Improving Female Students’ Physical Fitness Through Volleyball Training: A Quantitative and Qualitative Analysis of the Implementation of an Experimental Model

The study focuses on the rationale and experimental verification of the effectiveness of a differentiated training model aimed at improving the physical fitness of female students in pedagogical specializations through volleyball training. The relevance of the research is determined by the need to enhance the physical fitness of university students under conditions of declining overall physical activity and limited opportunities for the individualization of the educational and training process in higher education institutions. The theoretical foundation of the study lies in modern concepts of individualization, progression, and variability of training load, which take into account the initial level of physical fitness and the individual characteristics of the students. A total of 101 female students participated in the research. At the ascertaining stage, the homogeneity of the samples was confirmed based on the main indicators. During the formative stage, the experimental group (EG) implemented the differentiated training model, which involved dividing the students into subgroups according to their physical quality profiles and making targeted adjustments to tasks and loads. The effectiveness of the model was evaluated using a set of quantitative and qualitative indicators. The results show that the EG demonstrated statistically significant improvements in all tests (p < 0.001), with medium to large effect sizes (Cohen’s d = 0.56–1.21). The qualitative analysis confirmed an increase in motivation, a higher level of engagement, improved team interaction, and enhanced self-assessment among EG students. These findings are consistent with previous research confirming the importance of individualizing the training process in university sports and demonstrate the potential of the differentiated training model as an effective tool for the comprehensive development of both the physical and psychological components of future teachers’ preparedness. The model can be recommended for implementation in physical education programs at higher education institutions, with further adaptation for different categories of students and integration of digital monitoring tools.