## 1 Introduction  
In higher education, teaching serves as the foundation and core function of academic institutions. High-quality instruction not only facilitates knowledge exchange and technology transfer but also attracts and cultivates talented students, thereby enhancing institutional reputation and contributing to national innovation capacity. With the rapid advancement of science and technology, instructional tools and pedagogical methods have continuously evolved, with various forms of digital technology increasingly integrated into classroom instruction [1]. In many countries including the United States and Germany, multimedia education systems have been widely applied in teaching practice [2]. In China, many universities have implemented digital learning platforms and learning management systems to assess student performance, learning preferences, and classroom engagement, thereby enabling more individualized support and attention to diverse learner needs [3]. Additionally, the adoption of virtual classrooms, e-books, and educational websites has improved the accessibility and equity of educational resources, supporting pre-class preparation, in-class participation, and post-class review [4]. In China, undergraduate physical education programs are generally structured as four-year, full-time degree programs governed by national standards set by the Ministry of Education. Nearly all universities and colleges offer such programs. These curricula are designed not only to prepare students to become qualified physical education teachers at the primary, secondary, and tertiary levels, but also to train individuals with advanced expertise to serve as professional coaches for competitive sports teams. Although the national curriculum provides a standardized framework, regional adaptations may occur based on local educational priorities or institutional capacities. The use of multimedia technologies--such as video and audio--has been shown to enhance students' comprehension and retention of instructional content, particularly in subjects with high levels of dynamism and interactivity, such as physical education [5]. Physical education classes often involve visual and experiential components, including movement demonstrations, peer interaction, and skill-based training. Integrating multimedia tools into physical education settings enables students to understand concepts and techniques more intuitively, thereby increasing engagement and improving instructional quality [6; 7]. Furthermore, digital technologies such as wearable devices and activity trackers provide real-time data on key physiological indicators (e.g., heart rate, speed, and step count). These tools not only help students monitor their physical condition and prevent injuries but also equip instructors with data to design personalized instructional plans, thereby improving physical education teaching effectiveness [8]. The adoption of interpretable machine learning has significantly improved predictive accuracy and enhanced transparency in educational research, particularly in analyzing student learning processes. Studies employing machine learning models have demonstrated that factors such as the frequency of physical education classes and the degree of digitalization in home and school environments positively influence Chinese secondary students' engagement in digital physical education activities [9]. In the context of physical education, interpretable machine learning models have also been applied to specific sports domains, including basketball training, martial arts techniques, and badminton stroke analysis [10; 11]. Despite the expanding use of digital technologies in physical education, the empirical application of interpretable machine learning to instructional research in this area remains in its infancy. In particular, systematic investigations into the differentiated and synergistic effects of various digital tools on teaching quality--through the lens of interpretable machine learning--are still notably lacking.