The application is intended for fitness trainers, their full and competent management of the training process of clients. Drawing up training programs includes: creating template programs, personal ones, creating a clear number of approaches, repetitions, weights and videos with technique for each exercise. Receiving reports from clients about each training day with comments. The preparation of nutrition programs includes: personal preparation of KBZHU, personal files with nutrition plans and recommendations. The application also includes: tracking the progress of each client in the training process, measurements and photos of physical fitness, creating your own video materials and using video materials with exercise techniques already available in the application. For clients, this is an easily accessible and understandable platform that allows them to receive personal guidance from a fitness trainer with his feedback and full inclusion in the entire process of training and nutrition. For trainers, the DO FIT platform is a new type of client management using a full-fledged personal approach, without the use of third-party services and interfaces. With the DO FIT app, trainers and clients will be able to reach new levels of interaction, personalization and online management at an accessible and superior level.