The project is entitled “Investigation, Mathematical Analysis, and Evaluation of the Impact of Stress on Cardiological Data.” Its primary objective is to conduct fundamental research through the application of a novel mathematical approach for analysing and evaluating the effects of mental and physiological stress on heart rate. Mental stress has been investigated through the development of an extreme virtual reality game using various stereoscopic technologies, and its impact on heart rate variability has been analysed. The influence of physiological stress has been studied during sports training sessions in order to assess training load based on heart rate variability.