## 4 Discussion
In the present study, a significant increase in vertical jump height was observed in the experimental group, rising from 42.4 cm to 45.8 cm (\(p<\) 0.01). Considering that our study included the evaluation of various sports disciplines, it is important to emphasize that each of them involves specific physical capabilities. On the field of play, athletes display distinct characteristics--such as strength, endurance, or speed--depending on the demands particular to each discipline. Although absolute strength significantly improved in sport climbing, basketball, sprinting, and football, no relevant changes were observed in the other disciplines. These findings align with [PERSON] et al. [50], who reported increases of up to 19% in both dominant and non-dominant limbs, although the interaction effects were not statistically significant. Nonetheless, these findings carry clinical implications, suggesting that Nordic hamstring exercises are beneficial for interventions targeting the hamstrings [51]. Most existing research has predominantly focused on football. A key strength of our study is the inclusion of a diverse range of sports disciplines, allowing for broader applicability of the findings. Notably, a slight decrease in absolute strength was observed in teakwondo athletes, which may be attributed to the specific demands and training modalities of that discipline. [PERSON] and [PERSON] [52; 53] advocate for the implementation of sport-specific parameters and more precise assessment tools to enhance the accuracy of strength evaluation across different athletic contexts. In terms of vertical jump performance, NHEs led to height increases in most disciplines, supporting [PERSON]'s [53] conclusion that these exercises enhance eccentric isokinetic strength and help reduce the risk of hamstring injuries. However, no significant improvements were found in cycling or teakwondo. The study's limitations include the inability to attribute the observed strength gains solely to the Nordic exercises, as both the control and experimental groups continued with their regular training programs. While no significant changes were recorded in the control group, slight improvements in absolute strength and vertical jump were noted. Caution is advised when prescribing and implementing NHEs, as these exercises, despite appearing simple, are technically demanding, especially for individuals who do not train regularly or follow a structured program. Additionally, due to the limited sample size, the results should be interpreted with caution. Future studies are recommended with larger samples, sex-based comparisons, and more detailed analyses, such as electromyographic evaluations before and after the intervention. This study explored disciplines like teakwondo, cycling, basketball, sprinting/athletics, and sport climbing--fields where research on the application of NHEs is limited. As such, this study provides both a theoretical and methodological foundation for future interventions in these sports. However, further research is needed to address limitations such as the lack of imaging tests to assess hypertrophy and other physiological adaptations resulting from the training.