What are the characteristics of professional league referees' running performance in different situations?

This study investigates the characteristics and patterns of referees' running performance under various match situations, using the Chinese Super League (CSL) as a case study.

Running performance data were collected and analyzed using ProZone^® (Leeds, UK) wearable tracking technology based on observations of field referees during the 2019 CSL season. The dataset comprises 30 referees across 240 matches, totaling 22,994 min of match time. Key metrics analyzed sprinting, high-speed running (HSR), fast running (FR), and total distance (TD). Each match was segmented on a minute-by-minute basis according to different situational contexts. Running performance was compared across situational variables, such as referee nationality, match periods (halves, 15 intervals, and any 5-minute intervals), and match situation (scoring status and differences).

No significant differences in running performance were observed between international and Chinese referees, except in FR. The highest levels of running activity were observed during the first half, the initial 15 min of the match, and additional time at the end of each half. During different phases of match progression, referees exhibited the highest running volumes when the match was tied, when the home team was behind, or when there was a significant score difference.

These findings offer valuable insights for designing referees' daily physical training programs. They suggest that referees should actively regulate their running pace during matches in response to dynamic changes in team scores to maintain optimal physical conditions.