Image copyright Izzy Wilkinson Image caption Sharon Gayter says she will be back at work on Monday

A 55-year-old ultra-runner has become the fastest woman to travel by foot between John O'Groats and Land's End.

Sharon Gayter said she felt "about 105" but was "relieved" after covering the 822 miles in 12 days, 11 hours, 6 minutes, and 7 seconds.

The previous record, set in 2008 and run from Land's End to John O'Groats, was more than four hours longer.

Mrs Gayter, from Guisborough, near Middlesbrough, said the final day was "painful" after only 90 minutes' sleep.

She added she was severely sleep deprived having only got about three hours on each of the other nights of the challenge.

"I wanted to break the record by as much as I could and push to my limits because you never know what's round the corner, like road closures."

Mrs Gayter set off from the northern tip of Britain at 07:30 BST on 21 July and finished in the south-west corner at 18:36 on 2 August.

Her time is yet to be verified by Guinness World Records.

Her planned route, which included some off-road sections, was 822 miles - the actual distance she ran will be confirmed only when her GPS tracker is downloaded.

The previous fastest journey was set by British runner Marina Anderson in July 2008. The men's record, set in 2001, is nine days, two hours, and 26 minutes.

'Body surprises me'

In 2011, the lecturer at Teesside University Business School broke both the men's and women's records for the distance covered running on a treadmill in seven days.

On her motivation, Mrs Gayter said: "I'm getting on now and I keep thinking that I can't do any more, but the body surprises me that it can.

"And while I can still [break records] I will."

Image copyright Izzy Wilkinson

Speaking from underneath the Land's End signpost, she added the first thing she was going to do was have her first shower in nine days.

The university lecturer said she would be back at work at 09:00 on Monday morning.

"I'm not looking forward to that I can assure you," she added.

Mrs Gayter was raising money for the mental health charity Mind, after three of her friends took their own lives.