How Shell Add-On Products Influence Varsity Football Helmet Performance?

PURPOSE: The study purpose was to investigate the laboratory-based performance of three commercially available shell add-on products under varsity-level impact conditions. METHODS: Pendulum impact tests were conducted at multiple locations (front, front boss, rear, side) and speeds (3.1, 4.9, 6.4 m/s) using two helmet models. Tests were performed with a single add-on configuration for baseline comparisons and a double add-on configuration to simulate collisions with both players wearing shell add-ons. A linear mixed-effect model was used to evaluate peak linear acceleration (PLA), peak rotational acceleration (PRA), and concussion risk, which was calculated from a bivariate injury risk function, based on shell add-on and test configuration. RESULTS: All shell add-ons decreased peak head kinematics and injury risk compared to controls, with the Guardian NXT producing the largest reductions (PLA: 7.9%, PRA: 14.1%, Risk: 34.1%) compared to the SAFR Helmet Cover (PLA: 4.5%, PRA: 9.3%, Risk: 24.7%) and Guardian XT (PLA: 3.2%, PRA: 5.0%, Risk: 15.5%). The same trend was observed in the double add-on test configuration. However, the Guardian NXT (PLA: 17.1%; PRA: 11.5%; Risk: 62.8%) and SAFR Helmet Cover (PLA: 12.2%; PRA: 9.1%; Risk: 52.2%) produced larger reductions in peak head kinematics and injury risk than the Guardian XT (PLA: 5.7%, PRA: 2.2%, Risk: 21.8%). CONCLUSION: In laboratory-based assessments that simulated varsity-level impact conditions, the Guardian NXT was associated with larger reductions in PLA, PRA, and injury risk compared to the SAFR Helmet Cover and Guardian XT. Although shell add-ons can enhance head protection, helmet model selection should be prioritized.

Examination of plasma biomarkers of amyloid, tau, neurodegeneration, and neuroinflammation in former elite American football players.

INTRODUCTION: Blood-based biomarkers offer a promising approach for the detection of neuropathologies from repetitive head impacts (RHI). We evaluated plasma biomarkers of amyloid, tau, neurodegeneration, and inflammation in former football players. METHODS: The sample included 180 former football players and 60 asymptomatic, unexposed male participants (aged 45-74). Plasma assays were conducted for beta-amyloid (Aß) 40, Aß42, hyper-phosphorylated tau (p-tau) 181+231, total tau (t-tau), neurofilament light (NfL), glial fibrillary acidic protein (GFAP), interleukin-6 (IL-6), Aß42/p-tau181 and Aß42/Aß40 ratios. We evaluated their ability to differentiate the groups and associations with RHI proxies and traumatic encephalopathy syndrome (TES). RESULTS: P-tau181 and p-tau231(padj = 0.016) were higher and Aß42/p-tau181 was lower(padj = 0.004) in football players compared to controls. Discrimination accuracy for p-tau was modest (area under the curve [AUC] = 0.742). Effects were not attributable to AD-related pathology. Younger age of first exposure (AFE) correlated with higher NfL (padj = 0.03) and GFAP (padj = 0.033). Plasma GFAP was higher in TES-chronic traumatic encephalopathy (TES-CTE) Possible/Probable (padj = 0.008). DISCUSSION: Plasma p-tau181 and p-tau231, GFAP, and NfL may offer some usefulness for the characterization of RHI-related neuropathologies. HIGHLIGHTS: Former football players had higher plasma p-tau181 and p-tau231 and lower Aß42/ptau-181 compared to asymptomatic, unexposed men. Younger age of first exposure was associated with increased plasma NfL and GFAP in older but not younger participants. Plasma GFAP was higher in participants with TES-CTE possible/probable compared to TES-CTE no/suggestive.

Relative Age Effect and ACTN3 R577X and ACE I/D Polymorphisms in Brazilian Football Players: An Association Genetic Study.

