Association of Physical Capacities with Peak Match Intensities and Match-to-Match Variability: An Exploratory Study in Young Male Football Players.

This study aimed to (i) describe the peak match intensities of youth football matches, (ii) quantify the variability of these peak intensities to provide references for monitoring players, and (iii) explore the association between physical capacities and peak match intensities. Match-running intensities were tracked for 32 young male footballers (age, 14.1 ± 0.8 y; height, 162.8 ± 8.3 cm; and 50.4 ± 9.6 kg) from three teams across 12 competitive matches. Peak match intensities were determined using a moving average technique, applied to total distance, high-speed distance (>14.4 km·h-1), average acceleration, and PlayerLoad™. The power-law relationships were constructed to derive an intercept and slope for the match variables, and linear mixed models were used to assess the association with physical capacities and estimate the between-player, between-match, and within-player variability. No clear associations were observed between any physical capacity and the intercepts or slopes derived from match-running intensities, with wide confidence intervals overlapping trivial effects. The coefficient of variation for peak match intensities was 7.1-20.9% (between-player), 4.4-10.3% (between-match), and 6.5-21.8% (within-player). The lack of a clear association between physical capacities and peak match intensities suggests that firm conclusions cannot be drawn from these findings. The reported peak intensities and match variability may aid performance practitioners to prescribe match-specific conditioning and monitor training drills but are specific to this cohort and competitive standard.