Looking For Fitness Center Located In Denver? Visit Green Door Fitness Green Door Fitness is the best Fitness Center located in Denver. They have a variety of trainers on-site to help you from a basic class to the lead-up to a rowing competition, they will take you to a new level on our ergs. They are centrally located so that everyone in and around Denver can easily find them and utilize their services. in Public bookmarkswith fitness-center-denverby 13 users