Nigel came up to me at the bar of the Berbere Palace hotel, in Ouarzazate, where I was bedding in for a 48-hour euphoric beer-drinking celebration after finishing the Marathon des Sables. “I owe you a drink,” he said. “When I saw you before we left for the desert, I said to myself, ‘She’ll be the first out.’” Brian, a former pro ice-hockey player, agreed. “You seemed disorganised and clueless.”

They were wrong. I finished the 21st Marathon des Sables 54th out of a field of 96 women, of whom only 75 finished the 150-mile race across the Sahara. Of the 731 competitors who had taken off on the previous Sunday’s start line, 585 crossed the finish line on the Saturday morning. I was near the back, but I was one of them.

The course doctors on the third day could not cope, and were visibly shocked by the number of casualties they were dealing with. In total, 146 pulled out and a record 62 saline drips had to be given. You would frequently see one of the 4WDs used by the 40 race doctors with some competitor sparko in the shade under the chassis, a saline drip hanging from the wing mirror going into their arm. In the rigid MdS rules, you are allowed one IV drip; two and you’re out.

The people who had drips would come round as good as new, boasting that they had needed seven, eight or nine bags to rehydrate them. The rest of us coped with cumulative low-level dehydration as best we could: skulling electrolyte drinks, necking salt tablets, eking out every drop of the water we were allowed (about 11 litres per day). Some got it wrong: one severe case of hyperpyrexia had a guy in a coma for several days; the doctors pulled others, incoherent and incapable of standing, from the race. I saw one woman — fit, greyhound-like — sobbing at the top of a hill, receiving a blood transfusion while, from a hovering chopper, the television cameras zoned in on her dramatic suffering.

My brother says that when I rang him from the manic joy of the finish line, I said: “It was Armageddon. They were dropping like flies.” But I don’t remember any of the tough stuff now. Like a mother holding a newborn, my post-race body was flooded with weird natural chemicals that erased any painful memories and left me euphoric.

The entire experience was surreal from the outset. After a five-hour journey from the Sahara’s edge to a small, flyblown desert town, hundreds of us flopped off coaches and stood wilting in the terrifying heat of the late afternoon. High-sided cattle trucks transported us to the first encampment, deep in the Sahara.

Emma and I, training and fundraising partners since last September, had crammed onto one truck next to two good-looking South African guys, Chris and Grant. Tent 72, our home for the next nine days, contained them and several other extremely fit, tasty blokes. The field of 635 men came in varying shades of significantly better than average. Despite an all-pervading sense of terror at the unknown ahead, Ems and I were single, overexcited and physically fit, which makes for an inconveniently high sex drive. We had just landed in the female equivalent of the Playboy mansion.

Two days of checks and acclimatisation lay ahead, during which the French organisers provided four-course meals with wine out of a field kitchen. There was the first of many long, miserable sandstorms. Our Berber tents, no more than sacks stitched together and held up with sticks, provided little protection from the relentless force-five wind, which hurled sand in our eyes, down our throats and into the delicate machinery of morale.

We had vainglorious briefings from the race’s organiser and founder, Patrick Bauer. I remember little, as I was locked in amusing banter with the boys in tent 65, Lochie, Gerry, Niall and Nick. Party animals, yes! Kindred spirits. Although, unlike me, they had done Ironman triathlons and numerous extreme physical endeavours. Gerry was planning to swim the Channel. I was skating the edge of another world, or, as one said, “flirting with the ultrafit lifestyle”.

Emma and I hugged and grinned on the start line. Finally, we were here. Bauer counted down to the start: “Neuf, huit, sept ... ” I looked around at the fit freaks from 32 countries, laughed hysterically and thought, this is mad, mad, mad. “ ... quatre, trois, deux, allez!”

As soon as we shot off, the fear dissipated, and in the already stultifying, 100-degree 9am heat, a singular determination sank in. Jack Osbourne, who was out there filming a TV show, said before we had even reached checkpoint one: “This is not fun.” Enthusiastically, I went into several reasons why he should hang in there. I realised then that I would probably get through the week. I had made peace with the task, the heat, the trudge, the weight of my backpack. I had mentally engaged with the fact that I had no control over these things now; stressing about them would wear me out. They had scared me for months back home. In a way, I had dealt with them already. Everyone had said that a large part of getting through the MdS was mental; one veteran I had been quietly seeing since I signed up (for motivational pillow talk) said this was 90% of it. Jack wasn’t psyched enough.

I took it slowly, averaging 17- to 20-minute miles. The 100 or more who dropped out over the first three days were often victims of overheating, as they pushed beyond the limits of physical reason in such high temperatures. The desert is not friendly. The Sahara, for me, had always evoked absurd and abstract romantic feelings. The Marathon des Sables never felt romantic — the mysticism was replaced by a raw, animal need to survive. The beautiful nihilism of the roaring nothingness remained, but aesthetic appreciation wilts to nothing under a furnace sun.

Yet, strangely, this was one of the most relaxing experiences of my life. There was nothing to do but move, be it trudging on through a sandstorm, wrapped like an Egyptian mummy against the skin-flaying effects of the desert’s fierce wind, or hot, weary, queasy ploughing up the calf-sucking dunes and butt-burningly steep sandy jebels (hills).

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