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 Hamstrings on focus: Are 72 hours sufficient for recovery after a football (soccer) match? A multidisciplinary approach based on hamstring injury risk factors and histology

Reference: J Sports Sci. 2024 Aug 1:1-17. doi: 10.1080/02640414.2024.2386209. Online ahead of print.
Authors: Gerard Carmona, Lia Moreno-Simonet, Pedro Luís Cosio, Andrea Astrella, Daniel Fernández, Joan Aureli Cadefau, Gil Rodas, Cristina Jou et al.
Summary: This study aimed to assess acute and residual changes in sprint-related hamstring injury (HSI) risk factors after a football (soccer) match, focusing on recovery within the commonly observed 72-h timeframe between elite football matches. We used a multifactorial approach within a football context, incorporating optical and ultrastructural microscopic analysis of BFlh (biceps femoris long head) muscle fibres, along with an examination of BFlh fibre composition. Changes in sprint performance-related factors and HSI modifiable risk factors were examined until 3 days after the match (MD +3) in 20 football players. BFlh biopsy specimens were obtained before and at MD +3 in 10 players. The findings indicated that at MD +3, sprint-related performance and HSI risk factors had not fully recovered, with notable increases in localized BFlh fibre disruptions. Interestingly, match load (both external and internal) did not correlate with changes in sprint performance or HSI risk factors nor with BFlh fibre disruption. Furthermore, our study revealed a balanced distribution of ATPase-based fibre types in BFlh, with type-II fibres associated with sprint performance. Overall, the results suggest that a 72-h recovery period may not be adequate for hamstring muscles in terms of both HSI risk factors and BFlh fibre structure following a football match.

2 Comparison of an Adaptive Ankle Brace to Conventional Taping for Rehabilitation of Acute Ankle Injury in Young Subelite Soccer Players: A Pilot Study

Reference: J Sport Rehabil. 2024 Jul 31:1-8. doi: 10.1123/jsr.2023-0290. Online ahead of print.
Authors: Dirk Krombholz, Steffen Willwacher, Tobias Consmüller, Anna Linden, Burkay Utku, Jessica Zendler
Summary: Ankle sprains are a common injury in sports, for which use of external ankle support during rehabilitation has been suggested to improve clinical outcomes. Thirteen soccer players experiencing acute lateral ankle sprain injury were provided a novel adaptive ankle brace or conventional ankle taping (control) as external ankle support throughout the injury rehabilitation process. All other clinical procedures were identical, and rehabilitation was supervised by the same team staff member. Time from injury to clearance to return to sport was tracked. Player experience with the ankle brace also was queried via electronic surveys. The median time to return to sport was less for the Brace group (52.5 d) compared to the Control group (79.5 d), but the distributions of the 2 groups were not found to differ significantly (P = .109). Player surveys indicated they felt the brace to be comfortable or very comfortable, with better freedom of movement than other braces and the same freedom of movement as wearing no brace. All players reported wearing the brace to be the same or better experience as ankle taping. These preliminary results indicate that the adaptive ankle brace is at least as effective as ankle taping for providing external support during the rehabilitation phase following acute lateral ankle sprain and suggest it may be a more effective ankle support solution in terms of patient compliance than conventional bracing or taping.

3 Relation of general-perceptual cognitive abilities and sport-specific performance of young competitive soccer players

Reference: Eur J Sport Sci. 2024 Jul 30. doi: 10.1002/ejsc.12171. Online ahead of print.
Authors: Nils Schumacher, Christoph Zaar, Jannik Kovar, Lorenz Lahmann-Lammert, Bettina Wollesen
Download link: https://onlinelibrary.wiley.com/doi/epdf/10.1002/ejsc.12171
Summary: In soccer, skill is significantly influenced by motor skills and physical constitution. In addition, perceptual-cognitive abilities are thought to affect sport-specific performance. Nevertheless, there are hardly any studies investigating the relationship of general cognitive abilities with sport-specific performance. Therefore, the aim of this study was to analyze relationships between general perceptual-cognitive abilities and soccer-specific performance in competitive youth sports. Thirty highly talented male youth soccer players aged 12-14 years completed various perceptual-cognitive (selective attention, cognitive flexibility, inhibition, working memory, peripheral perception, and choice response) and sport-specific on-field tests. Cognitive abilities were assessed using a computer-based test system. Soccer-specific performance skills were evaluated by two sport-specific on-field tests. The relation between perceptual-cognitive abilities and soccer-specific performance was examined using a correlation analysis as well as a four-stage regression analysis. Overall, the expression of general perceptual-cognitive abilities was found to have an impact on performance in soccer-specific test situations, particularly cognitive flexibility and selective attention. Our results suggest that general cognitive tests could be an important tool for the evaluation of cognitive abilities in soccer. This study brings together key approaches in expertise research and makes a significant contribution to a better understanding of expertise in soccer.

