As previous literature updates, I have performed a PubCrawler search looking for football articles in NCBI Medline (PubMed) and GenBank databases.
Following studies were retrieved for this week:
#1 Validation of a Combined Heart Rate and Accelerometry Method for Measuring Total Energy Expenditure in Soccer Players During Precompetition Training
Reference: J Strength Cond Res. 2026 Jun 25. doi: 10.1519/JSC.0000000000005571. Online ahead of print.
Authors: Nahyun Kim, Sihyung Lee, Motoko Taguchi, Taewoong Oh, Seungah Han, Kazuko Ishikawa-Takata, Jonghoon Park
Summary: Understanding energy expenditure in athletes during intensive training periods is essential for optimizing performance and recovery. Accurate assessment of total energy expenditure (TEE) and activity energy expenditure (AEE) during precompetition training is important. Accordingly, TEE and AEE were assessed using the doubly labeled water (DLW) method. We also validated a combined method using exercise energy expenditure (EEE) through heart rate (HR) and nonexercise activity thermogenesis (NEAT) through accelerometry (ACC) in collegiate soccer players, examining EEE and NEAT variability in relation to TEE. Korean male collegiate soccer players participated in the study. TEEDLW and AEEDLW were measured over 8 days using DLW (n = 14). Resting metabolic rate (RMR) was assessed with the Douglas bag method. TEECOM was calculated as the sum of RMR, HR-derived EEE, and ACC-derived NEAT (n = 10). TEEDLW and AEEDLW were 4,119 and 2,066 kcal·d-1, respectively. TEECOM and AEECOM (4,090 and 2,028 kcal·d-1, respectively) closely matched TEEDLW and AEEDLW (4,062 and 2,002 kcal·d-1, respectively), showing high validity (r2 = 0.81 and 0.73, respectively). Bland-Altman analysis revealed small mean differences: 21.17 kcal·d-1 for TEE and 25.75 kcal·d-1 for AEE. Heart rate-derived EEE correlated strongly with AEEDLW (r = 0.77, p = 0.009), while ACC-derived NEAT and HR-derived EEE were negatively correlated (r = -0.74, p = 0.014). Higher TEE and AEE values corresponded with increased training volume. The combined HR and ACC method proved highly valid for group-level TEE assessment. Owing to individual variability in EEE and NEAT, precise measurement of these components remains crucial for accurate TEE predictions in athletes.
#2 Interrelationships Among Physical Fitness, General Motor Coordination, and Soccer-Specific Technical Skills in Youth Soccer Players
Reference: Sports (Basel). 2026 Jun 5;14(6):233. doi: 10.3390/sports14060233.
Authors: Vanessa Rocco, Stefano Amatori, Roberto Bensi et al.
Download link: https://www.mdpi.com/2075-4663/14/6/233
Summary: Soccer performance is characterized by high motor and cognitive complexity, resulting from the interaction between, among others, physical and technical components. However, evidence regarding the relationships among physical performance, motor coordination and soccer-specific technical remains limited. Therefore, this cross-sectional study aimed to investigate the associations among these domains in youth soccer players. Forty-nine male U15 participants (age: 14.3 ± 0.5 years) underwent anthropometric assessments, physical fitness testing (10 m, 30 m sprint, CMJ, YYIRT1), a general motor coordination test (Harre Circuit Test), and soccer-specific technical evaluation (F-MARC test battery). Associations among variables were assessed using Spearman correlations and exploratory principal component analysis (PCA) based on a Spearman correlation matrix with oblimin rotation. Significant associations emerged between general motor coordination, physical performance variables, and several soccer-specific technical skills. The PCA identified three partially overlapping components, cumulatively explaining about 70% of the variance, highlighting the multidimensional and interconnected nature of soccer-related performance capacities. General motor coordination demonstrated relevant loadings in both coordinative/technical and physical-performance-oriented domains. These findings suggest that youth soccer performance should not be interpreted through isolated physical or technical characteristics, but rather as the result of interactions among coordinative, neuromuscular, and technical factors. Consequently, multidimensional and individualized training approaches integrating physical, coordinative, and technical stimuli may represent relevant strategies for youth soccer development.
#3 Performance and Inter-Limb Asymmetry in Relation to Peak Height Velocity and Injury-Related Variables in Adolescent Male Soccer Players
Reference: Sports (Basel). 2026 Jun 2;14(6):227. doi: 10.3390/sports14060227.
Authors: Alberto Roso-Moliner, Rafael Albalad-Aiguabella, Demetrio Lozano et al.
Download link: https://www.mdpi.com/2075-4663/14/6/227
Summary: Adolescent footballers exhibit smaller change of direction (COD) deficits than adults, suggesting distinct biomechanical profiles; however, the role of physical performance variables in COD, considering maturation and injury-related factors, remains poorly understood. This study aimed to examine the relationships between sprint, jump, and COD performance, maturation status, and injury-related variables in young male footballers. Fifty-six national-level players (age: 16.67 ± 0.86 years) performed unilateral vertical and horizontal jump tests, 20 m linear sprint tests, and 180° COD assessments. Maturation status was estimated using peak height velocity (PHV), and injury incidence and severity were recorded over one competitive season. Associations were observed between PHV and sprint performance during the initial acceleration phase (0-10 m; p < 0.01). Unilateral jump measures were associated with sprint and COD performance, whereas inter-limb asymmetries showed limited associations with performance outcomes. Horizontal jump performance was also associated with the percentage-based COD deficit (%CODD). With respect to injury-related variables, injury incidence was associated with countermovement jump (CMJ) measures, with greater CMJ asymmetry being associated with higher injury incidence, while both unilateral CMJ variables were retained in the regression model. Overall, these findings suggest that biological maturation and unilateral neuromuscular performance may be relevant factors associated with youth football performance, whereas inter-limb asymmetry appears to play a more limited role; CMJ-related measures may warrant further consideration in relation to injury incidence in adolescent footballers.
#4 Health Behaviours in Soccer Support Staff: 24-Hour Movement Adherence Is Positively Associated with Diet Quality
Reference: Sports (Basel). 2026 May 29;14(6):224. doi: 10.3390/sports14060224.
