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

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.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Interindividual differences in physical function and their impact on regular player selection among junior high school soccer athletes.

[Purpose] Unlike professional teams that use comprehensive evaluations, player selection in local and school-level soccer teams relies on the coaches' practical experience. This study investigated the differences in physical function between regular and non-regular male junior high school soccer players to provide valuable insights into player selection. [Participants and Methods] We assessed grip strength, rebound jumps, muscle strength, agility, short-distance running, anaerobic power, and countermovement jumps in 55 Japanese junior high school boys, who were divided into regular (R) and non-regular (NR) groups. Moreover, the age, height, and weight of the groups were compared. [Results] The analysis revealed significant differences in countermovement jumps and anaerobic power, while accounting for age and physique. [Conclusion] These results suggest that countermovement jumps and anaerobic power may constitute determining factors for regular and non-regular players, even when age and physical characteristics are considered.

Predicting the occurrence of in-season groin pain in male high school soccer players: a cohort study.

[Purpose] This study investigated whether pre-season HAGOS (Japanese Copenhagen Hip and Groin Outcome Scores) and eccentric muscle strength of the hip muscles predict in-season groin pain incidences in high school soccer players. [Participants and Methods] This study had a cohort design. The participants were male high school players under 18 years playing in the Japan Soccer League, which is an elite-level soccer league of that age category in Japan. The HAGOS and the strength of hip abductor and adductor muscles in eccentric contraction were measured before the season, and hip and groin pain incidences were recorded during the season. Multiple logistic regression analysis was performed to investigate the factors derived from the pre-season HAGOS and hip muscle strength tests, presumably pertaining to the development of in-season groin pain. [Results] The eccentric adductor muscle strength of the dominant leg and the HAGOS were selected as factors associated with groin pain during the season. [Conclusion] Low pre-season HAGOS and weak dominant-leg eccentric adductor muscle strength were suggested as factors to predict in-season groin pain occurrence in male high school soccer players.

Examining the Prevalence of Anterior Cruciate Ligament Injuries on Artificial Turf Surfaces Compared to Natural Grass Surfaces in Athletes: A Scoping Review.

The anterior cruciate ligament (ACL) is commonly injured in sports such as American football and soccer. It is currently unknown if ACL injuries are more prevalent on natural grass or artificial turf fields. The purpose of this scoping review is to analyze research studies evaluating the effect of the playing surface on the prevalence of ACL injuries. We hypothesize that athletes face a greater risk of suffering ACL injuries while playing on artificial turf compared to natural grass. Our team conducted a comprehensive literature review by screening three databases (PubMed, Embase, and Cochrane) that comprised a wide range of peer-reviewed articles on ACL injuries suffered on natural grass and artificial turf surfaces. Inclusion criteria consisted of epidemiological and cohort studies published after 1990 that were written in English and focused on athletes ranging in skill level from youth to professional. Exclusion criteria consisted of biomechanical studies, review articles, and papers that focused on injuries of structures other than the ACL. Bias was assessed with the MINORS criteria. Results were presented by injury rates, calculated ratios, and confidence intervals. The final analysis included nine papers published in peer-reviewed journals. Three of nine papers found that ACL injuries are more likely to occur on artificial turf than on natural grass. Three papers found that there is no difference in the prevalence of ACL injuries between surfaces and one paper stated that ACL injuries are more likely on natural grass than artificial turf. Two papers did not report confidence intervals for ratios comparing injury rates between playing surfaces. There is no consensus in the current literature regarding the prevalence of ACL injuries on artificial turf versus natural grass surfaces. The primary limitation of this study was that the papers used a variety of methods to compare rates of ACL injuries on artificial and natural surfaces, making comparisons between the nine papers difficult.

Evolution of passing network in the Soccer World Cups 2010-2022.

