Effects of Integrative Neuromuscular Training on Physical Performance in Adolescent Soccer Players: A Systematic Review

BackgroundThe highest incidence of injury is seen in adolescent playing pivoting sports such as soccer, basketball, and handball.Objective: To examine the effectiveness of a neuromuscular prevention program in reducing knee...

Change of direction (COD) maneuvers are frequently performed during soccer games and are critical for performance. Adolescent players often display immature COD maneuvers, suggesting that COD technique modification training may be a more effective approach for adolescent athletes. This study investigated the acute effects of COD modification training on COD performance and kinematics in male adolescent soccer players. Twenty-nine male junior high school soccer players participated in this study and were divided into two groups: 16 players underwent 15-min COD technique modification training (COD group), while 13 players engaged in 15-min linear sprint training. The participants performed Pro-Agility and 20-m sprint tests before and after the intervention, and the total times were measured. COD deficit (CODD) was calculated as the difference between these times. Center of mass (COM) velocity and trunk and lower limb kinematics were computed from three-dimensional kinematic data collected during the Pro-Agility test using a markerless motion capture system. Each section of the Pro-Agility test was divided into acceleration and deceleration phases based on the COM velocity; Stop marks the moment of direction change. Two-way (group and time) mixed ANOVA was conducted with Bonferroni corrections for post-hoc comparisons. No significant interactions were observed in the total time of the Pro-Agility test, CODD, 20-m sprint time, or average acceleration and deceleration in each phase (p > 0.05). On the other hand, the COD group showed significant interactions and improvements in average deceleration from final foot (FF) contact to Stop (p = 0.012, g = 0.639), penultimate foot hip flexion angle at Stop (p = 0.042, g = 0.496), COM-FF horizontal distance at Stop (p = 0.008, g = 0.650), and FF ground contact time (p < 0.001, g = 0.803). A 15-min COD technique modification training led to partial, immediate improvements in kinematic parameters among adolescent soccer players but did not enhance overall COD performance or acceleration/deceleration ability.

Background. Functional Movement Strength Training (FMST) integrates functional, strength, and plyometric exercises to enhance neuromuscular coordination and movement performance. Although these training modalities have been investigated individually in soccer, their combined effects on core muscle activation and trunk kinematics during jumping heading in adolescent players remain unclear. Objectives. This study aimed to examine the effects of an eight-week FMST program on core muscle activation and trunk kinematics during jumping heading in adolescent male soccer players. Materials and Methods. A quasi-experimental pretest–posttest design with a control group was employed. Thirty adolescent soccer players were allocated into an Experimental Group (EG; n = 16), which completed an eight-week FMST program (three sessions per week), and a Control Group (CG; n = 14), which continued regular training. Muscle activity was assessed using surface electromyography, and kinematic variables of the neck, trunk, hip, knee, and ankle were analyzed during the preparation, take-off, and ball-contact phases of jumping heading. Data were analyzed using Linear Mixed Model analysis. Results. A significant Group × Time interaction was observed for rectus abdominis (RA) activation (p &lt; 0.05), with greater increases in the EG compared to the CG. Furthermore, significant interactions were also found for hip angle during the preparation phase, and for neck angle and trunk tilt during the take-off phase (p &lt; 0.05). No significant differences were identified during the ball-contact phase. Conclusions. Using FMST was associated with increased RA activation and phase-specific modifications in trunk-related kinematics during jumping heading. These findings suggest that integrated training approaches may enhance trunk control and neuromuscular coordination in adolescent soccer players.

