Jack LaLanne flashes the classic weightlifter's bicep curl at a 50th anniversary party for the Hollywood Walk of Fame. This was in Hollywood, California (duh) on November 3, 2010. Jack LaLanne was born on September 26, 1914, so he was legit 96 years old in this shot.
Alas, it didn't last: LaLanne died of pneumonia two months later, on January 23, 2011. Per Wikipedia, "According to his family, he had been sick for a week, but refused to see a doctor. They added that he had been performing his daily workout routine the day before his death."