A father has said there were "really dark moments" in his 1,600 mile run to raise funds for his disabled son.
Lewis Herbert, 16, has Lennox-Gastaut syndrome, which has left him unable to walk or talk and he requires 24-hour care.
His father, Gary, 41, gave up alcohol and set himself a target of 100 miles for every year of Lewis's life.
So far he has raised £13,000 towards adaptations at their home in West Hunsbury, Northampton.
Mr Herbert said he completed the challenge two months ahead of schedule, running an average of 40 miles every week.
He said: "There have been plenty of really dark moments and countless self-doubts on a weekly basis about whether I would be able to get to, or get anywhere close to, my mileage target.
"It has quite simply been the hardest and most relentless thing I have ever done in my life, and my body has been in absolute bits."
Earl Spencer, who is the patron of the Life for Lewis charity, said it was an "outstanding achievement" and he was "full of admiration" for Mr Herbert.
The campaign has also had support from ex-England and Northamptonshire cricketer Graeme Swann.
Mr Herbert thanked all those who had supported him and said he was "extremely emotional".
"I can't quite comprehend it all, but once it's sunk in it will be an achievement I will be able to look back upon with a tremendous amount of pride, I'm sure," he said.