Beneath the sort of harvest moon made for lovers, 42-year-old Sharon Gayter jogged gingerly, jubilantly, into John o' Groats late on Friday night to claim the most extraordinary of world records.

It was 11.23pm - 12 days, 16 hours and 23 minutes since she'd set forth on foot on the 837 mile journey from Lands End, almost 18 hours inside the previous women's world best.

Despite injury, despite asthma, she had covered an average 65 miles a day for 13 successive days. Unlike the golden Gayter, we should perhaps all pause here, and try to take it in.

Meticulously, she'd planned the run for two years, spent £4,000 of her own money to fund it, used ten different pairs of shoes, seen her feet expand from size five to size seven, lost six pounds from an already spare frame, made it on her husband Bill's 45th birthday with 37 minutes to spare.

The support crew stretched a toilet roll across the finishing line, placed a chair (and a blanket) two feet behind it. Her overriding emotion was relief, she said; John o' Groats reacted apathetically.

There were no pipes and no drums, no television, no other media, no - next to no - emotion.

Local councillor John Graham had generously turned out to present a plate from the Highland Council; alone in the bar of the Groats Inn, two aged Scots turned curmudgeonly backs on the proceedings.

"When most people break world records they do it in big stadiums with cheering crowds. I suppose it would have been nice to have had a few people here, but it's the record which counts," said Sharon.

"I remember when Jonathan Edwards achieved his records he was literally jumping for joy. With me it's just the feeling that I won't have to put a pair of shoes on tomorrow."

One of the support vans had details of the "World record attempt" emblazoned on the side One of the supporters found some duct tape. Proudly, triumphantly, he obliterated the word "attempt."

Originally from London, Sharon Gayter came north because there were more hills, met her husband when both drove buses on Teesside, gained an MA in sports science and physiotherapy, is presently unemployed lives with Bill and their dogs in Guisborough.

Her sport is ultra running, a UK international since 1994, the country's top 24-hour athlete for ten years in succession.

Physically and geographically, this was taking ultra to extremes. "I just had the feeling that I'd been pootling around, never making my mark on history," she'd said.

"I wanted to do something really to be remembered by, and I wanted to do it in Britain."

Though it is she who was pounding the road, it is she who is driven, a perfectionist determination so fierce that over 837 miles she'd refused to let the support van move so much as a metre with her inside it - not even when sleeping, not even to return, inch perfect, whence it began.

It was a perfectionism which also led to strong words when, at the end of a gruelling day, they'd parked the support vans half a mile from where she expected them to be.

"There was an altercation," says Alan Young, fellow ultra-runner and support team member. "She's been very good, remembered her pleases and thank yous which she didn't expect to, but there were a few words on that occasion."

"It just wasn't what we'd agreed," says Sharon.

After a few photographs and a drop of Tesco champagne, she hirples the 25 yards to sign the book in the Groats Inn. For pipes and drums read pints and drams; they've locked the door.

The 525 mile train journey from Darlington to Wick has taken about 12 hours, the taxi to the mainland's northernmost extremity overtaking her within three miles of John o' Groats. It's as if she's asked "What time can you get here?" (though manifestly, of course, she hasn't.)

Though all the team has acted as bicycle escort, the job has frequently fallen to the magnificent Bill - behind her all the way, though once (to his wife's considerable chagrin) he fell asleep on the bike.

Though he still knows her as the Wicked Witch of the South, and she calls him Grumpy Gayter, they're real lovebirds, these two - married at Gretna Green, took a one-way honeymoon cruise on Lake Windermere, ran back.

For his 40th birthday she bought him 40 presents, each wrapped in newspaper. For his 45th, he has nothing wrapped in newspaper but a world beater for a wife. "I've not had time to think about much else," she says.

The talk among the waiting reception committee - support crew, Coun Graham, the photographer we've hired from Thurso - is of the other lengths to which people will go to get from one end of Britain to the other.

The photographer also reckons we're better seeing John o' Groats by night. "It's a horrible, horrible place," he says. Someone's even stolen the finger posts which pointed thence to world capitals.

Coun Graham remembers a chap who claimed to have gone the distance with a finger permanently up his nose, the photographer recalls someone who swam it - in a pool inside an articulated lorry.

There've been horse riders, wheelchair athletes, someone in a supermarket trolley, another on a quad-bike. Most are cyclists, including the group which left Lands End at the same time as Sharon. She beat them.

She crossed the Forth Bridge with a guy who'd done it in 67 days. "If I hadn't thought I could break the world record, I'd have packed in. All sorts of people have done it one way or the other, I wanted to create something that would be very hard to beat."

At least John Graham's impressed. "She wisnae kiddin', was she?"

She'd planned to run four four-hour sessions every day, an hour between each and five hours sleep at night, and to survive chiefly on pasta and rice with tuna and stewing steak as a treat.

That it didn't quite work out was chiefly because, near Wigan, she stood on an acorn, pulled a muscle and for four days was reduced to brisk walking pace.

"They reckon it's been one of the best ever years for acorns," says Alan Young, laconically. "They're bringing in pigs especially to eat them, I read it in the Telegraph this morning."

The injury also meant that one night she managed just three hours sleep - and then covered 68 miles next day. "We were absolutely flabbergasted," says Alan.

"I was at an ultra runners meeting a few weeks ago and no one really thought she could do it. This is going to cause a real stir in ultra-athletics."

Sharon admits the biggest problem was sleep deprivation. "I suppose it's like being drunk, you just get into a sort of stupor. You don't think of how many hundred miles there are to go, just getting through the next four hours.

"My feet are sore, but I'm ten times better than I expected to be. I can't believe how perfectly everything worked, how this wonderful support crew got everything so spot on."

In Hereford, she'd suffered an asthma attack - "The traffic started queuing up as soon as we got to the speed limit signs, the fumes were terrible" - her run sponsored for Asthma UK.

Many had been generous, including an improbable group of bikers in the caf on Shap Fell. Between Wick and John o' Groats they came across two elderly Scots who remembered Dr Barbara Moore's John o' Groats to Lands End walk, 23 days in 1960.

"They were in a beaten up estate car," says Ivor Roberts, another support team member. "We told them about Sharon and Asthma UK and they immediately started emptying their pockets. Unfortunately they'd been to the boozer; I think we got twopence."

About midnight, the two vans head towards a caravan site in Wick. Sharon slides beneath the blankets in the rear - bare footed, fully clothed, beaming beatifically. Bill's driving like a paramedic with a spinal patient in the back.

"It's been a hard slog, a big weight off our shoulders," he says. Next month he has his other hip replaced.

Sharon's talking of taking it easy - "maybe for a week or two" - and of the next big one, a 190k unsupported race through the Libyan desert next March.

We decline an invitation to bunk down in the other van, leave them to the blessed sleep of the deserving.

Just moments before, a thought of some profundity occurs to the new world record holder. "So that," she says, "is what happened to my bog roll."

Friday's column sought the identity of the test cricketer who'd scored a double century at Lord's and played rugby union for Blaydon. None knew: it was Martin Donnelly of New Zealand.

John Briggs in Darlington today invites readers to name the two Sunderland footballers who've gone to the World Cup finals as part of an England squad.

Ever the squaddie, the column returns on Friday.