The Relative Age Effect (RAE) suggests older athletes within an annual cohort have advantages over their younger peers. We hypothesized that younger athletes could overcome these disadvantages through favorable α-actinin-3 (ACTN3) and angiotensin converting enzyme (ACE) polymorphisms. This study aimed to: 1) examine RAE prevalence among Brazilian football players; 2) investigate the distribution of the ACTN3 and ACE polymorphisms; and 3) explore the association between polymorphisms and RAE across competitive levels and positions. The sample included 627 male players from first-division Brazilian teams in four age categories: U15 (n = 172), U17 (n = 166), U20 (n = 161), and Professionals (n = 128). A control group was established using data from the general Brazilian population documented in previous studies Results showed RAE presence across all competitive levels and positions. Players with the ACTN3 R allele, especially the RR genotype, had the strongest associations with football players, particularly among defenders. On the other hand, the distribution of ACE polymorphism was not significantly different between controls and players, except in the U17 category, where the I/I genotype was more common. Relatively older players had higher total genotype scores than younger counterparts in the overall sample and defender subgroups. In conclusion, RAE is prevalent among Brazilian football players, with older athletes benefiting from favorable ACTN3 and ACE polymorphisms, contrary to our initial hypothesis.

Knee muscle strength, body composition, and balance performance of youth soccer players.

BACKGROUND: Muscle strength and balance abilities have been related to game performance injury prevention. This study aimed to (1)  assess knee muscle strength performance based on intra- and inter-limb asymmetries, (2)  investigate the relationships between knee muscle strength, body composition, and balance, and (3) analyze the variance in the overall stability index (OSI) explained by knee muscle strength indicators after controlling for age and body composition. METHODS: The sample included 104 young male soccer players (16.0 ± 1.6 years). Body composition, knee muscle strength, and balance ability were assessed. A paired samples t-test was used to examine differences between the preferred leg (PL) and the non-preferred leg (NPL). Pearson correlations and hierarchical multiple regression were conducted to explore the relationships between strength, body composition, and balance. RESULTS: No significant inter-limb asymmetries were detected for the knee flexors (KF) and knee extensors (KE) performance. The hamstrings-to-quadriceps ratio does not suggest the existence of intra-limb asymmetries (p = 0.06). Significant and negative correlations were found between KF (r = -0.38, p ≤ 0.01) and KE (r = -0.58, p ≤ 0.01) for the PL. Concerning the NPL, KE also revealed a significant and negative relationship with balance (r = -0.30, p ≤ 0.01). Significant and positive relationships were found between bodyweight, fat-free mass, and balance. After controlling for age and body composition, knee muscle strength could explain between 13% and 30% of the variance observed in the OSI (NPL and PL, respectively). CONCLUSIONS: The results underline knee muscle strength as an important predictor of balance. Thus, training programs targeting knee muscle strength development should be considered during the season periodization by coaches and their staff throughout the players' developmental stages.

Systematic video analysis of ACL injuries in professional Spanish male football (soccer): injury mechanisms, situational patterns, biomechanics and neurocognitive errors - a study on 115 consecutive cases.

Objective: A few video analysis studies have been published in recent years, but none specifically on Spanish football. We aimed to describe the mechanisms, situational patterns, biomechanics and neurocognitive errors related to anterior cruciate ligament (ACL) injuries in professional Spanish football matches. Methods: We identified 167 consecutive ACL injuries across 12 seasons of the top two leagues in Spanish football. 115 (69%) injury videos were analysed for mechanism and situational pattern, while biomechanical analysis was possible in 81 cases. Neurocognitive errors were investigated for all non-contact injuries. Three independent reviewers evaluated each video. ACL injury epidemiology-month, timing within the match and pitch location at the time of injury was also documented. Results: More injuries occurred in defensive (n=68, 59%) than offensive (n=48, 41%) (p<0.01) playing situations. 16 (14%) injuries were direct contact, 49 (43%) indirect contact and 50 (43%) non-contact. Most injuries (89%) occurred during four main situational patterns: (1) pressing/tackling (n=47, 47%); (2) tackled (n=23, 23%); (3) landing from a jump (n=12, 12%) and regaining balance after kicking (n=6, 6%). Injuries generally involved a knee-dominant loading strategy in the sagittal plane with abducted hip and knee valgus. Of the non-contact injuries, 39 (78%) were deemed to involve a neurocognitive error. More (58%) injuries occurred in the first half of matches (p<0.01). Conclusions: ACL injuries in Spanish football occurred similarly with non-contact and indirect contact mechanisms (44%). Four in five non-contact injuries involved a neurocognitive error. Most injuries occurred during four previously identified situational patterns, with more injuries earlier in the match.

