## 4 Discussion
In contrast to the above study, researchers observed in the Spanish LaLiga that the most sprints with speeds greater than 30 km/h were performed during the first and last 15 min periods [27]. In agreement with our findings, previous studies [27; 28] report that the greatest sprint distance was observed during 0'-15' and 46'-60'. They also mention that players' performances decreased during the last 15 min of each half. Differences between studies may be due to variations in GPS speed zones, data collection methods, differences in participants, and naturally, the impact of contextual variables. Specifically, running performance can be influenced by the location of the match (home or away) and the current score of the match (win, loss, draw). In a recent study [29], it is reported that high-intensity running, Acc, and Dec were higher in away matches. Additionally, higher values were observed when the match was tied compared to when the team was winning or losing. In the present study, excluding the period of 76'-90'+ (which includes extra time), it was observed that the total distance covered by all players decreased during the first two 15 min periods of the second half. The observed progressive decrease may likely be explained by the effect of fatigue [25; 28]. However, another factor that may influence this is the effective playing time. Specifically, a previous study reports that the effective playing time during the period of 0'-15' is 66%, while during the period of 76'-90', it is 55% [9]. These differences in effective playing time may be due not only to fatigue but also to tactical factors such as maintaining the score (for the team that benefits). Additionally, the position and tactical role [25] appear to influence the running performance of players during the 15 min periods. Specifically, center defenders (CDs) were observed to have the lowest running performance in all time periods both in total distance and in high-intensity running. Regarding total distance, central midfielders (CMs) covered the greatest distance in most of the 15 min periods, which were followed by wingers (Ws). In high-intensity running distance, wingers (Ws) and fullbacks (FBs) dominated in the first three 15 min periods, while in the time periods of the second half, forwards (FWs), wingers (Ws), and fullbacks (FBs) outperformed the others. The running performance of players in all positions in zones 3, 4, and 5 (z3, z4, z5) showed similar variation. Specifically, the longer duration of the 30'-45'+ and 76'-90'+ periods seem to have influenced these results. Notably, in the final period (76'-90'+), CDs (center defenders), FBs (fullbacks), and FWs (forwards) ran the most meters at high intensity. Excluding these two periods, there was a decrease in high-intensity running performance across all positions during the 61'-75' period. Compared to the running performance in the first period, CDs reduced their performance by 20%, FBs by 23%, CMs (central midfielders) by 23%, Ws (wingers) by 35%, and FWs by 19%. Regarding the variations in players' running performance in relation to position and 15 min periods, it appears there are not many studies that have investigated this. Specifically, in one of the studies we found, [PERSON] et al. (2022) [10] observed that concerning the total distance in the last 15 min, players in all positions covered less distance compared to the first 15 min (CD \(-\)13%, FB \(-\)12%, CM \(-\)15%, W \(-\)15%, and FW \(-\)17%). A recent study reported that center defenders (CDs) exhibited the lowest running performance during the 15 min periods of the match, whereas wingers (Ws) showed the highest physical performance (Acc, Dec, sprint running distance, high metabolic load distance), and central midfielders (CMs) covered the greatest distance [25]. The superiority of players in wide positions in terms of the distance covered at high intensity is also mentioned in previous studies [4, 27]. Additionally, the formation can affect the running performance of the football players [30].