One of the common injuries in soccer is hamstring strain, so improving hamstring flexibility can partially prevent the occurrence of these injuries. The aim of the present study was to compare the effects of six weeks of static stretching (SS), proprioceptive neuromuscular facilitation (PNF), muscle energy technique (MET), gross tonic technique (GT), and foam rolling (FR) on hamstring flexibility in adolescent male soccer players. Ninety male soccer players (mean aged = 13.01 ± 1.11 years) were randomly assigned to five intervention groups and a control group (n = 15 each), underwent a 6-week intervention, with flexibility assessed pre- and post-intervention using a universal goniometer and the active knee extension test. One-way ANCOVA, controlling for pretest values, showed a significant difference between groups (F(5, 83) = 22.79, p < 0.001, η² = 0.57). All intervention groups showed significant improvement compared to control (p < 0.001). The GT group was superior to MET (p = 0.01; Cohen’s d = − 1.23), PNF (p = 0.004; Cohen’s d = − 1.40), and FR (p = 0.02; Cohen’s d = − 1.19), but no difference was observed with SS (p > 0.05; Cohen’s d = − 0.75). All methods improved hamstring flexibility, but GT was the most effective (except when compared with SS). These findings suggest the potential use of GT in training programs to reduce injury and improve performance in adolescent soccer players. However, since the study included only adolescent male players and no long-term follow-up was performed, generalizability is limited. Registry: Iranian Registry of Clinical Trials; registration number: IRCT20240306061185N2; date of registration: 08/03/2024.

This pilot study investigated the effects of a two-week integrative neuromuscular training (INT) program on dynamic balance in male high school soccer players in Shandong, China. Twenty participants were randomly assigned to an experimental group (EG, n = 10) performing INT - combining strength, balance, agility, and coordination exercises, or a control group (CG, n = 10) following conventional soccer training. Dynamic balance was assessed pre- and post-intervention using the Y-Balance Test (YBT). Generalized Estimating Equations (GEE) were used to analyze group, time, and interaction effects. Both groups showed significant improvements in YBT composite scores over time (p &amp;lt; 0.05), but the EG demonstrated greater enhancement, particularly in the posteromedial direction (p = 0.04). These findings suggest that short-term INT can effectively improve neuromuscular coordination and dynamic postural control in adolescent soccer players. Incorporating INT into regular soccer training may enhance performance and help prevent injuries.

Plyometric exercise is a major tool for improving explosive actions. This study aimed to compare the efficacy of a vertical and horizontal plyometric training program on stretch-shortening performance variables in adolescent soccer players. Thirty-two male soccer players (aged 12.09 ± 0.89 years, with soccer experience 5.37 ± 1.58 years) were divided into horizontal plyometric, vertical plyometric, or control groups. The horizontal and vertical plyometric groups participated in a 6-week training program that was performed twice per week, with a 48-h interval, in conjunction with regular soccer training. The control group participated only in regular soccer training. Vertical jump height, reactive strength index, leg stiffness, ground contact time, standing long jump distance, agility, and 10 and 20 m sprint performances were tested as stretch-shortening performance variables of the participants. Stretch-shortening performance variables were assessed before and after completion of the training program. The results showed that either horizontal or vertical plyometric training had no effect on VJH, RSI, GCT, or Kleg performance (F = 2.14, 1.32, 0.66, 1.03; p > 0.05). Furthermore, there was no effect on SLJ, 10 m sprint, 20 m sprint, or agility performance (F = 2.06, 0.14, 0.06, 0.27; p > 0.05). A 6-week horizontal or vertical plyometric intervention was found to be insufficient to elicit stretch-shortening performance enhancement in adolescent male soccer players. Although there was no performance change in any group, it was observed that the players enjoyed plyometric training. Therefore, coaches could safely use plyometric exercises to design enjoyable training programs.