4 Is Travel Associated With Match Performance in Elite North American Professional Soccer? An Exploratory Study

Reference: Int J Sports Physiol Perform. 2024 Jul 30:1-9. doi: 10.1123/ijspp.2024-0035. Online ahead of print.
Authors: Garrison Draper, Paul Chesterton, Matthew David Wright
Summary: Travel fatigue impacts cognitive and physiologic systems, but its association with elite soccer match performance is unclear. In this retrospective observational study, we aimed to explore the association between travel and match outcomes in elite North American soccer. Travel data and match outcomes (team points or goals scored and conceded) and physical performance outcomes from 26 elite professional soccer teams and their players were analyzed (148 matches [team-based data] and 1252 player matches from 297 players; age 22.7 [4.5] y). Player- and match-level correlations between performance measures and both acute and cumulated travel metrics were analyzed. Cumulative travel metrics were positively associated with team (travel distance [r = .20; 95% CI, .03-.25], travel time [r = .20; .06-.37], and time away [r = .20; .06-.37]) and individual player (travel distance, [r = .14; .08-.19], travel time [r = .17-.23], and time away [r = .13; .07-.18]) high-intensity running. Cumulative time away was negatively associated with team points (r = -.14; -.28 to -.001) and positively associated with goals conceded (r = .14; .01-.27); no clear association between acute travel metrics and match outcomes or physical performance was observed. As travel cumulated, away teams and their players ran more but for less reward (team points), although the magnitude of these associations was small. These data are exploratory and do not imply a causal relationship; however, further research should consider cumulation of travel.

5 Comparing video feedback and video modeling plus video feedback for improving soccer skills

Reference: J Appl Behav Anal. 2024 Jul 30. doi: 10.1002/jaba.2903. Online ahead of print.
Authors: Samantha K Martinez, Raymond G Miltenberger, Shreeya S Deshmukh
Summary: This study compared the effects of video feedback (VF) as a stand-alone intervention and video modeling plus video feedback (VMVF) for improving soccer players‘ static ball control skills. Research has suggested that VF alone and VMVF produce substantial improvements for young athlete’s skills, though no studies have compared the two. Therefore, we used a multiple-baseline-across-participants design with embedded alternating treatments to compare VF and VMVF. Two 10-year-old female soccer players and one 9-year-old male soccer player participated. The first author implemented the VF and VMVF training procedures and assessed the same three target behaviors across participants. The results suggested that VF and VMVF produced similar increases in performance for two of three participants and that VMVF produced slightly greater increases for one participant. In addition, both interventions were effective at substantially improving ball control skills from baseline levels and relative to a control skill.

6 The Effect of Combined Transcranial Direct Current Stimulation and Pneumatic Compression as Part of a Comprehensive Recovery Strategy in Professional Male Top-Level Soccer Players

Reference: J Strength Cond Res. 2024 Jul 23. doi: 10.1519/JSC.0000000000004844. Online ahead of print.
Authors: Daniel Soares Gonçalves, Luciane Aparecida Moscaleski, Gisele Maria da Silva, Ryland Morgans, Alexandre Hideki Okano, Alexandre Moreira
Summary: This retrospective study aimed to examine the effect of transcranial direct current stimulation (tDCS) combined with lower limb pneumatic compression during the postmatch recovery period in top-level professional male soccer players‘ physiological and perceptual markers of recovery status. During the 2022 season (baseline), pneumatic compression was performed as part of the recovery strategy, applied the day after official match play and psychophysiological measurements (pain, sleep, perceived recovery, and creatine kinase [CK] sampling) were performed on the second day postmatch. During the 2023 season, the tDCS protocol was introduced, with its application being performed simultaneously (in conjunction) with pneumatic compression. Recovery sessions following 10 matches in the 2022 season and following 10 matches in the 2023 season were included in the analyses. Compared with 2022 (baseline; pneumatic compression isolated), the players perceived an increased recovery on the second day postmatch when tDCS was used in conjunction with the pneumatic compression (mean = 12%; p = 0.008) and rated improved sleep quality for the nights after applying tDCS combined with pneumatic compression (mean = 7.5%; p = 0.029). On the second day postmatch, a significant reduction was observed in muscle pain/soreness (mean = 64%; p < 0.0001) and the CK concentration decreased when baseline (pneumatic compression isolated) was compared with tDCS + pneumatic compression (mean = 76%; p = 0.001). In summary, combining pneumatic compression with tDCS may enhance the effects of both interventions, leading to greater overall improvements in recovery. Further research is warranted to confirm these findings and explore the underlying mechanisms in more detail.

