Competitive Soccer Research Articles

The Effects of Antioxidant Supplementation on Soccer Performance and Recovery: A Critical Review of the Available Evidence

Background Soccer is linked to an acute inflammatory response and the release of reactive oxygen species (ROS). Antioxidant supplements have shown promising effects in reducing muscle damage and oxidative stress and enhancing the recovery process after eccentric exercise. This critical review highlights the influence of antioxidant supplements on performance and recovery following soccer-related activity, training, or competition. Methods: English-language publications from the main databases that examine how antioxidant-based nutrition and supplements affect the recovery process before, during, and after soccer practice or competition were used. Results: Coenzyme Q10 (CoQ10), astaxanthin (Asx), red orange juice (ROJS), L-carnitine (LC), N-acetyl cysteine (NAC), beetroot (BET), turmeric root, and tangeretin reduce muscle damage (creatine kinase, myoglobin, cortisol, lactate dehudrogenase, muscle soreness). Tangeretin, docosahexaenoic acid (DHA), turmeric root, and aronia melanocarpa restrict inflammation (leukocytes, prostalagdin E2, C-reactive protein, IL-6 and 10). Q10, DHA, Asx, tangeretin, lippia citriodora, quercetin, allopurinol, turmeric root, ROJS, aronia melanocarpa, vitamins C-E, green tea (GTE), and sour tea (STE) reduce oxidative stress (malondialdehude, glutathione, total antioxidant capacity, superoxide dismutases, protein carbonyls, ascorbate, glutathione peroxidase, and paraoxonase 1). BET and NAC reinforce performance (endurance, jump, speed, strength). Conclusions: Further research is needed to determine the main mechanism and the acute and long-term impacts of antioxidant supplements in soccer.

Oral but Not Topical Sodium Bicarbonate Improves Repeated Sprint Performance During Simulated Soccer Match Play Exercise in Collegiate Athletes.

This study investigated the effect of oral and topical sodium bicarbonate (SB) on soccer-specific performance during simulated soccer exercise. In a block randomized, double-blind, crossover design, 10 collegiate male soccer players (stature: 181.7 ± 3.2cm, body mass: 81.7 ± 10.5kg) performed soccer-specific performance tests (countermovement jumps, Illinois agility, 8 × 25m repeated sprints) throughout a 90-min soccer-specific aerobic field test (SAFT90) following 0.3g/kg body mass SB in capsules (SB-ORAL), 0.9036g/kg body mass PR Lotion (SB-LOTION), or placebo capsules and lotion (PLA). Soccer-specific performance tests were conducted pre-SAFT90, during half-time and post-SAFT90. Blood samples were analyzed for acid-base balance (pH; bicarbonate, HCO3-) and strong ions (sodium, Na+; potassium, K+). Average sprint times were quicker for SB-ORAL than PLA during half-time (3.7%; p = .049; g = .57) and post-SAFT90 (4.9%; p = .041; g = .66). SB-ORAL increased pH and HCO3- prewarm-up and during half-time (p < .05), and lowered K+ during half-time (p = .035) compared with PLA. SB-LOTION increased pH (p = .019) and lowered K+ (p = .012) during half-time compared with PLA. SB-LOTION increased Na+ postexercise compared with PLA (p = .008). Repeated sprint times during simulated soccer exercise improved for SB-ORAL, which might have been mechanistically underpinned by elevated blood buffering capacity and greater regulation of strong ion concentration. Consuming SB in capsules is a more effective strategy than topical SB application for improving blood buffering capacity and repeated sprint performance throughout competitive soccer matches.

EEG differences in competitive female gymnastics, soccer, and esports athletes between resting states with eyes closed and open.

Athletes heavily rely on visual perception for performance. This study delves into electroencephalographic (EEG) brain activity among gymnastics, soccer, and esports athletes during resting states with eyes closed (REC) and open (REO) and compares differences in EEG alpha power from REC to REO (∆ EC-EO Alpha) across athlete groups. Forty-two female participants, including 14 from each athletic discipline, underwent two 5-minute EEG recordings, first during REC and then during REO conditions. Absolute EEG power was analyzed for delta (δ), theta (θ), alpha (α), and beta (β) frequency bands across various brain regions, and ∆ EC-EO Alpha values were computed. During REC, soccer players exhibited heightened α power at the midline frontopolar (Fpz) and β power at the midline occipital (Oz). Conversely, during REO, soccer players displayed increased δ power at Fpz and midline frontal (Fz) and reduced α power at the midline central (Cz) compared to gymnasts, along with elevated θ power at Fpz. Esports athletes demonstrated higher δ power and decreased α power at Fpz and Cz compared to gymnasts. Gymnasts exhibited distinct cortical activation patterns characterized by lower ∆ EC-EO Alpha at multiple electrode sites. These findings highlight sport-specific cortical activation patterns linked to visual attention among athletes. Understanding these neural adaptations could refine training methods and enhance performance outcomes in sports.