This study investigates the evolution of passing networks (PN) at both team and player levels in the FIFA World Cups (WC) from 2010 to 2022. Analyzing 256 matches (7328 player observations) using a multiple-camera tracking system across four WCs, we considered six playing positions: goalkeeper (n = 521), central defender (n = 1192), fullback (n = 1223), midfielder (n = 2039), winger (n = 1320), and central forward (n = 1033). We used 17 network metrics and considered contextual variables such as team formation, and team ranking. Linear mixed-effect models analyzed differences in team and player PN parameters by year and team strength. Results showed a shift from possession-play to direct-play from the 2010 to 2018 WCs, with possession-play returning in 2022. Specifically, high- and low-quality teams significantly decreased their density, average degree (AD), modularity, and average path length in 2018 (p < 0.05). High-quality teams showed increased density, AD, and average weighted degree in 2022 (p < 0.05). Midfielders and central forwards exhibited significantly lower centrality parameters, whereas central defenders and goalkeepers showed increased centrality parameters (p < 0.05). This study highlights the evolutionary trends of passing relationships from a network analysis perspective over twelve years, providing insights into the changing dynamics of team interactions and positional prominence in elite soccer.

Can heat conditions affect the heart rate responses, perception of effort, and technical performance of young male football players during small-sided games? a comparative study.

BACKGROUND: Soccer coaches often employ small-sided games (SSGs) to elicit both physiological and technical responses from players. However, numerous contextual factors can influence the outcomes of these games. This comparative study aimed to investigate how environmental temperature (< 21ºC and > 29ºC) impacts heart rate responses, perception of effort, and technical performance in young male football players during SSGs. METHODS: This study compares temperatures below 21ºC (∼ 20.4 ± 0.4ºC) with temperatures above 29ºC (∼ 29.7 ± 0.6ºC). This repeated measures study design involved 60 male football players at a trained/developmental level, selected from under-16 and under-19 teams. It aimed to assess the effects of the 3v3 format, conducted repeatedly under conditions of 21ºC and above 29ºC. Throughout the games, mean heart rate responses (HRmean), measured via heart rate sensors; rate of perceived exertion (RPE), assessed using the CR-10 Borg scale; and successful passes and lost balls, tracked through an ad hoc observational analysis tool, were monitored. RESULTS: No significant interactions were observed (time*age group) in meanHR (F = 0.159; p = 0.691; [Formula: see text]=0.003), RPE (F=0.646; p=0.425; [Formula: see text]=0.011), number of passes completed (F=0.204; p=0.654; [Formula: see text]=0.003), and number of lost balls (F = 0.157; p = 0.694; [Formula: see text]=0.003). Overall, significantly higher heart rate responses in mean HR (p<0.001) and RPE (p<0.001) were observed at temperatures above 29ºC, while significantly more passes were completed at temperatures below 21ºC (p<0.001). CONCLUSIONS: Heat conditions significantly intensified the psychophysiological responses in players, concurrently leading to a significant impairment in the number of passes. Coaches should contemplate implementing mitigation strategies to avert performance declines during heat conditions when utilizing SSGs.

The effects of heading motion and sex on lower extremity biomechanics in soccer players.

BACKGROUND: Soccer is one of the most popular sports worldwide, which subsequently increases the number of injuries experienced by players. Furthermore, a large percentage of all anterior cruciate ligament injuries occur while playing soccer. In order to more clearly understand injury mechanisms, it is important to make the testing environment as real-life as possible. Inclusion of an external focus and secondary task, such as heading a soccer ball, may increase joint loading during landing. The purpose of this study was to investigate the effect of a forward heading motion on lower extremity kinetics and kinematics between sexes during a stop-jump task and a jump-heading task. METHODS: Ten male and ten female soccer players performed stop-jumps with no soccer ball present and jump-headings with a soccer ball present. Three-dimensional kinematics and kinetics were collected and analyzed during the landing. 2 × 2 mixed design analysis of variances (ANOVA) were performed to examine sex × jump task interactions and determine the main effects of sex and jump task. RESULTS: Results indicated jump-heading yields greater peak vertical ground reaction forces, an 8% increase in peak knee extension moments, a reduced initial knee flexion angle by approximately 5°, and an increased initial hip flexion angle by approximately 7°. Additionally, females exhibited 5.6° greater peak knee abduction angles compared to men, regardless of task. CONCLUSIONS: Inclusion of an overhead target may have distracted the athletes from focusing on frontal plane knee control when landing, and could potentially lead to increased ACL stress.

