Elite Football Research Articles

Correlations between sports-related polygenic profiles, postural stability, power and strength performances of elite football players

Correlations between sports-related polygenic profiles, postural stability, power and strength performances of elite football players

The Temporal Pattern of Recovery in Directional Dynamic Stability Post Football-Specific Fatigue.

Rising injury rates within football require further understanding of the etiological risk factors associated with lower-limb injury. To examine the temporal pattern of recovery of directional dynamic stability measures post football-specific fatigue. Eighteen male elite footballers completed baseline assessments of directional dynamic stability measures (Overall Stability Index, anterior-posterior stability [A-P], medial-lateral stability [M-L] on level 1 of the Biodex Stability System). Post Soccer-Specific Aerobic Field Test90 measures were repeated immediately, +24 hours, +48 hours, and +72 hours. The main effects for the recovery time and direction of stability were supplemented by regression modeling to describe the temporal pattern of recovery. Significant main effects for time were identified for all directions of stability (Overall Stability Index, A-P, and M-L) up to +48 hours postexercise (P ≤ .05). The quadratic pattern of temporal recovery highlights a minimum of 37.55 to 38.67 hours and maximum of 75.09 to 77.33 hours. Additionally, a main effect for direction of stability was observed, with significant differences identified between A-P and M-L stability at all time points (P ≤ .001). Reductions in directional dynamic stability +48 hours postfatigue highlight implications for training design, recovery strategies, and injury management for performance practitioners. Interestingly, A-P stability has been highlighted as being significantly reduced compared with M-L stability at all time points, regardless of the fatigue exposure. Practitioners should consider the reduction of stability in this plane in relation to common mechanisms of injury in the knee to inform injury-risk-reduction strategies.

Examining the career dynamics of elite football referees: a unique identification profile

ABSTRACT Research into the career dynamics of high-performance level match officials across sports is scarce. The present study analyses the career dynamics of elite football referees from childhood to the elite level, creating a context of life design and a pattern for identifying individuals with potential talent. Twelve international and elite football referees participated in semi-structured in-depth interviews utilizing narrative inquiry. Participants were asked to recall all football refereeing–related experiences associated with their life stories from childhood to obtaining their FIFA Elite Referee (FER) position. Data analysis indicated that there were two common discourses (early and later) in an elite football referees’ career which helped to shape their job role with increased meaningfulness, providing invaluable insights for reaching the FER position. The interviewees experienced specific on- and off-field, reactions during their career (early and late) in order to prepare themselves to face challenging and conflict-related situations in football refereeing. Based on career stages, types of job crafting, and job characteristic levels, we developed the unique career dynamic identification profile of elite football referees. Accordingly, we argue that a talented individual needs to undertake individual training and career-based goal setting in their early career, whilst later in their career the elite referees should move towards collective training and game-based goal setting. The paper discusses the wider implications of the research findings, including their transferability to other societal groups populations, such as public sportspeople, talented individuals, national football federations, referee departments, and concludes by considering suggestions for future research.

Load Monitoring Practice in European Elite Football and the Impact of Club Culture and Financial Resources.

Load monitoring is considered important to manage the physical training process in team sports such as Association Football. Previous studies have described the load monitoring practices of elite English football clubs and clubs with an established sports-science department. An examination of a broader international sample is currently not available. In addition, previous research has suggested factors that may improve the implementation of load monitoring practices, such as a strong club belief on the benefit of evidence-based practice (EBP) and high club financial resources. However, no study has examined yet the actual impact of these factors on the monitoring practices. Therefore, this study aims (1) to provide an overview of load monitoring practices in European elite football and (2) to provide insight into the differences in implementation between clubs by examining the impact of the club beliefs on the benefit of EBP and the club financial resources. An online survey, consisting of multiple choice and Likert scale questions, was distributed among sports-science and sports-medicine staff (n = 99, 50% response rate). Information was asked about the types of data collected, collection purposes, analysis methods, and staff involvement. The results indicated that external load data (e.g., global navigation satellite system, accelerometer…) was collected the most whilst respondents also indicated to collect internal load (e.g., heart rate, rating of perceived exertion…) and training outcome data (e.g., aerobic fitness, neuromuscular fatigue…) for multiple purposes. Considerable diversity in data analysis was observed suggesting that analysis is often limited to reporting the gathered data. Sports-science staff were responsible for data collection and analysis. Other staff were involved in data discussion to share decision-making. These practices were positively impacted by a stronger club belief on the benefit of EBP and greater financial resources. Creating an organizational culture, characterized by a strong belief on the benefit of EBP, is important to increase the impact of load monitoring. However, the actual potential may still be largely determined by financial resources. High-level clubs could therefore play a leading role in generating and sharing knowledge to improve training practices and player health.

