Evidence that the relationship between perceived exertion and total effort decreases over the course of a U-17 football tournament

The objective of the study was to evaluate the relationship between perceived effort and external load markers in the opening match evaluated in sequential matches within a youth soccer international tournament. Data were obtained from a total of 6 games of the FIFA® under-17 World Cup 2019 and were analyzed in each period and the full match time (entire match). Physical activity profiles were obtained using GPS units. The match activities were divided into the following categories: total load (TL), total distance covered (TDC), number of accelerations (Acc) and decelerations (Dec), distance covered at high-speed (HSR), and distance covered sprinting (Sprint). The rating of perceived exertion (RPE) was obtained after every match. The TL observed in the first period and the entire match was higher compared to the average of the other matches. However, the RPE in the first match was lower when compared to the average of the other matches. Consequently, TL/RPE ratio was higher in the first match compared to the average for the other matches. The TDC, the HSR and the Sprint were higher in the first half and the entire match in the first match compared to the average of the following matches. The data found in the present study indicate that the first match may present higher mental and psychological stress relative to the physical strain compared to the ongoing matches during the tournament and may be an important information for coaches during short-term international tournaments.