Authors: Olivia C Coope, Tilly J Spurr, Alex L Levington et al.
Download link: https://www.mdpi.com/2075-4663/14/6/224
Summary: Soccer support staff operate under demanding schedules and high-performance environments while guiding players‘ movement, sleep, and nutrition; however, their own lifestyle behaviours remain under-researched. This exploratory study assessed adherence to the Canadian 24-Hour Movement (24HM) guidelines and its association with diet quality (DQ) in professional and semi-professional soccer support staff. A cross-sectional survey collected data from 236 staff in the United Kingdom and Spain. Movement behaviours were measured using the Whole Day Matters Toolkit and DQ using the validated Mini-EAT questionnaire. A graded 24HM score (0-8) summed binary adherence across four general (MVPA, LPA, sedentary time, sleep) and four secondary (muscle-strengthening, sedentary interruptions, screen time, sleep-wake time) behaviours. Associations with DQ were estimated using adjusted multiple linear regression. Only 7.6% of participants met all eight guidelines. Each one-point increase in the graded score was associated with 0.89-point higher DQ (95% CI 0.29-1.49, p = 0.004), with stronger associations observed for secondary behaviours (β = 1.27, p = 0.006) than for general behaviours (β = 0.38, p = 0.50). A graded 24HM scoring approach showed a graded association with DQ in soccer staff, with secondary movement behaviours showing a stronger association. All findings should be interpreted as exploratory and hypothesis-generating.
#5 Acute Capillary Plasma Biomarker, Neuromuscular, and Perceptual Responses to Standardised Soccer Match Play in Elite Players: A Descriptive Study of Asynchronous Multi-Domain Recovery
Reference: Metabolites. 2026 May 29;16(6):370. doi: 10.3390/metabo16060370.
Authors: Lun Du, Jie Xiao, Chunpeng Li, Shuning Liu, Yaji Jiang, Yue Dou, Haotian Zhao, Wen Zhong, Kai Zhao, Chang Liu
Download link: https://www.mdpi.com/2218-1989/16/6/370
Summary: Soccer match play induces substantial mechanical, metabolic, inflammatory, and neuromuscular stress, yet post-match monitoring in applied settings often relies on isolated markers, venous sampling, or limited time points. This observational repeated-measures study aimed to describe whether capillary-derived biomarkers, neuromuscular performance, and perceptual measures showed asynchronous recovery during the first 48 h after a standardised soccer match in elite players. Twenty-two elite male outfield soccer players completed a standardised 90 min match. Capillary blood biomarkers, countermovement jump (CMJ), 20 m sprint performance, maximal voluntary contraction (MVC), and delayed onset muscle soreness (DOMS) were assessed before the match, immediately post-match, and at 24 and 48 h post-match. Time effects were analysed using repeated-measures mixed-effects models, and associations between biochemical and functional responses were examined descriptively. Match play induced clear but domain-specific disturbances. IL-6 and cortisol rose rapidly immediately post-match, whereas hsCRP, CK, LDH, myoglobin, and DOMS showed delayed peaks during early recovery. CK, LDH, myoglobin, and soreness remained above baseline at 48 h. CMJ and sprint performance were impaired after the match but largely recovered by 48 h, whereas MVC showed its greatest decrement at 24 h. Exploratory associations indicated that larger muscle damage responses tended to co-occur with greater strength and jump decrements and higher soreness, but these analyses were not causal. Recovery after a standardised elite soccer match was multidimensional and non-synchronous across physiological, neuromuscular, and perceptual domains. A capillary-based, multi-domain assessment strategy may provide a feasible descriptive perspective for field-based observation of post-match fatigue.
#6 Return to play is reliable, but market value declines after proximal hamstring repair in elite soccer players
Reference: J Exp Orthop. 2026 Jun 22;13(2):e70775. doi: 10.1002/jeo2.70775. eCollection 2026 Apr.
Authors: Gianluca Ciccarelli, Edoardo Monaco, Valerio Nasso et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13284677/pdf/JEO2-13-e70775.pdf
Summary: The purpose of this study was to quantify return-to-play (RTP) time, post-operative performance and market-value trends after proximal hamstring repair in top-tier European league soccer players. It was hypothesized that surgery would achieve a high RTP rate but be accompanied by reductions in player performance and valuation. Male first-team players from the five major European leagues who underwent surgical repair of proximal hamstring ruptures between 2019 and 2022 were identified collaboratively with the InjuryMechanisms platform. Publicly available data (Transfermarkt) was accessed to extract demographics and season-by-season metrics for two seasons before and two seasons after injury. Outcomes were RTP time, matches missed, percentage of minutes played per season (MPS), goals, assists and market value. Non-parametric Friedman test with Dunn-Bonferroni post hoc test assessed longitudinal changes. Twenty players (mean age, 25.3 ± 4.4 years) met the inclusion criteria. All returned to professional competition without reoperation. Mean RTP was 160 ± 76 days, with 21.5 ± 11.5 matches missed. Goals and assists were unchanged across seasons (p > 0.05). MPS showed a non-significant reduction from 50.2 ± 15.5% pre-injury to 34.5 ± 16.3% in the first post-operative season and partially recovered to 43.0 ± 23.9% in the second season. Mean market value significantly declined from €22.1 ± 36.7 and €20.4 ± 34.4 million in the two pre-injury seasons to €15.2 ± 27.4 million two seasons post (p < 0.001). Surgical repair of proximal hamstring rupture allowed reliable return to competition in elite soccer players, with preserved performance. However, players experienced a transient, non-significant reduction in competitive involvement during the first post-operative season and market value significantly declined despite favourable performance outcomes.
#7 Relationship between hamstring flexibility (askling H-test) and isokinetic strength ratios in elite soccer players with prior hamstring strain injury: A cross-sectional study
Reference: J Back Musculoskelet Rehabil. 2026 Jun 23:10538127261462651. doi: 10.1177/10538127261462651. Online ahead of print.
