To the authors' best knowledge, this is the first study to simultaneously examine the running performance according to ball-in-play, ball-out-play, ball possession, and different moments of soccer match-play in professional players. In addition, physical demands were observed considering each playing position. The main results were: (a) ball-in-play presented higher running outputs compared to ball-out-play; (b) no-ball possession reported greater running performance than ball-possession in all playing positions; (c) fullbacks and central defenders/midfielders presented higher physical demands during no-ball possession than ball-possession; (d) in general, greater running performance was observed during the offensive/defensive transition compared to offensive/defensive organization; (e) in general, we found greater values of running performance during defensive organization/transition compared to offensive organization/transition; (f) in contrast, wide midfielders and strikers showed higher external load metrics during the offensive transition than defensive transition.
As hypothesized, the overall analysis, considering playing positions (fullbacks, central defenders, wide midfielders, and central midfielders) showed greater values for all match running performance variables (refer to Tables 1 and 2). Specifically, during the ball-out-play condition, there are more opportunities to create anticipation towards the opponent. Players stay still to try to surprise the opponent, creating movements when the ball is in play. However, when analyzing by players' positions, the striker did not register significant differences between ball in/out of play in the TDrel, ACCrel, DECrel and number of ACC, despite a similar evident trend. Previous studies have reported that match running performance is playing position-dependent, with the strikers covering lesser distances during the match [30] but engaging in a greater amount of high-intensity running [31, 32]. This is possibly related to their need to complete sprints away from defending players to generate space or capitalize on goal-scoring opportunities [33]. Nevertheless, those studies did not compare ball-in-play and ball-out-play conditions.
In the ball possession condition, when analyzing all positions together, differences were observed in all running performance variables, except for SRrel. Indeed, disparities have been reported when comparing running with and without the ball, suggesting that players experience greater physiological stress [24] and energy expenditure [25] in the former condition. In this context, players encounter difficulties achieving greater velocities when running with the ball, explaining our results. Therefore, it has been recommended that high-speed run with the ball should be included wherever possible in soccer-specific routines [34]. Nevertheless, our results were not align with other studies that recorded trivial differences in match running, even with high (51–66%) or a low (34–50%) percentages of ball possession [1, 35, 36].
A positive effect of ball possession on fullbacks and midfielders was expected; however, wide midfielders did not showed difference in running performance variables when comparing the ball possession conditions. On the other hand, fullbacks covered greater distances on moderate and high-speed (MSRrel and HSrel), in high acceleration (ACCrel), and presented a greater number of ACC and PLrel in the no-ball possession condition. These values could depend on the tactical strategy implemented, as the number in each player position will influence the physical demands [27], i.e., the running performance variables. Moreover, although it has been argued that success might be characterized by greater movement while in possession, willingness to create space, and maintain possession [36], only a short distance (only 1.2–2.4% of the total distance) is covered by players with the bal; most of the efforts are made without the ball [37].
As expected, the offensive/defensive transition showed greater running performance when compared to the offensive/defensive organization. As highlighted by Mota and Clemente [27], the offensive transition actions try to take advantage of the opponent's disorganization; conversely, in the defensive transition, players try to reach the defensive organization as fast as possible. Therefore, both transitions depend on great physical capabilities such as a fast change of direction, a high sprint velocity, and a substantial fast reaction [27]. In the present study, when analyzing all player positions together, the greater running performance in the transition action was observed in all offensive/defensive transitions compared to offensive/defensive organization, except the number of ACC that showed no difference between offensive transition and organization. Indeed, transitions are crucial phases of the game since most goals and risks occur during these moments [38], being identified as one of the key five moments of play in soccer [10, 38, 39]. In this sense, it has been suggested that coaches should include training situations that simulate these demands [40]. This includes identifying the appropriate context and manipulation of task constraints and enhancing players' tactical behavior [41]. Additionally, specific soccer training formats, such as small-sided games, can contribute to improving physical capacity [42].
The importance of defensive actions in soccer has been highlighted in different studies [43, 44], indicating that defensive pressure is higher in successful defensive plays compared to unsuccessful defensive plays [45, 46]. However, greater efforts are required in defensive organization/transition to achieve that. The results of the present study are in accordance with that great effort, as it was found greater values of running performance during defensive organization/transition compared to offensive organization/transition. When comparing defensive with offensive organizations, only in SRrel differences were not found; in the other variables, the defensive organization showed better running performances. Nevertheless, those differences were unclear when comparing the offensive and defensive transition phases. As indicated above, transition phases are more demanding from a physical point of view; perhaps that is why so many differences were not observed.
When analysing the different players' positions, it was observed that running performance was highly dependent on their positions, which follows the literature (e.g., [31, 37, 40]). In general, it was observed that wide midfielders (TDrel, ACCrel, and PLrel) and strikers (HSRrel, ACCrel and Number of ACC) showed superior external load metrics during the offensive transition than defensive transition. Those results could be related to their need to complete sprints away from defending players to generate space or capitalize on goal-scoring opportunities [33]. Hence, midfield players were found to have the smallest time spent walking and jogging but covered the largest distance in low- and moderate-speed running [37]. Considering that, once again, researchers encourage coaches to create optimal training programs for all players according to their tactical roles and individual abilities [40].
Our study has some limitations. First, caution is recommended when interpreting our results, given that the analyses were conducted solely based on the matches of one season and a single team. Additionally, the sample difference in the number of matches for each independent variable analyzed can be regarded as a limitation of this study. Second, we did not consider the influence of other contextual factors on running outputs (e.g., match location, quality of opponents, match status, and team formation). However, this study provides some strengths that should be recognized: (i) to the best of our knowledge, this is the first study to analyze the integration between tactical (phases and moments) and physical (GPS metrics) dimensions in professional soccer according to each playing position; (ii) we consider a myriad of external load parameters, including distance- and accelerometry-based measures. Further studies are recommended to analyze the interactive effects of contextual factors according to ball-in-play, ball possession, and different phases of match-play on running performance.