Assessing physical fitness adaptations in collegiate male soccer players through training load parameters: a two-arm randomized study on combined small-sided games and running-based high-intensity interval training.

Objective: To evaluate the effects of a 4-week intervention combining small-sided games (SSGs) and high-intensity interval training (HIIT) on physical fitness in collegiate male soccer players. Methods: Twenty-one soccer players were randomly assigned to either the HIIT + SSGs group (n = 11) or a control group (n = 10). Physical fitness was assessed at baseline and 1-week post-intervention, including countermovement jump (CMJ), change of direction (COD) test, sprint test, repeated sprint ability (RSA) test, and 30-15 Intermittent Fitness Test (30-15IFT). The intervention comprised eight sessions over 4 weeks: four SSGs and four HIIT. Results: The intervention group showed small to moderate improvements: mean RSA improved by 4.5% (p = 0.07), CMJ increased by 3.2% (p = 0.12), and 30-15IFT scores enhanced by 6.8% (p = 0.09). Key predictors of group membership included heart rate load per minute (OR 1.602) and various GPS variables. Conclusion: The 4-week intervention combining SSGs with HIIT did not produce statistically significant improvements in most physical fitness variables compared to the control group. Although there were positive trends in variables such as RSA and 30-15IFT, these changes were modest and not statistically significant. The results suggest that while the combined SSGs and HIIT approach shows potential, its impact on physical fitness over a 4-week period is limited, with some variables, like CMJ, even showing decreases.

Characteristics of potential head injury situations at the FIFA World Cup Qatar 2022TM.

This exploratory video analysis study aimed to review characteristics of potential head injury situations during a men's professional international football tournament. For 64 matches of the FIFA World Cup Qatar 2022™ FIFA analysts used match footage to record all potential head injury situations. A potential head injury situation was defined as a player staying down for more than 5 s and/or requesting medical attention, and where the body impact location included the player's head. Characteristics were further recorded for match, player (i.e. player action including aerial duels), medical assessment, and outcome (e.g. substitution). Descriptive statistics are reported as well as Pearson's Chi-squared test (or Fisher's exact test) to explore potential head injury situations more likely to result in medical attention. In total, 149 potential head injury situations occurred in 56 matches (mean 2.33/match, range 0-6) involving 117 players. Eight matches resulted in no incidents. Aerial duels were the most frequent match characteristic leading to a potential head injury situation. Injury stoppage with on-pitch medical assessment occurred in 35 of the 149 potential head injury situations (23%), with pitch-side assessment also occurring in 15 situations (10%), resulting in four concussion substitutions. Players were more likely to require medical attention for potential head injuries sustained when the ball was loose (χ2 = 6.88; p = 0.038) when the injured player was jumping (FET p = 0.044) and for head-to-head contact (FET p = <0.001). Further exploration of aerial duels during match play which do and do not lead to potential and actual head injuries is recommended.

Injury surveillance in Spanish professional female soccer players: A three-season retrospective study.

INTRODUCTION: Despite the popularity of soccer at the male elite level, data on the incidence of injuries in female players are limited. The study aimed to evaluate the injury incidence and rates in female soccer players in a professional setting over 3 consecutive seasons. METHODS: Data compiled from 71 elite female players with different playing positions and belonging to the same team were analyzed. The location and severity of injuries were reported according to international consensus statements on the process of conducting epidemiological studies in professional soccer. The injury incidence rate (IIR) for matches and practices and the rate ratio (RR) were calculated, and time-loss injuries during the season were also recorded. RESULTS: A total of 53 injuries were documented, with an overall IIR of 1.08 injuries per 1000 h and an overall rate ratio of 0.61. The lower limbs were the most affected region (86,8 %). The majority of these injuries occurred around the thigh and knee and were predominantly traumatic, with markedly higher rates of injury during match play (2.78 injuries per 1000 h) when compared to injury incidence during training (0.79 injuries per 1000 h). Traumatic injuries accounted for 48 (91 %) and 24 (45,3 %) were indirect contact injuries. Reinjuries amounted to 15 % of total injuries and August was the predominant month for injury, being goalkeepers the least injured players (13.2 %). CONCLUSIONS: Female professional soccer players displayed injury incidence rates and patterns comparable to those of male players. This study provides epidemiological information that will help to inform future injury surveillance studies and the development of prevention strategies to reduce the number of injuries in elite female soccer players, focusing specifically on thigh and knee regions. All match involvements should be considered when exploring associations between the type of exposure and injury risk.

