Elite Female Football Research Articles

Effects of COVID-19 Lockdown on Body Composition and Physical Performance of Elite Female Football Players

The COVID-19 pandemic led to an unusual situation in sports. Players were forced to stay at home for an undefined period of time and not allowed to use any training facilities or even exercise outdoors. Therefore, this study aimed to examine the effects of the COVID-19 lockdown on physical performance and body composition in elite female football players. During the confinement period, 19 players (n = 19, M = 27 years; SD = 4.19) volunteered to participate in the present study. Participants were confined during 5 months and performed six remotely guided sessions a week, designed and structured by a certified fitness coach. Pre- and postconfinement period, players were tested for body composition, strength in the squat exercise, vertical jump, 30-m sprint, kicking velocity, and intermittent endurance capacity (Yo-Yo Intermittent Recovery Level 1). Fat mass and muscle mass remained unaffected after the confinement period, while only body mass showed a significant increase between periods (1.19%; p = .014). In addition, physical performance measures postconfinement showed positive changes in kicking (p < .001; effect size = 1.02), in contrast to a reduction in mean propulsive velocity against 40-kg load and Yo-Yo Intermittent Recovery Level 1 total distance covered (p: .041 and .010, respectively). Present findings indicate that the implementation of home-based training programs during confinement periods could be sufficient stimulus to maintain body composition and physical performance (i.e., strength, vertical jump, and sprint), although they might not be sufficient to maintain intermittent endurance capacity in elite female football players.

Evaluation of Neuromuscular Fatigue According to Injury History in a Repeat Sprint Ability Test, Countermovement Jump, and Hamstring Test in Elite Female Soccer Players

Sprinting is a fundamental component of the professional soccer player’s ability to achieve the highest performance in the sport. The aim of this study was to analyze the influence of hamstring injury history on the neuromuscular fatigue produced by an RSA test in elite female football players. Nineteen female elite soccer players of the Second Spanish Soccer Division participated in the study. The participants were divided into: (1) a Control group who have not suffered previous muscular injuries and (2) a Hamstring group with previous hamstring injury at least one season prior to the protocol. The players performed a protocol consisting of a Repeat Sprint Ability Test (RSA) (6 × 40 m; 30 s rest), and CMJ and Hamstring tests before and after the RSA. The different variables of the study were compared between groups with a two-way ANOVA for repeated measures. The main findings from the present study were that, in subjects with previous hamstring injury, the performance was impaired compared with the control group: (1) in the initial meters of the sprint during an RSA there was a higher percentage difference between SprintTT and ideal Split in 0–10 m compared to 0–20 m in the hamstring group (p = 0.006; ES = 0.51); and in situations of high fatigue there was a higher %Dif1vs6 compared to %Dif1vs5 (percentage difference between the first sprint and fifth sprint) in the hamstring group (p = 0.005; ES = 0.54) compared with the control group. It seems that in elite female soccer players with previous hamstring injury, RSA-induced fatigue produces a greater decrease in the performance in the first 10 m of the sprint compared to the control uninjured players.

Strength and Biomechanical Risk Factors for Noncontact ACL Injury in Elite Female Footballers: A Prospective Study.