Relationship between testosterone and cortisol with anthropometric characteristics in professional male soccer players

Pre-season training has been demonstrated to modify the physical fitness and hormone levels in professional soccer players. The present study aimed to analyze the relationships between testosterone and cortisol with anthropometric characteristics in a professional male soccer team after the pre-season period. Fourteen volunteer professional male soccer players participated in this study. Significant decreases in anthropometric characteristics were found. For biochemical measures, cortisol (13) =-5.25, p=.001, d=-.27), testosterone (t (13) =-8.10, p=.001, d=-.65) and C/T ratio (t (13) =-4.07, p=.001, d =-0.2) significantly increased after the pre-season period. Moreover, moderate negative relationships were observed between the percentage of change in body weight, r=0.61, p=.01, body fat percentage, r=.53, p=.04, and testosterone. The present study revealed that the improvements in body composition after intense training in the pre-season period could stimulate anabolic activities such as increases in muscle mass, which is an important result in terms of quality of performance and prevention of injury risk, especially throughout the competitive soccer season. Testosterone and cortisol should be considered for future research as stress and recovery state indicators. In fact, professional soccer staff can use these parameters in combination with other indicators to optimize workloads and avoid overreaching and overtraining. Keywords: Testosterone; cortisol; professional soccer players; performance; physical fitness

Physical fitness, psychological characteristics, and game performance in youth male soccer players of different levels of competition

ABSTRACT This cross-sectional study examined the differences and associations regarding physical fitness, psychological characteristics, and game performance between elite (n = 64), sub-elite (n = 82), and non-elite (n = 97) youth male soccer players aged 16.2 ± 0.5 years. Physical fitness parameters were assessed using field tests, psychological characteristics were evaluated using validated questionnaires and technical – tactical data were recorded during a competitive soccer match using a multicamera, semiautomatic optical tracking system. Elite players demonstrated superior performance in cardiorespiratory fitness, countermovement jump (CMJ), 10 m sprint, and agility, compared to the sub-elite and the non-elite players. Also, the elite and sub-elite players had faster 40 m sprints than the non-elite players. Game performance was significantly better in the elite group than the other groups and was associated with coping with the adversity and coachability, tension-anxiety, anger-hostility, and fatigue-inertia subscales. Among the physical fitness parameters examined, only agility and CMJ were associated with game performance. In conclusion, elite youth soccer players performed significantly better in various physical fitness and psychological parameters and demonstrated a higher game performance indicator score compared to their sub-elite and non-elite peers. Results suggested that physical fitness and psychological parameters are essential predictors of game performance.

Evaluation of Blood Lactate among Different Player Roles: A Pilot Study on Competitive Young Male Soccer Players.

Soccer match requires anaerobic and aerobic energetic metabolism. The aim of this pilot study was to investigate the changes in blood lactate concentration in young male soccer players in different playing roles at different time points after the soccer match. Following an initial screening of 134 young soccer athletes, 8 male athletes (average age of 15.5 ± 5 SD) were chosen for their characteristics similar to those of competitive athletes. Players were categorized as goalkeeper, central defender, central midfielder, and forward. Blood lactate concentrations were determined using a portable device at different times (10 min, 5 and 16 h) after the soccer match by a maximum effort test on a treadmill. The data were analyzed by one-way analysis of variance ANOVA, followed by Bonferroni's post-hoc test. The following results (mean ± SD) were obtained: VO2max (%) 60.33 ± 3.10; blood lactate (mM) end match (10 min) 2.17 ± 0.78, post-match-early (after 5 h) 2.2 ± 0.42, postmatch-late (16 h) 3.2 ± 0.84. ANOVA analysis indicated that the blood LA concentrations at end-match (10 min) and post-match-early (5 h) were statistically significative lower than those determined at post-match-late (16 h) (p < 0.05). These results suggest that aerobic mechanisms can also use LA as an energy source, contributing to the reduction of its blood concentration. This effect can be due to reduced maximal work during a soccer match and to the LA removal during exercise at reduced intensity. These data can provide indications for planning suitable training strategies for young male soccer players.