Potential financial loss and risk factors for hamstring muscle injuries in elite male Brazilian soccer players: a season-long prospective cohort pilot study.

Purpose: The aim of this pilot study was to analyze the potential financial loss and a range of potential risk factors for hamstring muscle injuries in elite Brazilian soccer. Methods: Thirty-four male players (age: 25 ± 6 years; stature: 180 ± 8 cm; body mass: 78 ± 9 kg; minutes played in matches: 2243 ± 1423 min) from an elite professional soccer club were monitored during a 12-month season. Muscle injury was identified by magnetic resonance imaging and the severity was defined according to the number of days away: minimal (1-3 days), mild (4-7 days), moderate (8-28 days), severe (>28 days). Potential financial loss due to the team's under achievements was determined. Dorsiflexion range of motion, eccentric knee flexor strength and isokinetic tests were performed during the pre-season. Association between dependent variables and the occurrence of injury was evaluated. Results: Nine hamstring muscle injuries with moderate severity were found in 8 athletes. Recovery time was 22 days off the field on average. Potential financial loss was $-43.2 million USD and earnings on merit money was 21%. Previous injury, increased flexor deficit 60°â€…/sec and increased flexor fatigue index 300°/sec were all associated with a greater chance of hamstring muscle injury. Ankle dorsiflexion range of motion was significantly lower in the injured group (35.6 ± 3° vs. 39.1 ± 4.9°; p = 0.017, effect size = -0.74). Conclusion: High financial burden was found in elite Brazilian soccer during one full season. Injured athletes had high hamstring fatigue index, knee flexor strength deficit, ankle range of motion restriction and previous hamstring muscle injury when compared to non-injured athletes. Therefore, preventive approaches in professional soccer players with previous hamstring injuries should be a priority.

Prevalence of physiological and perceptual markers of low energy availability in male academy football players: a study protocol for a cross-sectional study.

Low energy availability (LEA) is a core feature of the female athlete triad and relative energy deficiency in sport (REDs). LEA underpins multiple adverse health and performance outcomes in various athletic populations, including weight category, endurance and aesthetic sports. Recent reports suggest LEA is highly prevalent in female football, volleyball and netball, with little known on male team-sport athletes. Therefore, the study aims to identify the prevalence of LEA among male academy football players (16-23 years), using surrogate markers that align with the International Olympic Committee REDs Clinical Assessment Tool-Version 2. A cross-sectional study design will be used with physiological and perceptual markers of LEA measured. The study will seek to recruit 355 players to complete several online questionnaires believed to be associated with LEA, measured using a 24-hour food and activity diary. Of the 355 players, a subsample (n=110) will complete an additional 3-day food and activity diary, provide a venous blood sample to measure levels of total testosterone and free triiodothyronine, and have resting metabolic rate (RMR) measured to determine RMRratio. The prevalence of LEA will be determined using the low (<30 kcal·kgFFM-1·day-1) domain of energy availability and divided by the total number of participants. Descriptive statistics will be used to summarise the whole group and difference status of energy availability (eg, low, reduced, optimal, high). A univariable and multivariable binary logistic regression analysis will be modelled to assess the association of various surrogate markers with the presence of LEA.

Developing a data-driven multimodal injury and illness prevention programme in male professional football based on a risk management model: the IP2 NetWork.