7 Performing Lower-Limb Strength Exercises Before or After Training Does not Influence Fatigue Indices in Competitive Youth Soccer Players

Reference: J Strength Cond Res. 2024 Jul 23. doi: 10.1519/JSC.0000000000004860. Online ahead of print.
Authors: Carson Gantzer, Drake Huff, Brooke Butterick, Samuel Chalmers, Paul Marshall, Ric Lovell, Jason C Siegler
Summary: A multicenter approach was used to conduct a controlled, laboratory-based study (Part A) in conjunction with an ecologically focused, field-based study (Part B) of the influence of timing on hamstring fatigue induced by lower-limb strength exercises. Part A required players to perform the FIFA 11+ warm-up before a simulated soccer training session, whereas the other session involved removing the lower-limb strength exercises from the warm-up and delivering them after the simulated session. For Part B, players completed 2 live training sessions, where one session included the Nordic hamstring exercise (NHE) as part of a standardized warm-up before training and the other session incorporated the NHE at the end of training. Maximal hamstring force (MVC), rate of force development (RFD), countermovement jump (CMJ), and sprint speed (SS) were assessed before, during, and after the simulation and field training, respectively, to quantify fatigue across both study cohorts. There was no suggestion that timing of the intervention had an influence fatigue in either Part A or B, with no condition (MVC [Part A & B]: p > 0.43; RFD: p = 0.43; CMJ: p = 0.10; SS: p = 0.62), time (MVC: p > 0.30; RFD: p = 0.72; CMJ: p = 0.87; SS: p = 0.85), or interactions (MVC: p > 0.93; RFD: p = 0.78; CMJ: p = 0.99; SS: p = 0.94) evident. Our findings suggest youth soccer coaches should not be concerned with the timing of interventions, allowing them to focus instead on adherence and player buy-in.

8 The Effects of Volume-Matched 1- and 2-Day Repeated Backward Sprint Training Formats on Physical Performance in Youth Male Soccer Players

Reference: J Strength Cond Res. 2024 Jul 23. doi: 10.1519/JSC.0000000000004859. Online ahead of print.
Authors: Raja Bouguezzi, Yassine Negra, Senda Sammoud, Aaron Uthoff, Jason Moran, Martin Behrens, Helmi Chaabene
Summary: This study examined the effects of a 6-week, 1 vs. 2 sessions of volume-matched weekly repeated backward sprint training (RBST) on measures of physical fitness in youth male soccer players. Thirty male youth soccer players from a regional soccer team were randomly assigned to a 2-day group (n = 15; age = 16.40 ± 0.64 years; Maturity-offset = 2.19 ± 0.65 years) or a 1-day group (n = 15; age = 16.27 ± 0.51 years; Maturity-offset = 1.91 ± 0.40 years). Measures of jumping ability, linear sprint speed, change-of-direction (CoD) speed, aerobic endurance (AE), and repeated sprint ability (RSA) were measured before and after 6 weeks of training. The training interventions involved 1 to 2 sets, each comprising 7 repetitions over a 20-m distance of RBST in the 2-day group, and 2 to 4 sets, also with 7 repetitions each over the same distance, in the 1-day group. Statistical analyses were conducted using the analysis of covariance model with baseline measurements entered as covariates. Results indicated that RBST over 2 days generated greater benefits compared with a single day for improving CoD speed (∆4.91 vs. 0.04%; effect size [d] = 0.78 vs. 0.00, respectively), linear sprint speed (10-m: ∆4.74 vs. 0.36%; d = 0.96 vs. 0.00, respectively; 20 m: ∆3.34 vs. 0.82%; d = 1.00 vs. 0.49, respectively), and RSA performances (RSAbest: ∆2.61 vs. 0.29%; d = 0.71 vs. 0.16, respectively; RSAmean: ∆2.86 vs. 0.89%; d = 0.59 vs. 0.16, respectively; RSAtotal: ∆2.86 vs. 0.89%; d = 0.62 vs. 0.41, respectively). However, similar improvements in the 2 RBST formats were observed on jumping (2-day group: ∆6.9%; d = 0.75; 1-day group: ∆10.6%, d = 1.26) and AE performance (2-day group: ∆17.24%, d = 1.04; 1-day group: ∆27.25%, d = 2.25). In summary, the findings suggest that, when volume is matched, spreading the RBST regimen over 2 days may result in greater improvements compared with a single-day approach for enhancing CoD speed, linear sprint speed, and RSA performance.