This study aimed to determine if a preseason field-based test battery was prospectively associated with noncontact anterior cruciate ligament (ACL) injury in elite female footballers. In total, 322 elite senior and junior female Australian Rules Football and soccer players had their isometric hip adductor and abductor strength, eccentric knee flexor strength, countermovement jump (CMJ) kinetics, and single-leg hop kinematics assessed during the 2019 preseason. Demographic and injury history details were also collected. Footballers were subsequently followed for 18 months for ACL injury. Fifteen noncontact ACL injuries occurred during the follow-up period. Prior ACL injury (odds ratio [OR], 9.68; 95% confidence interval (95% CI), 2.67-31.46), a lower isometric hip adductor to abductor strength ratio (OR, 1.98; 95% CI, 1.09-3.61), greater CMJ peak take-off force (OR, 1.74; 95% CI, 1.09-3.61), and greater single-leg triple vertical hop average dynamic knee valgus (OR, 1.97; 95% CI, 1.06-3.63) and ipsilateral trunk flexion (OR, 1.60; 95% CI, 1.01-2.55) were independently associated with an increased risk of subsequent ACL injury. A multivariable prediction model consisting of CMJ peak take-off force, dynamic knee valgus, and ACL injury history that was internally validated classified ACL injured from uninjured footballers with 78% total accuracy. Between-leg asymmetry in lower limb strength and CMJ kinetics were not associated with subsequent ACL injury risk. Preseason field-based measures of lower limb muscle strength and biomechanics were associated with future noncontact ACL injury in elite female footballers. These risk factors can be used to guide ACL injury screening practices and inform the design of targeted injury prevention training in elite female footballers.

Coping with the loan transition in professional association football

The present study generated a qualitative examination of male professional football players’ experiences of stress during the loan transition using the Demand Resources and Individual Effects (DRIVE) Model. Purposeful sampling was used to recruit participants (M age = 23; SD = 2.5) from various Premier League (n = 2), Championship (n = 8), and League (n = 1) clubs across the UK who have experienced a loan to another club. Guided by a critical realist philosophical orientation, semi-structured interviews were deductively developed based upon the DRIVE model to stimulate contextual discussion about the pre-transition resources (e.g. organizational support), perceived transition demands (e.g. performance pressure) and appraisals. Finally, players were asked to discuss their strategies for coping (e.g. situational coping) with loan demands and if they deemed this coping to be effective. Braun and Clarke’s (2013) thematic content analysis was utilised. Deductive thematic analysis was used to identify and evidence themes that were articulated in relation to the demands experienced, appraisals associated with such demands, and the coping strategies used to manage these demands. An inductive approach was used to code sub-themes from the data, on the basis of players’ specific experiences that had not yet been exemplified in the existing literature. This study presented loan transition demands (performance and organizational), contextual individual differences (situational coping, dispositional coping, and protective factors) and loan resources (transition preconditions and during loan) that may assist individuals’ performance and well-being. Practitioners would be advised to work with players on facilitating pre-transition resources and identify perceived demands they consider important to their transition process. Future research should seek to explore the loan transition within elite female football.

Body composition and physical performance measures in elite female football players: differences across playing positions and associations with kicking velocity and curve sprint performance

This study aimed to: i) analyze the differences in anthropometric, body composition, physical, and technical parameters in elite female football players across distinct playing positions; ii) examine the correlations between kicking velocity (KV) and physical performance, and the relationships between linear sprint and curve sprint (CS) times. Twenty-six female players (n = 26, age: 27 ± 4 years) of an elite football team completed the following assessments: anthropometric, body-composition, squat one-repetition maximum (1RM), 30-m linear sprint, 17-m CS, vertical jump, endurance, and KV measurements. In terms of body composition, only muscle mass was significantly different (P = 0.046) in favor of forwards compared to midfielders. Regarding physical performance, overall, jump and sprint capacities were superior in defenders and forwards compared to midfielders (P < 0.05). Linear and CS times (P < 0.05, r = −0.450 to −0.573) and load at 1 m · s−1 in the squat (P < 0.05, r = 0.508) were significantly correlated to KV. Lastly, moderate to strong correlations were observed between linear and CS times (r = 0.396 to 0.916). In conclusion, in this international team, physical performance was higher for defenders and forwards compared to midfielders, especially in terms of sprint and jump abilities. Additionally, significant relationships were detected between strength- and speed-related qualities and KV.

Study protocol: prevalence of low energy availability and its relation to health and performance among female football players

Enduring low energy availability (LEA) is associated with several potentially serious physiological and mental conditions. LEA has been found highly prevalent among female elite athletes within endurance sports, thus hampering...

