COVID-19 affects match running performance in professional soccer players

Objectives: To compare the match running performance of male soccer players in the Brazilian A series before and after being infected with COVID-19. Methods: The sample consisted of 20 professional soccer players from Rio de Janeiro-based teams during the 2020 and 2021 seasons, pre- and post-COVID-19 infection. Match running performance data were collected using a Global positioning system (GPS), and the analysis includes average data across 1 to 17 games pre-infection and 1 to 13 games post-infection per player. Results: COVID-19-infection induced an unclear effect on the total distance traveled during the match [SWC-Factor = -1.9, 90 % CL (-4.7; 0.9)], the number of sprints at speeds over 24 km/h [SWC-Factor = 1.1, 90 % CL (-1.7; 3.9)], maximum speed reached [SWC-Factor = 0.1, 90 % CL (-2.6; 2.9)], the number of decelerations [SWC-Factor = -2.2, 90 % CL (-5.0; 0.6) ], explosive efforts [SWC-Factor = -2.4, 90 % CL (-5.1; 0.4) ], distance traveled at speeds between 0 and 7 km/h [SWC-Factor = 2.4, 90 % CL (-0.4; 5.2) ], and distance traveled at speeds between 7 and 14 km/h [SWC-Factor = -1.8, 90 % CL (-4.5; 1.0) ]. However there was a moderate and significant decrease in distance covered during high-intensity running, defined as speeds greater than 20 km/h [SWC-Factor = -4.2, 90 % CL (-7.0; -1.5) ], the number of accelerations greater than 3 m/s² [SWC-Factor = -3.6, 90 % CL (-6.4; -0.9) ], and distance traveled at speeds between 14 and 20 km/h [SWC-Factor = -3.5, 90 % CL (-6.2; -0.7) ]. The results also showed that COVID-19-infection led to a substantial decrease in minutes played during matches [SWC-Factor = -4.0, 90 % CL (-6.8; -1.3)], affecting the analysis of match variables' absolute values. Conclusion: The results suggest that players infected with COVID-19 experienced changes in match running performance, notably decreases in distance covered during high-intensity running and increases traveled at speeds between 0 and 7 km/h. Further analysis of other player populations (in other leagues) is necessary to verify these findings. Keywords: Coronavirus, Physiology, Task Performance and Analysis, Match running, External Load.