Authors: Mary Kamal Nassif Takla, Mai Raouf Mohamed Rageh, Mohamed Aboalata Mohamed Aboalata, Elsaieed Ahmed Attia
Summary: Recurrent hamstring strain injuries are associated with deficits in eccentric strength and altered muscle-tendon extensibility, which may persist and contribute to reinjury risk. The aim was too examine the relationship between hamstring flexibility, assessed by Askling H-test, and isokinetic strength ratios; concentric-to-eccentric (Con:Ecc) and hamstring-to-quadriceps (H:Q) in elite soccer players with previous hamstring strain. Fifty-two male professional players (27 ± 5 years) with clinically confirmed prior hamstring injury completed the Askling H-test and bilateral isokinetic testing at 60°·s⁻1 (concentric) and 180°·s⁻1 (eccentric). The mean of three maximal efforts was used to calculate peak torques. Pearson correlations and multiple linear regression examined the relationship between flexibility, age, and strength ratios (α = 0.05). Mean ± SD Con:Ecc ratio was 86 ± 9% and H:Q ratio 63 ± 7%. Hamstring flexibility correlated inversely with the Con:Ecc ratio, moderately in the dominant limb (r = -0.65 [95% CI -0.78 to -0.46], p < 0.001) and weakly in the non-dominant limb (r = -0.34 [95% CI -0.56 to -0.06], p = 0.02). No significant correlation was observed between flexibility and the H:Q ratio (p = 0.38). Flexibility remained an independent predictor of the Con:Ecc ratio after adjusting for age (β = -0.61, p < 0.001; R2 = 0.38). Reduced hamstring flexibility is associated with a higher Con:Ecc ratio, indicating relatively reduced eccentric capacity, but is not related to H:Q balance. These findings highlight the role of flexibility in hamstring strength balance and warrant longitudinal investigation.
#8 Muscular profiles of adolescent female soccer players: a cross-sectional comparison of hamstring-to-quadriceps and vastus medialis-to-vastus lateralis characteristics
Reference: J Orthop Surg Res. 2026 Jun 23. doi: 10.1186/s13018-026-07063-0. Online ahead of print.
Authors: Sonoka Ichikawa, Mikuri Tanaka, Rina Watabe, Ikumi Morikawa, Daigo Matsumoto, Kaede Mada, Ryota Akagi
Download link: https://link.springer.com/content/pdf/10.1186/s13018-026-07063-0_reference.pdf
Summary: To characterize multifaceted muscular profiles potentially associated with knee joint sports injuries in adolescent female athletes, we compared hamstring-to-quadriceps (H:Q) ratios derived from isometric torque and isotonic power, as well as the relative muscle quality characteristics of the vastus medialis (VM) and vastus lateralis (VL), between adolescent female soccer players and recreationally active controls. In this cross-sectional study, 97 adolescent females (soccer: n = 62; control: n = 35) were categorized into older (≥ 162 months) and younger (< 162 months) cohorts. Assessments of both legs included isometric peak torque and isotonic peak power of the knee extensors and flexors using a dynamometer, along with ultrasound-derived muscle echo intensity and shear modulus of the VM and VL at rest. The H:Q ratios were calculated from both torque and power, whereas VM:VL ratios were derived from echo intensity and shear modulus to evaluate relative muscle quality characteristics. The isometric H:Q ratio was significantly higher in the soccer group than in the control group (pooled across age groups and legs; soccer: 55.3% ± 9.8%; control: 51.0% ± 10.4%). However, no significant between-group differences were observed in the isotonic H:Q ratio (soccer: 86.3% ± 21.1%; control: 81.4% ± 27.9%) or in the VM:VL ratios for echo intensity (soccer: 91.0% ± 10.4%; control: 91.8% ± 7.2%) and shear modulus (soccer: 84.0% ± 22.8%; control: 83.9% ± 23.2%). Furthermore, the isometric H:Q ratio showed no significant effects for age or leg dominance, whereas the isotonic H:Q ratio was significantly higher in younger participants and in the non-dominant leg. These findings suggest that isometric and isotonic H:Q ratios capture distinct aspects of knee muscle function. Additionally, no significant differences were observed between elite soccer players and recreationally active peers in the isotonic H:Q ratio or ultrasound-derived VM:VL ratios, suggesting that highly trained adolescent female soccer players do not necessarily exhibit distinct dynamic power or resting muscle quality. These multifaceted muscular profiles may provide exploratory laboratory-based reference data, although longitudinal studies are needed to determine how these characteristics relate to actual injury incidence.
#9 Muscle Oxygen Saturation as a Marker of Internal Load in Elite Soccer: A Case Series
Reference: J Strength Cond Res. 2026 Jun 23. doi: 10.1519/JSC.0000000000005483. Online ahead of print.
Authors: Sven Herzog, Manuel Philippi, Andri Feldmann et al.
Summary: Accurate monitoring of internal and external load during training is essential for optimizing performance and managing fatigue. In soccer, heart rate (HR) is commonly used to assess internal load. This study examined the use of muscle near-infrared spectroscopy, which measures muscle oxygen saturation (SmO2), as a potential alternative to HR by providing real-time insights into local muscular effort. Seventeen elite male professional soccer players (21.2 ± 4.01 years) performed an incremental treadmill test to exhaustion, of whom 14 had complete data sets suitable for threshold analyses. During the test, HR, expired gases, and SmO2 of the vastus lateralis were continuously measured to identify ventilatory, lactate, and SmO2 breakpoints. On a separate day, HR and SmO2 were recorded in a subset of five players during small- and large-sided games (SSG and LSG). A repeated-measures analyses of variance comparing HR corresponding to the three different thresholds indicated that HR at BP2 (178 ± 5 beats·minute-1) was similar with HR at LT2 and VT2 (177 ± 7 beats·minute-1 and 181 ± 6 p = 1.000 and p = 0.0920, respectively). Bland-Altman analysis indicated acceptable agreement between HR thresholds, while SmO2 thresholds showed wider limits of agreement and greater individual variability. During small-sided game and LSG, players spent significantly more time above SmO2-based thresholds compared with HR-based thresholds (p < 0.05), with the largest differences observed during LSG. These findings suggest that SmO2 is more responsive to high-intensity, intermittent activity and may better reflect local muscular demand than HR. Incorporating SmO2 into training and match monitoring may enhance internal load assessment and support more individualized performance and recovery strategies.
