Why limit it to three categories.
Uncle Rico - Those who think they are better than they are and spend their time "training", living in their parents basement and working at the shoe store into their early 30s. Tells everyone they are a pro runner because they once won prize money in a race. Runs club nationals every year and finishes in the bottom half.
Cats in the Cradle - The working dad with the stay at home wife and kids that still tries to run 80-100 miles a week so he can get his Boston qualifier. Wife will either divorce him or poison his coffee.
Forest Gump - Pretty much any ultra marathoner. Could also use the term YETI or Kaczynski here.
Warrior Games - Huskier hobby joggers that do cross fit. A lot of divorcees fall into this category.
Fat Dad - AKA hobby joggers, AKA Clydesdales, etc.
Age Grouper - Not fast enough or too old to contend with youngsters. Has a room dedicated to his age group medals and ribbons.