BBC Radio One presenter Greg James has told of his nerves ahead of a gruelling charity challenge that concludes in Norwich.
The former UEA student will raise money for Sport Relief by completing five triathlons in five cities in five days, in an effort he is calling the Gregathlon.
He will cover around 50 miles per day - 'saying it out loud makes me feel sick' - with a 40 mile bike ride, 10 mile run and one mile swim.
Starting in Belfast on Monday, he will criss-cross his way around Britain via Cardiff, Glasgow and Sheffield before storming across the finish line in Norwich on Friday, February 12.
Listeners will be able to keep up to date with his progress, as he will be presenting his 4pm Radio One show after each day's triathlon.
He approached Sport Relief last year and the triathlon plan was hatched.
'I said let's make them as hard as possible,' he said. 'They're actually longer than Olympic triathlons.'
Norwich is a favourite place of his, and he hopes to run and cycle through the heart of the city.
'The idea is that we use the city as best as we can,' he said. 'It'll be through the city, very much using it and on roads and cycle paths.
'I'll be running past places I used to live, maybe along the Unthank Road and my old haunts.'
He will be running with former Olympian professor Greg Whyte, who has trained celebrities including David Walliams and Davina McCall, and organisers are keeping the exact route under wraps.
Preparation has been tough, but he said he had relished the challenge.
'I've always enjoyed running,' he said. I've done that since I was a teenager, and I've always liked being active.
'At UEA, drama and radio took over and I didn't join any sports clubs, but I did use the Sportspark a lot.
'I didn't do much team sport when I was at uni, but when I have a goal I tend to respond very well to it.
'It's almost like training to eradicate the fear of failing.'
He aims to finish the distance by 3.30pm each day, before his 4pm show.
'That's going to be the interesting thing, particularly by the Friday,' he said. 'What sort of state am I going to be in? I don't know.
'That's the frightening thing.'
His Norwich show will be broadcast from The Forum, and he will meet family and friends to celebrate.
'We're going to go and paint Norwich red after,' he said. 'By which I mean have one red wine.'
Greg was in Norwich for the Radio One Big Weekend at Earlham Park last year, and it was announced this week that this year's festival will be held in Exeter.
While he will be involved in coverage again, he joked: 'I won't be as emotionally involved.'
The Sainsbury's Sport Relief Games are coming to Norwich from Friday, March 18 to Sunday, March 20.
For details and to sponsor Greg, see sportrelief.com
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here