Physical and technical performance in and after the worst-case scenario in matches of the Chinese Super League of soccer.

This study aims to investigate the changes in physical and technical performance of professional soccer players during effective playing time after the worst-case scenario (WCS) identified by the high-intensity running (HIR) distance using rolling average. A total of 576 matches (n = 13,298 observations) from the 2019 to 2021 season of the Chinese Super League (CSL) were analyzed by a video tracking system. Generalized mixed linear models were established to determine the mean changes in the value of 7 physical and 24 technical performance-related parameters in the effective playing time from the 5 min of WCS (Peak5) to the initial 5 minutes post-WCS (Post5). Results showed that: (1) For all the players in the Post5 total distance, HIR distance, and Sprint decreased by 16.6% (ES; ± 99%CL: 0.57; ± 0.04), 77.2% (2.78; ± 0.06), and 86.1% (2.11; ± 0.08), respectively. The number of efforts, average duration, average speed, and average length of HIR declined by 70.8% (2.26; ± 0.06), 31.7% (0.78; ± 0.05), 3.1% (0.52; ± 0.05), and 22.9% (0.83; ± 0.05), respectively; (2) In the Post5, a substantial decrement in the number (0.23; ± 0.03), average speed (0.32; ± 0.06) and average length (0.37; ± 0.06) of running with the ball, and average speed receiving the ball (0.5; ± 0.05) was observed for all players. While only trivial changes were detected in all the other technical performance-related parameters. It can be concluded that, in the Post5, there is a temporary decline in physical output and the physical-related technical parameters for players, however, there are no meaningful changes in other technical performancerelated parameters.