Elite female football players’ perception of the impact of their menstrual cycle stages on their football performance. A semi-structured interview-based study

ABSTRACT Objectives This study assesses how female footballers perceive how their menstrual cycle impacts their physical and psychological performance, informing future research and intervention. Methods Semi-structured interviews, developed using piloting and peer review took place with fifteen elite female footballers from two English WSL clubs (age: 25.2 [18–33]). Data was audio recorded, transcribed verbatim, and analysed thematically using NVivo. Results All players (100%) perceive their menstrual cycle to negatively impact performance. Analysing 27,438 words of data revealed five themes: A) symptoms, B) preparation, C) performance, D) recovery, and E) management. Over half (53%) of players experienced decreased appetite and sleep quality prior to performance during menstruation. Competitive performance was perceived to be most negatively impacted during menses (54 references) following by the pre-menstrual stage (23 references). During menstruation, the most impacted physical performance indicators were power (93%) and fatigue (87%). Psychologically, confidence, focus, and reaction to criticism were commonly affected (66.7%). Players reported missing training (13.3%) and matches (13.3%) due to severity of impact. Recovery was affected during the pre-menstrual (26.7%) and menstrual (66.7) stages. Players self-manage symptoms using over the counter (66.7%) and prescription (26.7%) medication, some prophylactically prior to competition (46.7%). Conclusions This first attempt to ascertain player perception in football exposes a clear negative impact on performance. The complex interplay of biopsychosocial and logistical factors, lack of awareness and education highlight the need for further research. Intervention is necessary and immediate initiation would be prudent, starting with simple measures such as basic self-management advice, education, and provision of sanitary products.

Dietary supplements for consideration in elite female footballers

The physical demands of professional female football have intensified in recent years. Supplements are only advised in addition to a healthy, balanced diet, but may warrant a greater prevalence in the professional game to support well-being, recovery and performance. Supplements used by players should be safe, legal and scientifically proven to be effective. An individual approach should be taken to using supplements dependant on the needs and goals of the player. Female players should aim to improve the frequency of protein intake throughout the day, whilst tailoring doses to individual body mass. Vitamin D supplementation is vital throughout the winter months in countries with limited sun exposure, however doses should be administered based on individual blood test results. Iron is likely to be important to the well-being of female athletes throughout the season, in particular during the menses. Omega-3 and collagen may be of greater benefit to female than male athletes during recovery from soft tissue injury, whilst probiotics and creatine are beneficial throughout the season for reducing risk of illness and optimising recovery, respectively. Ergogenic supplements for football include beta-alanine, nitrate and caffeine. Caution should be taken with caffeine use due to the varying tolerance of difference athletes and sleep impairments that can follow.

ANALYSIS OF HIGH-SPEEDRUNNING AND SPRINT RUNNING IN ELITE FEMALE FOOTBALL COMPETITIONS

Introduction: Although football is recognized as the fastest growing sport globally, scientific literature on female footballis still limited. Available published data in understanding the physical demands of female football players have described the necessity of a high level of physical conditioning during matches with average heart rates of 84-86% maximum heart rate and an average of 9.1-11.9 km in total distance covered in the running. The most commonly utilized physical performance measures reported are high-speed running (19km/h-23km/h) and sprinting (>23 km/h). A better understanding of football's physical, technical and tactical demands has resulted from investigations of both training and matches by wearing a global positioning system unit.Objective: This study aimed to assess the running speed and the proportions of different types of running during official competitions in elite female football players.Material and Method: A total of 22 female players (16 seniors and six juniors) that are part of a Romanian First League female football team -Politehnica Timisoara, have been monitored for running speed and covered distance in 6 official matches, which represent a quarter of the championship period. The assessment period was ten weeks (August-October 2021). The monitored parameters (total distance, distance/minute, low speed running, high speed running, sprint running, and maximum speed) wereobtained using K-Sport GPS with a high sampling rate of 50 Hz.Results: During the six analyzed matches the following average values were found: total covered distance -7906.33 ± 1176.68 m, distance/minute -90.83 ± 3.72 m/min, low-speed running distance-7598.50 ± 1102.16 m, high-speed running distance -308 ± 101.31 m, sprint running distance -69.50 ± 28.54 m, and maximum speed -25.13 ± 0.84 km/h.Conclusion: Regarding the monitored parameters (total distance, average speed, proportion of different speed running, maximum speed), we observed a constancy between different matches. During female football matches, high-speed running and sprinting covered 4.77% of the total distance. Based on this data, a future training objective would be the enhancement of this percentage in order to optimize the key moments of the matches.

