Analysis of movement demands, high-intensity running and temporary fatigue during elite youth soccer match play

Soccer is an intermittent team sport with a wide range of movement demands. These movement demands include unpredictable changes in intensities that are a crucial component of soccer performance (Di Salvo et al., 2008, International Journal of Sports Medicine, 30, 205–212). Understanding the demands of these periods may enable practitioners to develop more effective and valid training programmes. The primary aim of the present study was to examine match demands of competitive elite-level youth football in Scotland with particular reference to the most intense 5 min periods as evidenced by high-intensity running. In addition, the secondary aim of this study was to evaluate whether temporary fatigue is evident during elite youth soccer matches. Locomotive movement intensities were classified as: standing (<0.7 km · h−1; <0.2 m · s−1); walking(0.7–6.9 km · h−1; 2.0–3.9 m · s−1); jogging (7.0–14.2 km · h−1; 2.0–3.9 m · s−1); running (14.4–19.7 km · h−1; 4.0–5.4 m · s−1); high-speed running (HSR; 19.8–25.2 km · h−1; 5.5–6.9 m · s−1); sprinting (≥25.2 km· h−1; ≥7 m · s−1). Following ethical approval, player movement data were collected from eight elite youth soccer players competing in the Scottish Professional Football League (SPFL) Under 20s league. Five competitive matches (45 individual files) were collected using a 10-Hz Global Positioning System(GPS) (Sprint, Catapult Innovations, Australia). A rolling 5-min time interval was used to identify the most intense periods of the game as suggested by Varley et al. (2012, International Journal of Sports Physiology and Performance, 7, 183–185). Peak periods of high-intensity Journal of Sports Sciences, 201 running were identified by the highest distance covered above 14.4; 4.0 m · s−1 within a 5-min period. In addition the post peak high-intensity running values were taken from the sequential 5 min immediately post the identified peak 5-min period. Average match values were also calculated for all locomotive movement intensities. All data were analysed using Statistical Package for the Social Sciences (SPSS for Windows, version 19.0, SPP Inc., Chicago, IL). Separate one-way ANOVA with Turkey’s honest significant difference (HSD) post hoc tests were used to identify differences between playing positions for movement intensities. Paired sample t-tests were used to determine differences in high-intensity locomotive rates between peak 5-min periods, subsequent 5-min periods and match averages. Analysis showed no significant difference between playing positions and movement intensities during peak 5-min periods and high-intensity running. Similarly no difference was observed in distance covered at intensities below 14.4 km· h−1 (standing, walking and jogging) between peak 5-min periods, subsequent 5-min periods and match averages. Players covered significantly more distance at high intensity (running, high-speed running and sprinting) in the peak 5-min periods than subsequent 5-min periods and match averages (P ≤0.001). Furthermore players covered significantly less distance at high intensities during post peak 5 min when compared with match averages (P ≤ 0.001). These results suggest that players perform significantly more high-intensity running in peak periods of match play than match averages. Furthermore, significant reduction in high-intensity running is observed in subsequent 5-min periods post peak, and this reduction is significantly lower than the match average, showing players cannot maintain high-intensity running locomotive rates for sustained periods of time. The current findings provide a detailed description of movement demands placed on elite youth soccer players. Having objective data to quantify peak periods of high intensity and subsequent recovery may prove useful when informing training prescriptions to adequately prepare players for the most intense periods of competitive match play.