Physical Determinants of Velocity and Agility in High School Football Players: Differences Between Position Groups

PURPOSE: The purpose of this study was to develop prediction equations for speed and agility within different position groupings of High School football players using age, height, body mass, and vertical jump as predictor variables. METHODS: A total of 987 athletes (14-18y) completed testing at a regional high school football combine. Athletes were divided into three groups according to their playing position: Linemen (LM; n = 354; 16.3 ± 0.8y; 179.4 ± 5.6cm; 105.1 ± 18.3kg), Big Skill Players (BSP; n = 189; 16.2 ± 0.9y; 175.5cm ± 5.2cm; 85.7 ± 11.6kg), and Skill Players (SP; n = 444; 16.4 ± 09y; 175.8 ± 5.9cm; 75.5 ± 8.9kg). The LM included offensive tackles, offensive guards, centers, defensive tackles, and defensive ends. BSP included linebackers, running backs, and tight ends. SP included wide receivers, corner backs, safeties, and quarterbacks. In sequential order, height (HT), body mass (BM), 40 yard sprint (40Y), 5-10-5 shuttle (SH), and countermovement vertical jump height (VJ) were determined on each player. HT and BM were measured using a stadiometer and an electronic scale, respectively. 40Y and SH were measured using hand-held stop watches; the highest of two trials was used for analysis. Two vertical jumps were completed on an electronic pressure mat; vertical jump height was calculated using flight time. For each position grouping, correlations (Pearson's r) were calculated between the four predictor variables (Age, HT, BM, and VJ) and 40Y and SH performance. Combined multivariate models were derived using backward elimination; p < 0.05 was set as the criterion for inclusion. Non-significant variables were eliminated from the final model. RESULTS: Final multivariate models are provided in Table 1. Within LM, 40Y was significantly correlated to AGE (r = -0.22), BM (r = 0.60), and VJ (r = -0.84); SH was correlated to AGE (r = -0.22), BM (r = 0.46), and VJ (r = -0.67). Within the BSP group, 40Y was significantly correlated to AGE (r = -0.20), BM (r = 0.30), and VJ (r = -0.77); SH was correlated to AGE (r = -0.27) and VJ (r = -0.47). Within the SP group, 40Y was significantly correlated to AGE (r = -0.31) and VJ (r = -0.61); SH was correlated with AGE (r = -0.26) and VJ (r = -0.37). CONCLUSIONS: These data suggest that VJ and Age are a strong predictor of 40y and SH regardless of position. BM is a strong indicator of speed within the LM, but is less important to other positions. The combined regression models are more accurate for 40Y than SH ind