A man is hoping to run the length of Africa - completing 360 marathons in 240 days.
Russell Cook, from Worthing, West Sussex, said he will run 39.1 miles (63km) every day, with no rest days.
The extreme challenge will begin on 5 February and is expected to take eight months.
Mr Cook said following struggles with his mental health, gambling and drinking, he hopes to look back at his life and say, "boy, we had a tear up".
The 25-year-old will run 9,320 miles (14,500km) during the challenge, crossing 16 borders - through cities, rainforests and a three-month stretch in the Sahara Desert.
He highlighted the geopolitical issues in the "lawless" region, as well as a lack of resources for him and his three-person support crew.
"Not many people live there, so in terms food, petrol and water, it's slim pickings," he said.
"Then you've got the sheer fact it's boiling hot during the day, freezing cold at night and I'll be running on sand, which is an absolute killer."
The challenge, in aid of The Running Charity and Water Aid, will begin in Tunisia and finish in South Africa.
But Mr Cook, nicknamed "Hardest Geezer", said the journey will start in earnest in the "seaside paradise" of Worthing, where he and his team are awaiting their final visa before driving through Europe to the northern tip of Africa.
"I've grown here, spent most of my life here," he said. "I'd love to put Worthing on the map in some kind of way."
The ultrarunner said he has no fears about the challenge, having previously run from Asia to London in 2019 - completing 71 marathons in 66 days through 11 countries.
"I don't think sitting here as an anxious mess is going to do me any favours," he said.
"From the age of 17, I've struggled with mental health, gambling and drinking. But since I've turned it around, I've carried on ploughing through and hope to create a big impact from this.
"I'm here for 80 years at best, and I want to look back when I'm an old man and say, 'boy, we had a tear up'."
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