Participant Experiences With a Community-Based, "Older Adult" Walking Football Initiative in Australia: A Qualitative Exploration.

Despite the growing popularity of walking sports, little is known about who is attracted to them, and what skills, motivations, and experiences encourage ongoing participation. The aim of this study was to gain an in-depth understanding of the phenomenon of walking football in Australia. The authors first conducted semistructured interviews with 53 older adults (M = 62.37 years, 30.19% female) participating in walking football in Australia. Next, they conducted thematic analysis to develop themes that represented participant perspectives. Results indicated that walking football led to several physical benefits, but the social and mental benefits seemed to be more closely associated with continued participation. The slower pace of walking football created a valuable option to engage in physical activity among those with injuries or severe health issues, as well as older adults concerned about injuries. The slower pace also shifted the focus of walking football away from fitness and ability, and toward technique and skill development, and this focus, along with the mix in abilities, led to informal coaching and mentoring roles which were highly valued among older participants. Participant views about competition in walking football were diverse, with some expressing a mild concern. Understanding such diverse experiences of walking football helps to better understand how different aspects of the sport influence the perceived benefits and likelihood of continuing for different people. Using these findings to further develop walking sports in Australia could have large impacts on the health and well-being of older people.

Mitigating the Risks of Lower Extremity Injuries in Soccer: A Comprehensive Analysis of Lower Extremity Injury Rates in Soccer Between 2014 and 2023.

Objective: With events such as the Copa America 2024, the 2026 World Cup, and the arrival of European stars in Major League Soccer (MLS), the already observed and forecasted rise of soccer in the United States (US) seems to be an inevitable outcome. Although regular participation in soccer features several benefits, including increasing cardiovascular health, decreasing stress, and promoting interpersonal relationships, the risk of injury, as is the case in any sport, is ever present. Although many sports that are popular in America feature high rates of concussion, rotator cuff injuries, and general upper extremity injuries, soccer, being more strenuous on the lower-half of the body, features a disproportionate rate of lower extremity injuries. An analysis of the frequencies of these injuries, relative to factors such as year of injury, age, gender, location of injury, and diagnosis of injury, may help organizational bodies and soccer leagues implement new regulations regarding the usage of protective equipment and rules regarding gameplay. This study aims to illuminate these takeaways in an effort to better patient care outcomes in soccer-related injuries. Method: This paper utilized the National Electronic Injury Surveillance System Database (NEISS) to compile data on lower extremity soccer-related injuries within the defined study period, 2014-2023. Inclusion criteria for the study involved all patients presenting to the emergency department (ED) within the study period and within the defined age range of 0 to 69 years old, with injuries sustained from or related to soccer. Using NEISS, trends were elucidated discriminating based on year of injury, sex, age group, location of injury, and diagnosis group of injury. Results: Within the defined study period of 10 years, from 2014-2023, there were approximately 843,063 total soccer-related lower extremity injuries which presented to various EDs across the US. Regarding majorities, the most injuries were sustained in 2014 (12.84% of total injuries), most patients sustaining injuries were male (66.6% of all patients), and within the age range of 10-19 years old (63.24% of all patients), with the most instances occurring at age 15. Lower extremity injuries were most reported to be affecting the ankle with 306,797 incidences (36.39% of total injuries seen) and the most frequent diagnosis group was reported to be strains/sprains with 396,420 (47.02% of total injuries seen) total occurrences. Conclusion: This study analyzes the incidents of lower extremity injuries while participating in soccer for the last 10 years, 2014-2023. The study provides new data regarding the frequency of injuries and their relative rate with respect to year of injury, age group, sex, location of injury, and diagnosis. The results of this study show injury majorities and trends which can be used to dictate changes in regulation regarding gameplay and the utilization of protective equipment in order to mitigate injuries related to the lower extremities in soccer.

