In-game monitoring of adolescent handball players: a preliminary examination of associations between external load parameters and objective and subjective fatigue markers

Background Advances in local positioning systems (LPS) have enabled detailed monitoring of external load in handball. However, the relationship between external load and internal fatigue under real match conditions remains insufficiently understood, particularly in adolescent players. This study examined associations between external load parameters and both objective and subjective fatigue markers during an official match and evaluated agreement between players ‘ratings of perceived exertion (RPE) and coaches’ ratings of observed exertion (ROE). Methods Highly trained adolescent male handball players ( n = 11; 8 complete cases; age: 16.1 ± 0.4 years) were monitored during a Bundesliga-level youth match. External load measures included playing time, total distance covered, accelerations, decelerations, fast running, and metabolic power recorded via the Kinexon LPS. Objective fatigue was assessed using the leg recovery test (LRT), while subjective measures included the Perceived Recovery Status Scale (PRSS), RPE, and ROE. Assessments were conducted pre-game (T 0 ), half-time (T 1 ), and post-game (T 2 ). Results Subjective fatigue measures changed markedly across the match. RPE increased (T 0 : 8.0 ± 2.45; T 1 : 14.6 ± 2.20; T 2 : 16.1 ± 2.85), while PRSS decreased (T 0 : 8.25 ± 1.91; T 1 : 6.12 ± 1.89; T 2 : 4.75 ± 2.43). PRSS and RPE showed moderate-to-strong associations with both volume- and intensity-based external load measures after each half. In contrast, LRT scores remained largely unchanged and showed minimal associations. Agreement between RPE and ROE improved over the match (correlations: T 1 = 0.58/0.43; T 2 = 0.68/0.60). Conclusion Subjective fatigue measures, particularly RPE, were more sensitive than objective neuromuscular testing for detecting match-related fatigue in adolescent handball players. Coaches’ ratings aligned increasingly with players’ perceptions, highlighting the practical value of subjective monitoring for in-game load management.