A London Marathon walker accidentally doubled the distance of her challenge after poor GPS reception on her phone meant an app failed to register her miles covered.
Jodey Hopcroft began her walk at 4.45am along the Norfolk coast earlier this month and set up her Virgin Money London Marathon app to track her progress.
But the 38-year-old said she noticed it failed to register her drive to her start point and later on when she had walked 20 miles it showed she had only completed 13 miles.
Ms Hopcroft, who has previously run the marathon four times, said she decided to walk this time as she had not completed any training.
"Once I had started I could not stop, everything would have been void," she told the Eastern Daily Press.
"I thought it would be fine, I did not have a secondary device so was a bit naive there, so I had to keep going until the app registered I had done 26.2."
After completing the challenge 15 hours later, she compared her distance on a map and realised she had walked 49 miles rather than 26.2 miles and started to laugh.
She said: "It is just so funny. The rain and cold and blisters were unbelievable, but it is a huge sense of achievement."
Ms Hopcroft, who was raising money for MS charity MS UK, added that she doesn't blame the app for the mistake, rather the poor GPS in the area.
A spokesperson for the Virgin Money London Marathon told Sky News: "We warmly congratulate Jodey for completing the virtual 2020 Virgin Money London Marathon.
"As we couldn't hold the event in London as normal this year, we invited participants to run the London Marathon - Your Way, from wherever they were in the world. More than 38,000 people completed the challenge, from Australia to California, but we doubt there were many that ran as far as Jodey did - she certainly did it her way.
"We did brief all runners to carry a secondary device as back up for recording their time and warned them that there may be areas of their chosen route where GPS would not function.
"We salute Jodey's strength, stamina and good humour and hope she raised plenty of money for MS-UK."
This year's London Marathon was completed virtually by amateur runners after it was postponed from April to October due to the coronavirus outbreak.
On 26 April, the original date of the marathon, Britons undertook the 2.6 Challenge instead, where they came up with an activity based around the numbers 2.6 or 26.
The numbers were a reference to both the distance of the marathon and its original date.
Sophie Allen, a charity worker from Romford, swan 2.6km in her back garden to raise money for London Air Ambulance service, while award-winning mixologist Paul Martin produced 26 cocktails in 26 minutes.
The new date of the marathon, on 4 October, saw only elite runners taking part in the challenge and a different route.
The usual London route was replaced by a looped 26.2 mile (42.2km) course around St James's Park.
There were no spectators allowed along the course this year.
Tens of thousands of people completed the distance at venues of their choice throughout the day.
Shura Kitata was named the winner of this year's marathon, knocking world record holder Eliud Kipchoge off the top and handing him his first defeat in seven years.