Youth footballers need longer rest periods to prevent injuries and ensure optimal regeneration

Study: Unleashing the performance potential of junior male soccer players: Investigating the effects of maturity, age, and physical workload on neuromuscular injury risk and recovery after competitive play. Image credit: matimix / Shutterstock

For young athletes, two days of rest are not enough, as muscle damage can last up to a week and can lead to a loss of performance and a higher rate of injuries.

In a study recently published in the journal youth, Researchers in Spain and the UK conducted a comprehensive physiological investigation into the relationships between fatigue markers after soccer matches and optimal recovery periods. Their study cohort consisted of 26 male elite academy players (U-14 = 14, U-16 = 12) who were assessed on eight parameters of post-match fatigue, including perceived well-being. Assessments were conducted pre-match (baseline) and 0, 48, 72, 96 and 120 hours post-match.

The results of the study show that landing mechanics was the only fatigue indicator that remained unchanged after a European league competition. Players' performance in all other indicators decreased significantly, ranging from 3.8% to 71.3% of baseline values. While most indicators returned to baseline values ​​after 48 hours of rest, muscle damage markers, namely creatine kinase (CK) and urea (UR), remained elevated until 168 hours, demonstrating that longer rest periods are necessary for muscle recovery. These results highlight the need for individualized recovery strategies for young athletes to optimize performance and reduce injury risk.

background

Young soccer players represent the future of the sport. Their coaches and league decision-makers therefore have a responsibility to ensure that they grow and develop sustainably without bottlenecks caused by overexertion or, worse, chronic injuries. Previous studies have attempted to investigate the perception of fatigue and performance decline in young male players, particularly in relation to force production, countermovement jumps (CMJ), sprint times and changes in physiological biomarkers (e.g. creatine kinase [CK] and urea [UR]). Although previous studies have produced inconclusive results due to insufficient sample sizes and a limited range of measures, they agree on one point: adequate recovery is crucial for sustained performance.

Although the results of these studies are inconclusive (often due to small sample sizes and narrow measurement ranges), most agree that a 48-hour rest period is a minimum requirement for sustained performance during a typical male academy football season (8-9 months). These findings have led policymakers to divide competitive seasons into 2-3 blocks, each containing 10-15 microcycles of training (2-4 sessions) and a match, allowing for up to seven days of post-match rest. However, this does not take into account training sessions between matches. Similar research on young female players suggests that two days of rest may not be enough, highlighting the need for gender-specific recovery guidelines.

About the study

The aim of the present prospective, observational, mixed longitudinal study was to investigate the effects of physical performance and perceived well-being after a soccer match and the time to return to baseline and to assess the influence of chronological age and maturity of the players on these outcomes.

Data for the study were collected from male youth field players (initial sample size 72) in two age groups (under 14 [U-14] and under 16 [U-16). Apriori sample size estimation using Cohen’s criteria revealed a minimum sample size of 12, given the study objectives. Participants with chronic musculoskeletal injuries or neuromuscular diseases, those without sufficient game time (

Data collection included health questionnaires, physical tests, and during-match performance assessments using high-accuracy GPS devices with integrated gyroscope, magnetometer, and accelerometer capabilities. Muscle fatigue biomarkers (UR and CK), performance metrics (CMJ height, reactive strength index [RSI]20m sprint time, leg stiffness [LS]and landing mechanics) and player-reported perceived well-being were assessed using a randomized circle approach to minimize testing bias.

Study results

Of the 72 participants initially enrolled in the study, 26 (U-14 = 14, U-16 = 12) met the inclusion criteria and were included in the analysis. Descriptive statistics showed that U-14 players had an average age of 13.9 years, height of 1.63 m, and weight of 51.0 kg, while U-16 players averaged 15.1 years, height of 1.73 m, and weight of 63.7 kg.

Physical performance results showed that, with the exception of landing technique, all other measures of players' physiological performance declined significantly after playing time (CMJ height = -5.3%, RSI = -9.6%, 20m sprint time = +3.8%, LS = -11.5%). Biomarkers of muscle damage showed even greater declines (CK = +71.3%, UR = +12.8%). Player-reported perceived well-being declined by -7.7%, partially reflecting the measured performance losses. Notably, maturity and age group did not significantly alter any of these outcomes.

Encouragingly, all other measured values, except for muscle damage biomarkers (UR and CK), returned to baseline after 48 hours of complete rest. However, CK and UR required longer periods, highlighting the need for careful management of post-match recovery periods in young players to prevent chronic fatigue and potential injury. Intraplayer assessments across the season showed that players with lower baseline values ​​(who had not recovered sufficiently from their previous match) performed worse and were significantly more prone to injury.

Conclusions

The present study highlights the need for sufficient rest periods (at least two days) between matches and intensive football training sessions in the U-14 and U-16 age groups. The results support structured recovery programs tailored to the individual player profile, especially for players with lower training status or pre-existing fatigue, to improve recovery and performance. Apart from landing mechanics, all eight performance and fatigue metrics assessed showed significant declines after matches, with 48 to 168 hours required for full recovery.

In particular, the cumulative effect of fatigue indicates the risk of higher injury rates and potential long-term physical debilitation if not properly managed. Coaches and league officials are urged to incorporate these findings into training and competition planning.