On Britain's first day of snow this winter, Nina Barough is nursing a sore throat brought on by bringing in the New Year at the top of her voice. And she has much to sing about - not least the fact that, because of her, Glasgow is to get its second Maggie's Cancer Caring Centre rather sooner than anticipated, becoming the first city in the UK to have two. The new £2.1m building, to be designed by the celebrated Dutch architect Rem Koolhaas, will be based at Gartnavel General Hospital, close to the new Beatson Oncology Unit.

It is 12 years since the Berkshire-based former magazine stylist - whose maternal grandparents were from Wishaw and Motherwell - first had the idea of power-walking the New York marathon in a bra as a novel way to raise money for breast cancer, making £25,000 in the process. And it's 11 years since her own shock diagnosis with the disease, and her single mastectomy, at the age of 41.

Since then, the hugely energetic 52-year-old has founded the Walk the Walk grant-making health charity, which organises the midnight Moonwalk marathon that takes place every year in London and Edinburgh. To date, Walk the Walk has raised £35m for breast cancer causes. The Edinburgh Moonwalk, launched in 2006 to mark the charity's tenth anniversary, has already contributed a staggering £4m. This year, Barough hopes to take a further £3m from 12,000 Scottish power-walkers. A substantial part of this money will go towards the new Maggie's.

"When we started the Moonwalk in Scotland, we didn't know how it would be received," she says. "But it's been a phenomenal success. The level of fundraising is staggering."

She made the decision to use some of the money to help expand Maggie's in Glasgow partly because of the area's worrying cancer statistics, and partly because the existing centre at the Western Infirmary, built five years ago to provide support for people with any kind of cancer, has already outgrown demand. The number of visitors has increased by 60% in the past two years; last year, there were 12,000.

"To me it is very important that the money goes towards supporting people who have cancer now, because while vital research is ongoing, it's important to help improve the quality of life for people who have it," says Barough.

Walk the Walk has already helped many Scottish hospitals to get more Paxman scalp coolers - devices that help block chemotherapy drugs from entering hair follicles and causing hair loss. "The effects of hair loss on cancer sufferers have been overlooked and underestimated," she says. "For many, it can be the final straw."

She explains that the NHS does not regard scalp coolers as vital equipment, because hair loss is not life-threatening. As a result, it does not routinely provide them in every hospital. "But I feel every cancer patient should have a choice," she says. "It's their right."

A great fan of the NHS, she nevertheless feels its resources are being swallowed up by people "who are unwell as a result of not taking responsibility for their own health".

"We could argue about the NHS until the cows come home, but the fact remains that one woman is diagnosed with breast cancer every 15 minutes."

The 60% increase in footfall at the first Glasgow Maggie's Centre does not, as might be inferred, correlate to the rate of diagnosis. But incidences of breast cancer have increased by 12% over the past 10 years. As Maggie's is about caring for people with cancer, the increased use of the centre illustrates what UK chief executive Laura Lee describes as a "culture change" in Scotland. "People are no longer bottling things up and they are beginning to understand that talking about cancer and seeking help is not a sign of weakness," she says. "That's why it's so wonderful to have the opportunity to grow."

Lee also points out that, while the causes of breast cancer are complex, it's thought that lifestyle factors such as obesity, poor diet and lack of exercise are why it is still on the increase in the UK, particularly in some pockets of Greater Glasgow and the west of Scotland.

Barough, who says she has "overcome" rather than cured her cancer, is a firm believer in the power of diet and exercise to help prevent, battle and recover from the disease. While many moonwalkers have, or have had, breast cancer, others are the partners, friends or relations of sufferers.

This month, Barough will send out an information booklet to the 30,000 women, men and children who have registered for the 2008 UK Moonwalks. It contains guidelines not only on how to practise but also on how to "eat the best you can". "To those people who can't afford organic food or don't have access to it, I say eat the best that you can, and always buy local," she says. "Don't buy stuff that means you're eating a plateful of chemicals. People are much too trusting about the food they buy in the supermarkets."

She has adopted an organic diet and power-walks around four marathons a year, with at least two five-mile mini-walks a week. She says her surgeon was astonished at how quickly she healed physically after her operation, although overcoming the psychological trauma took longer. "I was power-walking within two weeks. I'm not an athlete, I'm a normal person, but I really enjoy feeling good. It's like a drug. Once you start seeing results, it's very motivating.

"My life has completely changed through Walk the Walk. I'm not particularly slimmer or lighter, but I'm healthier. Never in my wildest dreams did I imagine I would be running a multi-million-pound charity. I've been very fortunate." She even met her husband, Guy Aubertin, through her work. He was at Playtex, the charity's sponsor, though he is now Walk's commercial director.

As a full-time chief executive, Barough is even busier than she was as a globetrotting freelance interiors and fashion magazine stylist - a job where she was constantly on the move. But she is now more conscious of the need to slow down, and is happy to have Guy to "make me put my pen down" when he thinks she is doing too much.

"My gut feeling is that stress has a part to play in triggering cancer, though research on that is ongoing," she says. "All I know is that I was not a big drinker, never smoked and had no family history of breast cancer. But I was going through a particularly uncomfortable separation from my partner when I was diagnosed. I think a certain amount of stress is good for you, but not when the balance is tipped." Regular power-walks, she says, are like "little oases of time to myself for problem-solving and thinking".

By contrast, she talks of the potentially dangerous "chain effect" of the sedentary lifestyle. "When you're not fit, you stop wanting to look at your body - which means you're not giving your body the attention it needs."

Although she says she was very shocked to discover she had breast cancer, she already knew something about the disease through contact with other women as part of that first Moonwalk back in 1996. "What hit me was the stark reality that if I can get it, anybody can get it. Breast cancer does not discriminate. That's a great leveller - and the reason I want to support such fantastic places as Maggie's Centres, which give such vital emotional and psychological support."

The year-on-year success of the Edinburgh event has enabled Barough to offer substantial help to Maggie's. The 2007 event raised £2.2m - £500,000 up on the inaugural year - and she anticipates a potential £3m in June. This means she was in a position to ask what the organisation's wishlist was and work out a way of fulfilling it.

The initial funding will cover architectural and planning costs, with second-stage funding in the pipeline. It was going to take about four years to build - but, with the Walk the Walk grant, the projected completion date has been brought forward by two years to 2010.

"I did feel Glasgow was the more needy because of its vast population base, its health record and the fact the existing Maggie's was already oversubscribed," she says. Securing the services of architect Koolhaas - the former teacher of Zaha Hadid, who designed the Maggie's centre in Kirkcaldy -is sure to help raise further funds.

"Money raised through Moonwalk has helped significantly speed up the process of getting a second Maggie's Centre," says chief executive Lee. "We were very keen not to increase the size of the existing Maggie's building because it can be rather daunting. With another domestic-sized building, we can continue to provide personal support. Nina and her power-walkers have proved a phenomenal force in making this possible."

Unique centres designed for everyone

The first Maggie's Centre, in Edinburgh, opened in 1996. It was named after the renowned garden designer Maggie Kewwick Jencks, who lived in Dumfriesshire and died of cancer in 1995. Her vision was to provide a "home from home" environment alongside cancer-treatment hospitals.

Each centre is built to a unique design in order to create an uplifting, inspiring atmosphere. Some have been designed by leading global architects including Frank Gehry, Zaha Hadid, Richard Murphy and Page and Park.

There are currently five centres in Scotland. Thanks to Walk the Walk, a second Glasgow centre will open in 2010. An interim service is to be launched at Wishaw General Hospital later this year.