Session-Level Fluctuations in Barbell Velocity Under Standardized Loading Conditions: Contextual Monitoring Perspectives in Elite Track-and-Field Athletes

This study examined whether barbell velocity measured under standardized loading conditions during routine resistance training may provide useful contextual information for athlete monitoring in elite track-and-field athletes. Although velocity-based training has been widely used for load prescription, its utility as contextual monitoring information under fixed external loads remains unclear. Eight national-level jump and throw athletes were observed over a six-week in-season period. Mean concentric velocity (MCV) was recorded during back squat exercises performed at a consistent external load (~60% 1RM) across 95 regularly scheduled training sessions. The overall mean MCV was 0.783 ± 0.057 m·s−1 (range: 0.68–0.89 m·s−1). Within-athlete session-to-session fluctuations ranged from 6.13% to 11.20%, exceeding both the coefficient of variation (2.06–3.80%) and the pooled typical error of measurement (0.019 m·s−1), suggesting that the observed variability was unlikely to be explained solely by measurement noise. Distinct individual velocity trajectories were observed under fixed individualized loading conditions, reflecting notable intra- and inter-individual variability within an ecologically valid training environment. These findings suggest that barbell velocity may provide contextual information regarding session-to-session fluctuations relevant to athlete monitoring under standardized loading conditions. Collectively, the findings suggest that barbell velocity measured under standardized loading conditions may provide contextual information regarding day-to-day variability during routine elite training.