9 The Effect of Traditional Strength Training on Sprint and Jump Performance in 12- to 15-Year-Old Elite Soccer Players: A 12-Month Controlled Trial

Reference: J Strength Cond Res. 2024 Jul 23. doi: 10.1519/JSC.0000000000004890. Online ahead of print.
Authors: Josua Skratek, Björn Kadlubowski, Michael Keiner
Summary: The aim of the study was to evaluate the effect of traditional strength training on maximum strength (1 repetition maximum in front squat [FS] and back squat [BS]), jump (squat and countermovement jump), and linear sprint (LS) performance (5, 10, and 30 m) in elite young soccer players. A 12-month longitudinal design was chosen, and 48 elite male youth soccer players (age: 12-15 years) were included. The subjects were divided in 2 groups (a strength training group [STG] and a control group [CG]). The intervention group trained for 1 year over a competitive soccer season with additional sessions to their regular soccer practice (4 sessions per week), while the CG did not complete any additional sessions to the regular soccer training (4 sessions per week). The additional strength training (2 sessions per week [each approximately 30 minutes]) consisted of either parallel FS or BS. The squat variants switched in each session. Data were analyzed using a 2 × 3 (group × time) repeated-measures analysis of variance. The main findings of this study were that the STG resulted in significant pretest and post-test improvements in maximum strength (d = 3.75-5.58), jump (d = 0.84-1.14), and LS performance (d = -0.25 to 0.44), while for the CG, smaller increases or performance decreases were measured (maximum strength: d = 1.64-2.7; jump: d = 0.12-0.31; sprint: d = 0.00-025). A significant interaction effect in all variables indicated significant (p < 0.05) stronger performance improvements compared with the CG. Traditional strength training in elite youth soccer players is recommended to increase strength and speed-strength (jump and sprint performance) and should be considered in long-term athletic development programs.

10 The Relationship Between Motor Competence and Landing Error Scoring System Performance in Youth Soccer Players

Reference: J Strength Cond Res. 2024 Jul 23. doi: 10.1519/JSC.0000000000004843. Online ahead of print.
Authors: Michael J Duncan, Theresa Heering, Jason Tallis, Lucas Guimaraes-Ferreira, Ricardo Martins, Matteo Crotti, Lisa Barnett, Natalie Lander, Mark Lyons
Summary: This study examined the relationship between motor competence (MC) and Landing Error Scoring System (LESS) performance in a sample of male junior grassroots footballers aged 10–13 years. Ninety-eight boys aged 10–13 years (mean ± SD = 11.7 ± 1 years) undertook assessment of MC, using the Test of Gross Motor Development (third edition) and anterior cruciate ligament (ACL) injury risk using the LESS. Height and mass were assessed from which maturity status was predicted. Multiple backward linear regressions indicated a significant model (p = 0.001), which explained 49% of the variance in LESS scores. Locomotor MC (β = −0.538, p = 0.001), object control MC (β = −0.261, p = 0.004), and age (β = 1.17, p = 0.03) significantly contributed to the model. Maturity offset (p = 0.100) was not significant. Analysis of covariance (controlling for age and maturity offset) indicated a significant difference in locomotor MC between those classified as poor for LESS. A similar result was observed for object control MC (p = 0.003, ηηp2 = 0.09), where those classed as poor for LESS had significantly poorer object control MC compared with those classed as excellent, good, and moderate. The results of this study indicate that there is a relationship between both locomotor and object control MC and errors in drop jump landing mechanics in boys aged 10–13 years, with MC explaining nearly 50% of the variance in LESS scores. Practically, this study indicates that MC, particularly locomotor MC, has potential to identify performance in jump landing tests that are associated with increased risk of ACL injury in boys who play grassroots soccer.