Background and aimAlthough many adolescent athletes experience mild or no symptoms following SARS-CoV-2 infection, the potential mid-term effects on physical performance have not been fully characterized. COVID-19 has been associated with alterations in physiological systems related to strength, speed, and aerobic capacity, which may persist after return to sports activity. Furthermore, limited information is available on postinfection recovery trajectories in adolescent athletes, and return-to-play recommendations for this population often rely on data derived from adults. The aim of this study was to evaluate the impact of SARS-CoV-2 infection on physical performance and the recovery trajectory over three months in adolescent male soccer players in Romania.MethodsA retrospective analysis was conducted on 120 male soccer players aged 12-16 years, equally divided into COVID-19 and non-COVID-19 groups. The COVID-19 group included athletes with confirmed SARS-CoV-2 infection by RT-PCR or rapid antigen testing, while the non-COVID-19 group consisted of athletes with no history of infection, confirmed by negative IgM/IgG serology. Participants underwent weekly fitness tests, including handgrip strength, 10 m and 30 m sprints, bench press, and beep test. For the COVID-19 group, results were analyzed at three time points: one month before infection, one month after infection, and three months postinfection. The Friedman test with Bonferroni correction was applied to assess intragroup changes over time, and differences between the two groups were analyzed using the Mann-Whitney U test. Effect sizes were calculated using Cliff’s delta (δ) for nonparametric comparisons.ResultsAll performance metrics showed significant deterioration one month postinfection (p < 0.001). Partial or full recovery was observed at three months. While bench press and 10 m sprint performance returned to baseline levels, handgrip strength, 30 m sprint, and beep test scores remained significantly lower than pre-COVID values. In contrast, the non-COVID-19 group showed stable performance and better results across all time points.ConclusionsSARS-CoV-2 infection was associated with significant, but predominantly transient, impairments in strength, speed, and aerobic capacity in adolescent soccer players. Although most performance parameters showed partial or complete recovery at three months postinfection, persistent deficits were observed in grip strength and cardiovascular endurance. These results suggest that the neuromuscular and aerobic systems may require longer recovery periods in adolescents compared with other components of performance. Structured functional monitoring and individualized return-to-play protocols are essential to ensure a safe and effective return to sport activity after COVID-19.

This study aimed to assess the anthropometric characteristics, nutrient intake levels, nutritional status of elite adolescent soccer players, and the dietary quality of athletes. Elite male adolescent soccer players of the youth soccer team of a soccer club in the Turkish Super League were included in this study by categorizing them into three separate groups as U14/U15 (n=32), U16/U17 (n=44), and U19 (n=17). Anthropometric measurements of the athletes and food consumption records for three consecutive days were recorded during the competition season. Although the available energy value of the U14/U15 group was higher than the other groups, the available energy was determined to be at a suboptimal level in all groups. The U14/U15 group had the highest Health Eating Index-2015 score (43.7±5.57), while the score was 42.9±4.79 in the U19 group and 42.1±3.69 in the U16/U17 group (p&amp;gt;0.05), and 93.5% of the players were determined to be in the group with poor diet quality. The carbohydrate intake of adolescent soccer players was 5.3±1.16 g/kg body mass/day in the U14/U15 group, while it was 4.4 ± 0.87 g/kg body mass/day in the U16/U17 group, and 4.4±0.94 g/kg body mass/day in the U19 group. In this study, it was found out that adolescent football players had a poor diet quality, their carbohydrate consumption was inadequate, their fat intake level was high, and the protein intake was high in the U14/15 group whereas it was at the recommended levels in other groups. Providing recurrent nutritional training to adolescent football players and their families would assist athletes in gaining healthy eating habits as well as increasing their performance.

Previous studies showed that FIFA +11 program reduces soccer players' sport injuries considerably, but there is limited information about the effect of this program on physical fitness of soccer players. Thus, the aim of this clinical trial was to study the effect of 11+ program on performance and physical fitness of adolescent soccer players. 82 soccer players (aged between 14 and 16) from 4 teams participated in this study. The teams were randomly divided into two groups: control and training. Training group participated in 30 weeks of FIFA 11+ comprehensive program. The players' performance was measured by a test collection. The players of both groups were tested one week prior to and one week following match season (an interval of 30 weeks). Data were analyzed by ANOVA with repeated measures 2x2. Analysis of data showed a significant group x time interaction in Sargent vertical jump test and Bosco repetitive jumping test. The training group showed more improvement than control group in these tests. But no significant differences were observed in pretest and posttest of Illinois agility, 40 and 20 yards speed, yoyo intermittent recovery level 1, sit and reach and dribbling tests between training and control groups. This study demonstrated that FIFA 11+ warm-up comprehensive program can increase Sargent vertical jump and anaerobic power of lower extremity muscles in adolescent soccer players but it did not influence other factors of physical fitness and performance.

