## 5 Conclusions  
This meta-analysis concludes that CNT is a highly effective method for improving COD performance, yielding superior results compared to standalone strength or glyometric training programs. However, its effectiveness is comparable to other combined training models like DT and AT. This suggests the primary driver of adaptation is the integration of both high-load strength and high-velocity power exercises within the same program, with the specific sequencing of those exercises being of lesser importance.  
The benefits of CNT are most pronounced in specific populations and contexts. The greatest performance gains were observed in younger athletes (<18 years), amateurs, and female athletes, who appear to have a greater capacity for neuromuscular adaptation to this training stimulus. Furthermore, CNT is particularly effective for enhancing performance in more complex agility patterns that require over three direction changes (e.g., T-Test, Illinois Test), making it highly relevant for sports like basketball, soccer, and handball.  
Based on these findings, practitioners are encouraged to implement CNT as a safe and potent strategy to optimize COD ability. For practical application, programs lasting longer than six weeks, with a frequency of two sessions per week and a strength intensity below 85% 1 RM, serve as an evidence-based starting point. This approach is especially recommended for developing youth, amateur, and female athletes, though future large-scale research is needed to further refine protocols for diverse populations.  
Future research should aim to conduct larger-scale RCTs to confirm these findings and address current limitations, such as the scarcity of research involving female athletes and the lack of double-blinding in existing studies. Further exploration of these factors will help identify optimal training protocols for diverse sports and populations.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15137385/s1](https://www.mdpi.com/article/10.3390/app15137385/s1)]([https://www.mdpi.com/article/10.3390/app15137385/s1](https://www.mdpi.com/article/10.3390/app15137385/s1)). Figure S1: Forest plot. Results of a random-effect meta-analysis comparing CNT with other intervention protocols in different age subgroups; Figure S2: Forest plot. Results of a random-effect meta-analysis in different gender subgroups; Figure S3: Forest plot. Results of a random-effect meta-analysis in different level subgroups; Figure S4: Forest plot. Results of a random-effect meta-analysis in different COD measures; Figure S5: Funnel plots for CNT vs. CON; Figure S6: Funnel plots for CNT vs. PT; Figure S7: Funnel plots for CNT vs. ST; Figure S8: Funnel plots for CNT vs. DT; Figure S9: Funnel plots for CNT vs. AT.  
Writing--data curation and writing--original draft, S.L.; writing--review and editing and visualization, Z.Y.; validation, T.X.; supervision, H.X.; conceptualization and supervision, R.L. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the Fundamental Research Funds for the Central Universities under grant numbers 2024 YDXL002 and 2025 KYPT04.  
Not applicable.  
Not new data were created.  
The authors declare no conflicts of interest.  
The following abbreviations are used in this manuscript:  
COD Change of direction  
CNT Complex contrast training  
ST Strength training  
PT Glyometric training  
DT Complex descending training  
AT Complex ascending training  
PAP Post-activation potentiation