#10 Injury Patterns in Soccer-Induced Maxillofacial Fractures and Ocular Trauma: A Narrative Review
Reference: Sports Med Open. 2026 Jun 23;12(1):78. doi: 10.1186/s40798-026-01049-2.
Authors: Anaas M Mergoum, Jacob Lentner, Brooke Echter, Jacob Roskam, Grant S Hamilton 3rd, James D Smith
Summary: Maxillofacial fractures and ocular trauma are significant injuries in soccer, with potential functional, aesthetic, and visual consequences if unrecognized. Few reviews have specifically examined both injury patterns in this sport. The purpose of this narrative review is to synthesize the current literature to identify injury patterns associated with maxillofacial fractures and ocular trauma in soccer, thereby aiding clinicians in timely diagnosis and management. Given the heterogeneity and limited quality of the available evidence, this review also highlights areas where further research is needed. The zygoma was the most commonly fractured maxillofacial bone in soccer (32.8%), followed by the nasal (28.4%), mandibular (25.8%), orbital (6.5%), maxillary (3.6%), and frontal sinus (2.8%) regions. Among mandibular fractures, the angle was the most vulnerable site, accounting for 39.2% of cases. Head-to-head contact was the most frequent mechanism resulting in injury; however, although less common, arm or elbow impacts were more likely to result in fracture when they occurred. Ocular injuries most often present as orbital or eyelid contusions and lacerations (37.1%) and hyphemas (19.5%), with direct ball impact as the primary cause. Boys (60.4%-69.5%) were at greater risk than girls for ball sport-related ocular trauma, particularly those aged 2-9 years, with soccer being the leading sport implicated. Overall, these trends are based largely on small case series, reflecting the low quality of available evidence. The zygoma is the most frequently fractured maxillofacial bone, typically resulting from head-to-head collisions. Direct soccer ball impact accounts for most ocular injuries in this sport, with orbital or eyelid contusions and lacerations most common, followed by hyphemas. Pediatric players may be particularly susceptible to soccer-related ocular trauma, possibly due to an underdeveloped orbital rim. Fundoscopic examination is essential after ball impact to detect vitreoretinal injury, even when visual acuity is normal. Further well-designed studies are needed to confirm these findings.
#11 Age-related differences during stop-ball small-sided games in youth soccer
Reference: J Sports Med Phys Fitness. 2026 Jun 23. doi: 10.23736/S0022-4707.26.17965-1. Online ahead of print.
Authors: Nicola Trotta, Luigi Armiento, Rosario D’Onofrio, Italo Sannicandro
Summary: Stop-ball small-sided games (SSGs-SB) have been proposed as an effective scoring method to influence physical and physiological responses in young soccer player. The aim of present study is to examine the differences in external and internal load variables across U-13, U-14 and U-15 players during SSGs-SB. Ninety-six male soccer players (32 players in each group) from teams competing in Italian regional championship were involved. The experimental design consisted of a 4 vs. 4 played on a 25×20 m pitch, including 4×3′ of work separated by 2 min of passive recovery. During SSG-SB, players were monitored using 18.18 Hz global positioning system devices (GPEXE® SYSTEM, EXELIO srl, Udine, Italy). Total distance, peak velocity, distance covered at high-speed running 13-18 km∙h-1, sprint running >18 km∙h-1, number of sprint, acceleration >2.5 m∙s-2, deceleration <-2.5 m∙s-2, maximal acceleration and deceleration, high metabolic load distance and rating of perceived exertion were measured. U-15 team exhibited greater physical demands compared with U-13 team (P<0.001 for all comparisons), whereas younger counterparts significantly (P<0.001) reported higher RPE scores than U-15 players. The present study suggests that SSGs-SB designs should be tailored according to chronological age to support an appropriate long-term development process in youth soccer
#12 Recovery kinetics following matches in congested vs. non-congested schedules: effects on pressure pain sensitivity, delayed onset muscle soreness, and muscular performance in soccer players
Reference: BMC Sports Sci Med Rehabil. 2026 Jun 23. doi: 10.1186/s13102-026-01813-7. Online ahead of print.
Authors: Xiaoshuang Wang, Yongxing Zhao, Yuqing Duan, Qiling Qiu
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01813-7_reference.pdf
Summary: This study investigated recovery responses in male Under-19 soccer players over a 48-hour period following a match, comparing congested (CW) versus non-congested (RW) schedules. Nineteen male provincial-level players (Tier 2: trained/developmental) who started and played at least 60 min in each match of both study weeks participated. Assessments of Countermovement Jump (CMJ) height (cm), Pressure Pain Sensitivity (PPS, kPa), and Visual Analogue Scale (VAS, au) were conducted at pre-match, 15 min post-match, 24 h, and 48 h post-match. No training or specific recovery strategies were implemented between assessments. Linear mixed-model analyses showed significant Week × Time interactions for PPS (p < .001) and VAS (p < .001), but not for CMJ (p = .071). Post-hoc contrasts indicated that CMJ height was significantly lower in the congested week at 24 h (- 1.31 cm, p = .027) and 48 h (- 1.59 cm, p < .001). PPS was lower during the congested week at 24 h (- 26.96 kPa, p < .001) and 48 h (- 23.09 kPa, p < .001), while VAS values were higher at all post-match time points (Post: +16.63 au; 24 h: +12.53 au; 48 h: +21.84 au; all p < .001). These findings suggest that fixture congestion delays neuromuscular and sensory recovery, reflected by prolonged impairments in jump performance and elevated pain sensitivity.
#13 Mood, technical performance, and physiological responses after 4 vs 4 small-sided soccer games of different durations: A pre-post study
Reference: Medicine (Baltimore). 2026 Jun 19;105(25):e49444. doi: 10.1097/MD.0000000000049444.
