The Effect of Contextual Variables on Match Performance across Different Playing Positions in Professional Portuguese Soccer Players

This study investigated the position-specific physical demands of professional Portuguese players. The effects of situational variables on the physical performance demands were also analysed (match location, match half and match result). Match performance observations were collected using Global Navigation Satellite System devices across 11 matches during a competitive season (2019-2020). Data were analysed according to five playing positions: goalkeepers (n = 11), central defenders (n = 42), wide defenders (n = 31), central midfielders (n = 34), open attackers (n = 28), and centre forwards (n = 14). Central midfield players completed the greatest total distance (10,787 +/- 1536 m), while central defenders covered the least distance (9272 +/- 455; p < 0.001). Open attackers covered the greatest high and very-high-speed distance (1504 +/- 363 m), number of high-speed decelerations per match (11 +/- 4) and were the fastest players (30.6 +/- 1.5 km/h), along with center forwards (30.6 +/- 2.0 km/h), versus all other positions (p < 0.05). Greater distances were performed in teams that were winning (9978 +/- 1963 m) or drawing (10,395 +/- 875 m) versus losing (9415 +/- 2050) p = 0.036 and p = 0.006, respectively. Increases in distance covered at walking speeds were observed during the 2nd half (1574 +/- 179 m) compared with the 1st half (1483 +/- 176; (p < 0.003). A higher number of decelerations across all speeds were performed in the 1st half (144 +/- 39) versus the 2nd half (135 +/- 37). The distance covered in home matches (10,206 +/- 1926 m) far exceeded away matches (9471 +/- 1932 m; p < 0.001). The number of faster accelerations were higher in away (7 +/- 5) versus home matches (6 +/- 4; p < 0.049). The data demonstrate the different physical demands of each playing position and suggest that situational variables influence physical performance. These findings suggest position-specific physical training is required to condition players for the bespoke demands of each playing position.