Variations in high-intensity running and fatigue during semi-professional soccer matches

The aim of the study was to determine the fatigue rates and pacing strategies of players during matches by quantifying high-intensity running (HIR) in rolling 5-min periods. Ten semi-professional players were monitored with 10Hz global positioning system (GPS) units during 12 official A-league matches. Match data was categorised into total distance covered and HIR (>3.7 m/min) for rolling 5-min intervals. Distance covered in the first half were used to classify players into low- (LAG), moderate- (MAG) and high-activity groups (HAG). The MAG showed a moderate difference in HIR at 5-min after the peak period. The HAG showed moderate to large declines in distance covered between the first 15 min of the second half (103.9 m/min). They also showed small to moderate declines in HIR during the first 10 min of the second half (25.7 m/min). The LAG showed a small to moderate increase in distance covered during the last 10 min of the second half (95.7 m/min) compared to the first half (84.4 m/min). First-half activity profiles had a significant impact on recovery after the most intense 5-min periods. Also, our study showed an end-spurt occurring towards the end of a match supporting the possibility of pacing strategies.