Training load, fatigue and post-match recovery in Italian Serie A youth soccer players

Franceschi, A ORCID: 0000-0002-9830-5640 (2026) Training load, fatigue and post-match recovery in Italian Serie A youth soccer players. Doctoral thesis, Liverpool John Moores University.

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Abstract

Monitoring training load and its responses is a fundamental component of the training process. For sports scientists and coaches working with adolescent soccer players, a key challenge lies in balancing training stress with adequate recovery to promote performance and development, while minimising maladaptation and injury risk. The aim of this thesis was to investigate the training load, acute fatigue and post-match recovery responses in Italian Serie A youth soccer players.
Study 1 (Chapter 3) quantified external and internal load across a competitive season in 90 high-level youth players (under-19, under-17, under-16, under-15). External load was measured via duration and global navigation satellite systems (GNSS), while internal load was assessed using heart rate (HR) and rating of perceived exertion (RPE). Under-19 and under-17 players exhibited higher training frequency, greater weekly accumulated external and sRPE-training load (sRPE-TL), and more pronounced daily load fluctuations across the microcycle compared to their younger counterparts (p < 0.05). In contrast, weekly accumulated HR internal loads were higher in under-15 players (p < 0.05). Match day (MD) session imposed the highest load across the microcycle (p < 0.05). These findings highlight the importance of monitoring the training process using a combination of external and internal load measures.
Study 2 (Chapter 4) determined the reliability and sensitivity to change of physical performance tests used for assessing post-match fatigue and recovery. Eighteen high-level youth players completed the isometric posterior chain (IPC) and the countermovement jump (CMJ) tests across four testing sessions. IPC and CMJ measures demonstrated acceptable levels of absolute reliability with coefficients of variation (CVs), ranging from 1.5 to 8.8%, and moderate to excellent levels of relative reliability, with intraclass correlation coefficients (ICCs), from 0.70 to 0.98. IPC peak force and torque, CMJ reactive strength index (RSI) modified, CMJ eccentric forces (mean breaking force, mean deceleration force, peak force, force at zero velocity) and CMJ mean power measures had post-match changes greater than their typical error (TE), demonstrating acceptable sensitivity in detecting performance changes at post-match. These measures may be more suitable for monitoring acute changes in physical performance at post-match.
Study 3 (Chapter 5) described the time course of recovery post-match and examined the effects of manipulating training volume 48 h following match-play. Forty-eight high-level youth players were assessed using physical performance tests (IPC and CMJ) and perceptual measures (muscle soreness and fatigue via visual analogue scales (VAS)) before (pre) and after (0.5 h post, 48 h post, 72 h post) an 80-minute match. At 48 h post-match, players were randomly assigned to a complete training (CT; n = 26) or a reduced training (RT; n = 22) group. Acute fatigue was evident with significant impairments at 0.5 h post-match (p < 0.05). At 48 h post-match, CMJ and perceptual fatigue returned to baseline (p > 0.05), whereas IPC and perception of muscle soreness were not fully recovered (p < 0.05), highlighting variations in recovery responses. CT players experienced higher training loads on MD+2 compared to RT (p < 0.05). A significant time x group interaction was observed for CMJ and IPC measures (p < 0.05), with reductions in physical performance observed in the CT group from 48 h to 72 h post-match (p < 0.05). A high-intensity training session administered on MD+2 may negatively influence performance recovery, whilst a moderate-intensity session may support the recovery process without further impairment of performance.
Study 4 (Chapter 6) characterised the acute fatigue responses to a typical training session combining physical performance, metabolic and perceptual measures in 13 high-level youth players. Pre- and post-training assessments included physical performance tests (IPC and CMJ), metabolomics analysis (via capillary blood sample) and perceptual measures (muscle soreness and fatigue via VAS). Physical performance and perceptual measures showed no changes post-training (p > 0.05), except for significant reductions in CMJ force at zero velocity, eccentric and concentric peak force (p < 0.05). Metabolomics revealed significant post-training alterations in 21 metabolites (p < 0.05), including increased metabolite concentrations related to carbohydrate, amino acid and lipid metabolisms. Although a moderate-intensity training session elicited minimal acute changes in physical performance and perceptual fatigue measures, it induced significant perturbations in the serum metabolome, particularly in energy metabolism pathways.
In summary, this thesis provides novel insights into training load, acute responses to training and match-play, and post-match recovery profiles of Italian Serie A youth soccer players. These findings offer practical recommendations for sport scientists and coaches seeking to optimise physical performance monitoring and refine training and recovery strategies in high-level adolescent soccer players.

Item Type:	Thesis (Doctoral)
Uncontrolled Keywords:	Performance; Training; Fatigue; Recovery; Football
Subjects:	Q Science > QP Physiology R Medicine > RC Internal medicine > RC1200 Sports Medicine
Divisions:	Sport and Exercise Sciences
Date of acceptance:	18 December 2025
Date of first compliant Open Access:	22 December 2025
Date Deposited:	22 Dec 2025 14:59
Last Modified:	22 Dec 2025 15:00
DOI or ID number:	10.24377/LJMU.t.00027752
Supervisors:	Enright, K, Robinson, M, Owens, D and Brownlee, T
URI:	https://researchonline.ljmu.ac.uk/id/eprint/27752

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