After a tough day in her surgery, GP Ann Dey steps into a new role - as a

ruthless fighter.

From nine to five, she helps cure aches and ailments and lends a sympathetic ear to worried patients.

But when work finishes, Ann practises a martial art designed to inflict pain on anyone who dares cross her.

The 32-year-old has just qualified as a black belt, first dan, in tae kwon do.

At 5ft 5in, many of her opponents tower over her but what she lacks in stature, she makes up for in power and technique.

Ann, who lives in Brighton and works at the East Street Medical Centre in Littlehampton, took up the sport three and a half years ago and soon became hooked.

She says: "I started not so much for self-defence, more as a way of getting fit. It is a full-body workout.

"But being capable of looking after yourself is also very useful.

"I think it gives you confidence, knowing you are fit and at least knowing you can probably run faster than an attacker.

"You have to be sensible and not put yourself in situations where there is potential danger.

"There is a temptation when you start learning a few things to think you are invincible but, of course, if you do martial arts, you have to respect them.

"You learn where the vulnerable parts of the body are and where you get the most effect.

"You can kill people so you have to be careful.

"If I had to step in and stop two men brawling, I would but it would be a very last resort."

Tae kwon do involves a certain amount of destruction, with a move similar to the karate chop.

Ann says: "It involves breaking plastic boards held vertically. It displays accuracy and power and focus."

After watching his wife go from strength to strength, Ann's husband, Will Thomas, took up the sport.

He is now a red belt and progressing. The couple train with tae kwon do master Ken James at Hove Park School.

As a 6ft 5in security guard for the Benefits Agency, Will's martial arts skills are a useful bonus.

Ann said: "He has come across areas of potential conflict in his job so it can come in handy for him too.

"We spar together but we don't compete. He's a foot taller than me."

But the sport is not all about brawn.

Ann says: "There are five rules to work by: Courtesy, integrity, perseverance, self-control and indomitable spirit.

"There is also a spiritual side and an intellectual involvement. I find it very calming because of the respect and courtesy involved and because you have to concentrate on what you are doing.

"Aerobics is fine if you like the same routine each time but tae kwon do makes you work and stretch yourself."