A model from Ampthill in Bedfordshire, who took up ultra marathon running to help cope with the death of his mother, is planning to run from John O'Groats to Land's End.
William Goodge has done a series of endurance events for charity since losing his mum, Amanda, to cancer in January 2018.
The 850 mile run across the length of the British Isles in August will be his toughest challenge yet.
- Click to watch a report by ITV News Anglia's Liz Summers
William says when his mother died he was at a crossroads and could have channelled his energy in a negative way.
He said: "I could either take this energy that I had, that was bad obviously, and go that route which is negative, drink and partying and all that or I could go the other way and try put it towards something good.
"This is when I found running and then that became my therapy."
William began clocking up the miles, training hard in between his busy work schedule as a model.
He has run a series on marathons and ultra marathons for charity. Ultra marathons are road races that can go on for miles more the than the 26.2 miles of a traditional marathon.
William is hoping to raise £100,000 for Save the Children when he embarks on his run from Scotland to Cornwall.
He'll be running alone with the support of family and friends.