BBC Radio 2 presenter Vernon Kay has raised more than £5m for Children in Need after completing his ultra-marathon.
The DJ ran from Leicester to Bolton - a distance of 116 miles - over four days.
Speaking to Radio 2 breakfast host Zoe Ball as he reached the finish line, Kay described it as "one of the most painful and joyous experiences I've ever had".
BBC Children in Need's televised appeal is under way on BBC One.
Kay has regularly been appearing live on Radio 2 to update listeners on his progress since he started the marathon on Tuesday.
"I'm absolutely exhausted, absolutely spent, physically, mentally," Kay said as he crossed the finish line just before 10:15 GMT.
He added jokingly: "Is there anyone here who can replace a knee?"
The Children in Need TV audience chanted his name as he came out on stage and learned the latest total raised for his efforts.
The challenge saw him stop off at some local landmarks in his hometown of Bolton, including his old school, before reaching the finish line.
"I'm so glad I went to St Joseph's first because that was a real boost," Kay said. "It just really elevates you... that's the pick-me-up I needed."
He told Ball: "It's been one of the most painful and joyous experiences I've ever had. People we've met along away. We've met some brilliant people who've donated all they can.
"It was just one foot in front of the other, that's what it was, and we've had a great team who've been absolutely brilliant, pushing me along and motivating me."
Kay joined the station as the new mid-morning host in May, following the departure of Ken Bruce.
Earlier on Friday, Kay joked that the rain had started just as he was heading for the finish line.
"We get to God's country, the beautiful sun is rising as I turn to my left and the rain is falling at a constant pace, I can't believe it. Can you believe it? We've done all them miles and we get eight miles away from Bolton and it starts chucking it down," he said.
Children in Need, the BBC charity which helps improve the lives of disadvantaged children and young people around the UK, will see actor Lenny Rush, 14, become its first-ever child presenter when the fundraiser airs on Friday.
The Bafta-winning actor will be joined by Ade Adepitan, Mel Giedroyc, Jason Manford, Chris Ramsey and Alex Scott for the three-hour live show.
It has raised more than £1bn for charities and projects since its first major appeal in 1980.
Rush, from Essex, who won a Bafta for best male comedy performance for his role as Ollie in the BBC series Am I Being Unreasonable?, appeared in a sketch show for Children in Need last year.
He told the BBC he was nervous, but added that "'the excitedness outweighs the nervousness'".
'I'm nervous but the excitedness outweighs the nervousness'
14 year old BAFTA winning actor Lenny Rush has spoken to #BBCBreakfast after becoming the youngest ever presenter of 'Children in Need'https://t.co/8iddJCVBBY pic.twitter.com/Qz9kAEW7x6
— BBC Breakfast (@BBCBreakfast) November 1, 2023
Friday's televised event will also include an exclusive behind the scenes look at the latest episode of Doctor Who.
There has also been a performance from Little Mix star Leigh-Anne Pinnock and a visit to Graham Norton's notorious Big Red Chair.