Victoria Principal was one of the main — and most popular — characters of the hit CBS drama Dallas. Principal played Pamela Barnes, the daughter of Digger Barnes. (Although it was later revealed that Pamela was not his biological daughter. What?! Spoiler alert, we know.) Principal, unable to come to a compromise on her contract, departed the show after the season 10 finale, when her character was severely burned in a driving accident. But Principal wasn’t without work following her departure from the show. She launched her own line of self-help and exercise books, which became very popular. Here’s Principal at the 1983 American Booksellers Convention demonstrating some of her exercise techniques.