Background: Current injury prevention programmes in football are limited by a one-size-fits-all approach, which predominantly focuses on preventive exercise programmes while ignoring differences in risk profiles between individuals and teams. Objective: To address this gap, we developed a new data-driven, customisable approach based on the principles of risk management. We collaborated with key stakeholders to identify focus areas for injury and illness prevention and determine their priorities. Setting: The team medical and coaching staff included members from 17 professional football clubs, the national team and a youth football academy in Qatar. Methods: In 2015, we launched a series of annual workshops under the Aspetar Sports Injury and Illness Prevention Programme. The workshops included club medical personnel and fitness coaches in a process to develop team-specific programmes for injury and illness prevention based on the principle of risk management. Over 2 years, workshops refined focus areas through discussions, surveys and small-group presentations, culminating in the creation a novel programme for football injury prevention. Results: Out of 44 focus areas first identified, 23 were selected as priorities for inclusion in multimodal injury and illness prevention programmes. The identified focus areas represent a variety of aspects, including social/behavioural/lifestyle, exercise programmes/training, load management, recovery and equipment. The top priorities included communication, the Nordic hamstring exercise, training load, recovery strategies, nutrition, sleep, warm-up, the Copenhagen adduction exercise and core and dynamic stability. Conclusion: We have developed a comprehensive framework for preventing injuries and illnesses in football grounded in the general principles of risk management. This framework has proven feasible and led to the creation of a new multicomponent programme, The Aspetar IP2 (Injury and Illness Prevention for Performance) NetWork, focusing on a range of areas beyond preventive exercise programmes only.

Don't forget to mind the mind: a prospective cohort study over 12 months on mental health symptoms in active professional male footballers.

AIMS: We examined the prevalence and incidence of mental health symptoms (MHS) in active professional male footballers over a 12-month period and investigated if MHS was associated with severe injuries or surgeries. PARTICIPANTS AND METHODS: Football Players Worldwide (FIFPRO) affiliated national unions invited active professional male football players to participate in the study. MHS was operationalised in symptoms of anxiety, disordered eating, depression, distress, sleep disturbance, alcohol misuse and drug misuse, all being assessed with validated questionnaires. RESULTS: Of the 101 participants enrolled, the prevalence of distress was 53% and MHS was between 6% for drug misuse and 48% for alcohol misuse. The incidence of distress was 29% and MHS ranged from 1% for anxiety to 11% for sleep disturbance. At baseline, players suffering from injury/surgery were more likely to report depression (OR 1.35; 95%CI 1.10-1.70) and disordered eating (OR 1.22; 95%CI 1.02-1.47). At follow-up, players who suffered injury or surgery were inclined to report distress (OR 2.15; 95%CI 1.26-4.31) and drug misuse (OR 2.05; 95%CI 1.01-4.04). CONCLUSION: There seems to be a greater prevalence of MHS in active professional male footballers than in the global population and other sports. After severe injury/surgery, the risk of developing MHS is increased, confirming that healthcare professionals should be aware of the mental health of injured players.

Implementing the Copenhagen Adductor Exercise and Nordic Hamstring Exercise in West African Academy Soccer Players: An Intervention Study.

BACKGROUND: This study implemented the Copenhagen Adductor Exercise (CAE) and Nordic Hamstring Exercise (NHE) to examine 1) whether CAE and NHE interventions are associated with adductor and hamstring strength gains in youth African male soccer players and 2) whether strength changes after a rest period and secondary intervention. STUDY DESIGN: Pre-post intervention study. METHODS: Forty-four African elite male academy players (age 14.7±1.5 [12-18] years) participated in twice weekly CAE and NHE interventions for 8- and 10-week periods separated by a 4-week rest. Long lever adductor squeeze strength and prone isometric hamstring strength were measured with mixed-effects linear regression models to observe strength changes over time. RESULTS: Ninety-six and 95% of CAE and NHE sessions were completed in each intervention, with no adverse events related to the execution of the exercises. Adductor squeeze strength increased during the first intervention (baseline 3.23 [2.99-3.47] N/kg, post-intervention 3.53 [3.30-3.76] N/kg, p=0.911) and was maintained following the rest period (3.52 [3.27-3.76] N/kg, p=0.999) and second intervention (3.60 [3.35-3.84] N/kg, p=0.002). Hamstring strength improved during the first intervention (baseline 4.95 [4.42-5.49] N/kg, post-intervention 5.48 [4.95-6.02] N/kg, p<0.001), decreased to baseline during the rest period (4.98 [4.44-5.53] N/kg, p=0.996), and did not improve during the second intervention (5.01 [4.46-5.55] N/kg, p=0.978). CONCLUSION: CAE and NHE interventions can be implemented at an elite African academy with high compliance. Adductor and hamstring strength improved in the first intervention, with no further improvements in the second intervention. Secondary interventions therefore should include higher exercise volume or load to improve longitudinal adductor and hamstring strength. Level of Evidence: Level III (Cohort Study).

