Tomorrow's Dubai Marathon is the next stop on Alex Flynn's mega tour to raise £1million (Dh5.878m) by running 10 million metres by 2014.
So far, the 39-year-old lawyer and adventure racer has accomplished 10 per cent of his challenge, which will benefit the Cure Parkinson's Trust.
Of the 963,805 metres already under his belt, 240km came in courtesy of one of the toughest races in the world, the Marathon des Sables across the Sahara Desert, and another 217km was achieved by completing the mountainous Europe135 ultra-marathon.
Astonishingly, Flynn also happens to suffer from Parkinson's disease.
It was June 2008 when the sport-mad lawyer was diagnosed with the degenerative and as yet incurable disease, a disorder of the central nervous system, which results in impaired motor skills, tremors and rigidity and can eventually leave sufferers trapped in a cocoon of their own body.
It is a day he remembers well.
"I used to go down the gym and go bananas and always get the shakes afterwards. I never thought it was an issue because other people got the shakes after working out," said Flynn, who has two sons, aged nine and 11, and lives in Henley, England, with his wife, Aurelie.
"But it was when I reached for a coffee cup and my right hand just would not stop shaking that I thought 'that's not me doing that'.
"It was like when somebody keeps tapping their foot and it's really annoying but you can't get them to stop."
Flynn went for tests and was referred to a specialist. "Most people would not be able to tell immediately that I have Parkinson's," he said. "The specialist turned up in his sharp suit and Ferrari and took one look at me and said, 'You've got Parkinson's.' That was hard."
Once the devastating news had sunk in, Flynn began to fight.
"I rally against it," he said. "I rally against it every day and I look at it as a choice. It's the worst thing that's ever happened to me but it's also given me a focus that I didn't have before.
"My wife was very supportive when I told her but the hardest thing was telling my sons that daddy has this disease and right now there is no cure. My family are everything to me and I was worried at how they would take the news but they were very mature, in fact, now they take the mickey [poke fun] out of me."
A keen adventure racer and successful lawyer who has also established a number of companies, Flynn has not taken a back seat from either his work or his training since his diagnosis.
Nor is he simply sitting back and accepting that there is no cure for Parkinson's, a disease that has actually had relatively little research money spent on it.
"Parkinson's is a costly disease to society in terms of the length of time sufferers require treatment and it affects a lot of people either directly or indirectly," said Flynn.
"It's about raising awareness and trying to raise the money to fund the research."
Flynn initially decided to run one million metres, but soon decided he had not set his sights high enough.
"One million metres isn't really that far," he said. "Ten million metres is much more of a challenge."
And fighting against a degenerative disease, coupled with the side effects of treatment as well as battling the extremes of weather, terrain and distance on the challenges he has set himself, has been tough.
"It's not easy and each race will get harder, and I often have a problem with my leg which simply stops working sometimes," Flynn said. "But if I can't run then I will walk and if I can't walk then I will crawl and if there is an obstacle then I will go over it and if I can't go over it then I will go under it until I have finished this challenge."
Flynn is made of steely stuff. He is the only Parkinson's sufferer to complete the Marathon des Sables, a race that has been too tough for many able-bodied athletes.
"That was the hardest one so far," Flynn said. "It was 145°F (62.7°C) and it was a long haul."
On his to-do list after Dubai is the 80km Thames Trot in London in February followed by a 2,447km run across Europe in June and the Challenge Henley Ironman in September. But for now Flynn is focusing on tomorrow's marathon, which must seem like a sprint in comparison.
"It does seem shorter but it's still 42km and any marathon is tough," he said. "My training has not been helped by a bout of flu. I expect because of my leg doing it's thing that I will have to walk a number of times which will be frustrating, but I'm running with a great friend, Bryan Garrett, and I'm really looking forward to it."
For more information about the 10 million miles challenge visit www.alexflynn.co.uk. More information about Parkinson's and the quest for a cure can be found at www.cureparkinsons.org.uk.