Two neighbors pull ahead of the rest in Tough Mudder's top 10: Armchair Expert Podcast at 0.76 and Fitbit at 0.76 — one a general-interest podcast, the other the only fellow Fitness brand in the set. Audience similarity here measures how closely two entities' audiences resemble each other in composition; these two scores sit noticeably above the rest of the top 10, which drops to 0.73 and below.

The shape is two-peak, and the two peaks point in different directions. Fitbit represents the expected fitness-adjacent cluster, but Armchair Expert Podcast — a Podcasts and Radio property — edges it out as the single closest neighbor. Below those two, the top 10 fans out across a wide range of subcategories: Tulsi Gabbard (Politicians, 0.73), Runner's World (Magazines, 0.73), a retail Electronics property (0.72), Buzz Aldrin (Government Officials, 0.70), Goose Island Beer Co. (Breweries, 0.70), Rob Lowe and Eugene Levy (both Actors, 0.70), and Jose Canseco (Athletes, 0.70). Only one neighbor — Fitbit — shares Tough Mudder's own Fitness subcategory. The rest span entertainment, media, politics, and retail, with no single subcategory dominating beyond the two actors.

The two-peak structure suggests Tough Mudder's audience bridges a fitness-tracker crowd and a broad, podcast-listening general audience — two distinct neighborhoods that don't obviously overlap by category.