Can Standardized Small-Sided Games Be Used as a Tool to Monitor Post-Match Fatigue in Male Academy Soccer Players?

This study aimed to analyze residual post-match fatigue using time-motion analysis across small-sided games (SSGs), fitness performance, and heart rate variability (HRV) in academy soccer players. Fifteen male academy players (18.3 ± 0.6 years) performed four SSG formats: 3 vs. 3 and 3 vs. 3 + 2 goalkeepers, played on small (25 × 18 m; 75 m2 per player) and large (36 × 25 m; 150 m2 per player) areas in a four-week experimental design. Two non-match weeks served as baseline weeks, and two weeks followed an official match. Time-motion during SSGs was monitored via GNSS. Before each training session (24, 72, and 120 h post-match), HRV, countermovement jump (CMJ) height, and maximum isometric force (MIF) of the hamstrings were measured. External load metrics were generally lower in post-match sessions than in non-match weeks; however, their low reliability limited the interpretability of SSG outputs. CMJ height was reduced, MIF was elevated post-match, whereas HRV showed distinct mid-week responses, decreasing in starters but increasing in non-starters. Post-match fatigue was evident in neuromuscular performance but was inconsistently reflected in SSG outputs. CMJ height reliably reflects post-match fatigue in male academy soccer players and should be prioritized when monitoring neuromuscular recovery.