Authors: Zouhaier Farhani, Hatem Ghouili, Samia Boukari et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13286436/pdf/medi-105-e49444.pdf
Summary: Small-sided games (SSGs) are widely used in soccer training to simultaneously develop technical, tactical, and physical abilities. Session structure, particularly duration and distribution (continuous vs intermittent), represents a key programming variable that may influence players‘ mood, technical performance, and physiological responses. However, the specific effects of different SSG formats remain insufficiently clarified. This study aimed to examine how varying bout configurations (1 × 12 min, 2 × 6 min, and 3 × 4 min) during 4 vs 4 SSGs affect mood states, technical-tactical performance, and physiological responses in male soccer players. Twenty male semiprofessional soccer players (age: 20.7 ± 0.7 years) completed 3 SSG formats performed on separate occasions: 1 × 12 min, 2 × 6 min, and 3 × 4 min. Mood was assessed pre- and post-session using the Profile of Mood States questionnaire. Physiological responses included percentage of maximal heart rate (%HRmax), blood lactate concentration ([La]), and rating of perceived exertion (RPE). Technical-tactical variables were analyzed through systematic video-based performance assessment. The 12-minute continuous SSGs significantly improved mood, evidenced by reductions in depression, confusion, tension, anger, and total mood disturbance, although fatigue increased post-session. In contrast, the 2 × 6 min format led to increases in depression and anger, while the 3 × 4 min format showed no significant mood changes. Technical-tactical performance was superior during the 12-minute condition, with higher passing accuracy, greater tackle success, and fewer turnovers compared to intermittent formats. Physiologically, the continuous 12-minute SSGs elicited higher %HRmax and rating of perceived exertion values than both intermittent conditions, as well as slightly higher blood lactate concentrations compared to the 3 × 4 min format. A continuous 12-minute 4 vs 4 SSGs appears to provide the most effective integrated training stimulus, enhancing mood regulation, technical-tactical performance, and physiological load. These findings suggest that uninterrupted SSG formats may better simulate match demands and support optimal psychophysiological adaptations in semiprofessional soccer players.
#14 ViewAdapt-Det: view-adaptive detection for soccer broadcasting videos
Reference: Sci Rep. 2026 Jun 23. doi: 10.1038/s41598-026-59307-y. Online ahead of print.
Authors: Chunwang Zhu, Yongli Zhang, Sheng Gao, Chenghao Wang, Chunyan Huang
Download link: https://www.nature.com/articles/s41598-026-59307-y_reference.pdf
Summary: Object detection in soccer videos plays an important role in intelligent broadcasting, tactical analysis, and player tracking. Frequent view switching driven by multi-camera coordination in soccer broadcasts introduces two distinct challenges for existing detection methods. First, in the temporal dimension, shot transitions cause abrupt visual changes between adjacent frames. Existing temporal aggregation methods forcibly fuse features from heterogeneous views, injecting cross-view noise that can degrade detection accuracy below single-frame baselines. Second, in the feature dimension, target appearance varies significantly across views: players in panoramic shots are low-resolution small objects characterized mainly by coarse contours and color, whereas the same players in close-up shots become high-resolution large objects with rich texture and fine-grained detail. A unified detection strategy struggles to handle both extremes simultaneously. We propose ViewAdapt-Det, a framework consisting of two complementary modules. The View-Aware Temporal Gating module (VATG) detects shot transitions and dynamically controls temporal aggregation intensity, suppressing historical frame contributions during view changes while preserving temporal enhancement during continuous sequences. The View-Conditioned Detection Modulation module (VCDM) infers the current view type and conditionally modulates detection features, allowing the detector to apply view-specific feature processing strategies that match the visual characteristics of each viewpoint. Experiments on SoccerNet-Tracking, SportsMOT, and our self-constructed BroadcastSwitch-Soccer dataset show that ViewAdapt-Det outperforms existing methods and demonstrates stronger robustness under abrupt shot transitions.
#15 Test-retest reliability and sensitivity of horizontal jump inter-limb asymmetry in youth soccer players across maturity stages
Reference: PLoS One. 2026 Jun 22;21(6):e0341344. doi: 10.1371/journal.pone.0341344. eCollection 2026.
Authors: Raouf Hammami, Yassine Negra, Halil Ibrahim Ceylan et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13286214/pdf/pone.0341344.pdf
Summary: The present study examined the test-retest reliability and sensitivity of inter-limb asymmetry derived from the single-leg hop test (SLHT) across different maturity stages in young male soccer players. Sixty-four youth soccer players aged 8-16 years participated in this study and were assessed using the SLHT to quantify inter-limb asymmetry. Participants were divided into prepubertal (n = 34; age: 8.1 ± 1.4 years; body mass: 35.7 ± 3.4 kg; height: 122 ± 9 cm; maturity offset: -2.38 ± 0.83 years) and post-pubertal groups (n = 30; age: 16.5 ± 0.3 years; body mass: 39.6 ± 6.1 kg; height: 154 ± 7 cm; maturity offset: 1.17 ± 0.45 years) according to individual peak height velocity. During the SLHT, participants performed maximal horizontal hops on each leg separately, and the greatest distance achieved was recorded for analysis. Inter-limb asymmetry demonstrated good relative reliability in both groups, with intraclass correlation coefficients of 0.78 and 0.92 for the prepubertal and post-pubertal groups, respectively. Absolute reliability was also acceptable, as the typical error of measurement was < 5% in both groups. Sensitivity analysis showed that the standard error of measurement (SEM) exceeded the smallest worthwhile change (SWC; 0.2 standard deviations) in the prepubertal group, indicating a marginal ability to detect small performance changes. In contrast, the SEM was lower than the SWC in the post-pubertal group, indicating good sensitivity for detecting small changes in performance. These findings indicate that SLHT-derived inter-limb asymmetry scores demonstrate acceptable reliability in youth soccer players across maturity stages, while sensitivity to detect small changes may differ between prepubertal and post-pubertal players. The results contribute to the methodological understanding of inter-limb asymmetry assessment in youth soccer and may assist practitioners and researchers in interpreting asymmetry data across different stages of maturation.
#16 Youth Soccer Participation and Brain Health Outcomes in Adolescent Athletes
Reference: JAMA Netw Open. 2026 Jun 1;9(6):e2619569. doi: 10.1001/jamanetworkopen.2026.19569.
