Importance of Strength and Power on Key Performance Indicators in Elite Youth Soccer.

Wing, CE, Turner, AN, and Bishop, CJ. Importance of strength and power on key performance indicators in elite youth soccer. J Strength Cond Res 34(7): 2006-2014, 2020-The purpose of this investigation was to examine the importance of strength and power in relation to key performance indicators (KPIs) within competitive soccer match play. This was achieved through using an experimental approach in which 15 subjects were recruited from a professional soccer club's scholarship squad during the 2013/14 season. Following anthropometric measures, power and strength were assessed across a range of tests which included the squat jump (SJ), countermovement jump (CMJ), 20-m sprint, and arrowhead change of direction test. A predicted 1 repetition maximum (1RM) was also obtained for strength by performing a 3-RM test for both the back squat and bench press, and a total score of athleticism (TSA) was provided by summing Z-scores for all fitness tests together, providing 1 complete score for athleticism. Performance analysis data were collected during 16 matches for the following KPIs: passing, shooting, dribbling, tackling, and heading. Alongside this, data concerning player ball involvements (touches) were recorded. Results showed that there was a significant correlation (p ≤ 0.05) between CMJ (r = 0.80), SJ (r = 0.79), and TSA (r = 0.64) in relation to heading success. Similarly, a significant correlation (p ≤ 0.05) between predicted 1RM squat strength and tackle success (r = 0.61). These data support the notion that strength and power training are important to soccer performance, particularly when players are required to win duels of a physical nature. There were no other relationships found between the fitness data and the KPIs recorded during match play, which may indicate that other aspects of a player's development such as technical skill, cognitive function, and sensory awareness are more important for soccer-specific performance.