Jasmin Paris, one of Britain's best known ultra runners, will race the notorious Barkley Marathons this year.
The Inov-8 ambassador will attempt to do what only 15 runners have done since the challenge started in 1986 – finish the mysterious event.
Only those completing each 20-mile-plus self-navigation loop with about 12,000ft of ascent within the 12-hour cut-off time will be able to proceed to the next. Ultimately five brutal laps of the tough terrain in Frozen Head State Park, Tennessee, must be completed. The date of the event is always kept secret - one of the endless quirky aspects of the publicity-shy event - but usually takes place in March or April.
No woman has yet completed the race. In 2019, another Inov-8 ambassador, Nicky Spinks, made it to lap two in terrible weather conditions.
The same year, Lazarus Lake, the event's eccentric organiser, predicted Paris could become the first female to conquer the challenge.
The Brit had then just become the outright record-holder for the 268-mile Montane Spine Race, arguably the country's toughest event.
According to Inov-8, the full-time vet and researcher has been training close to her home in the Pentland Hills of Scotland at 4am.
She said: "I know it’s going to be very hard, possibly impossible, but at the same time that’s what makes me want to run it."
Paris believes her success will come down to her mental as well as physical endurance and she has demonstrated she has both in abundance.
"It’s more about seeing what I can do myself, whether I have what it takes to complete it. I think that will come down to my mindset, as much as my physical capabilities," she said.
As for the physical aspect, she has been putting in some impressive-looking training sessions in preparation despite the recent tough weather.
"Wanting to get maximum ascent but being unable to run anywhere exposed (due to the risk of being blown away), has forced me into doing hill reps up and down the safest stretches of hillside," she said. "On one morning, this involved 22 ascents of Castlelaw, accumulating 5,500m (18,000ft) ascent in 7 hours. It was hard to stay motivated on those reps in the dark, with wind and hail blowing horizontally into my face. But the thought of how much harder Barkley was going to be kept me going. In turn, I hope that once I get out there, I can draw on all that training, and remind myself of the sacrifices I made to be there."