High-intensity activity profile in elite youth soccer match-play

![CDATA[Work-rate data from time-motion analyses has suggested that fatigue in soccer match-play is observed during the initial stages of the second half and in the latter stages of the game. However, there is no descriptive data available for youth players, especially at youth team age (U18). 13 youth team players (Age: 16–18 years) representing an English League One Club wore 5 Hz GPS (MinimaxX, Catapult, Australia) units in 10 competitive league games during the 2008/2009 season. Cases (n = 51) selected for analysis were taken from players who completed the 90 min duration of the fixture in the same tactical position. The locomotor activities were categorised as high-intensity running (HIR; 14.0–35.0 km/h), very high-intensity running (VHIR: 19.0–35.0 km/h) and sprinting (25.0–35.0 km/h). The players covered 8830±816 m during the game (range: 6972–11597 m), of which 18% (1575±416 m) was covered at HIR and 9% above the VHIR threshold (794±282 m), and 1.4% of the distance was covered sprinting (125±76 m). The total distance covered during the second half was 18% lower than the first half, with similar decrements in HIR (20%), VHIR (20%) and sprinting (24%). The first 15 min period accounted after half time showed a reduced performance compared the corresponding stage of the 1st half in HIR (0–15: 284±100 vs 45–60: 231±106 m; p = 0.001), VHIR (0–15: 155±79 vs 45–60: 116±73 m; p<0.001), and sprinting (0–15: 28±32 vs 45–60: 16±17 m; p<0.01): with this period accounting for 62, 75 and 100% of the total 2nd half decrement, respectively. The total distance covered during youth team match-play is lower than that typically observed in professional players; however youth players performed similar proportions of high intensity work to that reported in previous studies. While a second-half reduction in high-intensity parameters was observed, this decrement was mostly denoted in the initial period after the half-time. This contrasts to previous investigations in which fatigue was manifested in the final 15 min, and our data suggest that half-time intervention strategies are warranted.]]