Henry Winkler believes retirement would be "deadly".
The Happy Days star admitted he is often asked if he is ready to give up working now he is 80 but he will only do so when he is physically "not able to do" it anymore.
Speaking to Michelle Obama and her brother Craig Robinson on their IMO podcast, he said: "People keep asking me, am I gonna retire or 'Have you retired?'
"And I think that is like the furthest thing from my imagination.
"I will retire when I am not able to do [this] more.
"I think that [retirement] is deadly."
The Barry actor is pleased he is still keeping busy.
He said: "I work a lot. I have several jobs."
Henry's History Channel documentary series Hazardous History - which looks into products and activities from the past which now seem reckless - has been renewed for a second season and he loved working on the show.
He said: "When they presented it to me, I just loved the facts of it. I thought, 'This is outrageous.' "
Henry is best known for playing Arthur 'Fonzie' Fonzarelli on Happy Days and he recently recalled how he thought his "life [was] over" when co-star Ron Howard, who portrayed his best friend Richie Cunningham, decided to quit the show in 1980.
He recalled to People magazine : "There was a phone booth right by the front door of stage 19. They said, ‘Oh, the phone is for you, Henry.'"
Ron - who has subsequently become one of the most successful directors in Hollywood - told his co-star at the time: "It's going to come out in the press in about 10 minutes, but I wanted you to know first, I'm not coming back."
Henry was initially shaken by the news but he ultimately encouraged his showbiz pal to follow his long-term ambitions.
Henry said: "My first thought was, 'I'm going to die now'. My great acting partner on this show, my good friend is no longer going to be here. My life is over.
"And that was in the first two seconds. Then I said, ‘Ron, we've talked about this since the beginning. All you want to do is be a director. It's in your DNA. Go and be the best you can be, and I cannot wait to see what you do.'"
