The man who started the fitness craze in the USA just passed away. Jack LaLanne (9/26/1914 - 1/23/2011) lived to be 96 years old. He hadn't had a dessert since 1929.
I guess he was never a bit actor, but perhaps some of his screen work as himself, could be considered bit work. IMDB credits him with six acting roles and 33 appearances as himself. It was not all TV either, he was in a few movies and documentaries.
His own fitness show on television ran for more than three decades. He played himself in the 1961 Jerry Lewis movie, The Ladies Man; and in 1990 in Repossessed with Linda Blair (b. 1959), Ned Beatty (b. 1937) and Leslie Nielsen (1926 - 2010). In 2006, in his final TV movie (a stinker called "The Year Without a Santa Claus"), he played Hercules when he was 92 years old!
Some of his fitness stunts amazed me. In 1936 he opened the first health club in the nation. In 1950 he performed 1033 push ups on TV in 23 minutes on "You Asked For It." When he was seventy years old, he swam a mile and a half, pulling seventy boats with a person in each one, while handcuffed and shackled. He is responsible for designing many of the exercise machines that are still in use today. And his TV show was aimed at helping us normal people attain fitness using things found around the home.
Now, not that I would want to become a nay-sayer on LaLanne, but it came to mind that George Burns (1896 - 1996) lived to be over 100 years old. Burns drank and smoked cigars. I am almost positive that he frequently had dessert. And he was a womanizer. An acquaintance of mine, some years ago, had been in a George Burns show somewhere. Burns was probably in his late 80s at the time. She needed a ride to the airport and Burns offered her a seat in his limo. All the way there she had to refuse his advances!
I guess there is no figuring it out. Just do the best you can. Goodbye, Jack, and I really do think your effort has helped many people over the years. If you see George up there, say "Hi" from all of us.