The Duke of Edinburgh is blessed with "James Bond-esque" genes, broadcaster Phillip Schofield has said after he worked with the royal for a new ITV documentary.
The This Morning presenter has been following his royal namesake on the programme which focuses on the Duke's charitable work.
Speaking about his experience working with the 95-year-old, Schofield told Hello! magazine: "There were days when I was shadowing him and talking to people he had spoken to and by the end of it, my feet were bloody killing me.
"Yes, there's royal duty, but nevertheless, he's blessed with some extraordinary James Bond-esque type genes."
"He's sharp as a tack, his memory is fearsome, his humour is razor sharp and he was extraordinary in the amount of time he would spend with people."
The programme - in which Schofield also talks to the Earl and Countess of Wessex about their involvement - will celebrate 60 years of The Duke of Edinburgh's Award, which helps young people.
The presenter also revealed Philip is "very funny", adding: "He was absolutely lovely. He's got a great sense of humour. He was joking 'Oh bloody hell, not you again,' he was very friendly."
The programme looks at how the Duke launched the scheme to provide life-changing opportunities for young people when he was 35.
Schofield said: "When you look at him as a younger man, he was a stunning looking guy and a (naval) Commander. He's actually bloody James Bond. He looked incredible, was very much the action man figure and so what better way to encourage people to do it than lead by example."
Asked what he thought the Duke's secret was, Schofield said: "You have to be blessed with a body that will see you through that so I think he's probably a very lucky man that genetically, he's robust. And propping all of that up is this dedication to duty. Real, old-fashioned, 'well that's it, crack on'."
The documentary, with the working title When Phillip Met Prince Philip: 60 Years Of The Duke of Edinburgh's Award, is being produced by Spun Gold TV, which made When Ant And Dec Met The Prince: 40 Years Of The Prince's Trust.
The latest issue of Hello! is out now.