The aim of this study is to analyze and diagnose the performance of endurance runners in track and field, focusing on three key indicators: technical, physiological, and managerial. Given the high rate of injuries and performance decline among endurance athletes, this research seeks to design an integrated and practical model that, by considering various dimensions of athletic performance, can lead to reduced injuries and improved efficiency. The study was conducted using a mixed-methods approach (quantitative–qualitative). In the qualitative section, semi-structured interviews were conducted with 15 national coaches, sports physicians, and sports management experts, and thematic analysis was employed. In the quantitative section, data were collected from 96 endurance athletes and analyzed using confirmatory factor analysis and structural equation modeling. The results indicated that disruptions in running technique, imbalances in training load, and weaknesses in managerial strategies play the most significant roles in causing injuries and performance decline. The final model of the research introduces a three-dimensional framework that, by integrating technical variables (stride pattern, core stability, movement symmetry), physiological variables (VO2max, muscular recovery, metabolic fatigue), and managerial variables (training program structure, coach-athlete interaction, support resources), is capable of explaining 71% of the variance in performance and injuries among runners. This model can serve as a valuable tool for coaches, sports physicians, and team managers in designing preventive programs and optimizing athlete performance.