With methods of the literature researches, mathematical statistics and logical analysis, a comparative study is carried out to analyze the important competition data of the recent four Olympic Games (from the 28th to the 31st) which Chinese women’s volleyball team and other strong world women volleyball teams (Brazil, Russia, America and Cuba) once took part in. The study finds out that the new developing trend of the world’s five strong women volleyball teams’ competitiveness shows mainly in the following two aspects: the training of the world women volleyball tending to be more masculine and the increasing proportion of serving points in the world women volleyball competitions. Meanwhile, it also verifies the three new models for the construction of Chinese women volleyball players’ physical fitness training: the athlete’s individual excellence to the sports team’s overall excellence; the understanding of the construction and deconstruction of volleyball technical models based on the tradition and innovation of volleyball tactics; the construction of the scientificalness of physical fitness training, according to the individuality of athletes, the characteristics of specific sports events and the comprehensiveness of sports events. In the end, it points out that the two-way complementary between the new developing trends of competitive level and the new model of physical fitness training Chinese women volleyball’s teams is the key to further enhance Chinese women’s volleyball team’s competitive level.

Based on the philosophical perspective, a methodological research on disciplinary research fields of Theories of Sports Training is carried out, which puts forward the primary issues, the key issues, the vertical developing issues and core issues that should be taken into considerations in the methodology of disciplinary researches of theories of sports training, reveals that the innovation in Theories of Sports Training needs more philosophical and methodological guidance.

Principles of sports training in Theories of Sports Training teaching materials and sports training works at home and abroad are combed historically and analyzed horizontally to frame principles system of sports training, with the purpose to make principles of sports training work for competitive sports events and to provide various coaches engaging in competitive training and competitions with theoretical guidance and practical help.

Objective:This study explores the biomechanical characteristics and potential sports injuries of reverse vertical jump (CMJ) in male firefighters of different grades based on spatiotemporal parameters, dynamic parameters, and kinematic parameters. Method:A total of 86 male firefighters were recruited (age: 29.01±5.11, height: 1.73±0.05, weight: 69.61±8.15, service years: 5.83±5.05, BMI: 23.36±2.31). The IMU insole was adopted as the measurement tool and the relevant index parameters were measured. SPSS29.0 was used for sorting and statistical analysis. Result:The results of some CMJ indicators of firefighters of different grades showed statistically significant differences. The right leg lift-off time of senior firefighters was lower than that of junior firefighters (P < 0.05). The flexion Angle of the left ankle landing of senior firefighters was lower than that of junior and intermediate firefighters (P < 0.05). The left leg propulsion speed of senior firefighters was lower than that of junior firefighters (P < 0.01), and also lower than that of intermediate firefighters (P < 0.05). Meanwhile, the right leg propulsion speed of senior firefighters was lower than that of junior firefighters (P < 0.05). There were statistically significant differences in the results of some CMH indicators among firefighters with different attributes. The right leg landing stability of the national team firefighters was higher than that of the professional team (P < 0.05). The commander's leg flight time, flight height, flexion Angle of the left ankle upon landing and the propulsion speed of the left leg were all lower than those of the firefighters (P < 0.05). Conclusion:As the rank of firefighters increases, their vertical jumping ability shows a declining trend. The decline of various indicators of senior firefighters (CMJ) is more obvious compared with that of junior firefighters, indicating that they have regressed in center of gravity control, strength level and joint range of motion, and have increased the potential risk of injury. The shock absorption capacity and stability of the right ankle joint of national team firefighters need to be improved more compared with those of professional team firefighters. Commanders have lower levels of center of gravity control, ankle range of motion and pushing force than firefighters, indicating a higher potential risk of injury for them during mission execution and strength and conditioning training.