By Denise Winterman BBC News Magazine

The shows are expensive to put on and the clothes have little to do with what people actually wear, so what is the point of London Fashion Week?

With 45 catwalk shows packed into the five days, many a Manolo will be worn out during London Fashion Week.

The fashionistas only had the weekend to recover from the exertions of New York, which kicked off the international autumn/winter collection schedule last week.

And in the coming days Milan and Paris complete the whirlwind circuit, which is repeated again in September for spring/summer.

For designers, the shows are the most expensive few minutes of their year. For buyers, much of the business has been done before a high heel hits the first catwalk. So why does the show go on?

The catwalk "circus" is more to do with PR than purchasing, says designer Wayne Hemingway. The co-founder of multimillion-pound fashion brand Red or Dead says London Fashion Week is a "necessary evil".

Many designers have decided to invite people to their showrooms instead for a more intimate showcase of their collection Designer Francisco Collado

"But it is a way of opening doors rather than doing hard business, " he says. "When we showed we were just glad when it was over."

It's the industry's very own Catch 22 that keeps fashion week going, says stylist Alicia Poole.

"Everyday fashion doesn't grab the headlines, but without the headlines designers can't sell their everyday brands. That's the reason designers do catwalk shows, even if they are exhausting and expensive," she says.

"The shows are no longer about the designs on the catwalk but the image they create. We might not spend thousands of pounds on an outrageous Alexander McQueen dress after seeing one of his catwalk creations in the newspaper, but if it looks cool we will buy into the brand and purchase what we can afford, like his latest perfume.

'Pointless'

"All the free publicity helps make a fashion label desirable to the average person and that sells the products stocked in the shops, from clothes to key rings."

Many designers find the catwalk shows an "exhausting and gruesome system", but cannot get the high profile publicity any other way.

A catwalk show might cost anything up to �500,000 to put on but the worldwide media coverage created by London Fashion Week is worth over �50m per season in total, says the British Fashion Council.

Fashion or fantasy?

For up-and-coming designers, it is a rare chance to get themselves on a big stage.

Francisco Collado, who is showing for the second year at London Fashion Week with design partner Carlos Garcia, says opinion is divided among designers over whether catwalk shows are worth the money and effort.

"Many designers have decided to invite people to their showrooms instead for a more intimate showcase of their collection," he says.

"But our aim is exposure, to promote Collado Garcia's image, so we consider the expense of a catwalk show worth it."

But freelance fashion buyer Anna Lane says in reality the shows are all about the spectacle and little else.

"From a buyer's point of view they are largely pointless," she says.

"We view and buy most of our lines way before the shows. There are so many packed into the week, we could never get to them all and get any real overview of the designs if we waited until London Fashion Week or Paris, New York and Milan.

"The shows are about image, creativity - getting across the designer's vision. A lot of the pieces are works of art and are supposed to be viewed, not bought. "