A Methodological Report: Adapting the 505 Change-of-Direction Speed Test Specific to American Football

ABSTRACTThe 505 involves a 10-m sprint past a timing gate, followed by a 180° change-of-direction (COD) performed over 5 m. This methodological report investigated an adapted 505 (A505) designed to be football-specific by changing the distances to 10 and 5 yd. Twenty-five high school football players (6 linemen [LM]; 8 quarterbacks, running backs, and linebackers [QB/RB/LB]; 11 receivers and defensive backs [R/DB]) completed the A505 and 40-yd sprint. The difference between A505 and 0-10 yd time determined the COD deficit for each leg. In a follow-up session, 10 subjects completed the A505 again, while 10 subjects completed the 505. Reliability was analyzed by t-tests to determine between-session differences, typical error (TE), and coefficient of variation (CV). Test usefulness was examined via TE and smallest worthwhile change (SWC) differences. Pearson’s correlations calculated relationships between the A505 and 505, and A505 and COD deficit with the 40-yd sprint. A one-way ANOVA (p < 0.05) derived between-position differences in the A505 and COD deficit. There were no between-session differences for the A505 (p = 0.45-0.76; ICC = 0.84-0.95; TE = 2.03-4.13%). Additionally, the A505 was capable of detecting moderate performance changes (SWC0.5 > TE). The A505 correlated with the 505 and 40-yard sprint (r = 0.58-0.92), suggesting the modified version assessed similar qualities. R/DB were faster than LM in the A505 for both legs, and right-leg COD deficit. QB/RB/LB were faster than LM in the right-leg A505. The A505 is reliable, can detect moderate performance changes, and can discriminate between football position groups.