Does Entry Velocity Matter? Static-Start and Pick-Up Acceleration Sprinting in Female Rugby Union Players

Background and Objectives: Most rugby sprints begin in motion, yet standardized testing uses static starts. This study compared static-start and pick-up acceleration at entry velocities of 1.5 and 3.0 m·s−1 in female rugby union players, examining positional differences and countermovement jump (CMJ) associations. Methods: Thirty-eight senior female rugby union players completed CMJ testing, static-start sprints, and LED-paced pick-up sprints. Linear mixed models compared sprint conditions and playing positions, while correlation and multivariable analyses examined CMJ associations. Results: Pick-up sprint variables showed excellent intra-session reliability (coefficient of variation = 0.63–4.29%; intraclass correlation coefficient = 0.90–1.00). Higher entry velocities reduced split times, mean acceleration and distance to maximal velocity, but not maximal velocity. Backs outperformed forwards across all static-start sprint outcomes, but some early positional differences (5 and 10 m times and 0–5 m acceleration) were non-significant in pick-up trials, despite broadly similar small-to-moderate effect sizes. CMJ-derived variables correlated with all sprint outcomes across conditions (p ≤ 0.046; r/rho = 0.33–0.85) and jointly explained additional variance (ΔR2 = 0.055–0.547; p ≤ 0.027), but none showed significant independent associations (p ≥ 0.140). Conclusions: Pick-up acceleration shortened split times and distance to maximal velocity, with backs generally outperforming forwards. CMJ variables correlated with sprint performance but showed no significant independent associations.