X Factor host Dermot O’Leary has admitted that “reality has set in” over his 24-hour dance marathon for Comic Relief.

The TV host, 41, will begin his moves at BBC Broadcasting House in London before finishing his challenge by dancing down Regent Street and into the London Palladium, where his efforts will be screened on live TV.

Dermot told Radio Times magazine that he texted Comic Relief founder Richard Curtis with the idea for Red Nose Day after dancing for six hours in Ibiza.

Dermot O'Leary Comic Relief
Dermot O’Leary has been finding training tough (Lucille Flood/Comic Relief/PA)

“Initially, I thought it sounded like a lot of fun, but two weeks ago, reality set in and it started to sound like an endurance test,” he said.

“No one’s really done it before, so it’s hard to train for, but at the moment I’m doing a combination of running and dance lessons for about eight hours a week. I’m in a perpetual state of lactic acid coursing through my veins.”

He added: “I’m determined to keep moving non-stop – though I’ve requested lots of indie, shoe-gazing music to make sure I can slow it down a bit. And if I’m not actually dancing, I’ll be seat dancing!”

Dermot O'Leary
Dermot apparently doesn’t have many moves (Jonathan Short/Invision)

Dermot said that he would “try something that involves some kind of technique” once an hour, but for “the rest of the time it’s just about keeping those feet moving”.

Richard told the magazine that he was not impressed with Dermot’s fund-raising plan at first.

“My first thought was it’s a terrible idea, because it’s a pretty well-established fact that Dermot O’Leary can’t really dance.

“He has one signature move, which he has performed at the start of The X Factor every week for the past eight years,” he said.