Welcome to the Mountainside Fitness app! Mountainside Fitness is Arizona’s largest locally owned health club chain, with locations throughout the Valley. The app allows our members to check class schedules at all of our locations, add a class to your calendar, and register for Peak Performance classes. Create personal goals and track your workouts both in the club and on the go. Our app allows members to sync with popular fitness tracking devices to stay motivated. And no need to carry a membership card, members are able to check in to the club with our app.