Authors: Inga K Koerte, Tim L T Wiegand, Elena M Bonke et al.
Download link: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2850561
Summary: Repetitive head impacts (RHIs) are associated with later-life neurodegeneration. Because soccer is the most widely played sport among youth worldwide, identifying early changes associated with RHI is important. The aim was to determine whether participation in 1 season of youth soccer is associated with changes in cognition, behavior, balance, brain structure or function, or blood biomarkers compared with noncontact sports. Prospective longitudinal cohort study at European centers (Munich, Germany; Leuven, Belgium; and Oslo, Norway). Male adolescent soccer players and noncontact athletes were each studied across a single competitive season with assessments at preseason, postseason, and 2 months later. Data were analyzed from January 2023 to March 2025. Soccer players were compared with noncontact athletes. In addition, self-reported heading of a soccer ball was assessed among soccer players as a measure of RHI. Cognition, behavior, balance, magnetic resonance imaging (brain structure, function, and biochemistry), and plasma biomarkers. Male adolescent soccer players (n = 82; mean [SD] age, 14.8 [0.6] years) did not differ from noncontact sport athletes (n = 47; mean [SD] age, 14.7 [0.7] years) in cognition, behavior, balance, cortical thickness, brain volumes, white-matter microstructure, or functional connectivity. At preseason, soccer players had higher total N-acetylaspartate (tNAA; β, -0.379 [95% CI, -0.627 to -0.131]; P = .003), glial fibrillary acidic protein (GFAP; β, -0.055 [95% CI, -0.103 to -0.006]; P = .03), and neurofilament light chain (NfL; β, -0.071 [95% CI, -0.122 to -0.020]; P = .01) than noncontact sport controls. Across the season, tNAA (β, 0.047 [95% CI, 0.020-0.074]; P = .001) declined in soccer players and increased in controls, converging by postseason. Group trajectories of GFAP and NfL did not differ between groups. Within soccer players, heading exposure was not significantly associated with changes in any outcome. In this cohort study of adolescent males, no statistically significant differences were detected over 1 season between soccer players and noncontact sport athletes in cognition, behavior, or brain structure and function. Group differences in GFAP and NfL may represent early signs of exposure, but lack of association with heading exposure warrants further investigation. These results highlight the need for large, multiyear studies to inform health policy.
#17 Systemic Degree of Perturbation of Plasma Markers Reveals Cumulative Biological Stress Across the Competitive Season in Professional Soccer Players
Reference: Sports Med. 2026 Jun 22. doi: 10.1007/s40279-026-02470-z. Online ahead of print.
Authors: Deivide Oliveira-de-Souza, Diego Viana Gomes, Juliano Spineti et al.
Download link: https://link.springer.com/content/pdf/10.1007/s40279-026-02470-z.pdf
Summary: Fixture congestion has emerged as one of the defining challenges of modern professional soccer, exposing players to repeated high-intensity demands with limited opportunities for recovery. Such cumulative exposure taxes multiple physiological systems and may lead to sustained biological strain throughout the competitive season. However, the integrated systemic impact of congested schedules remains incompletely characterized. We aimed to characterize the systemic physiological impact of cumulative competitive load across a full professional soccer season using an integrated biomarker framework. In this prospective longitudinal investigation, we employed the systemic degree of perturbation score, an adaptation of the molecular degree of perturbation, to circulating biochemical, hematological, and metabolic biomarkers obtained from professional soccer players across a full competitive season. Multi-dimensional analyses were employed to characterize systemic alterations associated with cumulative competitive load. A progressive increase in systemic perturbation was observed across the competitive season. The relative contribution of individual biomarkers shifted over time, with late-season phases characterized by more integrated muscular-inflammatory-metabolic profiles. Myoglobin and monocyte-related markers consistently contributed to systemic degree of perturbation values across competitive quarters, and network analyses demonstrated progressive changes in correlation architecture involving muscular, inflammatory, and metabolic mediators. These results provide a comprehensive view of the physiological burden imposed by a professional soccer season and describe a progressive integration of muscular, inflammatory, and metabolic responses under cumulative competitive load. This integrated perspective supports the potential utility of biomarker-based monitoring frameworks for characterizing seasonal biological strain in elite athletes.
#18 Scheduling Repeated-Sprint Training on Different Microcycle Days in Professional Soccer Players: A Randomized Crossover Study
Reference: J Strength Cond Res. 2026 Jun 22. doi: 10.1519/JSC.0000000000005572. Online ahead of print.
Authors: Alberto García-Santamaría, Alexis Padrón-Cabo, Diego Fernández-Penedo, Pablo B Costa, Ezequiel Rey
Summary: This study compared the acute neuromuscular, mechanical, and perceptual responses to repeated-sprint training (RST) performed on match day minus 4 (MD-4) vs. match day minus 3 (MD-3) in professional soccer players. Seventeen male outfield players completed 2 experimental microcycles using a randomized, counterbalanced crossover design. Each player performed a high-volume RST protocol (3 × 10 × 30 m) on either MD-4 or MD-3, with a 1-week washout in between. External (GPS) and internal (rating of perceived exertion) loads were recorded during RST. Countermovement jump, muscle mechanical properties (MyotonPRO), and perceptual markers (total quality recovery, Hooper Index) were assessed pre- and postintervention (MD-2). No significant differences were found in training load between conditions (p > 0.05). Countermovement jump performance decreased significantly after RST (p = 0.031), with no interaction effect. Delayed onset muscle soreness (DOMS) and fatigue increased in both conditions, but DOMS was significantly higher after MD-3 RST (p = 0.030). Total quality recovery scores also decreased (p = 0.003), with no change in muscle tone, stiffness, or elasticity. These results suggest that although RST elicits similar load regardless of day, performing it closer to match day may increase residual soreness. Coaches are advised to schedule high-intensity RST earlier in the microcycle to optimize recovery and match-day readiness.
#19 Balancing the Game: The Relationship of Lower-Limb Asymmetry With Youth Soccer (Football) Performance – Laboratory vs. Field Insights
Reference: J Strength Cond Res. 2026 Jun 22. doi: 10.1519/JSC.0000000000005570. Online ahead of print.