Nutritional optimization for female elite football players—topical review

Women's football is an intermittent sport characterized by frequent intense actions throughout the match. The high number of matches with limited recovery time played across a long competitive season underlines the importance of nutritional strategies to meet these large physical demands. In order to maximize sport performance and maintain good health, energy intake must be optimal. However, a considerable proportion of female elite football players does not have sufficient energy intake to match the energy expenditure, resulting in low energy availability that might have detrimental physiologic consequences and impair performance. Carbohydrates appear to be the primary fuel covering the total energy supply during match-play, and female elite football players should aim to consume sufficient carbohydrates to meet the requirements of their training program and to optimize the replenishment of muscle glycogen stores between training bouts and matches. However, several macro- and micronutrients are important for ensuring sufficient energy and nutrients for performance optimization and for overall health status in female elite football players. The inadequacy of macro-and micronutrients in the diet of these athletes may impair performance and training adaptations, and increase the risk of health disorders, compromising the player's professional career. In this topical review, we present knowledge and relevant nutritional recommendations for elite female football players for the benefit of sports nutritionists, dietitians, sports scientists, healthcare specialists, and applied researchers. We focus on dietary intake and cover the most pertinent topics in sports nutrition for the relevant physical demands in female elite football players as follows: energy intake, macronutrient and micronutrient requirements and optimal composition of the everyday diet, nutritional and hydration strategies to optimize performance and recovery, potential ergogenic effects of authorized relevant supplements, and future research considerations.

Factors Associated with Hip and Groin Pain in Elite Youth Football Players: A Cohort Study

BackgroundDespite hip and groin pain being commonly reported in elite youth football players, little evidence on risk factors exists. Risk factors in adult football players include reduced hip adductor strength and hip adductor/abductor strength ratios, and lower Copenhagen Hip and Groin Outcome Score (HAGOS) subscale scores. It is unknown if these factors are also predictive of pain development in youth football players.ObjectiveTo identify whether preseason hip adductor and abductor strength and HAGOS subscale scores of male and female elite youth football players are associated with in-season or historical (lifetime) hip and groin pain.MethodsPreseason hip adductor and abductor strength testing and the HAGOS were undertaken by 105 elite male (n = 58) and female (n = 47) football players aged 11–15 years. Medical staff documented both players’ self-reported historical and in-season hip and groin pain. Univariate and multivariate logistic regression models were undertaken with main outcome measures in-season hip and groin pain and historical hip and groin pain and independent variables of hip muscle strength, hip muscle torque and HAGOS subscale scores.ResultsTwenty-three players (21.9%) self-reported in-season hip and groin pain, while 19 players (18.1%) self-reported historical hip and groin pain. Pre-season hip adductor and abductor variables and HAGOS subscale scores failed to predict in-season hip and groin pain. However, a higher body mass index (odds ratio [OR] = 1.32; 95% CI 1.01, 1.73, p = .043) and being male (OR 5.71; 95% CI 1.65, 19.7) were associated with having in-season hip and groin pain (R2 = 0.211). There was also an association between historical hip and groin pain (R2 = 0.579) and both HAGOS subscale Quality of Life (odds ratio [OR] = 0.84; 95% CI 0.77, 0.91, p < .001) and mean abductor torque (OR = 11.85; 95% CI 1.52, 91.97; p = .018).ConclusionPre-season hip adductor and abductor strength and HAGOS subscale scores did not predict subsequent in-season hip and groin pain in elite youth football players. However, pre-season higher hip abductor strength and lower HAGOS scores were retrospectively associated with historical hip and groin pain.