11 Sex Differences in Physiological Responses to a National Collegiate Athletic Association Division I Soccer Season

Reference: J Strength Cond Res. 2024 Jul 23. doi: 10.1519/JSC.0000000000004882. Online ahead of print.
Authors: Bridget A McFadden, Alan J Walker, Harry P Cintineo, Brittany N Bozzini, David J Sanders, Alexa J Chandler, Shawn M Arent
Summary: Identifying physiological changes that occur in response to workload demands can help to elucidate athlete management and recovery strategies. The purpose of this study was to compare the physical and physiological demands between men and women throughout the course of a collegiate soccer season. Men (N = 23) and women (N = 26) soccer players participated in blood draws before preseason (T1) and every 4 weeks thereafter (T2-T4). Workload was determined at all practices and games via heart rate and global positioning satellite monitoring systems. Repeated measures multivariate analysis of variance and linear mixed models were used to assess workload and biomarker responses throughout the season (p < 0.05). Both teams experienced the highest workloads during the first 4 weeks of the season (p < 0.05), which was followed by several biomarker perturbations. Sex-by-Time interactions were observed for total cortisol, growth hormone, insulin-like growth factor-1, thyroxine, thyroid-stimulating hormone, vitamin D, and omega 3 fatty acid index (p < 0.05). Additional Sex effects were observed for free and total testosterone, estrogen, prolactin, sex-hormone binding globulin, creatine kinase, and iron levels (p < 0.05). Women soccer players experienced further Time effects for free cortisol, iron, ferritin, and percent transferrin saturation (p < 0.05). Male soccer players experienced additional Time effects for total testosterone, estrogen, creatine kinase, interleukin-6, triiodothyronine, and ferritin (p < 0.05). Despite similar patterns of change in workloads, differential fluctuations in physiological markers were observed between the sexes. Understanding sex differences in response to comparable workloads may enhance exercise prescriptions for better athlete management plans. Additional strategies to increase iron may be warranted in female athletes.

12 How Do Young Soccer Players Train? A 5-Year Analysis of Weekly Training Load and its Variability Between Age Groups in an Elite Youth Academy

Reference: J Strength Cond Res. 2024 Aug 1;38(8):e423-e429. doi: 10.1519/JSC.0000000000004813.
Authors: Darragh R Connolly, Sean Stolp, Antonio Gualtieri, Duccio Ferrari Bravo, Roberto Sassi, Ermanno Rampinini, Aaron J Coutts
Summary: The aim of this study was to quantify the session rating of perceived exertion (sRPE), duration, and training load accrued across typical training weeks undertaken by youth soccer players. Differences between starters, nonstarters, and variations in training load variables were also investigated. Data were collected from 230 elite youth players in 4 age groups (U15, U16, U17, and U19) during 5 competitive seasons. Mixed models were used to describe variation between age groups and compare starters with nonstarters, with season as a fixed covariate effect. Week-to-week variation in training load was expressed as the percentage coefficient of variation. The main findings may be used to highlight a significant effect of age and playing status on training intensity, duration, and internal training load. Weekly training load increased progressively from the U15 to U17, with significant differences between each age group (p < 0.03). Lower mean weekly perceived intensity (sRPE) was noted in U15 when compared with the older age groups (4.2 vs. 4.6-4.9 arbitrary unit for U16 to U19, p < 0.001). Low weekly training load variation was observed across the different phases of the season in each age group, with the preseason exhibiting the greatest variance (3.6-6.2%). Differences in the training load are likely more attributable to changes in training duration rather than sRPE. Control of session duration seems to play an important role when aiming to control load in the academy environment, and practitioners should closely monitor the differences in duration and load being recorded between starters and nonstarters.