The Physical Progress of a Professional Scottish Soccer Academy Over a Ten-Year Period.

Background: Increases in high-intensity locomotor activity of match play have been recorded in elite soccer. This places an onus on academy practitioners to develop players for the future demands of the game. At an academy level, locomotor data are not available for analysis over a longitudinal period, and thus changes can only be assessed with physical attribute assessment. The aim of the present study is to establish if changes in physical capacity were observed in a professional Scottish soccer academy over a ten-year period. Methods: A retrospective analysis was completed where linear mixed effect (LME) models were individually fitted to explain variation across each measure of physical capacity. Model selection was undertaken with likelihood ratio tests where the initial complex models were compared to simpler nested models to arrive at the final model by maximum likelihood. Results: The main findings were that most recent players' sprint test data revealed a significant improvement in 5m, 10m and 20m sprint performance, greater increases in CMJ performance in older age groups, and greater increases in YYIR1 performance at U13 and U14. Most physical results showed increased performance with greater relative height and weight. Conclusion: Players recruited more recently to academies are fitter than they were previously. Reference values within clubs that establish first team requirements will contribute to appropriate planning and implementation of training.

The isometric and isokinetic knee extension and flexion muscle strength profile of elite soccer players.

BACKGROUND: This study aimed to further complete normative data sets for the strength profile of the thigh in soccer players by performing isometric and isokinetic measurements in a large sample per player position. METHODS: In total, 364 soccer players were divided into subgroups according to their pitch position. All players performed isometric and isokinetic strength measurements during active competition period using an isokinetic dynamometer (System 3, Biodex®, ENRAF-NONIUS, New York, USA). RESULTS: Isokinetic strength of m. Quadriceps was significantly (p = 0.023) higher in strikers compared to central midfielders in both the dominant (+ 9%) and the non-dominant (+ 4%) leg. No further differences were found in isometric or isokinetic strength per playing positions. CONCLUSIONS: We have shown that strength profiles do not differ between playing positions on the field. This is valuable information for elite soccer high performance coaches and medical staffs aiming to improve daily training efficiency and rehabilitation of their players.

The Influence of the Dominant Leg in Body Asymmetries in Children and Adolescent Male Soccer Players.

The current study aimed to examine (a) whether the dominant leg (DL) was associated with the contralateral side of functional scoliosis and (b) if any of the postural asymmetries' evaluation variables may be a reliable predictor of the functional scoliosis development in young male soccer players. Six hundred-nine (n = 609) male soccer players (age: 10.8 ± 2.7 years; height: 147 ± 17 cm; weight: 43.4 ± 14.6 kg; DL: Right 81.6%, Left 14%, Both 4.4%) participated in this study. The spinal asymmetries evaluation included thoracic kyphosis, lumbar lordosis, truncal rotation, shoulders alignment from posterior view, anterior and posterior pelvic tilt, anterior superior iliac spine (ASIS), hamstring tightness, and lower extremities discrepancy. A significant association was observed between the DL and the truncal rotation side: χ2(4) = 30.84, p = 0.001, V = 0.16. Participants with longer left legs were likelier to present a spinal asymmetry (OR = 1.18). The participants with higher left shoulders were 2.13 times more likely to have spinal asymmetry than the participants with normal shoulders level. Participants with left ASIS higher were 3.08 times more likely to present asymmetry than those with normally aligned ASIS levels. There was also a significant association between the DL and the side of truncal rotation: χ2(2) = 13.30, p = 0.001, V = 0.449. Logistic regression analysis for the functional scoliotic group and truncal rotation side demonstrated that the taller participants and participants with shorter right legs were more likely to have asymmetry on the left side (OR = 1.29, OR = 0.32). Participants with greater right hamstring stiffness were likelier to have a truncal rotation on the right side (OR = 0.93). Participants with higher left shoulders were 0.20 times less likely to have a truncal rotation on the left side than the participants with normal shoulders level. In conclusion, leg dominance in children and in youth soccer players may be a factor causing truncal rotation on the contralateral side. Additional causes, such as leg length discrepancy and pelvic tilt, may progressively lead to functional scoliosis.

