Graham Walker, 36, laced up his running shoes last Sunday and took to the streets of London to complete the marathon course in four hours and 35 minutes.

He has so far raised more than £2,000 for Bliss, a charity dedicated to supporting special care babies and their families.

The charity is close to his heart because his sister's daughter, Ellie, was born prematurely and only survived for 11 days.

Mr Walker, who is the reception team leader for Spire Leeds Hospital, said: "Running the marathon was very good until I got to about 20 miles and then I just hit the wall and the pain.

"The experience was just fantastic and during the last mile I was in absolute agony but I just kept pushing and told myself to keep on going.

"Ronnie the Rhino and a couple of people dressed as bananas were at the starting line with me and as I was running there were people in thongs – they must have been freezing!

"I even overtook Emmerdale's Eric Pollard at 19 miles.

"The spectators that lined the streets and the atmosphere were just amazing.

"Running for the charity really hit home about Ellie and my sister was really proud that I was running for Bliss."

Mr Walker has trained for nearly a year but only started long runs in December.

He added: "This was the first time that I have run a marathon but I would love to do it again next year to help raise money for premature babies.

"I have lost about two stone while training. It is hard to run the distance but I've put in my homework and have been training every other night right through the winter.

"My family have been brilliant towards me and very very proud, especially my dad.

"The running won't stop there. I'm running the Sheffield Half Marathon with Spire Leeds Hospital consultant Stephen Pollard two weeks later."