The key to improving the effectiveness of the sports education system and ensuring the well-being of future national champions is to understand the subtle mechanisms of interaction between young athletes' social support, mental toughness, and self-efficacy. The present study aimed to identify the nature of the relationship between the components of social support perceptions and the level of student-athletes' engagement in the athletic training process, and to determine the mediating effects of self-efficacy and mental toughness in this relationship. The study involved 167 first- and second-year student-athletes studying at the Academy of Physical Education and Mass Sports who were asked to take a questionnaire that included the analysis of four indicators: the studied level of involvement, social support, mental stability and self-efficacy. The obtained data were subjected to statistical processing in the form of correlation, regression and mediator analyses. The results of the study showed statistically significant positive correlations between all the studied variables. It should be emphasized that the total of independent variables explained 74% of the model variation (R² = 0.735), which emphasizes the importance of psychological mechanisms in transforming social support into specific behavioral patterns of sport involvement. The study makes a significant contribution to the theoretical and practical sphere of sport psychology and pedagogy of higher education: in theoretical terms, the work expands the understanding of the mechanisms of the influence of social support on sport performance, offering an empirically grounded model that includes self-efficacy and mental toughness as key mediators, and from a practical point of view, the recommendations proposed by the authors can serve as a basis for the development of educational programs in the system of higher education in the field of sport engagement. Of particular value is the identification of the combined effect of self-efficacy and mental stability, which indicates the need for a holistic approach to the psychological training of future champions of Kazakhstan.