Influence of Relative Pitch Area (RPA) on the Physical Demands Across Late-Stage Age Categories in Elite Academy Soccer

Introduction & Purpose: Small-sided games (SSGs) are widely used in soccer training to recreate the physical, technical and tactical demands of official matches within controlled environments (Morgans et al., 2014). Manipulating pitch size, player numbers, and rules, allows SSGs to develop these demands, especially physical performance (Bujalance-Moreno et al., 2019). The interaction of pitch size and player numbers can be quantified through the relative pitch area (RPA; m2*player-1) (Hill-Haas et al., 2011; Olthof et al., 2019). A larger RPA elicits greater total distance, high-speed running, and sprinting demands (Riboli et al., 2020). However, limited evidence exists on age-related differences in physical demands among late-stage academy players. Therefore, this study investigated age-related differences in physical performance between U18 and U21 elite academy players across SSG formats defined by RPA. Methods: Thirty-seven male elite academy players (U18: n=17; U21: n=20) from one club performed SSGs over 9 weeks. Formats were classified by RPA as small (>125 m2*player-1), medium (125-225 m2*player-1), and large (>225 m2*player-1). Physical performance was measured via 10 Hz GPS with embedded inertial sensors. Outcome measures (per minute) were total distance (TD), high-speed running distance (HSRD; >20 km*h-2), sprinting distance (SD; >25km*h-1), accelerations (>2 m*s-2), and decelerations (>2m*s-2). Two-level mixed-effects models (measurements nested within players) tested effects of age category and SSG format (p