13 Seasonal Changes in Match Demands and Workload Distribution in Collegiate Soccer Across Two Seasons

Reference: J Strength Cond Res. 2024 Aug 1;38(8):1440-1446. doi: 10.1519/JSC.0000000000004802.
Authors: Sean Floersch, Chad Vidden, Andrew T Askow, Margaret T Jones, Jennifer B Fields, Andrew R Jagim
Summary: The purpose of this study was to examine seasonal changes in match demands in a collegiate women’s soccer team. Forty-eight NCAA Division III women soccer athletes (age: 19.5 ± 1.2 years; height: 1.67 ± 0.05 m; body mass: 64.8 ± 7.4 kg; fat-free mass: 50.0 ± 4.5 kg; body fat %: 22.6 ± 6.0) were equipped with wearable global positioning systems with inertial sensors and heart rate (HR) monitors during matches throughout the 2019 (n = 22) and 2021 seasons (n = 26). Players were classified by position: flank player (FP; n = 28), center midfielder (CM; n = 11), and center back fielder (CB; n = 9) and as starters (S, n = 17) or reserves (R, n = 31). Variables included HR, training load, total distance, high-speed distance, distance per minute, and weighted distance. Differences in match and practice session demands were analyzed using linear mixed-effects models with season (2 levels; 2019 and 2021) as a fixed factor, with alpha set to p = 0.05. Data across all matches and training sessions were collapsed and presented as mean ± SD for descriptive purposes and then grouped by session type (i.e., match or training) and position. Athletes traveled more distance at high speeds during match play in the 2021 season compared with 2019 (mean difference, 95% confidence intervals [CI]) (200, 95% CI: 104, 304 km; p < 0.05) but had a lower training load in 2021 compared with 2019 (-50, 95% CI: -63, -36; p < 0.05) during match play. For training sessions, mean HR (4, 95% CI: 2, 5 bpm), total distance (0.5, 95% CI: 0.4, 0.7), distance per minute (5.6, 95% CI: 4.5, 6.7 m·min-1), high-speed distance (43, 95% CI: 43, 18, 67 m), high accelerations (8.6, 95% CI: 5.4, 11.8 n), and high accelerations per minute (0.1, 95% CI: 0.1, 0.1 n·min-1) were all higher in 2021 compared with 2019 (p < 0.05). As a team, several differences in measures of external workload were found between seasons in both session types (training and matches). Variations in positional demands of match play appear to fluctuate by year.

14 Effectiveness of 12-Week Core Stability Training on Postural Balance in Soccer Players With Groin Pain: A Single-Blind Randomized Controlled Pilot Study

Reference: Sports Health. 2024 Jul 27:19417381241259988. doi: 10.1177/19417381241259988. Online ahead of print.
Authors: Fatma Chaari, Sébastien Boyas, Haithem Rebai, Abderrahmane Rahmani, Sonia Sahli
Summary: Core stability training (CST) is effective in improving postural balance, core endurance, and self-reported outcomes in different populations. This study aimed to investigate the effect of CST in soccer players with groin pain (GP). The hypothesis was that CST would improve postural balance performance, core endurance, and self-reported outcomes in soccer players with GP. Soccer players with GP who met the selection criteria were assigned randomly to a CST (CSTG, n = 10) or a control (CG, n = 10) group. The CG undertook no additional physical activity program besides their usual training. The CSTG performed a 12-week CST comprising 76 ~75 min sessions. Static (force platform) and dynamic (Y-Balance test) postural balance, core endurance (McGill trunk endurance tests), and self-reported outcomes (Copenhagen Hip and Groin Outcome Score [HAGOS]) were assessed before and immediately after the 12-week CST. Significant improvements were seen in dynamic postural balance (P = 0.04 to <0.01), HAGOS scores (P = 0.02 to <0.01), and core endurance measures (P < 0.01) in the CSTG in posttest compared with pretest session and compared with CG. Static bipedal postural balance measures showed significant improvements (eyes open, P = 0.02; eyes closed, P < 0.01) in the CSTG in posttest compared with pretest session. However, no significant differences (P > 0.05) were observed between CSTG and CG after the training period. A 12-week CST improved static (foam surface) and dynamic postural balance, core endurance measures, and HAGOS scores. The beneficial effect of CST on improving postural balance, core endurance, and self-reported outcomes in soccer players with GP suggests that this training would be an important feature of rehabilitation programs for these players. Coaches and clinicians should prioritize CST training when designing rehabilitation programs.

15 Perspectives on reasons why football and handball players sustain acute and severe knee injuries: a mixed-methods concept mapping study