SoccHealth: a health status examination of former professional football (soccer) players within the German National Cohort.

The long-term health effects of football (soccer) have received significant attention in recent years. While brain health is currently the focus of this interest, potential long-term risks or benefits related to cardiovascular and metabolic diseases and cancer are also of interest to sports medicine professionals. However, studies assessing the overall health risks for professional football players remain scarce. We introduce 'SoccHealth', a satellite project to the German National Cohort (NAKO), Germany's largest population-based cohort study. SoccHealth examined 348 former professional football players aged 40-69 using the infrastructure and comprehensive examination programme of NAKO. The German Statutory Accidental Insurance for Professional Athletes identified and invited male players, while female players were recruited among former national team members. Details of the examination programme and the sociodemographic and career-related characteristics of the participants are described. The identical examination programme for the NAKO participants provides the opportunity to draw general population controls according to various definitions and focus on the respective research question to be analysed. This report delineates one approach to evaluate the long-term health effects of football across a broad range of diseases.

Implementation of a mixed-methods heat acclimation programme in a professional soccer referee before the 2022 FIFA world cup in Qatar: a case study.

Objectives: This case study reports the real-world practicalities of implementing a mixed-methods heat acclimation (HA) programme before the 2022 FIFA World Cup. Methods: One male English soccer referee (age: 44 years; height: 1.82 m; body mass: 76.0 kg) who had officiated professionally for over 17 years and had over 10 years' experience officiating in European and international matches undertook an 11-session HA programme over 22 days. On days 1 and 22, a 30 min fixed-intensity heat tolerance test (9 km.h-1, 2% gradient, 40°C, 40% relative humidity) was performed, and physiological and perceptual responses were measured. A mixed-methods HA approach was used, including environmental chamber isothermic training, post-temperate training saunas and hot water immersion. Results: Compared with the pre-test, peak core temperature reduced by 0.40°C (38.4 vs 38.0°C; minimal detectable change (MDC) = 0.34°C), peak skin temperature reduced by 0.5°C (36.7 vs 36.2°C; MDC=0.28°C) and peak heart rate reduced by 5 b·min-1 (167 vs. 162 b·min-1; MDC=4 b·min-1) in the post-test. In the post-test, the sweat rate increased by 17% (1.94 vs 2.27 L.h-1; MDC=0.42 L.h-1). Peak thermal sensation (7 = 'hot') and the rating of perceived exertion (3 = 'moderate') were unchanged between the tests. However, peak thermal comfort (3 = 'slightly uncomfortable' vs 2 = 'uncomfortable') was rated lower in the post-test. Conclusion: The HA programme elicited positive physiological but indifferent perceptual responses, highlighting that mixed-methods HA can be implemented when a referee still has officiating, travel and training responsibilities during the HA window.

On-field concurrent validity of flight time-based countermovement jump height during fatigue: A comparison between inertial measurement units worn at different locations on the body.

We explored the feasibility of utilizing immediate changes in flight time-based vertical countermovement jump height as an on-field measure for fatigue-induced decrements in performance. Comparing Inertial Measurement Units (IMUs) worn at five body locations (feet, shorts for thighs and pelvis, waist strap, and thorax in a standard GPS vest) with a force plate as a reference, we enlisted 19 amateur football players who performed a series of 10 maximal 30 m sprints (initiated every minute). Maximal jumps were executed immediately before and after each sprint, with the latter jumps recorded on a force plate integrated into the field. Bland Altman's bias (-0.49 cm) and limits of agreement (1.01 cm) were minimal for the feet IMUs. The thorax IMU had the highest bias (-6.35 cm), but the limits of agreement (2.73 cm) were similar to the other locations. Repeated measures correlations (rmcorr) between force plate and IMUs were excellent for the feet (rmcorr = 0.98) and good for the thorax (rmcorr = 0.86) and other locations except for the waist strap. In the fatigued state, within-session coefficients of variation ranged from 4.0% (pelvis in shorts) to 6.5% (waist strap). These findings suggest that body-worn IMUs possess the potential for a prompt and straightforward on-field vertical jump assessment to monitor acute fatigue.

