Brent-- yes! Those legs!! It's hard for one to keep their eyes on the appliances.
I saw her show in Dayton, Ohio around 1982. She was fifty or fifty one then and was still kicking just as high and really didn't look too much older than in the video.
Alex--I wonder the same thing. It doesn't seem right. Unfortunately, the human body wears out faster than automatic washers. And we are a little harder to repair. lol
On the bright side, Mitzi still has a traveling show even today at age 82. From what I hear she doesn't dance much but sings and has a humorous monologue that keeps the audience rolling in laughter. (Debbie Reynolds who is the same age, also still has a show, as well and is equally funny.)