For most of us, that thirst for adventure comes with some built-in comfort zones. Charlotte Francis meets a woman who's cast aside such soft ideas in her quest to cross the Sahara, on foot and, apart from a nomad guide, alone.

Paula Constant had always dreamt of doing something different than the 9-5 routine. But when she decided on a trek across the Sahara, a project that turned into a three year adventure, she encountered plenty of "idea assassins". In the face of pressure to settle down, get a proper job and get on with life, Paula remained steadfast.

Writing had always been very much her dream and she saw the trek as a building block to a future career. "Anyone starting a business or embarking on an adventure says it takes three years to build and five years to break even, so I kept that in the back of my mind the whole time."

Paula started out on the London to Cairo trek in August 2004, reaching Morocco a year later, and has already walked a staggering 12000km, of which 7200 have been in desert terrain. Continuing on after the break up of her marriage six weeks into the west-to-east Sahara crossing from Mauritania to Cairo, Paula's trek was forcibly interrupted due to political unrest in Niger last September. Undaunted, she will return to complete it later this year if the rebel situation has been brought under control, and plans to arrive in Cairo by May 2008.

The daughter of mould-breaking parents - her mother was Australia's first female stenographer typist and her father sailed solo from Australia to England at the age of 70 - Paula has also been inspired by explorers such as Sir Wilfred Thesiger and in more recent times, that other well known "camel lady", Robyn Davidson. She confesses to having a noble view of hardship in an alien environment.

The reality of conditions in the desert - where winds can gust for four to five days at a stretch, depositing sand in your ears and making it impossible to sleep or wash - soon put paid to Paula's romantic image of a woman striding across the desert. Similarly, her idea of having plenty of time to practise yoga and meditation never quite materialised. "The dawn salutations to the sun never happened, but I do yoga stretches and packing up the camels each morning involves yogic movements."

Contrary to popular belief, the desert is a busy place. "The Sahara is one of the most inhabited and social places on earth. Tracts of it are isolated but people do live there and tents are concentrated around grazing and water." Paula says she finds more opportunities for peace and seclusion in the bush and mountains around her hometown of Mansfield in Victoria.

"It is rare to go a day without meeting a nomad." She explains the strong sense of community in the Islamic and Bedouin cultures: "We're accustomed to our own space but in the desert my space is your space, and you share your food, tea and tent in a very ritualised way. The laws of hospitality in the desert are very strict.

"Nomads are never in a rush and tea drinking can last three hours, by which time the next lot turn up." Paula has learnt to switch off from clock watching, but needs to remain aware of the distance covered each day. She has a strict rule not to stop at any tents while walking. "I would never have got beyond Tombouctou!" she laughs. "A tent visit may last six hours."

More tiring are the constant questions. "If you have walked 30km in a day and are exhausted and need to prepare food, it can be tiring explaining yourself to people who have never stepped out of their own environment."

She is repeatedly asked, "Where is your husband, will you marry me, do you ride the camels, give me money..." A white woman and three camels walking across the desert is, after all, a rare sight. As far as she is aware, when her trek is complete Paula will be the first woman to have crossed the Sahara solo and on foot.

Although perceived as a wealthy white woman in some areas and asked for anything and everything from her clothes to tea, sugar, rice and medical supplies, the Bedouins living deep in the desert practise tolerance, acceptance and kindness towards all who pass. "They would never ask for anything and operate to a different etiquette. It is very humbling. If you need their turban or shoes, they will give it to you. And they always find something to laugh about."

Always fascinated by the Bedouin and Islamic cultures and keen to understand the geography and history of such a dramatic desert landscape, she travels with a nomad guide. Paula has a GPS, speaks some Arabic, plans her own route and looks after her three camels, but the nomads speak the local languages - including Tamashek in Niger and Mali - and know the terrain and where to find water and grazing. "As a white woman walking alone in a male Islamic society, the nomad guides can also act as a buffer zone," she says.

I ask about her other travelling companions, the camels. "It took a while to love them," she confesses. She still has two of the three original camels that she started out with in Mauritania (a Tuareg chief is currently looking after them until she returns). "They are brave, faithful and funny, and I have learnt to trust them. They soon pick up on a bad guide and get bolshie."

It was her decision to sack her first guide in Nouadhibou, Mauritania, that led to one of her most challenging experiences. Proud to have got rid of the guide, things were going well until a camel slipped his nose ring and took off with the pack containing her money and passport in the direction of the landmines on the border of the Western Sahara. Battling a urinary tract infection, Paula had no idea how to rope him and had to track him for more than 30km.

