Determined dad David Courtenay has climbed Mont Blanc and trekked 50 miles across the Arctic Circle but he insists his latest challenge – pounding the streets of Barrhead – was his toughest yet.

David’s epic feats have raised thousands of pounds for charities which have supported his son Adam, who was born with a rare brain condition.

But the 38-year-old Barrhead man said the sleep deprivation and fatigue induced by his gruelling bid to run four miles every four hours for 48 hours pushed him to the limit.

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 fellow Barrhead resident and long-time friend Nikki Watt and his cousin Allen Wales, from Neilston, 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.

Their impressive efforts were in support of the Glasgow Children’s Hospital Charity and Children’s Hospices Across Scotland (CHAS).

Adam, who has Sturge-Weber Syndrome, spent a lot of time at the Royal Hospital for Children during the first couple of years of his life.

He 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.

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