## 4 Discussion
The results presented in this study have not shown an association in any polymorphism of _ACE_, _ACTN3_, _AMPD1_, _CKM_, and _MLCK_ in the response effect in the CMJ and the concentric mean power, even though 14 out of 38 players increased their jump height by more than 1.19 cm (SWC for jump height) without any modifications in their body weight. This leads us to confirm that these 14 participants were able to generate greater impulse (F-t) during the contact phase of the jump, which led to a higher velocity at takeoff and finally leading to a greater jump height. This is also confirmed by the higher concentric mean power observed in those same 14 participants (Figure 1). The knowledge of new variants and new profiles that affect these abilities can be found to deepen the knowledge of this new field of research until now unknown and which for the first time is presented together with genes involved in neuromuscular performance. This investigation shows, for the first time, that genetics could be a significant factor in the predisposition to the response in terms of neuromuscular performance in amateur football players, especially in concentric mean force, showing new candidate genes associated with the etiology of the response to training and power capacities: _ACTN3_, _AMPD1_, and _MLCK_. Despite the strengths of this investigation, this study presents several limitations: (i) the amateur standard of football players recruited for this study may well have confounded these results, as the neuromuscular performance have been influenced by lower levels of strength/fitness and/or lower levels of scientific support in this population. Thus, the small effect of individual genetic polymorphisms (which is multifactorial even in professional football players) is more likely to be elucidated in a higher standard of football players; (ii) given the small effect size of an individual genetic polymorphism and the multifactorial nature of neuromuscular performance, the sample size is too low to provide any meaningful information regarding a genetic association with the strength/power. In the future, the authors will collect more data by significantly increasing the sample size and conducting a follow-up; (iii) this study has only presented two temporal evaluation points. This lack of intermediate evaluations hinders our understanding of whether there have been fluctuations in vertical jump capacity between measurement points and (iv) given the difference in strength and muscle mass values, future research should consider these variables as covariates and/or conduct these analyses based on the gender of the soccer players. Additionally, these potential fluctuations could be related to the training load experienced by the participants. This is also a limitation of this study, as the total training load (sRPE) suffered weekly by the participants is unknown, which could result in the different \"training doses\" experienced and have implications for the interpretation of our results. After 20 weeks of training during the competitive period, there were no generalized increases or decreases in the neuromuscular performance of the lower body, measured through the CMJ test. There were positive responders to training who did increase jump height, although there was no significant relationship with any of the analyzed polymorphisms. However, positive responders in the concentric mean force exhibited a lower frequency of the AA genotype and a higher frequency of CA genotype for the c.37885C-A polymorphism of _MLCK_, as well as a lower frequency of the TT genotype of _ACTN3_ and the CC genotype of _AMPD1_. These results suggest that genetic analysis could be a potential tool to anticipate individual training adaptations in amateur soccer players. There were no changes in CMJ-derived metrics in amateur soccer players, suggesting that neuromuscular performance (at least for this performance marker) is not modified by 4 months of soccer training in amateur male and female players.