**3.1 Possession games´ comparison with small-sided games and competition: Physiological responses**

There are studies using POGs with different designs and player numbers in comparison with official games. For instance, Vilamitjana et al. [14] compared three POGs formats (65–110 m<sup>2</sup> per player) with official matches (1-4-2-1-3 and 1-3-4-3), and then differentiated the final performance according to the positions occupied by the players on the field (**Figure 3**). They concluded that the cardiovascular response in 6 vs. 6 and 7 vs. 7 was match-compatible and related to cardiovascular performance, the mean values in POGs were no different from the matches, with the exception of 8 vs. 8 formats. In relation to the high-intensity running and sprinting work rate, the authors found low percentages in both patterns when compared with competition.

In Ref. [31], the authors compared SSGs with POGs in three different formats. They concluded that both formats with a smaller number of players (5 vs. 5, 7 vs. 7; 73 and 98 m2 per player, respectively) do not induce high-speed movement compared with the ones with larger pitches and more players (10 vs. 10; 135 m2 per player). This effect was due to a larger pitch area and less pressure received from opponents, with a greater number of options for passing the ball among players. The main task during both games was that players could not progress with more than two touches (no difference in the designs for each format were detailed, as the only difference described was that POGs were played in a "non-oriented area" and the SSGs were played with goalkeepers and goalposts). The results determined that very high-intensity distance (19.8–25.2 km/h) covered was higher in SSGs in relation to POGs (no significant difference was found at >14.4 km/h), with a larger number of high-intensity accelerations (> 3.0 m/sec2 ) and decelerations (<sup>&</sup>lt; 3.0 m/sec2 ) in favor of SSGs when compared with POGs for the format 5 vs. 5.

As a counterpart of this, a descriptive study was made with typical POGs training sessions (oriented area games) and conventional SSGs designs (**Figure 4**), 5 vs. 5

#### **Figure 4.**

*Possession games and conventional small-sided game designs and diagram representation for 5 vs. 5 formats studied by Vilamitjana et al. [42]. In brackets, the width and length of the pitch used in each design (in meters).*

formats (70 m<sup>2</sup> ), in comparison with official matches (1-3-4-3 and 1-4-2-1-3) [42]. The analysis of the data described higher performance in POGs during seven of the forehead nine study variables (total distance, player-load, high-intensity work rate, high-speed intensity work rate, number of runs in high-intensity running, and highspeed running and maximal speed) except in high-intensity accelerations (> 3.5 m/ seg<sup>2</sup> ) where the SSGs values were higher than POGs, while in high-intensity decelerations (<sup>&</sup>lt; 3.5 m/seg<sup>2</sup> ), no significant differences were obtained. When the data were discriminated by field position, central defenders and midfielders obtained similar values to competition situation in the variables of high-intensity work rate (> 14.9 km/h) and very-high-intensity work rates (> 19.9 km/h). The current findings suggest that POGs are a very interesting tool to stimulate the physical demands to which players will be exposed to during matches. Moreover, SSGs could be utilized as an exercise with greater intentionality when it involves stimulating the accelerations that the player performs during a specific execution time [42].
