Does the leap-for-distance test correlate with short sprint performance in young soccer players? A between- and within-player analysis

This study analysed the longitudinal relationship between short sprint time and the leapfor-distance test using novel motion tracking in young soccer players. Players (n = 144, age 14.8 1.8 years) from six English Elite Player Performance Plan category three clubs completed two linear sprints (10 m, 20 m) and a leap-for-distance test (cm), on three to seven occasions across three seasons. Within-player (repeated measures) and betweenplayer (mean of the repeated measures) correlation coefficients were calculated and stratified by pre-and post-peak height velocity (PHV). Very large, negative between-player correlations were found for leap-for-distance vs. sprint time (10 m: r = -0.70, 95% CI [-0.77, -0.61]; 20 m: r = -0.77, 95% CI [-0.83, -0.70]). Correlations were large for pre-PHV (10 m: r = -0.52, 95% CI [-0.71, -0.26]; 20 m: r = -0.62, 95% CI [-0.78, -0.39]) and moderate-to-large for post-PHV (10 m: r = -0.43, 95% CI [-0.60, -0.24]; 20 m: r = -0.54, 95% CI [-0.68, -0.36], respectively). Within-player correlations were trivial-to-small for all players (10 m: r = -0.14, 95% CI [-0.24, -0.06]; 20 m: r = -0.24, 95% CI [-0.34, -0.16]) and for pre-and post-PHV subgroups (r's < -0.30). Leap-for-distance is a useful discriminator of sprint performance but should not be used for tracking intra-player sprint changes in young soccer players, irrespective of maturation.