First-time anterior cruciate ligament injury in adolescent female elite athletes: a prospective cohort study to identify modifiable risk factors

PurposeTo identify modifiable biomechanical and neuromuscular anterior cruciate ligament (ACL) injury risk factors for first-time ACL injury in adolescent female elite football and team handball players.MethodsAdolescent female elite football and handball players with no previous ACL injury participated in the present study. At baseline, players were tested during side-cutting manoeuvres performed in a 3-dimensional motion analysis laboratory with concomitant electromyography (EMG) measurements. Maximal isometric lower limb muscle strength was assessed by handheld dynamometry. Players were prospectively followed for 2 years after baseline testing, and all magnetic resonance imaging (MRI) verified ACL injuries were registered. The effect of 16 risk factor candidates on the relative risk (RR) of ACL injury was estimated using Poisson regression analysis.ResultsNinety players (age 16.9 ± 1.2 years) were included in the analyses. Nine first-time ACL injuries (injury incidence 10.0% (95% confidence interval (CI) 5.4–18.6%)) were registered during the 2-year follow-up period. Four risk factor candidates were significantly associated with the risk of ACL injury: (1) hip flexion angle at initial contact (IC) [RR 0.56, 95% confidence interval (CI) 0.34–0.92], (2) internal knee rotation angle at IC [RR 1.13, 95% CI 1.08–1.19], (3) semitendinosus EMG activity 50 ms prior to IC [RR: 0.62, 95% CI 0.43–0.89], and (4) external hip rotator strength [RR: 0.77, 95% CI 0.66–0.89].ConclusionFour distinct ACL injury risk factors related to the side-cutting manoeuvre were identified in a population of adolescent female elite football and team handball players with no previous ACL injury. As ACL injury typically occur during side-cutting, intervention programmes to modify these risk factors pose a promising strategy for ACL injury prevention in adolescent female elite football and team handball.Level of evidenceII.

Association of the British Athletic Muscle Injury Classification and anatomic location with return to full training and reinjury following hamstring injury in elite football

BackgroundThe relationship between hamstring muscle injuries (HMIs) that involve the intramuscular tendon and prolonged recovery time and increased reinjury rate remains unclear in elite footballers.ObjectiveTo determine the association of time...

When different logics meet: the crisis communication of a national head coach in elite football

ABSTRACT Through a longitudinal study of how a national head coach in men’s football defended and explained persistent losses, the following questions were addressed: What was the content of the media criticism, how did the coach react and why, and how did the media react to his response? Despite persistent losses, the coach praised his team and never admitted having done something wrong. The media, in turn, criticised the coach for his rhetoric, his lack of humility, and his lack of professional skills. He consistently responded with denials, which reinforced the media criticism. As such, he himself created a space for the ‘media hunt’. Overall, this study illustrates the dynamics that arise when professional sports logic and media logic meet. It indicates that the ‘media hunt’, at least to some extent, can be avoided if coaches know media logic and which crisis responses are the most effective in different situations.

엘리트 및 아마추어 축구 선수의 정적 평형성 유지를 위한 머리, 몸통의 흔들림 비교 분석

Purpose: The objective of our study is to understand the characteristics of static balance for elite and amateur football athletes based on the analysis of head and trunk sways.<BR> Method: Angular variables (mean, maxima, minima angle, angular displacement & velocity, and cumulative angle change) of roll, pitch, and yaw were measured using one-leg standing of elite (n=10) and amateur (n=10) athletes. Independent sample t-test (p=.05) was employed for statistical analysis.<BR> Results: A roll angle for the head sway of elite athletes (1.68±.60°) was measured greater by 85% than that of amateur athletes (.91±.58°).<BR> Conclusion: It is shown that elite football athletes exhibit higher sway than amateur football athletes, particularly for their head and trunk sways. This study may be applicable for developing a program that is aimed towards improving the balance of football athletes.

Injury incidence and burden in a youth elite football academy: a four-season prospective study of 551 players aged from under 9 to under 19 years

ObjectiveInvestigate the incidence and burden of injuries by age group in youth football (soccer) academy players during four consecutive seasons.MethodsAll injuries that caused time-loss or required medical attention (as per...

