THE possibility of one day having a six-pack like that of Denise Lewis and Linford Christie is what keeps gym-goers crunching, pulsing and sit-upping. The pain and agony of abdominal exercises is worth it for a washboard stomach.

But how many people do their exercises only to end up with a domed tummy instead of a perfectly flat, muscley one? Pilates instructor Liz Moore, who teaches at Redworth Hall Hotel's Bodysense health club, says it's because we aren't exercising the right muscles.

"There are four layers of muscles in the stomach. Starting from the outside, there are the rectus abdominous, for which people do sit-ups and crunches, underneath those are the internal and external obliques which allow us to move from side to side.

"Then underneath those is the transversus. It's a large, deep muscle that goes right around the stomach area to the spine at the back, a core muscle that holds everything else together. If you only work your rectus abdominous the transversus thinks it has nothing to do, and a weak transversus can cause back problems."

Pilates works this major muscle but the exercises designed to build strength aren't as painful as typical abs work, the movements being more gentle and controlled and working deep inside.

This idea of working inside out and building a "girdle of strength" is central to the Pilates technique. It rebalances the body and brings it into correct alignment. Ultimately, you should notice your body looking leaner, longer and more toned.

And that's all without getting sweaty and exhausted.

Most of the exercises are done on the floor. The key to success is understanding the concept of "zip and hollow", and if you've never been in touch with your "pelvic floor" before, you will be after trying Pilates.

A comparatively static technique, it's slow, controlled and calming. However, it does demand concentration and being able to respond to what your body tells you. In that sense, it's a good way to relieve stress and tension - when you're doing a Pilates class you haven't time to think about anything else.

It was developed by the late Joseph Pilates, who was born in Germany in 1880. A frail child, he turned to physical fitness programmes to improve his body shape, taking part in sports as varied as diving, boxing and gymnastics.

The Pilates method draws on different disciplines, building strength without adding bulk, balancing strength with flexibility and encouraging harmony between body and mind.

It's ideal for athletes who want to enhance their performance without risking injury, is suitable for beginners and is good for people with back problems.

Liz, who trained partly with the country's best known Pilates instructor Lynne Robinson, teaches three classes a week at Redworth Hall: Thursdays at 10.30am and 5.45pm and Fridays at 2pm. Classes are open to non-health club members, but are restricted to 12 people so that Liz can give one-to-one attention.

With her help, there's nothing stopping you achieving that perfect flat stomach - without those painful crunches.

l For more information about Pilates, call the Body Control Pilates Association information line on 0870 169 0000 or visit the website at www.bodycontrol.co.uk

l We have teamed up with Bodysense to offer readers the chance to spend a complimentary day at the health club, enjoying the facilities, which include the gym, swimming pool, sauna, steam room and spa bath. Visitors can also pay for beauty treatments at the Emmanais salon or hair appointments at Saks. To qualify, just collect FOUR different Bodysense articles, then contact the health club to book your free day on (01388) 770649.