Effects of pitch configuration on internal and external load during small-sided games with stop-ball rule in young soccer players

Purpose Small-sided games (SSGs) are currently one of the most common drills used and have been progressively growing in youth soccer. The aim of this study was to investigate the effects of different pitch sizes for SSGs-stop ball (SB) on external and internal load in young soccer players. Methods Ten young soccer players (13.8 ± 0.42 years; 168.8 ± 6.21 cm; 55 ± 7.07 kg) performed 4 vs 4 SSGs-SB (4 × 3 min, 2 min recovery) on 20 × 25 m and 30 × 38 m fields. Distance covered (DC) in jogging 3–8 km/h, distance covered at moderatespeed running 8–13 km/h, at high-speed running 13–18 km/h, at sprint running > 18 km/h, peak speed (PS), sprint number (SN), maximal acceleration (MA), maximal deceleration (MD), distance in acceleration > 2.5 m/s2 (ACC) and deceleration < –2.5 m/s2 (DEC), high metabolic load distance (HMLD, 35–50 W/kg; > 50 W/kg) and rate of perceived exertion (RPE) (CR-10) were measured. Results Large SSGs-SB produced higher values than smaller pitches for PS (<i>p</i> < 0.001, lines 14–19: ES: 1.62), SN (<i>p</i> < 0.001, ES: 1.64), MD (<i>p</i> < 0.05, ES: 1.24), DC at moderate-speed running 8–13 km/h (p < 0.05, ES: 0.95), high-speed running 13–18 km/h, (p < 0.05, ES: 1.10), sprint running > 1 8 km/h (<i>p</i> < 0.05, ES: 1.02), HMLD (35–50 W/kg, <i>p</i> < 0.05, ES: 0.92; > 50 W/kg, <i>p</i> < 0.001, ES: 1.40). Small SSGs-SB displayed higher values than larger pitches for MA (<i>p</i> < 0.001, ES: 1.52), DC in jogging 3–8 km/h (<i>p</i> < 0.001, ES: 2.01), both for distance in ACC and in DEC (<i>p</i> < 0.001, ES: 1.77; <i>p</i> < 0.05, ES: 1.30, respectively). Conclusions Large SSGs-SB elicited a significant increase in external and internal load, while lower dimensions affected MA, DC in jogging 3–8 km/h, in ACC and in DEC. Finally, practitioners should take this information into account in order to properly schedule training sessions.