Work Out in the Zone (previously known as Work Out) is an American reality television series on Bravo, which premiered on July 19, 2006. The show is centered on fitness trainers and models located in the many cities of California. The first three seasons featured many of the trainers who work for fitness trainer Jackie Warner, and some other aspects of the gym and its clients as well as Warner's other fitness ventures, and private life. The third season of Work Out ended on June 10, 2008, and was subsequently canceled. A fourth season is currently held in production, with eight different trainers cast for the show. Warner will not return for the fourth season, after the network was not pleased with her interaction with the other trainers. The fourth season, which revamped the show's concept, mainly featured top fitness model and former army ranger Greg Plitt, who was the only cast member to return from the previous season.