For most people the 13.1 miles of the Great North Run would be more than enough.
But when Newcastle graphic designer Danny Jarvis reaches the race’s end, on South Shields seafront, his endeavours will be only half over.
The foolhardy fundraiser, 36, has only ever run one marathon before - and that was four years ago - but hopes this September to reach the end of North East’s famous run, then turn around and do it all over again.
“After the last marathon I did in memory of my mum I swore I’d never do another but this cause was so important I decided to have another go,” said Danny, from Newcastle, who is running in aid of Round Table Children’s Wish.
Round Table Children’s Wish, which counts football manager Harry Redknapp and DJ Judge Jules among its patrons, looks to make wishes come true for children with life-threatening illnesses.
Since its foundation in 1990 a wide variety of wishes have been granted including trips to Disneyland Paris, swimming with dolphins, being a zoo-keeper for a day, shopping sprees and visits to meet sporting heroes.
“I wanted to run for Round Table Children’s Wish after I heard so many inspirational stories about the children they help,” said Danny. “So I’ve planned a route covering an extra 13.1 miles which I’ll run at the end, and I’m hoping to raise £1,000.”
Samantha Read, from the charity, said: “It’s only through the efforts of people like Danny that we can make wishes come true for children who have often suffered a great deal.”
Along with the other 55,999 runners who set out from Newcastle’s Central Motorway on September 7, Danny will be in with a chance of becoming the Great North Run’s one millionth finisher.
The race will become the first major mass participation running event to reach the milestone - a landmark that is being celebrated with days of events, including a spectacular opening ceremony on the Tyne on September 4.
And ahead of the festivities engineers have started attaching a huge Great North Run sign to the Tyne Bridge.
Commissioned by Nova, organisers of the run, the Bupa Great North Run sign – which was first put up last August – is made from aluminum and is powder-coated in blue. At night it is lit up with white LED lights.
As the work progresses, people in Newcastle are being encouraged to take “selfies” of themselves with the sign in the background, tweeting them to the organisers official @Great_Run Twitter account using the hashtag #bridgeselfie.