Martin Short's character Uncle Jack is based loosely on real-life 90-year-old fitness guru Jack LaLanne. Speech mannerisms, style of dress, and even the dyed jet-black hair are all trademarks of LaLanne, who, unlike Short's character, remains extremely mobile and agile at the time of this episode's first airing.
This is Martin Short (Martin Short)'s first and only appearance as Uncle Jack, although the character is mentioned again in episodes 2.12, Hand to God (2005), and 3.8, Making a Stand (2005).
Jack Dorso (Martin Short)'s name sounds very similar to "jacked torso"-a reference to Uncle Jack's perennially jacked torso ("jacked" being a slang term typically used to describe anyone who is strong and muscular).
This episode marks the final season 2 appearance of Stan Sitwell (Ed Begley Jr.) and Lucille 2 (Liza Minnelli). Sitwell returns in Season Three's finale, Development Arrested (2006).
Stan Sitwell (Ed Begley Jr.) and Lucille 2 (Liza Minnelli) both go to spin class, where they presumably meet again, having first met at the country club when Gob (Will Arnett) and Lucille 2 joined Michael (Jason Bateman), Sally Sitwell (Christine Taylor), and Stan Sitwell. In episode 1.12, Marta Complex (2004), Buster (Tony Hale)'s line "I thought you had class," although possibly referring to class in the sense of dignity, poise, etc. also implied that Lucille 2 attended a class. In this episode, we learn this is the class Buster was possibly referring to.