Authors: Dominykas Bartusevičius, Jūratė Stanislovaitienė, Daniele Conte
Summary: This study aimed to assess the relationships between: (a) laboratory- and field-based leg symmetry indexes (LSIs); (b) laboratory- and field-based LSIs and physical and ball-kicking velocity (BKV) performances; (c) physical and BKV performances. Twenty-nine male youth outfield soccer (football) players (age = 14.9 ± 0.9 years, stature = 177.1 ± 7.2 cm, body mass = 64.9 ± 9.8 kg, maturity offset = 1.6 ± 0.9 years) were recruited for the study. Laboratory-based testing included concentric peak torque of the knee extensors and flexors using an isokinetic dynamometer at 60 and 180°·s-1. Field-based testing encompassed the Y-balance test, single-leg countermovement jump, single-leg long jump, countermovement jump, 10- and 30-m sprints, and BKV. LSIs were calculated for both laboratory- and field-based tests using unilateral tasks. The relationships were assessed using Pearson’s (r) and Spearman’s rank correlation (ρ). Results showed trivial-to-small (p > 0.05) relationships between laboratory- and field-based LSIs. Furthermore, laboratory- and field-based LSIs showed trivial-to-moderate relationships with physical and BKV performances (p > 0.05). Moreover, BKV showed large positive relationships with countermovement jump (r = 0.531-0.572) and single-leg countermovement jump (r = 0.594-0.649), a moderate-to-large relationship with single-leg long jump (r = 0.488-0.646), and a large negative relationship with 30-m sprint (r = -0.503 to -0.536). Our findings suggest laboratory and field-based LSIs cannot be used interchangeably, and LSI should not be relied upon as an indicator of physical and technical performance. Coaches should focus on enhancing lower-limb explosiveness, given its strong association with BKV performance among youth soccer players.
#20 Enhancing physical, technical, tactical, and cognitive performance in female youth football players using eye-tracking and neurofeedback training: an exploratory study
Reference: Front Psychol. 2026 Jun 10:17:1835322. doi: 10.3389/fpsyg.2026.1835322. eCollection 2026.
Authors: Sílvio A Carvalho, Pedro Bezerra, José E Teixeira, Pedro Forte, Rui M Silva, José M Cancela-Carral
Download link: https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2026.1835322/full
Summary: This study aimed to investigate the effects of an intervention combining eye-tracking and neurofeedback training on technical, tactical, and cognitive performance in young female football players. A cross-sectional study was conducted with eight female youth football players (15.6 ± 1.2 years) recruited from a FIFA-certified training centre. Anthropometric measures (body mass, standing height, and seated height) were recorded, and biological maturity was assessed using the Mirwald equation. Performance was evaluated using standardized tests: Loughborough Football Shooting Test (LSST) for technical skill, Yo-Yo Intermittent Recovery Test Level 1 (YYIR1) for endurance, and a system of tactical assessment in football (FUT-SAT) instrument for motor and tactical proficiency. For clarity, we define the measurement moments used throughout this article: baseline assessments are denoted as moment 1 (M1) and post-intervention assessments after the six-week training period as moment 2 (M2). Eye-tracking metrics, decision-making indexes, and neurofeedback parameters were analysed using i-Brain and i-Tracker technologies. Players showed significant improvements in technical and tactical performance, particularly in shooting velocity and offensive unit efficiency, alongside enhanced decision-making stability and defensive coordination. Eye-tracking metrics revealed increased fixation efficiency and reduced revisit counts, indicating more effective visual search strategies. YYIR1 performance improved, suggesting that the intervention did not impair intermittent recovery capacity. The integration of eye-tracking and neurofeedback training demonstrated potential for enhancing cognitive and technical performance in female youth football players. Improvements in shooting accuracy, decision-making speed, and gaze efficiency suggest that these technologies could be valuable additions to traditional training methods.
#21 Visual search behavior and decision-making in expert and less-experienced football referees across different foul situations: an eye-tracking study
Reference: Front Psychol. 2026 Jun 10:17:1871146. doi: 10.3389/fpsyg.2026.1871146. eCollection 2026.
Authors: Zilu Zhou, Rancheng Tao, Kongyun Huang, Changjing Zhou
Download link: https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2026.1871146/full
Summary: Modern football imposes considerable demands on referees‘ rapid foul judgements, yet the dissociation between accuracy and efficiency of officiating expertise across different foul situations remains poorly characterized. The present study compared 15 national-level and 15 Class-3 male football referees in three typical situations: ball-contesting, tactical foul and handball. Participants viewed 30 real-match video clips and made one technical and one disciplinary decision per clip while an EyeLink 1000 Plus eye tracker recorded global eye-movement indices and area-of-interest (AOI) measures. Data were analyzed with 2 (group) × 3 (situation) mixed-design ANOVAs and independent-samples t-tests. Decision accuracy did not differ between groups for either technical or disciplinary judgements, although a robust situation main effect was observed [technical accuracy F (2,56) = 116.45, p < 0.001, η2 p = 0.81; disciplinary accuracy F (2,56) = 13.73, p < 0.001, η2 p = 0.33]. For decision efficiency, disciplinary reaction time showed a Group × Situation interaction [F (2,56) = 4.16, p = 0.021, η2 p = 0.13]; simple-effect analysis indicated that national-level referees responded faster than Class-3 referees in ball-contesting situations [F (1,28) = 6.07, p = 0.020, η2 p = 0.18]. Pupil diameter showed an analogous interaction (p = 0.026), although within-situation simple effects did not reach significance. AOI analyses revealed that national-level referees fixated the upper body of the fouling player earlier in ball-contesting situations [t(26.02) = -2.38, p = 0.024, d = 0.87] and revisited the attacker’s lower body and the defender’s upper body less often in handball situations (both p < 0.05, d ≥ 0.80). Within this video-based task, expertise-related differences emerged primarily in efficiency-related indices rather than overall accuracy; sample size, the simulated nature of the stimuli and ceiling-or-near-chance effects in some conditions limit generalization, and the findings warrant validation in real-match settings.
