The influence of contextual factors on the physical demands of soccer match-play

This observational longitudinal study examined the impact of six contextual on the match demands of professional soccer players using Principal Component Analysis (PCA). Data were collected from 17 male players across 37 official matches (September 2023–May 2024) of a Tier 3 Spanish team, utilizing 10 Hz GPS units. PCA, combined with hierarchical cluster analysis, effectively reduced the 17 initial external load metrics to eight representative variables, optimizing relevant information and minimizing redundancy inherent in performance monitoring systems. Six contextual factors (match outcome, location, player position, goal difference, halftime score evolution, and competitive block) were analyzed for their influence using ANOVA. Results indicated that player position was the most influential variable (p ≤ 0.001, large effect sizes), significantly affecting all external load metrics, with distinct profiles for forwards, midfielders, and defenders. Specifically, forwards excelled in high-intensity actions; midfielders recorded higher values in medium-intensity distances and decelerations, while defenders consistently exhibited the lowest overall physical demands. Match location significantly influenced high-intensity distance and decelerations (higher at home, small effect sizes). The competitive block showed a significant effect only on low-intensity distance, peaking during intermediate periods, suggesting that effective load management strategies mitigated fluctuations in high-intensity activity. Conversely, match outcome, goal difference, and score difference evolution had no significant effects on most physical demands. This study confirms player position as the predominant contextual factor and highlights the utility of PCA in refining load monitoring. Practical applications include individualized training regimens tailored to positional demands and optimized monitoring strategies for efficient performance analysis.