Greater hip internal rotation range of motion is associated with increased dynamic knee valgus during jump landing, both before and after fatigue.

The aim of this study was to analyse sex-specific differences contributing to dynamic valgus in competitive soccer players before and after a standardised fatiguing protocol. Thirty-nine healthy female and male competitive soccer players (19 females and 20 males) were recruited for the purpose of this study. Bilateral medial knee displacement (MKD) was assessed during drop jump landings using a three-dimensional motion capture system before and after a standardised fatiguing protocol. In addition, all soccer players underwent clinical examinations, including rotational hip range of motion (ROM), isokinetic strength testing and magnetic resonance imaging (MRI) of the hip and knee. Sex-specific and fatigue-dependent differences were reported, and the influence of demographic, clinical and radiographic factors on MKD was analysed via multiple linear regression models. Compared with male soccer players, female soccer players demonstrated a tendency towards increased MKD during drop jump landings before (p = 0.09) and after the fatiguing protocol (p = 0.04). Sex-specific differences included increased hip internal rotation (IR) ROM, decreased hip external rotation (ER) strength and increased femoral torsion in females (all p < 0.002). According to the multiple linear regression models (stepwise method), increased hip IR ROM (90° of flexion) and the non-dominant leg remained the sole independent predictors of increased MKD during drop jump landings before (p < 0.01 and p = 0.02, respectively) and after fatigue (p < 0.01 and p < 0.01, respectively). An increase in hip IR ROM in females was linearly related to MKD after fatigue (R2 = 0.25; p < 0.01). Female soccer players exhibited increased dynamic valgus before and after fatigue, which is likely attributed to joint mobility, as well as muscular and anatomical differences, such as increased hip IR ROM, reduced hip ER strength and increased femoral torsion. In particular, females with increased hip IR ROM were more susceptible to effects of fatigue on MKD, which may increase their risk for anterior cruciate ligament injury. Level III.

Misconduct among Spanish grassroots soccer players: evidence for their management

ABSTRACT Purpose Identifying antisocial behaviour among child and youth players is crucial for managing and fostering a safe, supportive, and enjoyable sport. This study aimed to describe and analyse the disciplinary sanctions received by players in Spanish grassroots soccer competitions (6-18 years old). Methodology Referee records from 275,844 games across 1,401 league competitions during five subsequent seasons were examined using ANOVA and Tukey's HSD post hoc test. Findings A total of 53,031 sanctions were documented, primarily mild (93.33%). The most common mild sanctions resulted from card accumulation (41.8%), double warning (24.5%), violent or dangerous play (6.5%), and contemptuous and inconsiderate attitudes towards referees (5.5%). Assaults (3.3%) and insults and serious offences (2.7%) received serious sanctions from referees. Severe sanctions (0.004%) were anecdotal. Furthermore, we found significantly (p < .05) more sanctions in 11-a-side soccer than in 8-a-side, in boys versus girls’ categories, and U18 and U15 boys’ groups compared to younger age categories. Practical implications The strategies adopted for improving sportsmanship should especially target players in the U18 and U15 male categories and those who are repeat offenders. Our findings can be used to guide the prevention and intervention efforts of all institutions and agents with responsibilities in children’s sports education.

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

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 12-14years 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.

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

Gantzer, C, Huff, D, Butterick, B, Chalmers, S, Marshall, P, Lovell, R, and Siegler, JC. Performing lower-limb strength exercises before or after training does not influence fatigue indices in competitive youth soccer players. J Strength Cond Res XX(X): 000-000, 2024-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.

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.

Skratek, J, Kadlubowski, B, and Keiner, M. 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. J Strength Cond Res XX(X): 000-000, 2024-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.

Return to Soccer After Acute Anterior Cruciate Ligament Primary Repair: A 2-Year Minimum Follow-up Study of 50 Amateur Players.