Sleep duration and quality are associated with nutrient intake in elite female athletes

ObjectivesSleep is important for athlete health and performance; however, the relationship between diet and sleep in elite female athletes is not well understood. This study examined associations between energy, macronutrient and micronutrient intakes, and sleep in elite female Australian footballers. DesignProspective cohort study. MethodsThirty-two players had their diet and sleep monitored for 10 consecutive days during pre-season. Sleep was monitored using activity monitors and sleep diaries. Sleep outcomes included sleep duration, sleep onset latency (SOL), wake time after sleep onset (WASO), and sleep efficiency (SE). Dietary intake was monitored using the smartphone applications Easy Diet Diary and FoodWorks. Relationships between nutrient intake and sleep were assessed using Generalised Estimating Equations. ResultsFor each 1-g·kg−1 increase in carbohydrate intake, WASO increased by 3.6 min (p = 0.007) and SE decreased by 0.6% (p = 0.007). For each 1-g increase in daily saturated fat intake, SOL decreased by 0.27 min (p = 0.030). For each 1-mg increase in iron intake, sleep duration increased by 0.55 min (p < 0.001). For each 1-mg increase in zinc intake, SE increased by 0.23% (p = 0.006). For each 1-μg increase in vitamin B12 intake, WASO decreased by 1.72 min (p < 0.02) and SE increased by 0.40% (p = 0.033). ConclusionsNutrient intake in elite female athletes is associated with sleep and may contribute to sleep problems. Research should explore causal relationships between nutrient intake and sleep, and the efficacy of dietary interventions for improving sleep in female athletes with nutrient deficiencies.

Position specific physical performance and running intensity fluctuations in elite women's football.

The purpose of the present study was to investigate the physical performance of elite female football players during match play along with transient alterations in running performance following 1- and 5-min univariate peak periods. 54 elite female players from four top-level Norwegian teams were monitored for one season (n=393match observations), and physical performance data collected using STATSport GPS APEX. Results revealed significant differences in physical performance between the positions during full match play, particularly between wide and central players. Both full backs (FBs) and wide midfielders (WMs) covered more total distance (TD), high-speed running distance (HSRD), and sprint distance (SpD) than center backs (CBs) (p<0.05-0.001), while WMs also covered more HSRD than both central midfielders (CMs) (p<0.01) and forwards (FWs) (p<0.05), and more acceleration -and deceleration distance (Accdist and Decdist ) than both CBs and CMs (p<0.01-0.001). A similar pattern was observed for the peak period analysis, with FBs and WMs covering more SpD in peak 1min than CBs and CM (p<0.001) and more SpD in peak 5-min than CBs, CMs, and FWs (p<0.001). Irrespective of the variable analyzed, greater distances were covered during the peak 5-min period than in the next-5 and mean 5-min periods (p<0.001). Significant (p<0.001), but small to trivial (Cohen's Dz : 0.07-0.20), decreases in distance covered were also observed for each variable following each univariate peak 5-min period. In conclusion, practitioners should account for differences in physical performance when developing training programs for female football players and be aware of transient reductions in physical performance following univariate peak 1- and 5-min periods. Specifically, the very high intensity in 1-min peak periods adds support to the principal of executing speed endurance activities during training to mirror and be prepared for the physical demands of match play.

Gut microbiota of elite female football players is not altered during an official international tournament.

