Determined dad David Courtenay has climbed Mont Blanc and trekked 50 miles across the Arctic Circle - but he insists his latest challenge in aid of Robin House was his toughest yet.

The 38-year-old endured sleep deprivation and extreme fatigue last month as he pushed himself to the limit to run four miles, every four hours for 48 hours.

It is the latest in a series of epic feats which David has completed to raise cash for charities which have supported his son Adam, who was born with a rare brain condition.

This time round the funds will be split between Glasgow Children’s Hospital Charity and Children’s Hospices Across Scotland (CHAS), which runs the Balloch children’s hospice.

David said: “To most people, the Arctic trek sounds harder but, while that was physically and mentally tough, it involved walking. This time, I was running and deprived of sleep.

“You are dragging yourself out of bed at 3.30am and your legs can hardly bend. Towards the middle of the second night was when it really started getting grim.”

David was not alone in his efforts, however, as long-time friend Nikki Watt and his cousin Allen Wales also rose to the challenge.

Other friends and family joined them on their individual runs, including David’s daughters Emma and Tegan, who cycled alongside him for some of the time.

At the end of the challenge, David’s wife Louise brought Adam to meet the trio, who then enjoyed a victory lap around the running track.

Adam, who has Sturge-Weber Syndrome, was born with a port wine stain birthmark covering his head and face, which has resulted in an extra layer of blood vessels over his brain.

This means his brain cannot develop in the way it can for others, due to a lack of blood and oxygen.

The youngster spent a lot of time at the Royal Hospital for Children during the first couple of years of his life.

Since he was a baby, CHAS has also provided the family with respite stays several times a year at Robin House, where Adam enjoys using the hydrotherapy pool.

David, now plans on cycling from his home in Barrhead to Balloch to present CHAS with their share of the funds, which fittingly works out as a round trip of exactly 48 miles.

“Robin House is tremendous.”