"I felt sick and scared, and had never had to totally rely on my GPS and compass before or rope a camel at night. It took two hours to rope him once I did find him. I was only two weeks into the expedition at this stage." Although part of her felt a failure, Paula realised how much she learnt and the experience helped her to gain confidence. She also drew strength from Sir Richard Branson's mantra in his autobiography, "Never Give up".

She didn't even though she often faced fear. "You become very grounded where you are, stop panicking, and look at things calmly and rationally. You realise it will all be okay, that the environment is not daunting; you just have to understand it and work with it." Neither did she ever feel in danger. "The Bedouin culture is open, trusting and non-violent."

She describes long-distance walking as a deep meditation, bringing, on some occasions, great clarity. En route to Tombouctou, a 26 day stretch and with a prickle infection in her feet, Paula recalls feeling "a weird sense of calm and gratitude for everything around me and that every night we found beautiful dunes to set up camp. It was coming up to the full moon when even the camels don't sleep. It gets very buzzy in the desert.

"Never mind how tricky the day has been, the half hour of dusk after cooking and cleaning up, looking out at the stars and the moon, is the best time of day," she says. When she told one of her guide how she savoured this magical time, he remarked, "Now you're a nomad!" She waxes lyrical about the sunsets and sunrises in the desert, and describes the energy at night shifting to a reassuring rhythm. "Here in Australia, the sky is different and you can't locate yourself."

In some ways the enforced break to her journey in Niger, while heartbreaking, turned out for the best, as Paula was fighting a kidney infection and fatigue. The next stage of the route would have been a stretch of 650km with only two wells. She would have needed to walk 45-50km each day and possibly through the night. "You can't stop until you find food and water for the camels." Yet Paula stresses she would have carried on if her passport had not been confiscated by the Minister of the Interior in Niger.

"I left the desert and had a very soft landing with hot showers and chef-prepared food at the home of the Canadian Consul (representing Australians in Niger) in Niamey (the capital). I ate hugely and put on 10 kilos in a week." Less glamorous was flying back via London and dealing with the London Underground at rushhour.

While the lessons in the desert have helped her to gain a clearer sense of her boundaries and expand her sense of gratitude and tolerance, her patience with whingers in supermarkets queues or people complaining about the size of a plane seat or the quality of inflight entertainment has lessened. "Flying back to Australia from London I was grateful to sit down for 24 hours, have meals brought to me and watch a bit of TV."

Paula is now preparing for her return to Niger to complete the remaining 3700km. "I am looking after my health, training with a polar expeditioner and building up muscle mass. Weight loss is a problem as, deeper into the Sahara, countries are very poor and my diet is very restricted. I eat nuts, dates when available, rice, onions and tuna (if I can buy it), sweet biscuits, and sometimes I slaughter a goat bought from a nomad. And of course tea, strong tea with lots of sugar."

Apart from her Birkenstock shoes, her other "luxuries" are her GPS and satellite phone, the joy of a strip wash and her swag, made close to home in Mansfield. She misses talking to family and friends, and speaking her own language, and sometimes - in addition to writing her journal in the cool of the evening - she records a video diary just for the sake of speaking English.

Her trek through the desert has strengthened her appreciation of home. Coming home to Australia from Niger was she says, "blissful". "If you tend to be contemptuous of Australia's materialism while you are away, you forget the comfort of your own culture, how comfortable, easy, polite and friendly it can be. My greatest joy is to sit in a pub with a glass of wine with no one staring at me.''

At the same time, Paula believes the Third World has a lot to teach us about community. She has also found that the Islamic culture has a much healthier approach to body image than here in the West. Not only is fat beautiful, but women are not embarrassed to be beautiful and even "ugly'" women have a strong sense of self worth. "It's a cultural issue and has changed my perception of women." She also talks of her love of Arabic poetry, which drew her to learning the language, and the songs of the desert, songs about love, war and journeys. As well as writing her second book about her desert trek (her first book, Learning to Walk, is under negotiation with a publisher), Paula is interested in running workshops for women to build confidence and self esteem around body image. She is particularly concerned about anorexic teenagers and thinks we need to change the way women are perceived.

Paula is also walking to raise awareness of breast cancer, donating a percentage of the proceeds of her book sales to the National Breast Cancer Foundation of Australia. Her mother has suffered the disease and is an ambassador for the charity.

She has no firm plans for future trips but fantasises about exploring more landscapes, and dreams of crossing the Australian deserts and kayaking the Niger river or even the Amazon. Once a nomad, always a nomad.