The current study aimed to investigate if the gut microbiota composition of elite female football players changes during an official international tournament. The study was conducted throughout ten consecutive days, encompassing seven training sessions, and three official matches. The matches were separated by 48-72h. Seventeen elite female football players from the Portuguese women's national football team participated in the study. Fecal samples were collected at two time points: at the beginning and end of the tournament. Fecal microbiota was analyzed by sequencing the 16S rRNA gene. Throughout the study, the duration and rating of perceived exertion (RPE) were recorded after training sessions and matches. The internal load was determined by the session RPE. The gut microbiota of players was predominantly composed of bacteria from the phyla Firmicutes (50% of relative abundance) and Bacteroidetes (20%); the genera Faecalibacterium (29%) and Collinsella (16%); the species Faecalibacterium prausnitzii (30%) and Collinsella aerofaciens (17%). Overall, no significant changes were observed between time points (p≥0.05). Also, no relationship was found between any exercise parameter and the gut microbiota composition (p≥0.05). These findings demonstrate that the physical and physiological demands of training and matches of an official international tournament did not change the gut microbiota composition of elite female football players. Furthermore, it supports that the gut microbiota of athletes appears resilient to the physical and physiological demands of training and match play.

Risk factors for ACL, hamstring strain, and hip/groin injuries in elite Australian female footballers: A prospective study.

Introduction: Female footballers are at high risk of sustaining lower limb injuries, with some of the most prevalent and severe injuries being hamstring strains, hip/groin pain, and knee ligament sprains. However, there is currently limited evidence to guide injury prevention strategies and injury risk assessment testing in female footballers. The aim of this study was to assess risk factors for ACL, hamstring, and hip/groin injuries in elite female footballers. Methods: Data were collected from 321 elite female Australian Football, soccer, and Rugby League players during pre-season. Players underwent field-based assessments of isometric hip adductor and abductor strength (ForceFrame), eccentric knee flexor strength during the Nordic hamstring exercise (NordBord), countermovement jump (CMJ) on dual forceplates (ForceDecks), and a single-leg triple vertical hop (TVH) using a makerless motion capture system (HumanTrak). Players were subsequently followed for injuries for 18 months. Risk factors were identified prospectively using simple and multiple logistic regression and decision tree learning. Results: A total of 12 anterior cruciate ligament (ACL) ruptures, 17 hamstring strains, and 12 hip/groin injuries were recorded. Risk factors for ACL injury included prior ACL injury (standardised odds ratio [OR]=12.3, P<.001), lower body weight normalised adductor torque (OR=2.1, P=.028), greater body weight normalised CMJ peak force (OR=1.9, P=.013), lower CMJ impulse (OR=2.0, P=.037), greater triple vertical hop knee frontal plane projection angle (OR=2.3, P=.014), and greater triple vertical hop lateral trunk flexion (OR=1.7, P=.038). Multiple logistic regression and decision tree models classified ACL injured players with high accuracy (sensitivity=67% and 75% respectively, and specificity=88% and 100% respectively). Risk factors for time-loss hamstring injury included smaller stature (OR=1.8, P=.030), greater between-leg asymmetry in CMJ peak force (OR=2.0, P=.011) and eccentric impulse (OR=1.9, P=.016). There were no statistically significant risk factors for hip/groin injury. Discussion: This is the first study to explore risk factors for lower limb injury in elite female Australian football codes. These results provide insight into the potential modifiable factors associated with subsequent injury in elite female footballers, which may inform player testing batteries and the design of targeted injury risk reduction strategies. Conflict of interest statement: Funding for travel was provided by Vald Performance (Brisbane, Australia) and SMA Research Foundation. My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.

Impact of prior ACL, hamstring or groin injury on lower limb strength and jump kinetics in elite female footballers

