An extended project of the World Class fitness clubs chain renewal first of all assumes the creation of a branded architectural style for the interiors of fitness clubs. Therefore, the architects considered the development of the conceptual matrix, which would be based on two principles: inalterability and adaptability, as the fundamental principle for the design competition. The basic idea was dynamics and movement. After winning the competition, the architects started to develop the concept in details and to implement it in a number of clubs. The arrangement of the interior space is based on the collision of two opposite principles and as a result energy is released. The colliding poles are represented by different colors and materials: white – plastic, viscous, anthropomorphic, feminine; and gray – concrete, heavy, brutal, muscular. Their interaction gives rise to red – energetic, pulsating, unifying. It fills the space with movement, metabolism, heartbeat, which is felt intuitively, and thus creates a tonic environment promoting activities in the clubs.