Andy Dibben might be the manager of a health club but he readily admits he is no runner.

That’s started to change since the 29-year-old, from Andrew Road, Eynesbury, decided to run this year’s London Marathon and in doing so fulfil an ambition he’s had since he was a teenager.

He will be raising money for the Royal National Institute of Blind People (RNIB), a charity close to his heart due to the support it has given his mum, Denise.

Five years ago, Denise, who is 63 and also lives in Eynesbury with husband Robin, was diagnosed with polymyalgia rheumatica, a disease which causes pain and aching in muscles and can lead to other serious health issues, including damaged eyesight.

“The disease wasn’t picked up in time and affected the optic nerve in her right eye where she lost her sight in 2012,” said Mr Dibben. “She’s down to 25 per cent in her left eye.

“She will never be able to regain her sight, it’s a case of saving what sight she has left.”

Mr Dibben, who is married to Beverley and has a 10-year-old stepson and two boys aged six and three, said his mum’s eyesight was a concern for the whole family.

“As a family, it’s tough when you’re told someone close to you is probably going to lose their sight.

“She’s got grandchildren and from our point of view it would be nice for her to be able to see them, as much as possible, grow up, but it’s going to be difficult.

“She’s the most positive one out of the lot which is a credit to her.”

The RNIB had been fantastic, said Mr Dibben, who is manager of LivingWell at the Hilton hotel in Northampton, from providing practical assistance such as a magnifying glass for reading tiny print on labels, to support over the phone if Denise needed to speak to someone.

Mr Dibben is training hard ahead of April 13 and is hoping to complete the course in five hours.

“I am no runner - it’s not my sport - but because I’m doing it for the RNIB, when things do get tough, it should carry me through,” he said.

“It’s made it more special and I’m more determined to do it.”

INFORMATION: To support Mr Dibben’s marathon effort, visit www.justgiving.com/andy-dibben.