## 4 Discussion
Regarding test-retest reliability, previous research such as that of [PERSON] et al. (2018) reported a coefficient of variation (CV) between 2 and 4% and a standard deviations of bias less than 100 N, indicating high consistency in repeated IMTP measurements. In this study, the standard deviation of the bias was considerably higher (224.6 N), which could affect the sensitivity to detect small or moderate changes in peak force. This suggests that although the IMTP is a reliable test, the higher variability observed in this study could make it more difficult to detect subtle changes in performance in trained athletes. This variability may also impact the interpretation of training program effectiveness, as current methods may not be sensitive enough to identify small or moderate strength improvements. For example, [PERSON] et al. (2017) reported average increases of 150-300 N in trained athletes. According to the limits of agreement in this study (\(\pm\)456.9 N), both tests may be too wide to distinguish these typical increases from methodological noise, highlighting the importance of having more precise and standardized protocols when closely monitoring training adaptations. In conclusion, while both IMTP and IBSqT show a low average bias and are capable of detecting changes in maximal force production, the wide limits of agreement and high variability observed in this study suggest that factors such as technique, familiarity with the protocol, and individual participant characteristics may influence the results. This increase in variability highlights the need for greater control and standardization in measurement protocols to improve the reliability and sensitivity of these tests in assessing isometric strength in trained populations. It is important to note that, for this study, the results were not divided by sex, which could reveal different parameters when interpreting results, consistent with the existing literature [24]. Another potential divergent factor could be the evaluator's learning curve with IBSqT, a test that lacks a standardized protocol. As the evaluator gains experience with the test, reliability may increase. Future research should aim to establish reliability data in elite athlete populations and explore the degree of correlation between IBSqT and athletic performance variables. A potential limitation of this study is that no sex-specific analysis was performed, as the primary objective focused on evaluating the reproducibility of maximum strength tests in general. This may slightly limit the extrapolation of the results to men and women separately, as there could be factors that influence the consistency of the tests differently based on sex. Future research could explore this variable in greater detail by including more balanced samples and conducting sex-specific analyses. Additionally, it would be valuable to examine how other variables, such as training level, prior experience, or anthropometric characteristics, might affect the reliability of these tests in diverse populations. The results indicate that PF and RPF are highly reliable metrics for both tests, demonstrating excellent within-session and between-session reliability. These variables showed consistent performance across multiple trials, highlighting their sensitivity to performance changes, which is crucial for evaluating maximal force production in strength athletes. However, the reliability of other measured variables, such as RFD and IMP, exhibited more variability. While RFD achieved acceptable reliability in certain time windows, it showed considerable variability within and between sessions, especially in the IBSqT. This suggests that RFD may require increased test familiarity or a more standardized protocol to enhance reproducibility. Additionally, while IMP demonstrated acceptable reliability in IBSqT, it did not achieve consistent reliability across all time windows in the IMTP.