Match running activity in very young soccer players

Aim. The aim of this study was to quantify match play intensity distribution in 8-10 years soccer players and to analyze the results in relation to age and physical capacity. Methods. Physical capacity of 12 under-10 (U10) and 15 under-8 (U8) male players was assessed by counter movement jump (CMJ), 20 meter shuttle run (20m-SR) and 10, 20 and 30 meters (10m, 20m and 30m) sprint tests. Shuttle dribble test (SHD) and slalom dribble test (SLD) were also performed to evaluate technical ability. Time motion analyses by global positioning system (GPS 10Hz, K-Sport) were performed during 30 (200 observations) national matches (3 times, 15 minutes each). Distance covered was categorized into 6 intensity zone (standing, walking, jogging, running, high-speed running, sprinting) according to transition from walking to running (1), ratio of the commonly used thresholds for senior (2) and ‘‘flying’’ 10m sprint time (3). Results. U10 vs U8 showed a better shuttle-running performance (1215±77 vs 872±78 m), a lower sprint time on 20m (4.15±0.05 vs 4.38±0.07 sec) and 30m (5.72±0.06 vs 6.31±0.08 sec) and a better technical ability (10.7±0.2 vs 11.8±0.2 and 22.3±0.3 vs 29.4±0.7 sec, in SLD and SHD, respectively). No differences were observed in CMJ (24.4±0.8 vs 23.3±0.9 cm) and 10m (2.45±0.02 vs 2.52±0.04 sec). Match running activity showed an higher total and high-intensity distance covered by U10 (3386±120 and 1369±95 m, respectively) vs U8 (2354±59 and 887±58 m, respectively). Considering only the players (n=16) that performed the entire match, distance covered at high-intensity in the third time was not significantly different from first and second time both for U10 and U8. Finally, a linear relationship (r2=0.62, p<0.01) was observed between high-intensity distance covered and 20m-SR performance in U10 and U8. Conclusions. This is the first study characterizing the running match activity of very young soccer players. If confirmed in a larger population, these data could be used by coaches and support staff as starting point in the design of effective training programs. References. 1) Saibene & Minetti. Biomechanical and physiological aspects of legged locomotion in humans. Eur J Appl Physiol, 2003, 88, 297-316. 2) Bradley et al. High-intensity running in English FA Premier League soccer matches. Journal Sports Sciences, 2009, 27, 159–168. 3) Harley et al. Motion analysis of match-play in elite U12 to U16 age-group soccer players. J Sports Sci, 2010, 28, 1391-1397.