Return to sport (RTS) after treatment of an anterior cruciate ligament (ACL) tear is a critical parameter to assess the outcome of a surgical procedure. However, few studies have investigated RTS after ACL repair. To evaluate RTS of a group of amateur soccer players at a minimum follow-up of 2 years after ACL repair. Case series; Level of evidence, 4. A retrospective review of all patients treated with acute ACL repair was conducted. A total of 50 amateur soccer players were included in the study. Patients were examined clinically or contacted to complete postoperative patient-reported outcome measures, namely the Knee injury and Osteoarthritis Outcome Score, the International Knee Documentation Committee questionnaire, the ACL-Return to Sport After Injury scale, and the Forgotten Joint Score-12. The patients' mean age was 25.8 ± 7.7 years (range, 14-47 years), and the mean follow-up was 34.3 ± 10.7 months (range, 24-51.3 months). The median Tegner Activity Scale score was 9. The ACL repair failure rate was 16% (8/50). The mean time from repair to failure was 23.1 ± 12.7 months (range, 6-44 months), and the mean age of patients who sustained ACL repair failure was 19.9 ± 3.3 years (range, 14-24 years), significantly lower compared with patients who did not experience ACL repair failure (26.9 ± 7.9 years; range, 16-47 years; P = .017). Multivariate analysis showed that age ≤21 years was the only significant risk factor for ACL repair failure (odds ratio, 5.45; confidence interval, 1.24-27.91; P = .041). Excluding the 8 patients who experienced repair failure, 31 of 42 patients (73.8%) returned to soccer after ACL repair, with 29 of the 31 (93.5%) returning at their preinjury level of play. Moreover, patients who played competitive soccer and returned to their preinjury level of play were significantly younger than those who did not return to their preinjury level of play (mean, 21.1 ± 3.4 vs 29.2 ± 9.5 years, respectively; P = .002) and had significantly better ACL-Return to Sport After Injury scores (mean, 96.6 ± 4 vs 87.8 ± 11, respectively; P = .044). In this study, 73.8% (n = 31) of patients returned to playing soccer, of whom 93.5% (n = 29) returned to their preinjury level after ACL repair. The failure rate was 16% (n = 8) and mainly involved patients ≤21 years old.

Comparing locomotor intensity indicators in soccer training and competition across contextual factors: a study of replaced coaches in a Portuguese professional 1st league team

This study aims to examine, for each head coach (HC) replaced, the association between training intensity and physical performances obtained in games. Furthermore, the study investigated how contextual factors influence locomotor and mechanical performance association. External load variables were collected using Global Positioning System (GPS) devices across the 4 weeks and 4 games before and after the replacement in a professional adult male soccer team. Six different HC records were analysed (48.8 ± 7.4 years of age; 11.2 ± 3.9 years as an HC) during a three-season span (2020/21–2022/2023). There were marked differences within player variability across the two coaching regimes. Game loads didn't reflect training-related performance, with differences ranging from −71.4% to −9.9%. Players under the outgoing coaches have greater coverage of meters per minute. Meters per minute, distance covered over 18 km/h and high-speed running (all in training) are found to be significant variables influenced by contextual factors. Within-subject and time, training loads did not reflect game-related loads/performances, with starters showing higher deficits (ranging from −79.0 to −14.5). The study suggests that changes in soccer HC can affect players' training intensity and game performance, influenced by various contextual factors and not directly correlated. This type of information might be very suitable to improve training load periodization and programming. For further research avenues, could be the study of the variation of the psychological states of the players at the time of the dismissal and hiring of the HCs, associating them with the physiological performance at the same moments.

The impact of different game formats on players’ and team performance in youth soccer competitions

The study aimed to investigate the impact of game formats on the running and technical–tactical performance of young soccer players, as well as on players’ dynamics of spatial occupation during competitions. Eleven players of a U-11 team (11.10 ± 0.39 years old) participated in three competitions specifically designed to analyze the impact of different game formats: 5vs5 (F-5), 7vs7 (F-7) and 11vs11 (F-11). Players’ running performance and dynamics of spatial occupation were analyzed using the GPSs devices from WIMU PRO™ devices (10 Hz). Players’ and team's technical–tactical performance was also analyzed using the Team Sports Assessment Procedure (TSAP) and the Offensive Sequence Characterization System (SCSO), respectively. It was observed that the teams tended to adopt a less direct style in the F-11 ( LpW: F7 vs. F-11 p = 0.001 and F-5 vs. F-11 p = 0.002), with a lower rate of spatial exploration (F-7 vs. F-11 p = 0.001 and &amp;&amp;F-5 vs. F-11 p = 0.001) and lower running demand ( Sprint: F-7 vs. F-11 p = 0.001 and F-5 vs. F-11 p = 0.014; HSR: F-7 vs. F-11 p = 0.001 and F-5 vs. F-11 p = .001). In addition, the F-11 allowed the players to have less involvement during the match (F-7 vs. F-11 p = 0.003; F-5 vs. F-11 p = 0.001), as well as a lower technical–tactical performance (F-7 vs. F-11 p = .003 and F-5 vs. F-11 p = .005). Our results highlight the importance of adjusting the game formats used in youth competitive environments to players’ intrinsic dynamics.