A new injury prevention program 'FUNBALL' improves cognitive performance of young football (soccer) players: A cluster randomized controlled trial.

The youth football injury prevention program 'FUNBALL' contains exercises requiring high cognitive demands, which are performed concurrently to the training of the respective motor task. This study evaluates whether the program increases cognitive performances of young football players. 1253 football players (aged 13-19 years old) were randomly assigned to either a control (CON) or an intervention (INT) group. The INT group performed the 'FUNBALL' program at least twice per week in their training sessions for one season (9 months). The CON group continued their training routine. From the total sample, the cognitive performance of 304 players (n = 135 CON; n = 169 INT) was assessed at the beginning and the end of the season using the Cogstate® Brief Battery, with the following subtests: One Back test (accuracy), Two Back test (accuracy), One Card Learning test (accuracy), Chase Test (correct moves per second), Set Shifting (accuracy), Identification test (speed), Detection test (speed), Groton Maze Learning Test (accuracy), and Groton Maze Learning Test Delayed Recall (accuracy). A multivariate analysis of variance (MANOVA) on the cognitive performance improvements from pre-to posttest showed that the INT group improved their performances more strongly than the CON group for all cognitive tests, namely for working memory, visual learning, visual motor control, attention, psychomotor function, memory, and executive function. The present study indicates that the exercise-based injury prevention program 'FUNBALL' may improve the cognitive performance of young football players. Future research should include an active control group, and should investigate whether the improvement in cognition also has beneficial effects on in-game performance. TRIAL REGISTRATION NUMBER: AsPredicted (https://aspredicted.org/2kb3b.pdf).

Case Report: Effect of providing penalty kicking tendencies on goalkeeper's motor behaviour and performance: a case study with an on-field intervention on youth football.

The penalty kick is a crucial action in a football match that may determine the final outcome. It features a direct interaction between the shooter and goalkeeper where both search for relevant information as a means to achieve their respective performance goals. A case study, composed of an on-field intervention, was designed to analyze the influence of providing in advance penalty kicking tendencies of the shooters on a youth goalkeeping movement onset and saving performance. Data collection took place over 8 training sessions where a U10 young low-skilled, male goalkeeper and shooters were subjected to a penalty-kick shootout task. In each session, the goalkeeper faced a set of 10 penalty kicks recorded by a high-speed HD camera which allowed to calculate the moment that the shooter hit the ball and the goalkeeper movement onset in the direction of ball trajectory. Results showed that the goalkeeper delayed response initiation in the retention phase, when compared to the baseline and training phases, by moving closer to the foot-to-ball contact time by the penalty shooter. From this study, it can be highlighted that goalkeeping saving actions were adapted to the provision of a priori information about shooter kicking tendencies, to sustain a higher performance of the young goalkeeper during the penalty duelling.

Forecasting thermal stress for sports tourists at the 2026 FIFA World Cup.

This study explores thermal stress conditions (i.e. heat, humidity, sunlight exposure) sports tourists can expect when attending the 2026 FIFA World Cup. Sports tourism's growth is driven by international mega-events like FIFA World Cups and Olympic Games. With planning ongoing for the 2026 FIFA World Cup football (soccer) tournament, what remains unstudied are the heat conditions spectators can expect at the 16 host stadiums in the United States, Mexico, and Canada. The inquiry is important considering (1) the tournament is taking place in warm-weather months of June and July, (2) thermal stress contributes to heat-related illnesses like heat stroke, and (3) many destination-bound tourists will be at elevated risk to heat. Accordingly, we report historical and forecasted thermal stress levels documenting expected conditions at each host stadium. Notably, forecasts indicate worsening thermal stress compared to long-term means, providing support for the study's methodology. Practical implications and limitations are provided.