Reference: BMJ Open Sport Exerc Med. 2024 Jul 30;10(3):e002048. doi: 10.1136/bmjsem-2024-002048. eCollection 2024.
Authors: Tine Alkjær, Elisabeth Bandak, Marius Henriksen, Robin Christensen, Kristian Thorborg, Mette K Zebis, Jesper Bencke, Pætur M Holm, Eva E Wæhrens
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11293416/pdf/bmjsem-10-3.pdf
Summary: The high incidence of knee injuries in football/handball challenges effective prevention. Identifying tangible and modifiable factors associated with a knee injury may innovate preventive actions. Engaging key stakeholders can reveal crucial insights that could improve knee injury prevention in football/handball. The aim was to investigate football/handball stakeholders‘ perspectives on reasons for acute and severe knee injuries to generate a conceptual model on important factors associated with knee injuries in football/handball. Mixed-method participatory Group Concept Mapping was applied to collect statements from football/handball stakeholders (players/coaches/healthcare staff/researchers) on the question, ‚What may explain why some players sustain a knee injury?‘. Participants rated the importance and feasibility of screening for each statement. Multidimensional scaling and hierarchical cluster analysis produced a cluster map, forming the basis for developing a final conceptual model. Stakeholders (n=37) generated and sorted 100 statements. Cluster analysis followed by cluster map validation yielded seven themes: (1) the player’s physical and motor skill profile, (2) preparation and training, (3) footwear and playing surface, (4) the sport’s impact on the risk of injury, (5) mental and physical fatigue, (6) history of injury and 7) genetics and context. A final conceptual model illustrating factors associated with knee injuries in football/handball was developed. Forty-six statements were identified as both important and feasible to screen for. Stakeholders‘ perspectives on knee injuries in football/handball revealed a complex interplay of factors. We developed a conceptual model fostering stakeholder dialogue for enhanced prevention. Key among its themes is ‚preparation and training‘.

16 Self-Reported Menstrual Health, Symptomatology, and Perceived Effects of the Menstrual Cycle for Elite Junior and Senior Football Players

Reference: Int J Sports Physiol Perform. 2024 Aug 1:1-9. doi: 10.1123/ijspp.2023-0522. Online ahead of print.
Authors: Georgia A Brown, Mark Jones, Brandi Cole, Anik Shawdon, Rob Duffield
Summary: The aim was to describe the self-reported menstrual health, symptomatology, and perceived effects of the menstrual cycle on athletic performance for national and international Australian football (soccer) players. Players from national and domestic teams were invited to complete an online questionnaire regarding menstrual health, use of hormonal contraceptives (HCs), negative symptomatology, and perceived disruption of the menstrual cycle to performance. Descriptive statistics and binomial regressions with odds ratios (OR) were used to report the relationship of menstrual-related variables with perceived performance disruption. A total of 199 players (20.9 [5.1] y) completed the questionnaire, with 18% of players reporting using HCs. One primary amenorrhea case was detected, and 26% of players reported menarche at age ≥15 years. For non-HC users, the prevalence of secondary amenorrhea was 2%, oligomenorrhea was 19%, and heavy menstrual bleeding was 11%. Ninety-seven percent of players reported experiencing physical or affective menstrual symptoms (5 [1.3] per player), and 40% of all players reported that menstrual symptoms impacted their ability to work, study, train, or compete. Furthermore, 40% of players perceived their training or performance to be disrupted by the menstrual cycle. Increasing number of menstrual symptoms (OR = 1.43; 95% CI, 1.28-1.62; P < .001), heavy menstrual bleeding (OR = 12.73; 95% CI, 3.4-82.8; P < .001), and pelvic pain (OR = 3.40; 95% CI, 1.7-7.2; P < .001) increased the likelihood of perceiving the menstrual cycle to disrupt performance. Heavy menstrual bleeding and HC use were low among this cohort of national and international footballers, whereas amenorrhea and oligomenorrhoea were comparable with other football populations. Nearly all players reported menstrual symptoms, and increased symptomatology was associated with greater perceived effects on performance.

17 Career trajectories, transition rates, and birthdate distributions: the rocky road from youth to senior level in men’s European football

Reference: Front Sports Act Living. 2024 Jul 17:6:1420220. doi: 10.3389/fspor.2024.1420220. eCollection 2024.
Authors: Paolo Riccardo Brustio, Alexander B T McAuley, Alexandru Nicolae Ungureanu, Adam Leigh Kelly
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11288826/pdf/fspor-06-1420220.pdf
Summary: This study aimed to assess youth-to-senior transition rates, quantify the magnitude of relative age effect (RAEs), and evaluate how RAEs affect these transitions in 9,527 men’s national football players of England, France, Germany, Italy, and Spain. Regardless of national team, only -15%, 25%, and 40% of U17, U19, and U21 players successfully transitioned to the senior team, respectively, whilst -14%-24% progressed to senior level without being selected during youth. Data suggested a skewed birthdate distribution favouring relatively older players at U17, U19, and U21 levels across all countries, whereas RAEs were also present in England, Italy, and Spain at senior level. Youth-to-senior transition rates were modulated by birthdate at U17 and U19, whereby Q4 players were -2 and 1.5 times more likely to successfully transition at senior level than Q1 players, respectively. Selection at youth international level does not guarantee selection at senior level, but does make it more likely. Moreover, relatively younger athletes are disadvantaged in youth categories, although are more likely to transition to senior level once they have entered the pathway.

