilates as the powerhouse of human activity, these abdominal muscles, hidden deep within the body, support the spine and torso, allowing limbs to move freely. Traditional exercises such as sit-ups may be the route to a rippling six-pack, but Pilates focuses instead on these deeper muscles.

The first task of the Pilates teacher is to unravel the tangled knot of bad postural habits. He or she will help you to realign your body so that your head is balanced evenly over your neck and spine, your pelvis sits level, your shoulders fall gently away from your neck and your feet point straight ahead with your weight spread across your soles. Only then do the exercises - which take two forms - begin.

Mat work exercises are a series of gentle stretching and breathing routines requiring a small area of floor space. For most people, this is the ideal introduction to Pilates, but there is also the option of studio work. These are similar exercises, but they use specialist equipment such as “the wunda chair” and “the four-poster bed”. As the names imply, the equipment bears a passing resemblance to items of furniture - a result of Pilates developing much of his work at an internment camp on the Isle of Man during the First World War, where he was forced to make use of whatever was to hand.

But what can Pilates - long popular with sports people and dancers - do for teachers? The answer is not so much what it can do, but what it can undo.

Back pain is the single most common physical complaint in the workplace, afflicting two-thirds of adults at some time. Unsurprisingly, teachers are among the worst sufferers. Hunching over a desk marking homework, lugging piles of books between classrooms, or simply standing in front of a class for hours on end all have the potential to push the body out of alignment and cause pain.

“Back trouble is the most common reason people turn to Pilates,” says London-based instructor Samya Tatone. It was also her own motivation for giving it a try. “I’d been suffering for years, yet when I walked out of my first Pilates session I was free of pain. I was an instant convert.”

There’s another advantage here for teachers. Because Pilates lengthens the spine, restoring space between scrunched-up vertebrae, you can “grow” up to two inches. Combine this with improved posture and balance, and it’s possible to acquire a new air of authority in front of a class. It’s the reason so many actors, seeking to captivate an audience, are also Pilates enthusiasts.

“A person who practises Pilates cuts a more commanding figure,” says Ms Tatone. “Their body language is positive. And when you are in control of your body, you also feel in control of your surroundings.”

Throw in some of the other benefits of Pilates - enthusiasts say it encourages proper breathing, relieves fatigue and improves your quality of sleep - and it begins to look like the perfect exercise for stressed-out teachers.

Tracking down an instructor should be easy enough; finding a good one may prove trickier. Christine Hocking, founder of Pilates Based Body Awareness, Britain’s largest provider of mat-based classes (also in London), warns that Pilates has become a victim of its own popularity. “Fitness instructors have all been retraining as Pilates teachers simply to cash in,” she says. “They do quick-fix courses so they know the exercises but they aren’t ‘switched-on’ about how to adapt and apply them. There are only 35 basic mat exercises, but it’s taken me 20 years to fully understand them.”

She has two tips. The first is to take a close look at your instructor. “If their body doesn’t look fantastic, forget it.” The second is to trust your instinct. “If you come out thinking ‘What’s all the fuss about?’ then you’ve got a bad teacher. Pilates can change your life. When you leave that first class what you should be thinking is ‘Wow!’” A wide range of Pilates books and videos are available. However, the exercises only work if done correctly, and beginners are advised to start with some tuition.Pilates Based Body Awareness: (fax) 0207 240 5922. A course of 10 classes (in central London) costs pound;68. For individual tuition contact Samya Tatone on 07941 093760. For further information on instructorsclasses check the internet or contact the Pilates Institute on 020 7253 3177