## 4 Discussion
Secondly, regarding interesession reliability, it is highlighted that the results showed high reliability between sessions three and four. In this case, less variability is observed between sessions three and four for the three positions, both in the peak force and in the average force. Specifically, in the dominant force, a CV of 13.09% and 10.75% was found in the peak and average force, respectively (sessions one and two) and 6.71% and 6.61% (sessions three and four). Thus, this is in line with other research, such as that of [PERSON] et al. [21] where they reached this conclusion on the reliability of the sprint with a CV of 4.3 to 20.7% (between sessions one and two) and 3.2-10.1% (between sessions three and four), conclusions similar to those of [PERSON] et al. [29] or those of [PERSON] et al. [28] with three devices for measuring force in the blocks, highlighting that for these authors, the intrasession CV was lower than the intersession as in our research. At the same time, this result is not new, given that authors such as [PERSON] et al. [30] also saw this need; therefore, familiarization with at least two sessions and two trials per session was essential to achieve adequate reliability [28]. It is noteworthy that in our case, the intraclass correlation coefficient (ICC), which shows the degree of agreement between the different measurements, was very high, especially in the average force in the three positions, but they were only higher in both the peak force as in the average strength at 0.80, between the third and fourth session, this value was considered adequate [31]. Given this first hypothesis, we can also respond to the second hypothesis, not including whether there was a trend in favor of greater reliability in peak force or average force. However, when there was familiarization with the instrument (from the second session), except in the bilateral position, the average force had greater reliability than the peak force. It is noteworthy that in all cases, the reliability of the instrument for the dominant leg was very high, both intrasession and intersession, both in average force and in peak force. This responds to the third of the hypotheses of the present study since it is hypothesized that the dominant leg would be the most reliable position. The higher reliability observed in the dominant leg position can be attributed to greater neuromuscular efficiency and improved motor control because the dominant leg is typically more engaged in dynamic movements. Additionally, the dominant leg, being more familiar with sport-specific actions, such as the starting block push-off, tends to have stronger musculature and better coordination, leading to reduced measurement variability. These biomechanical factors optimize the force transmission and contribute to a more consistent performance, thereby explaining the high reliability in this position. As it is the position with greater ergonomics and where there is greater familiarization in athletes, it is notable that this result exists, given that in unfavorable ergonomic conditions, when modifying the leg, performance and reliability can be reduced [32]. The dominant leg typically generates a greater and more consistent force during the push-off phase, which significantly contributes to the acceleration phase of a sprint. This reliability in force production ensures a more stable and efficient start, which is crucial for achieving optimal sprint times. It would be interesting to see if, with higher level sprinters, it could be considered that the differences were even greater with respect to the other two positions due to the lack of habit of the technical gesture, given that the front leg produces the greatest impulse, but learning the use of the starting blocks also has a great impact on performance, especially due to the pre-tension accumulated in the muscles [33].