Introduction: Prior injury is a risk factor for lower limb injury in female footballers. An improved understanding of the impact of the most common and severe injuries on lower limb strength and biomechanics may help to optimise rehabilitation strategies and decrease subsequent injury rates. The aim of this cross-sectional study was to compare lower limb strength and countermovement jump (CMJ) kinetics between elite female footballers with and without a history of anterior cruciate ligament reconstruction (ACLR), hamstring strain, or hip/groin injury. Methods: 369 elite female Australian football, soccer and rugby league players aged 15–35 years underwent assessments of isometric hip adductor and abductor strength, eccentric knee flexor strength, and CMJ vertical ground reaction forces. Players reported their lifetime history of ACLR, and whether they had sustained a hamstring strain, or hip/groin injury in the previous 12-months. Strength and jump/landing kinetics, including between-leg asymmetry, were compared between players with and without prior injury. Logistic regression was used to determine the variables that best distinguished between players with and without prior injury. Results: Players with a unilateral history of ACLR (n=24) displayed asymmetry (injured<uninjured leg) in eccentric knee flexor strength (mean difference=-6.9%, 95%CI=-9.1 to -4.8%), isometric hip abductor strength (mean difference=-2.4%, 95%CI=-4.4 to -0.4%), and peak landing force (mean difference=-5.9%, 95%CI=-11.0 to -0.9%). Together, between-leg asymmetry in eccentric knee flexor strength, isometric hip abductor strength, and CMJ peak landing force distinguished between players with and without prior ACLR with 93% accuracy. No differences in strength or CMJ kinetics were observed between players with and without a history of hamstring or hip/groin injury. Discussion: Elite female footballers with a history of ACLR, but not hamstring or hip/groin injury, exhibit persistent between-leg asymmetries in lower limb strength and jump kinetics following a return to sport. To address the effects of prior injury, ACLR rehabilitation programs for elite female footballers should consider targeting between-leg asymmetries in eccentric knee flexor strength, isometric hip abductor strength, and CMJ kinetics. Conflict of interest statement: Funding for travel costs associated with data collection was provided by Vald Performance (Brisbane, Australia) and SMA Research Grant. My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.

Impact of prior anterior cruciate ligament, hamstring or groin injury on lower limb strength and jump kinetics in elite female footballers

ObjectiveTo compare lower limb strength and countermovement jump (CMJ) kinetics between elite female footballers with and without a history of anterior cruciate ligament reconstruction (ACLR), hamstring strain, or hip/groin injury. DesignCross-sectional. SettingField-based. Participants369 elite female Australian football, soccer and rugby league players aged 15–35. Main outcome measuresIsometric hip adductor and abductor strength, eccentric knee flexor strength, and CMJ vertical ground reaction forces, including between-leg asymmetry. Players reported their lifetime history of ACLR, and whether they had sustained a hamstring strain, or hip/groin injury in the previous 12-months. ResultsPlayers with a unilateral history of ACLR (n = 24) had significant between-leg asymmetry in eccentric knee flexor strength (mean = −6.3%, 95%CI = −8.7 to −3.9%, P < .001), isometric hip abductor strength (mean = −2.5%, 95%CI = −4.3 to −0.7%, P = .008), and CMJ peak landing force (mean = −5.5%, 95%CI = −10.9 to −0.1%, P = .046). Together, between-leg asymmetry in eccentric knee flexor strength, isometric hip abductor strength, and CMJ peak landing force distinguished between players with and without prior ACLR with 93% accuracy. ConclusionElite female footballers with a history of ACLR, but not hamstring or hip/groin injury, exhibit persistent between-leg asymmetries in lower limb strength and jump kinetics following a return to sport.

Understanding the Presence of Mental Fatigue in Elite Female Football

ABSTRACT Purpose: Previous research investigating the impact of induced mental fatigue in football (soccer) has demonstrated associated performance decrements in physical, technical, tactical and decision-making performance. A common limitation amongst this research is the protocols used to induce mental fatigue which provides low ecological validity, and the inclusion of recreational or sub-elite players. Therefore, understanding the presence of mental fatigue in elite football can provide insight into protocols with greater ecological validity. Methods: The current study used focus groups with 10 elite female football players, focusing on five topics (travel, fixture congestion, receiving tactical information, pre-match routine and pressure to win) related to the perceived causes of mental fatigue in elite football (directed by anecdotal quotes in elite football and research-based theories). Results: Several themes emerged from the data; travel fatigue, inability to switch off from football, fatigue experienced following team meetings, use of pre-match music and internal pressure to succeed. Conclusion: These findings present practical recommendations to reduce mental fatigue in elite football settings, such as considering the timing, content and duration of team meetings, providing players with free time/rest where possible, and considering the modality of coaching instructions during matches.

