Sir Rod Stewart "will never retire"

Rod told Britain's HELLO! magazine: "I don't see any possibility of slowing down anytime soon.

"And as I get older, I only really want to do things that give me great pleasure."

Penny - with whom Rod has sons Alastair, 18, and 13-year-old Aiden - added: "He loves what he does so much and will never retire.

"He's a workaholic and constantly on the move. I struggle to keep up with his training schedule. He works out three or four times a week - even on tour."

The 'Maggie May' hitmaker has six other children from previously relationships and while it takes "a lot of planning" to get the whole family together, Rod and Penny love seeing them all at once - though they need "diplomacy" and "understanding" to keep things running smoothly.

Penny said: "We like to take every opportunity to bring the family, children, and grandchildren together. Part of the family lives in America, part in England, so it requires a lot of planning, but at least two or three times a year, the whole clan comes together...

"There are the usual family ups and downs. You have to use a lot of diplomacy, be patient and understanding. In the end it's worth it because you experience this wonderful bond that only a family can have. The epicentre of it is ultimately Rod: he's the Rodfather."

Rod believes he is a much more "present" dad now than he was decades ago.

He said: "I used to be much more preoccupied with myself and my career. But I've learnt from my mistakes and am more present."

And the 'Loose Women' presenter credits her husband's big family for keeping him young at heart.

She said: "I think it's family. Especially the younger generation. They give him strength and drive.

"He's not your average 79-year-old man. He can't sit still and is always on the go. I like to treat myself to a facial or a massage. He can't do that. He can't have a massage for more than half an hour; he gets up and leaves."

The couple met in 1999 and married in 2007, and still have a "healthy attraction" to one another.

Penny gushed: "You need a healthy attraction. Rod and I can have dinner in a crowded room or just the two of us - we always have eyes for each other. There's this look, this connection, this message without words."