The impact of microdosed plyometric training on speed and explosive abilities of football players during the pre-season

Microdosed training distributes a given training stimulus into shorter, more frequent sessions. This study investigated whether a microdosed plyometric program produces similar adaptations to a traditional plyometric program when the total number of plyometric contacts is closely matched in elite youth football players. In this quasi-experimental, two-group study, twenty-four elite U19 players were allocated to a traditional training group (TRG, n = 12, 2 sessions·week⁻¹, ~ 40 min·session⁻¹) or a microdosed group (MDG, n = 12, 3–4 sessions·week⁻¹, ~ 20 min·session⁻¹). Allocation was nonrandomized and matched on countermovement jump (CMJ) height and modified reactive strength index (RSI mod) from a drop jump (DJ), with standing broad jump (SBJ) used as a tiebreaker. Total plyometric contact volume was closely matched over an 8-week intervention. Primary outcomes were 30 m sprint mechanical outputs (1080 Sprint: peak speed, peak force, peak power), DJ RSI mod, and CMJ metrics. Secondary outcomes were the 15–0–5 change of direction (CoD) test outputs (time, acceleration, and deceleration), and SBJ. Within-group pre–post changes were tested using paired t-tests and between-group comparisons using independent t-tests on change scores (α = 0.05). Nonparametric tests were conducted as sensitivity analyses. Effect sizes are reported as absolute Hedges’ g (|g|). Primary outcomes improved in both groups: DJ RSI mod increased by 14.3% (TRG) and 12.5% (MDG), CMJ height by 4.5% and 9.6%, and 30 m sprint peak speed by 2.3% and 2.5% (within-group |g| = 0.02–1.09). Secondary outcomes were mixed across SBJ and 15–0–5 metrics (within-group |g| = 0.00–1.17). Between-group comparisons of change scores showed no evidence of differences (all p > 0.05). With closely matched total plyometric contacts, analyses showed no evidence that short-term adaptations differed between microdosed scheduling and a two-session format in U19 players. Microdosing may allow the same weekly dose to be delivered in shorter, more frequent sessions when scheduling is constrained. ClinicalTrials.gov (NCT07193706). Retrospectively registered on 18 September 2025.