The motivation for choosing this topic is the connection between software engineering and the current hobby. Also, one of the motives is the need for such a way of working, which appeared during the pandemic. The main goal is to create a web application that will optimize and enable online training with a fitness trainer. An MVC application will be built that allows the trainer to register new users. The application is accessed by logging in. The trainer will see all his clients and will be able to create and review personalized workouts for each, exercises with names, sets, repetitions, weight and performance in the training. In addition to the training, the trainer will have the opportunity to create and review the diet plan. The web application also allows the client to review his training and exercises that the trainer has compiled for him for the following week and which the client trains according to. The client has the possibility to view his diet plan in a way to see what he should eat for breakfast, lunch and dinner. With the diet plan, the client sees the calculated daily calories with daily macronutrients. On his account, the client can review the performance of each exercise through video material and monitor the progress in the form of a graphic display. Through the same application, a physiotherapist can provide support to a certain client in the form of advice that the client sees on his account. The communication between the database and the web application will take place through the ASP.NET Core Web Programming Interface - API.