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

## TL;DR

This study explores how external load parameters relate to fatigue in adolescent handball players during real matches.

## Contribution

It introduces a preliminary analysis linking external load with both objective and subjective fatigue measures in youth handball.

## Key findings

- Subjective fatigue measures like RPE increased significantly during the match.
- PRSS and RPE showed strong associations with external load parameters.
- Coaches' ratings aligned more with players' perceptions as the match progressed.

## Abstract

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).

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 (T0), half-time (T1), and post-game (T2).

Subjective fatigue measures changed markedly across the match. RPE increased (T0: 8.0 ± 2.45; T1: 14.6 ± 2.20; T2: 16.1 ± 2.85), while PRSS decreased (T0: 8.25 ± 1.91; T1: 6.12 ± 1.89; T2: 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: T1 = 0.58/0.43; T2 = 0.68/0.60).

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.