18 Persistence and activity levels of primitive reflexes in young high-level football players

Reference: Front Sports Act Living. 2024 Jul 17:6:1409257. doi: 10.3389/fspor.2024.1409257. eCollection 2024.
Authors: Julie Bastiere, Thibault Lussiana, Damien Young, Cyrille Gindre, Laurent Mourot
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11288865/pdf/fspor-06-1409257.pdf
Summary: Primitive reflexes (PR) induce involuntary automatic movements in response to specific stimuli. This study aimed to determine the prevalence of active PR in young high-level football players. Sixty-nine national-level football players from a French academy were tested (17.0 ± 1.4 years; 69.6 ± 8.0 kg; 178.9 ± 6.9 cm) to evaluate the persistence of PR, following the methodology of the Institute for Neuro-Physiological Psychology (INPP) and the classification by a global score (GS). Based on the sum of seven tests, each was rated between 0 = null and 4 = max. The GS is classified into five categories from no activity to maximal (0-1 = no activity, 2-7 = low, 8-13 = medium, 14-21 = high, and 22-28 = maximal). Around two-thirds (68.1%) of players presented active PR at different activity levels. Among them, a small proportion (7.2%) had medium GS, while 60.9% had a low GS. The GS was not dependent on field position or the age of the players (p > 0.05). However, playing football in an age category higher than their own was associated with significantly more active primitive reflexes (PR) compared to being in their age category (p < 0.01). The results showed that 72.7% of „upgraded“ football players had low GS and 18.2% had medium GS, compared to 55.3% and 2.1% in the non-upgraded group. The findings of the current study demonstrate that PR could still be active in a healthy population of high-level football players. Practicing a single sport for years and upgrading players could create a negative environment that can ultimately lead to the activation of otherwise integrated PR.

19 Evaluation of a football fitness implementation initiative for an older adult population in a small-scale island society

Reference: Front Public Health. 2024 Jul 16:12:1406601. doi: 10.3389/fpubh.2024.1406601. eCollection 2024.
Authors: May-Britt Skoradal, Tórur Sjúrðarson, Helgi Winther Olsen, Eli Nolsøe Leifsson, Vincent Pelikan, Magni Mohr, Annika Helgadóttir Davidsen
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11286383/pdf/fpubh-12-1406601.pdf
Summary: The proportion of older people increases globally, which calls for sustainable interventions promoting healthy aging. Therefore, we aimed to evaluate the potential of Football Fitness as a sustainable model to promote quality of life, mental health, and physical function for older adult. The study was conducted in collaboration with a municipality, a football club, and a university, and was designed as a randomized controlled trial. A total of 66 people (34 women, 32 men) older than 60 years were randomly assigned (60/40) to a Football Fitness (FOT) (n = 38, 20 women, 18 men) and a control group (CON) (n = 28, 14 women, 14 men). FOT participated in Football Fitness for 12 weeks. Quality of life (QoL) and mental wellbeing were determined pre-and post-intervention. Physical loading and Flow experience were measured in one representative training session. Blood pressure (BP), Yo-Yo Intermittent endurance test level 1 (Yo-Yo IE1), sprint performance, postural balance, and body composition were also performed pre-and post-intervention. An improvement in mental wellbeing was observed for both groups from pre- to post-intervention (p values <0.001) with no between-group differences. Regarding QoL, the environment domain improved in FOT compared to CON (p = 0.02). Mean Flow (M = 5.69; SD = 1.07) and perceived importance (M = 4.20; SD = 1.42) and average experienced difficulty was M = 5.23 (SD = 2.67), perceived skill (M = 5.23; SD = 2.56), and perceived balance (M = 5.64; SD = 1.56). These levels of flow can be characterized as being high. A between-group effect (p = 0.02) existed for systolic BP, which decreased (p < 0.01) by -5% [-8; -1%] in CON and remained unchanged in FOT. Both groups improved the Yo-Yo IE1 to a similar extent, with 28% [11; 44%] (p = 0.001) in FOT and 27% [9; 46%] in CON (p = 0.005). Postural balance improved (p = 0.004) by 38% [13; 63%] in FOT only, resulting in a superior (p = 0.01) balance score in FOT compared to CON post-intervention (p = 0.004). Football Fitness improved the environmental quality of life domain and postural balance in older adults. Additionally, it appears to be a feasible group activity for older adults that promotes high flow and physical loading during training.