For most runners taking part in next month’s London Marathon it will be enough of a challenge to complete the gruelling 26.2 miles, but Dave Heeley, who is blind, will have run six marathons around the world before he even starts.
As a seasoned marathon runner Dave, better known as Blind Dave, leaves nothing to chance when setting out on a run.
But despite keeping the faith with West Bromwich Albion, he will not be boarding a bus to Wembley for the FA Cup semi-final like thousands of Baggies fans, instead he will be bracing himself for the first of his seven marathons on seven continents over seven days.
At 12.01am GMT on April 7, the 50-year-old father-of-three will set off on the first 26.2 mile run with his sighted guide Malcolm Carr , in the Falkland Islands.
"It’s absolutely typical, but I have every confidence they’ll pummel Portsmouth and I’ll be back in plenty of time for the FA Cup final," said Mr Heeley. "I had a feeling that might happen but I’m prepared. I’ll have a radio with me so I will hear the commentary at least,"
If missing the FA Cup semi-final is not bad enough, Mr Heeley had to reorganise the second leg at the last minute, after Argentine government officials refused him permission to fly over their airspace to run in Chile.
"But like everything else we’ve found a way round and instead we’ll run the second marathon in Rio de Janeiro, in Brazil, so it’s not too gloomy is it," he added.
The runs will continue in Los Angeles on April 8, then on to Sydney, Australia, on April 10, with marathons in Dubai, United Arab Emirates, on April 11 and Tunis, Tunisia, on April 12, before heading back to the UK to run the London Marathon on April 13.
Mr Heeley will be the first blind person to complete the 183.4 mile challenge, and only the second runner to do so, after polar explorer Sir Ranulph Fiennes and Dr Mike Stroud lay down the gauntlet in November 2003.
"That’s what sowed the original seeds in my mind, I just knew that I had to do that one day," said Mr Heeley, who began marathon running in 2000. "My running guide at the time had picked up an injury, and when I got a new partner I felt it was a bit harsh presenting him with the idea straight away.
"I’ve spoken to Sir Ranulph who described his experience as ’Seven days of hell: Eat when you can, sleep when you can and run when you can, but at least it’s only for seven days’."
After completing the arduous New York Marathon in November 2006, Mr Heeley and Mr Carr continued training, and began planning the Seven Magnificent Marathons challenge, which they hope will raise more than £20,000 for Guide Dogs for the Blind.
A relentless training schedule, drawn up by the Sports Institute Northern Ireland, has seen both men run between 50 and 180 miles a week, as well as pool running, track sessions and weights.
"It’s been pretty much a full-time job since we started," added Mr Heeley. "I’ve lost 1.5 stone, stopped drinking – and usually I do enjoy a few pints – to reach peak condition, and I feel totally ready for this.
Mr Heeley, who is from West Bromwich, was born with a hereditary condition called retinitis pigmentosa, which causes the rods and cones of the retina to degenerate, although the first symptoms do not appear until adolescence.
These can include night blindness, gradual loss of the visual field, ultimately leading to blindness.
"My grandfather was blind through this and I’ve always had night blindness. I was diagnosed at 10 and by 17 I was virtually blind," he said.
"The fact I’m blind has made me get up and do something, and although I’ve run in some fantastic events at home and abroad, I’ve never seen them.
"More than anything though, I’d love to see my daughters who are now four, six and 17, but I’ve accepted that I never will. They don’t need a dad who’s depressed or down."
But if the thought of missing his beloved Baggies play at Wembley next month was bad enough, he has one more hurdle to jump.
Mr Heeley admits: "I’m terrified of flying, and this challenge involves flying about 29,000 miles in a week. It won’t stop me but the closer it gets the more I try not to think about sitting on that plane for hours in the air.
"We finish our marathons challenge in London, and although it’ll be my seventh it is going to be the most emotional day of my life.
"I don’t think I’ll be crying at the finish line, I think I’ll have started to feel the emotion once the gun goes off."
* For more information about the Seven Magnificent Marathons and to sponsor "Blind Dave" go to www.7mm.org.uk