The Association Between the Development of Cam Morphology During Skeletal Growth in High-Impact Athletes and the Presence of Cartilage Loss and Labral Damage in Adulthood: A Prospective Cohort Study With a 12-Year Follow-up.

BACKGROUND: Cam morphology develops during skeletal growth, but its influence on cartilage and the labrum in high-impact athletes later in life is unknown. PURPOSE: To (1) explore the association between the presence and duration of cam morphology during adolescence and the cartilage and labral status 7 to 12 years later and (2) report the prevalence of cartilage loss and labral damage in a population of young male athletes (<32 years old) who played professional soccer during skeletal growth. STUDY DESIGN: Cohort study (Prognosis); Level of evidence, 2. METHODS: A total of 89 healthy male academy soccer players from the Dutch soccer club Feyenoord (aged 12-19 years) were included at baseline. At baseline and 2.5- and 5-year follow-ups, standardized supine anteroposterior pelvis and frog-leg lateral radiographs of each hip were obtained. At 12-year follow-up, magnetic resonance imaging of both hips was performed. Cam morphology was defined by a validated alpha angle ≥60° on radiographs at baseline or 2.5- or 5-year follow-up when the growth plates were closed. Hips with the presence of cam morphology at baseline or at 2.5-year follow-up were classified as having a "longer duration" of cam morphology. Hips with cam morphology only present since 5-year follow-up were classified as having a "shorter duration" of cam morphology. At 12-year follow-up, cartilage loss and labral abnormalities were assessed semiquantitatively. Associations were estimated using logistic regression, adjusted for age and body mass index. RESULTS: Overall, 35 patients (70 hips) with a mean age of 28.0 ± 2.0 years and mean body mass index of 24.1 ± 1.8 participated at 12-year follow-up. Cam morphology was present in 56 of 70 hips (80%). The prevalence of cartilage loss was 52% in hips with cam morphology and 21% in hips without cam morphology (adjusted odds ratio, 4.52 [95% CI, 1.16-17.61]; P = .03). A labral abnormality was present in 77% of hips with cam morphology and in 64% of hips without cam morphology (adjusted odds ratio, 1.99 [95% CI, 0.59-6.73]; P = .27). The duration of cam morphology did not influence these associations. CONCLUSION: The development of cam morphology during skeletal growth was associated with future magnetic resonance imaging findings consistent with cartilage loss in young adults but not with labral abnormalities.

Secondary injury prevention reduces hamstring strain and time-loss groin injury burdens in male professional football.

OBJECTIVES: This study aimed to assess the effectiveness of a systems-based secondary injury prevention intervention aimed at early detection and management of hamstring strain injury (HSI) and time-loss groin injury in an Australian male professional football club. DESIGN: Prospective cohort study. SETTING: Australian male professional football club. PARTICIPANTS: Data were collected from male professional football players (n = 73) from a single football club. MAIN OUTCOME MEASURES: Unilateral knee flexion and side-lying hip adduction maximum voluntary isometric contractions were monitored routinely in-season, two days post-match (≥40 h [h]) during a three-season intervention period. Strength reductions greater than the tests' minimal detectable change percentage prompted intervention. HSI and time-loss groin injury burdens were calculated per 1000 player hours and compared with those from an immediately preceding two-season control period, to assess the effectiveness of the intervention. RESULTS: Across the intervention period, there was a decrease in HSI (4.98 days absence/1000 h (19.8%) decrease) and time-loss groin injury burdens (0.57 days absence/1000 h (49.1%) decrease) when compared with the control period. CONCLUSIONS: A systems-based secondary injury prevention intervention shows preliminary positive findings in reducing HSI and time-loss groin injury burdens within a male professional football club, compared with usual care only.

