A 48-year-old ‘couch potato’ is set to run 69 miles from Carlisle to Newcastle in aid of Cancer Research UK.

Mark Grundill from Guilden Morden will be aiming to complete the ultra distance on Saturday, June 20.

He said: “I am not the build of a runner, more of a couch potato.

“But I have been training and after a few half marathons and a couple of marathons, I think it’s now or never for the ultra.”

To make things even tougher, Mark will have to carry a backpack with things like a first aid kit, survival bag, blister kit, whistle and a water bladder with a minimum of one litre of liquid.

So far Mark’s fundraising page shows he has raised almost half of his £300 target.

During the mammoth endurance test later this month, hardy runners will take in the sites of Hadrian’s Wall, Carlisle Castle and Newcastle’s Quayside.

Mark’s training plan took a blow in September when he started getting pain in his hip.

After seeing a consultant, he was told he had fluid on his pelvic bone which meant he was unable to do any training for five months.

The maintenance engineer said: “This was a big knock to my training.

“The other problem was at 17 stone, I was doing my hips no favours so was told I had to lose about three stone – which is hard to do when you can’t train.

“But it hasn’t stopped me, I am now just over 15 stone and don’t look like a runner.”

The Wall event is in its fourth year and competitors will have to tackle a mix of on-road and off-road terrain.

About 1,000 people apply for the annual endurance event.

To donate to Mark’s ultra-marathon challenge in aid of Cancer Research UK, visit his JustGiving fundraising page at www.justgiving.com/Mark-Grundill2014.