Acute pre- and post-competitive soccer match-play changes in neuromuscular factors, physical performance, and muscle response in youth male players

ABSTRACT There is a paucity of literature analyzing the impact of fatigue from actual competitive soccer match-play on measures of neuromuscular function and muscle damage markers in youth players. Aims The main purpose was to analyze the acute pre- and post-competitive soccer match-play changes in measures of landing mechanics, stretch-shortening cycle capability, physical performance, muscle damage, and match intensity. A secondary purpose was to explore whether the players’ maturity status and chronological age were associated with post-soccer match-play responses. Methods Thirty-two male youth outfield soccer players from two chronological competition age groups (U14 and U16) were assessed pre-and post-competitive soccer match-play for 2D dynamic knee valgus at landing (DKV), leg stiffness, reactive strength index, 20 m sprint time, CMJ-Abalakov jump height, creatine kinase and urea activity and visual analogue scale for muscle soreness (VAS). Players’ maturity status was also estimated using a previously validated regression equation. Results There were statistically significant (p < 0.05) post-competitive soccer match-play impairments in all measures of stretch-shortening cycle capability and muscle damage markers assessed irrespective of the age group. Likewise, significant post-match play alterations in landing mechanics (DKV of the dominant leg) and physical performance (sprint time and jump height) scores were documented for the U14 players. Significant interactions between maturity and landing mechanics and VAS responses to competitive soccer match-play were also found whereby more mature players demonstrated larger post-match changes. Conclusion The findings of this study suggest the existence of a negative influence of competitive match-play on neuromuscular function and muscle damage in youth soccer.

The Impact of Corporate Governance on Financial Performance in Professional Sports Clubs: The Case of Italian Serie A

This paper explores professional football clubs&amp;#39; corporate governance challenges, recognizing them as symptoms of a deeper management crisis. The need for more effective managerial practices within these organizations is evident in the prevailing issues. This study aims to assess how corporate governance quality impacts the profitability and sustainability of Italian Serie A football clubs. Through the analysis of governance variables and financial indicators from the 2018/2019 season, the research identifies crucial factors. These factors encompass the business model, board composition, board age, control bodies, and internal procedure transparency. The results highlight the significant influence of corporate governance variables on club performance and insolvency risk. Enhanced governance quality is associated with higher profitability and viability, even among clubs facing financial difficulties. These findings hold significance for academics, practitioners, and regulators interested in understanding corporate governance practices within the competitive soccer market and their impact on financial performance. Future research should expand the sample and incorporate a comparative analysis of major European football leagues, accounting for varying legal frameworks. Moreover, the repercussions of the COVID-19 pandemic on the football industry must be considered in forthcoming investigations. The pandemic&amp;#39;s financial consequences will likely differ based on each club&amp;#39;s business model, international reputation, financial structure, and governance approach.

DOPING CONTROL IN MALE SOCCER PLAYERS IN BRAZIL: 10 YEARS OF FOLLOW-UP.

To understand the Adverse Analytical Finding (AAF) that have occurred in Brazilian soccer in a recent 10-year period, comparing them to international data, to know the Brazilian profile. A review of the AAR in the Doping Control Commission database of the Brazilian Football Association from 2008 to 2017. The AAR in professional male soccer players between 2008 and 2017 were considered. The sample selected in this research was composed of 40,092 doping tests, with 113 AAR, identified in 18 different competitions (0.28%) in the professional category, in Brazilian national and state competitions between 2008 and 2017, flagged in doping control exams through urine samples. Stimulants were detected most frequently (31.0%), followed by glucocorticoids (21.2%), diuretics, and masking agents (19.5%). The Brazilian Championship series did not show a relationship with any of the World Anti-Doping Agency (WADA) groups of substances. Series A showed 0.07% of AAR, Series B 0.21%, Series C 0.75% and Series D 1.49. The rate of AAR in Brazilian soccer was 0.28%, lower than the average for all soccer worldwide, and shows similar percentages among field positions. Stimulants were the most prevalent drugs. The national elite soccer competitions showed significantly fewer cases than the lower divisions. Level of Evidence II; Retrospective Study.