Searching for the perfect goalkeeping personality. Myth or reality?

Background: Psychological factors such as personality characteristics are influential factors of the goalkeeping performance in football (soccer). Not only for individualized treatment in practice, also from a scientific point of view, profiling goalkeepers is a relevant part of understanding athletes. The aim of this study was to investigate personality traits of goalkeepers of different expertise, age, and sex. Methods: Using the Five Factor Model of personality we assessed personality traits of 132 male and female football goalkeepers ranging from youth to senior and low to elite level. A series of analysis investigated differences between the groups focusing on expertise, age, and sex. Results: Significant differences in the personality trait agreeableness between groups of different expertise and sex could be detected. Although a significant difference in neuroticism levels of males and females could be shown. Conclusion: This study was a first step of profiling football goalkeepers of different expertise, age, and sex. The study calls for more replication in this specific field of football and goalkeeping in general to understand the influence of personality characteristics on sport performance.

Alpha Neurofeedback Training in Elite Soccer Players Trained in Groups.

Neurofeedback training is applied in the world of sports as a means to improve athletes' performance. Training sessions are usually organized on an individual basis, one at a time. Here we investigated if the training could also be organized in groups. Forty-one national-level football (soccer) players (26 females, 15 males) carried out training sessions simultaneously in groups of up to 13, using a wearable device with Bluetooth connection, during their regular training hours at the club. It was possible to obtain good EEG measurements using this setup, albeit with a somewhat higher data loss than usual in standard laboratory sessions. The brain's alpha activity was trained using music-based neurofeedback in a crossover design. A training session consisted of alternating periods of neurofeedback and execution of cognitive tasks. EEG alpha (8-12 Hz) activity was higher in the neurofeedback periods compared to the cognitive task periods, and the reverse was true for beta (13-30 Hz) activity. The training program resulted in an increase of 34% in alpha activity associated with the training, and improved the athletes' performance on task switching and mental rotation tasks. In addition, self-reported sleep duration, as well as scores on the Being in Shape questionnaire (Feeling of Control and Flow) also improved. This study shows that neurofeedback training is feasible in groups of athletes, which can stimulate its application in team sports.

Enhancing Protocols for Concussion Management in Professional Soccer Events.

AIM: Every year, there are an estimated 1.7 to 3.8 million sports-related traumatic brain injuries. A sports concussion results from an external force or a blow to the head or body, causing cranial encephalic trauma that can affect motor skills and brain function, producing varying symptoms related to an alteration in neurological functioning. Soccer poses a risk of concussions due to heading, where the player's head directly hits the ball to redirect or accelerate it. However, most concussions are caused by contact between players, such as head-to-head or head-to-elbow contact. This study analyzed the incidence of concussions or mild traumatic brain injuries in professional soccer during the "Copa America 2019" to understand the feasibility of soccer concussion protocols and propose evidence-based enhancements. METHODS: The data were previously collected by our first two authors, O. Pangrazio and F. Forriol, during the 46th edition of the "Copa America 2019," where the South American Football Confederation implemented the Concussion Fast Recognition Protocol to detect traumatic brain injuries. The descriptive basic data will help to raise awareness and motivate further research in this field. We have analyzed and correlated it with global data to provide a comprehensive review and tangible evidence of the population size where soccer protocols are typically applied, thus calculating incidence rates to measure it mathematically. RESULTS: Our study reveals that the incidence rate of concussions during the "Copa America 2019" was 5.3 per 1,000 athlete exposures, with a total of three concussions occurring among 567 players. Despite the effectiveness of current protocols in detecting concussions rapidly and accurately, the relatively low incidence rate at this level of professional competition poses a challenge to validating these protocols. These results indicate that while the protocols in place are efficient, the testing and validation of new tools and approaches would be more beneficial at different levels of play where the incidence rates of concussions are higher. In environments with a greater frequency of concussions, the robustness and reliability of these protocols can be more thoroughly evaluated, ensuring they provide optimal protection and care for athletes. CONCLUSION: The incidence of concussions is low in professional soccer tournaments. Protocols are necessary to protect players and educate sports professionals. However, their validation is difficult given the low incidence of concussions at this level of competition. Our proposed protocol helps unify a basic approach in the field and an advanced approach in any emergency department, providing better detection of concussions and improved outcomes for players. This protocol should be validated in populations with higher incidence rates to demonstrate its effectiveness.