#22 Comparative Analysis of Markerless Motion-Capture Models for Assessing Football Kinematics During 30 m Long-Pass Tasks
Reference: Sensors (Basel). 2026 Jun 8;26(12):3654. doi: 10.3390/s26123654.
Authors: Donghao Wang, Junkai Yu, Shiqin Chen, Jingran Yang, Weichao Jiang, Yikang Gong, Chong Luo
Download link: https://www.mdpi.com/1424-8220/26/12/3654
Summary: This study was based on a 30 m inside-foot long-pass scenario and aimed to preliminarily evaluate the agreement between MediaPipe Pose, DWPose, YOLO-Pose, and Xsens, as well as their practical utility under real-field conditions. Twelve elite male football players performed 15 consecutive long-passes, with data collected simultaneously using Xsens and two smartphones positioned at 15° and 35° to the right front of the participants. The Intraclass Correlation Coefficient (ICC (2,1)) and Bland-Altman analysis were used to evaluate discrete kinematic measures. Continuous kinematic agreement was assessed using Root Mean Square Error (RMSE) and the Coefficient of Multiple Determination (CMD), while Statistical Parametric Mapping (SPM) and Statistical non-Parametric Mapping (SnPM) compared differences across the entire analysis interval. Across the three models, CMD ranged from 0.13 ± 0.17 to 0.67 ± 0.25, and RMSE ranged from 9.88 ± 8.20° to 39.92 ± 10.44°. The SPM and SnPM results showed that significant differences were mainly concentrated in the bilateral hip, knee, and ankle joints. The three models cannot yet be used for field-based high-precision kinematic data measurement; however, MediaPipe Pose and DWPose may be selectively used for rapid screening of movement patterns and analysis of movement trends in football-specific technical movements.
#23 Fast-Food Consumption Frequency, Food-Choice Motivations, and Mediterranean Diet Adherence in Young Football Athletes: A Cross-Sectional Study
Reference: Nutrients. 2026 Jun 9;18(12):1850. doi: 10.3390/nu18121850.
Authors: Leandro Oliveira, Mariana Salgueiro, Marta Esgalhado
Download link: https://www.mdpi.com/2072-6643/18/12/1850
Summary: Dietary behaviours in young athletes are shaped by multiple behavioural, social, and environmental influences, which may contribute to the coexistence of healthy and unhealthy eating patterns. This study aimed to explore factors associated with fast-food consumption frequency and adherence to the Mediterranean diet (MD) among young football athletes. A cross-sectional study was conducted among 94 male football players aged 10-16 years from a Portuguese football club. Adherence to the MD was assessed using the Mediterranean Diet Quality Index for Children and Adolescents (KIDMED) index. Fast-food consumption patterns and food-choice motivations were evaluated through a structured questionnaire. Anthropometric measurements were obtained using standardised procedures. Correlation, linear regression, and ordinal regression analyses were performed. Most participants demonstrated high adherence to the MD (96.8%), with a median KIDMED score of 12.0 (IQR: 10.0-13.0). Although 88.3% of participants reported consuming fast food, intake frequency was generally low, with 67.0% reporting consumption never or only once per month. Higher fast-food consumption frequency was associated with lower fruit and vegetable intake and higher consumption of sweets and pastries. No significant associations were observed between fast-food consumption frequency and overall MD adherence, Body Mass Index z-score, or fat mass percentage. Higher health-related motivation scores were associated with lower odds of more frequent fast-food consumption (OR = 0.248; p = 0.021), whereas greater decision autonomy regarding restaurant choice was associated with higher consumption frequency (OR = 4.036; p = 0.010). Young football athletes showed high adherence to the Mediterranean diet despite the presence of fast-food consumption, suggesting that healthy and unhealthy dietary behaviours may coexist within the same population. Behavioural factors, particularly health motivations and food-choice autonomy, appear to influence fast-food consumption independently of overall diet quality and anthropometric status.
#24 Aerobic Fitness Is the Main Determinant of Match-Related Physical Performance Decline in Professional Football Players (Part 2)
Reference: J Strength Cond Res. 2026 Jun 10. doi: 10.1519/JSC.0000000000005546. Online ahead of print.
Authors: Leo Antenucci, Christian Schmidt, Davide Malatesta
Summary: High-intensity efforts are critical in football performance and declines in running distance and acceleration (ACC) and deceleration (DEC) capacity are often observed after the 60th or 75th minute, partly indicating player fatigue. This study investigated the decline in physical performance during a professional football match and its relationship with physical fitness parameters. Global navigation satellite system data from an entire Swiss first-division season (30 matches) were analyzed for 19 professional football players. The players‘ speed at the first and second lactate thresholds (sLT1/sLT2) and peak incremental speed (PIS) were assessed using a maximal incremental treadmill test. The maximal sprint speed (MSS) was determined from match data to calculate the anaerobic speed reserve (ASR = MSS – PIS). The distance covered in low-/high-/very high-speed running (LSR/HSR/VHSR) and sprinting using individual thresholds (<sLT2, sLT2-PIS, PIS-30% ASR, >30% ASR), and the number of ACCs/DECs performed in 4 intensity zones (ACC1/2/3/4/DEC1/2/3/4: ±0.5-1.0, 1.0-2.0, 2.0-3.0, >3 m·s-2) were measured across 6 periods (P1-P6) of 15 minutes of matches. The vertical peak power was measured using squat and countermovement jumps. Significant (p ≤ 0.05) declines (4-27%) were observed after the 60th minute across all running, ACC/DEC intensity zones, and in total distance (TD) and total number of ACCs/DECs (ACCTOT/DECTOT) counts, except for sprint distance and ACC1/DEC1. Moderate-to-large correlations were found between aerobic fitness (sLTs and PIS) and decreases in TD, ACCTOT/DECTOT, and high-intensity running, ACCs/DECs between P1 (0-15 minutes) and P5 (60-75 minutes) (r = 0.46-0.67; p ≤ 0.049). Coaches should focus on enhancing players‘ aerobic fitness to improve their ability to maintain physical performance throughout match-play.