Background: Spinal asymmetries and postural deviations are common concerns in young athletes, particularly those engaged in sports requiring repetitive and asymmetrical movements. Soccer, as a dynamic sport, involves high levels of trunk rotation, rapid directional changes, and frequent loading asymmetry, which may predispose players to spinal deviations. This study aimed to investigate the regional prevalence of primary and secondary angle trunk rotation (ATR) in adolescent male soccer players across different age groups. Methods: A total of 502 male participants (291 soccer players and 211 nonathletes) aged 11 to 14 years were included in the study. Participants underwent scoliosis screening using a scoliometer following Adam’s forward bending test. ATR measurements were recorded at the thoracic and lumbar spinal regions, with primary ATR (ATR-A) and secondary ATR (ATR-B) assessed separately. A chi-square test (χ2) evaluated the association between training level and the regional prevalence of ATR across different age groups. Results: No significant differences were observed in the regional prevalence of ATR-A and ATR-B in the 11-year-old group. However, by age 12, significant differences emerged in ATR-A prevalence (χ2(3) = 16.469, p = 0.001), while ATR-B remained nonsignificant (χ2(2) = 4.040, p = 0.133). In the 13- and 14-year-old groups, significant associations were found for both ATR-A (χ2(3) = 57.219, p < 0.001; χ2(4) = 34.157, p < 0.001) and ATR-B (χ2(3) = 31.481, p < 0.001; χ2(2) = 17.805, p < 0.001), with moderate to strong effect sizes. Conclusions: While no significant differences were observed in younger players, 13- and 14-year-old soccer players exhibited a significantly higher prevalence of ATR than nonathletes. The findings suggest that soccer players exhibited a higher prevalence of spinal asymmetries, particularly in older age groups, with lumbar ATR being more pronounced. The study highlights an increasing trend of spinal asymmetries with training level among young soccer players, likely due to the cumulative effects of asymmetric movement patterns. These findings emphasize the need for early detection and corrective interventions to mitigate potential long-term musculoskeletal imbalances in adolescent soccer players.

PurposeThis study aimed to elucidate the influential predictive risk factors of Osgood–Schlatter disease (OSD) on the support (non-kicking) leg among adolescent soccer players considering peak height velocity (PHV) age and investigate the cut-off values of the predictive variables.MethodsA cohort of 302 Japanese adolescent male soccer players aged 12–13 years were followed over 6 months. All players underwent physical examination, tibial tubercle ultrasonography, anthropometric and whole-body composition measurements, and muscle flexibility test of the support leg at the baseline. The developmental stage was evaluated from the PHV age. The OSD of the support leg was diagnosed 6 months later; players were divided into the OSD and control (CON) groups. The predictive risk factors were analyzed by multivariate logistic regression analysis.ResultsThere were 42 players who had developed OSD at baseline and they were excluded from the study. Among the 209 players, 43 and 166 belonged to the OSD and CON groups, respectively. The predictive risk factors of OSD development were PHV age ± 6 months at baseline (p = 0.046), apophyseal stage of tibial tuberosity maturity at baseline (p < 0.001), quadriceps flexibility ≥ 35° at baseline (p = 0.017), and decrease in gastrocnemius flexibility in 6 months (p = 0.009).ConclusionPHV age ± 6 months at baseline, apophyseal stage of the tibial tuberosity at baseline, quadriceps flexibility ≥ 35° at baseline, and decrease in gastrocnemius flexibility in 6 months are predictive risk factors of OSD development in the support leg among adolescent male soccer players. It is crucial to know the PHV age of each player, and not only the flexibility of quadriceps muscle but also the gastrocnemius should be monitored to predict OSD.Level of evidenceII.