Tibial Supra-Tubercular Deflexion Osteotomy During Revision Anterior Cruciate Ligament Reconstruction

Background: A deflexion osteotomy may reduce anterior translational forces imparted upon an anterior cruciate ligament (ACL) reconstruction (ACL-R) graft, thereby reducing risk of ACL graft failure in patients with excessive congenital posterior tibial slope. Indications: A 13-year-old female competitive soccer player with 13.7° of posterior tibial slope presented with failure of a prior ACL-R. Technique Description: A vertical incision is made along the medial border of the patellar tendon and the proximal tibia is exposed. The planned osteotomy is templated under fluoroscopic guidance by placement of 2.4-mm Steinmann pins. A supra-tubercular deflexion osteotomy is made with a sagittal saw and osteotomes, with care to maintain the posterior cortical hinge. Compression staples are utilized for fixation of the osteotomy site. Revision ACL-R is then performed. Results: There were no immediate complications following surgery. Surgical management led to radiographic improvement of the patient's posterior tibial slope and clinical resolution of anterior translational knee instability. Discussion/Conclusion: The senior author's preferred technique for a tibial supra-tubercular deflexion osteotomy in association with a revision ACL-R is presented. A deflexion osteotomy is a surgical option for patients with excessive (&gt;12°) posterior tibial slope in the setting of a prior failed ACL-R. This case demonstrates the efficacy of a tibial supra-tubercular deflexion osteotomy in the revision ACL-R setting by reducing posterior tibial slope, thereby lessening anterior translational forces on the ACL graft in a patient at high risk of graft failure. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Psychological risk factors for a first hamstring strain injury in soccer: a qualitative study.

Hamstring strain injuries (HSIs) remain one of the most burdensome injuries in soccer. Current recommendations to prevent sports injuries suggest the importance for coaches and medical staff to consider psychological and contextual risk factors and to specify them according to the injury type and context. HSI risk factors in soccer have been widely investigated, mainly from physiological and biomechanical perspectives. However, psychological and health-related risk factors are still unexplored. Therefore, the objective of this study was to determine the psychological and health-related risk factors for a first HSI in male competitive soccer. Individual semi-structured interviews were conducted with ten male competitive soccer players, who had recently sustained a HSI. Based on multifactorial models of sports injury causation, soccer players' individual, contextual, and situational risk factors at the time of their first HSI were investigated. Interviews were analyzed using thematic analysis with deductive and inductive approaches. Individual psychological risk factors included common at-risk personality traits, obsessive passion for soccer with competitive motivational goals, strong athletic identity, and poor health literacy. The injured players were exposed to a controlling coaching style, with a fear of negative staff evaluations, and had recently experienced life stressors. They were injured during matches or overload periods and were highly engaged in the activity. Previously injured soccer players exhibit a lack of perspective concerning the repercussions of their actions on their health. From a preventive viewpoint, these results suggest enhancing the players' health literacy, supporting their autonomy, and moderating the controlling coaching style.

Indicators of Fatigue during a Soccer Match Simulation Using GPS-Derived Workload Values: Which Metrics Are Most Useful?

Research into women's competitive soccer matches has shown distance and high-speed running (HSR) reductions over time, but the effects on some GPS-derived metrics have not been investigated. The purpose of this project was to examine the utility of common GPS metrics for indicating fatigue from the T-SAFT90 match simulation in collegiate soccer players. Unlike in competitive matches, changes to these metrics occurred as early as 15 min, with HSR, average and max speed, and speed intensity (SI) exhibiting significant declines. HSR and SI were even further decreased in later periods, with HSR lower in minutes 30-40 (T30-35 and T35-40) than T15-20 and lower in T70-85 than T45-60. SI showed a similar pattern of continued decline, reaching its lowest value in the last three time segments. Accelerations and decelerations were also decreased beginning at T15-20 and T20-25, respectively, but the fatigue index (FI), dynamic stress load (DSL), and step balance (SB) were unchanged. It can be concluded that in contrast to competitive matches where players can dictate their own intensity, a match simulation may result in a quicker onset of fatigue, but not all GPS-derived values change as expected in fatiguing environments. Coaches and sports scientists may use these findings to properly monitor fatigue in real time.