A whole new meaning to sleep walking, ultra athlete and former Teesside bus driver Sharon Gayter has embarked upon the craziest event of her life. This one endureth for ever.

Sharon, occasionally known by her husband as the Wicked Witch of the South but for six years Britain's top woman ultra runner, is back on the buses, too.

She is one of six clinically chosen competitors - 170 applied - in the Flora 1000 Mile Challenge, which began outside Buckingham Palace on Sunday.

Her Majesty was not thought to be in attendance.

Though they are strictly limited to one mile an hour, it's probably the hardest slog on earth. That she is also asthmatic may help explain the long odds offered by Ladbroke's.

Briefly and brutally explained, the Challenge involves running or walking a mile in each of 1,000 successive hours, culminating after almost six weeks with a Sunday morning stroll on the London Marathon - not so much going the extra mile, as staggering the extra 26.

"Fear is creeping into my thoughts more. I hadn't realised it would be so hard," says Sharon, good stuff in a little bundle.

Just getting to the Marathon start line on April 13 means previously covering 38 circuits of the course - with a maximum hour and a half sleep at any time by covering miles back to back.

The others include the chap who completed last year's London Marathon in a 120lb diving suit, the man who holds the world record for 24 hours on a treadmill and a woman who beat Frankie Dettori in a flat race.

Even now, however, they are simply following - somnambulating - in Captain Robert Barclay's footsteps.

Barclay faced the same challenge over a half mile course at Newmarket in 1809, having wagered 1,000 guineas that he could do it and accepted another £100,000 - around £40m today - in side bets.

Many feared he would die in the attempt; Barclay carried a pair of pistols at all times to help ensure that no bad losers tried to pre-empt that occurrence.

Eight days after finally putting his feet up, he set sail for the Napoleonic Wars.

Sharon and friends will earn around £10,000, grabbing what sleep they may in a specially equipped London bus which sedately will follow their progress.

She plans to walk during the day, run - to allow more snatched sleep - at night.

Possible problems, it's said, include delusion, mental exhaustion massive mood swings and generally going bananas.

Sharon, who lives in Guisborough with husband Bill and assorted dogs - children would have interfered with training - left the buses after being beaten up, took a sports science degree and now lectures at Teesside University.

Her warm weather training in Australia earlier this year was partly funded by supermodel Elle MacPherson, to whom Sharon had acted as masseur during filming in Middlesbrough. "She couldn't believe I hadn't a sponsor," she says. This is day six, 37 to go. It may not run and run, but she hopes somehow to stumble to a conclusion