Rod Stewart's children are his "fountain of youth".

The 68-year-old British singer has six adult offspring and shares two small tykes with his wife Penny Lancaster.

Alastair, seven, and two-year-old Aiden always expect Rod to get involved in their games, no matter how energetic. Rod regularly plays soccer with the older lad, even though he has knee problems.

'He comes home from school and says, 'Dad, let's go!' Then I have a stretch and go play,' Rod told People magazine.

'If there's a fountain of youth, it's children.'

Rod grew up in North London, the youngest of five children.

He was neither rich nor poor as a child and enjoyed his modest upbringing.

Rod admits raising extremely wealthy kids brings some unexpected challenges.

'I battle constantly with whether I'm not spoiling my children,' he said.

'I try to instil my values in them, and they'll say, 'Dad, we didn't grow up like you. Where's the comparison?' But they're great. They keep me alive!'

Rod has sold over 100 million records since he began his musical career in the 1960s.

Apparently his toddler boy Aiden has absolutely no idea what his dad's occupation is.

"My two-year-old son doesn't even know what I do for a living yet... he's never seen me on stage. He's coming to his first concert in one of the British shows. He thinks I'm a plumber, like my dad was,' Rod told the BBC recently.