A 23-STONE man is taking on an epic challenge to run 150 kilometres in a month to raise money for a rare condition.

John Irvine, from Inverkeithing, will run 5K a day for 30 days in the hope of raising £1,000 for The Marfan Trust.

It may seem crazy but the 32-year-old retail manager wanted to push himself to the limit for his close friend, Kate Stevenson, from Linlithgow, who battles every day with Marfan Syndrome (MFS).

MFS is a disorder of the body's connective tissues, a group of tissues that maintain the structure of the body and support internal organs and other tissues.

Typical characteristics include being tall, having abnormally long and slender limbs, fingers and toes, heart defects and lens dislocation.

There is currently no cure and health professionals can only manage the symptoms currently.

Speaking to the Press on day three of the challenge, John said: "I knew this was going to be tough but I probably underestimated just how hard it was going to be.

"But I knew I had to do something challenging for people to donate.

"The money will go towards research into Marfan Syndrome.

"Just in the last 18 months, Kate has gone through open-heart surgery twice and she's only 35.

"It's a hidden disability and looking at Kate you wouldn't think there was anything wrong.

"That's why I want to fund more research into this horrible condition."

Due to the drastic physical challenge in just three days, John has lost four pounds in weight already.

He's completing each 5K through a combination of outdoor and treadmill runs and his grand finale will be on November 13.

"I've never done any running before apart from Tough Mudder," John added.

"It's like my nemesis!

"I weigh 23 stone, I'm not a fit person, so you get the idea!

"I try to do something for charity every year, usually it's something that's potentially dangerous like throwing yourself out of a plane or that makes me look like an idiot.

"So this is a double-edged sword. But it's also a positive thing for me.

"I'm not feeling sore yet but it's early days and I've been warned that this will probably change drastically!

"I do know I'm feeling very tired though.

"There'll be a massive feeling of accomplishment when I'm done.

"You want to give up but when it's done I feel really good.

"People are also following my blog so it's also raising more awareness about the condition.

"Kate was rather excited when I said I was doing this.

"She was really touched that someone would do this on behalf of her."

To donate, visit https://www.justgiving.com/fundraising/bigjs30days