Optimal Drop Heights for Determining Reactive Strength Performance in Youth-Is 1 Drop Height Sufficient to Generate Trustworthy Conclusions for Training Practice?

This study critically examines the suitability of using a single drop height to assess the reaction strength index in trained and active participants, a key component of athletic performance. Using a cross-sectional design, 377 trained (n = 163) and active (n = 214) participants aged 14-18 years performing drop jumps from 4 different heights (24, 32, 40, and 48 cm) were studied. The primary aim was to explore the individual differences in reaction strength index at these heights and to assess whether a single height can reliably represent stretch-shortening cycle capabilities. While the repeated measures analysis of variance did not reveal any significant differences, the Bland-Altmann analysis revealed significant individual discrepancies between the performance of the drop heights, resulting in a mean absolute error of 32.1 and a mean absolute percentage error of 20.6%. These results strongly suggest that a single drop height is not sufficient to determine performance in the stretch-shortening cycle. This has important practical implications as it can lead to underestimates of performance trends. The study advocates the inclusion of a range of drop heights in routine testing to accurately measure reactive power and thus improve the effectiveness of individualized training programs for young athletes/active youth.

The effect of a combined cooling intervention on cognitive function in the heat during an intermittent running protocol.

Despite optimal cognitive function being essential for performance, there is a lack of research on the effectiveness of combined cooling interventions on team sport athlete's cognitive function when exercising in the heat. In a randomised, crossover design, 12 unacclimatised men (age: 22.3 ± 3.0 years, body mass: 73.4 ± 5.1 kg, height: 181.0 ± 5.3 cm and V ˙ O 2 $\dot{\mathrm{V}}{\mathrm{O}}_{2}$ max: 51.2 ± 9.5 mL/kg/min) participated in a control (CON) and combined cooling trial (ice slurry and ice collar; COOL). A battery of cognitive tests were completed prior to, during (at half-time) and following a 90-min intermittent running protocol in the heat (33°C, 50% relative humidity (RH)). Perceptual and physiological measures were taken throughout the protocol. In CON, response times were quicker on the Stroop task complex level (p = 0.002) and the visual search test complex level at full-time (p = 0.014) compared to COOL. During COOL, response times were quicker at half-time on the Stroop task complex level (p = 0.024) compared to CON. Lower rectal temperatures were seen during COOL (CON: 37.44 ± 0.65°C and COOL: 37.28 ± 0.68°C) as well as lower skin, neck and forehead temperatures (main effect of trial, all p < 0.05). Lower ratings of thermal sensation and perceived exertion and enhanced thermal comfort were recorded during COOL (main effect of trial, all p < 0.05). Whilst minimal differences in cognitive function were found when using the combined cooling intervention, the findings highlight a practical and effective strategy to improving many physiological and perceptual responses to intermittent exercise in the heat.