The Impact of Chronotype on the Sleep and Training Responses of Elite Female Australian Footballers.

The primary aims of the present study were to examine the impact of chronotype on sleep/wake behaviour, perceived exertion, and training load among professional footballers. Thirty-six elite female professional football player’s (mean ± SD: age, 25 ± 4 y; weight, 68 ± 7 kg) sleep and training behaviours were examined for 10 consecutive nights during a pre-season period using a self-report online player-management system and wrist activity monitors. All athletes completed the Morningness-Eveningness Questionnaire (rMEQ) on the first day of data collection. Eleven participants were morning types, seventeen participants were intermediate types, and three participants were evening types. Separate linear mixed models were conducted to assess differences in sleep, perceived exertion, and training behaviours between chronotype groups. Morning types woke up earlier (wake time: 07:19 ± 01:16 vs. 07:53 ± 01:01, p = 0.04) and reported higher ratings of perceived exertion compared to intermediate types (6.7 ± 1.1 vs. 5.9 ± 1.2, p = 0.01). No differences were observed between chronotype groups for bedtime, time in bed, total sleep time, sleep efficiency, training duration, or training load. In circumstances where professional female football players are required to train at a time opposing their natural circadian preference (e.g., morning type training in the evening), their perceived exertion during training may be higher than that of players that are training at a time that aligns with their natural circadian preference (e.g., evening type training in the evening). It is important for practitioners to monitor individual trends in training variables (e.g., rating of perceived exertion, training load) with relation to athlete chronotype and training time. Future research should examine the relationship between chronotype, training time, and rating of perceived exertion across different training durations.

The 12-lead electrocardiogram of the elite female footballer as defined by different interpretation criteria across the competitive season

ABSTRACT Pre-participation screening (PPS), using a 12-lead electrocardiogram (ECG), is recommended to identify athletes at risk of sudden cardiac death (SCD). ECG interpretation criteria have been developed to address the concern arising from high false-positives in athletes. There are limited ECG data in elite female footballers. The aims of this study were to (1) compare the ECG outcomes using three published ECG criteria (European Society of Cardiology [ESC], Seattle, International) in elite female footballers and (2) compare ECG data at three different stages of a competitive season. Eighty-one elite female footballers (21 ± 4 yr) completed a medical assessment, anthropometrics, resting blood pressure and a resting 12-lead ECG. Each 12-lead ECG was interpreted in accordance with (1) ESC; (2) Seattle; (3) International Criteria to determine training-related and non-training-related ECG changes. A subset of thirteen (26 ± 4 yr) footballers had repeated resting ECG tests at three time points across the competitive season. Eighty percent of females had training-related ECG patterns. Sinus bradycardia (65%) and early repolarization (42%) were the most common. Using the ESC Criteria 25% (20/81) of the athletes were considered to have an abnormal ECG, compared to 0% using the Seattle and International Criteria, mainly due to alterations in QT length criteria. There were no clinically significant differences in ECG data across a competitive season. The Seattle and International ECG Criteria significantly reduced the number of ECG false-positives in elite female footballers and the time point of PPS within a competitive season is unlikely to alter the PPS outcomes. Abbreviations: AMSSM: American Medical Society for Sports Medicine; ANOVA: Analysis of Variance; BSA: Body Surface Area; ECG: Electrocardiogram; ESC: European Society of Cardiology; FA: Football Association; FIFA: The Fédération Internationale de Football Association (FIFA); F-MARC: FIFA Medical Assessment and Research Centre; LAE: Left atrial enlargement; LVH: Left ventricular hypertrophy; PPS: Pre-participation screening; SCD: Sudden cardiac death