Lumbar spondylolysis (LS) has distinct pathologic stages, and worsening LS can cause poor bone union and low back pain. However, the risk factors involved in LS pathogenesis remain unclear. To identify risk factors associated with the pathologic progression of LS at the L5 in adolescent male soccer players. Case-control study; Level of evidence, 3. A total of 189 male adolescent soccer players aged 12 to 14 years were recruited. We used lumbar magnetic resonance imaging (MRI) to examine adolescent soccer players' lumbar lordosis (LL), sacral slope (SS), sacral rotation angle, maturity stage of the lumbar vertebral bodies, and bone marrow edema (BMO) at L5. In addition, whole-body dual-energy x-ray scans measured bone mineral density and content as well as trunk lean body mass. Moreover, we tested the flexibility of the iliopsoas, hamstrings, and quadriceps, as well as evaluated the range of motion (ROM) of the hip in both external and internal rotation. LS stages were determined using computed tomography (CT)-like and short-tau inversion recovery (STIR) modes. The change over the 6-month period was the main outcome; participants were classified as "worsened,""improved," or "no change." The worsened group was defined by a pathological progression on CT-like mode or new BMO appearance on STIR mode without CT-like change. Multiple logistic regression analysis was then performed to identify risk factors for the pathologic progression of LS. Of the 163 players analyzed, 47 (28.5%) showed LS progression. BMO (odds ratio [OR], 5.54; 95% CI, 2.23-13.76), SS relative to LL (OR, 5.58; 95% CI, 2.32-13.51), sacral rotation angle ≤-1.5 or ≥1.5 (OR, 5.74; 95% CI, 2.36-13.96), and hip external rotation ROM (OR, 4.30; 95% CI, 1.67-11.06) were significantly associated with the pathologic progression of LS. Our study demonstrated that the risk factors for LS progression in male adolescent soccer players include BMO, sacral anteversion relative to LL, sacral rotation, and restricted hip external rotation ROM. Early BMO detection and sacral malalignment improvement may prevent pathologic LS progression in male adolescent soccer players.

Bone properties in child and adolescent male hockey and soccer players

Biochemical markers such as cardiac troponin I (cTnI) and N-terminal pro B-type natriuretic peptide (NT-proBNP) have become indispensable tools for the diagnosis of myocardial injury, providing highly sensitive and specific information about cardiac cell damage and wall stress. The purpose of the present research was to examine the response of cardiac biomarkers to a soccer game in adolescent male soccer players. Twenty-two trained adolescent male soccer players (14-16y) were selected in a purposive manner. Blood samples were taken before, immediately after, and 2 and 24 hours after the game for the determination of cTnI and NT-proBNP. Serum concentration of cTnI and NT-proBNP increased immediately and 2 hours after the soccer game (P < .001). After 24 hours, the levels of cTnI dropped but remained above baseline (P = .002), whereas serum NT-proBNP levels returned to baseline. At no time point did any of the values exceed the upper reference value. This is the first study to investigate the acute responses of cardiac biomarkers to a soccer game in adolescent male players. The postgame elevation of cardiac biomarkers and their rapid recovery are indicative of a physiological rather than a pathological response.

The time of day (TOD) has a significant influence on physical performance through circadian rhythms, which regulate body temperature, muscle function, and hormone levels. While extensively studied in adults, the impact of TOD on adolescent athletes remains underexplored. This study aimed to investigate the effects of TOD on maximal short-term physical performance in adolescent soccer players, to guide evidence-based decisions regarding the structuring of training and competition schedules. Nineteen male adolescent soccer players (mean age: 14.58 ± 0.7 years) participated in a randomized trial, performing at four TOD sessions (08:00 h, 11:00 h, 15:00 h, and 18:00 h) with recovery periods of at least 48 hours between sessions. Performance metrics included oral temperature (OT), medicine ball throw (MBT), 5-meter sprint (5m-T), 20-meter sprint (20m-T), Illinois Agility Test (IAT), and Illinois Agility Test with Ball (IAT-B). Results revealed significant TOD effects. OT increased notably from 08:00 to 18:00 (p < 0.001). Physical performance metrics (MBT, 5m-T, 20m-T, IAT, and IAT-B) improved significantly at 11:00, 15:00, and 18:00 (all p < 0.05) relative to 08:00. The 18:00 session consistently produced the highest performance levels. At the same time, no significant differences were observed between 11:00 and 15:00 (all p > 0.05). Our results suggest that time of day significantly influences short-term maximal physical performance in adolescent male soccer players, with peak performance levels consistently observed in the late afternoon (18:00 h). This appears to reflect diurnal variations in core temperature, hormonal activity, and neuromuscular readiness, which likely enhance sprint speed, agility, and explosive power at this time. These findings indicate that coaches and youth sport practitioners should consider scheduling high-intensity training sessions and performance assessments in the late afternoon to optimize physiological conditions for training and evaluation. Aligning training and competition timing with circadian rhythms may therefore support improved athletic output and more accurate performance monitoring in youth soccer settings.