Comparison of Physical Condition Profiles of Elite and Non-Elite Youth Football Players

Performance of a football player in a competitive match is influenced by good physical condition in training, competing, or in everyday life. Comprehensive ability is the hope of all football coaches. The study was conducted to determine how the comparison of the physical condition profile of youth football players in the elite and non-elite categories at the provincial level football federation, especially in SSB in the Special Region of Yogyakarta.The research method used in this research is descriptive quantitative. The subjects of this study were students or soccer athletes in elite and non-elite youth football players. The population that the researchers determined was elite and non-elite youth football players at football schools or football clubs in the DIY Province. The sampling technique was carried out by means of purposive random sampling. The instrument in this study used the MFT / Yoyo Intermitent Test, Vertical Jump Test, 30 meter Sprint Test, Illinois Test, and Sit And Reach.Based on the results of the study, it shows that the body mass index component with an average of 19.53 elite players and 19.78 non-elite players. Flexibility, elite players 34.40 and non elite players 31.14. The leg power of elite players is 45.52 and for non-elite players is 45.28. The speed component is 4.48 for elite and non-elite players, 4.95. For coordination, the elite players are 53.04 and the non-elite players are 51.20. The agility of the elite players is 18.68 and the non-elite players are 18.99. Meanwhile, the aerobic endurance for elite players was 39.85 and non-elite players were 37.97. So it can be concluded that the physical condition of soccer players which includes body mass index, flexibility, leg power, speed, coordination, agility and endurance, elite players show better results compared to non-elite players.

Semitendinosus and biceps femoris long head active stiffness response until failure in professional footballers with vs. without previous hamstring injury

ABSTRACT This study sought to examine the active stiffness of semitendinosus (ST) and biceps femoris long head (BFlh) during a knee flexor isometric contraction at 20% of maximal voluntary isometric contraction until failure in elite footballers (n = 50, age: 22.3 ± 5.3 years; height: 1.82 ± 0.08 m; body mass: 74.7 ± 9.0 kg). Active stiffness was assessed using ultrasound-based shear wave elastography by means of shear modulus quantification. Comparisons were performed between limbs with (n = 11) vs. without (n = 89) previous hamstring injury. A similar time until failure in the knee flexor fatigue task was observed between groups (p = .401). At the start of the task, lower limbs with previous hamstring injury showed a lower BFlh active stiffness (31.0.1 ± 10.4 kPa, p = .023) and BFlh/ST active stiffness ratio (0.50 ± 0.29), and no differences for ST (72.8 ± 26.8 kPa, p = .221) compared to lower limbs without previous hamstring injuries (BFlh: 38.0 ± 9.6 kPa; ST: 64.0 ± 18.4 kPa; BFlh/ST: 0.65 ± 0.27). During the task, the ST active stiffness in both groups decreased from 80% of task time (p = .032), in the absence of changes in BFlh active stiffness (p = .534), resulting in an increase in BFlh/ST active stiffness from 80% of task time (p = .029). No differences between limbs were observed during the fatigue task for all parameters (p > .099). Future research is warranted to verify if the differences found represent an increased risk of hamstring injury. Highlights The hamstring's active stiffness response to a fatigue protocol in soccer athletes with a history of injury is unknown. Athletes with previous injury showed less active stiffness in the biceps femoris long head. Similar response to fatigue was observed between athletes with and without hamstring injury history.

Does the chronotype distribution vary between different level football leagues? Insights gained from Czech elite football players

ABSTRACT Chronotype refer to individuals’ time-of-day preferences for activities, which can be classified as “morning types = (M-types)”, “evening types = (E-types)”, and “neither types (N-types)”. The primary aim of this study was to compare the chronotype distribution of Czech First League (1L) and Czech National Football League (2L) male elite football players, which was divided into two secondary aims: (i) statistically identify and compare the number (presence) of particular chronotypes in 1L, and (ii) statistically identify and compare the number (presence) of particular chronotypes in 2L. The present cross-sectional study employed a self-reported standardized questionnaire, the Composite Scale of Morningness, to study the chronotype distribution among the male elite football players. The chronotype distribution of 139 (85 from 1L with mean age ± S.D. = 25.5 ± 3.7 years and 54 from 2L age = 24.4 ± 4.5 years) players was assessed. Overall, 61 (71.8%) of the participants from 1L were mainly N-types, followed by M- and E-types. Similarly, 40 (74.1%) participants from 2L were mainly N-types, followed by M- and E-types. The statistical analysis of the 1L players showed a significantly higher presence of N-types compared to M- and E-types (χ2 (2) = 57.62, p < .05, V = .58). The same results were detected in 2L, where the N-type was identified in the majority of football players (χ2 (2) = 57.62, p < .05, V = .58). The statistical comparison of the number of presented chronotypes did not show a significant difference (F = 3.29, p > .05, V = .16) between players of the 1L and 2L. Thus, N-types are dominant among Czech elite football players, and the chronotype distribution of male elite football players from the Czech First League and the Czech National Football League does not vary.

Analysis of the worst-case scenarios in an elite football team: Towards a better understanding and application

ABSTRACT This study investigated the variability in the worst-case scenario (WCS) and suggested a framework to improve the definition and guide further investigation. Optical tracking data from 26 male players across 38 matches were analysed to determine the WCS for total distance, high-speed running (>5.5 m.s−1) and sprinting (>7.0 m.s−1) using a 3-minute rolling window. Position, total output, previous epoch, match half, time of occurrence, classification of starter vs substitute, and minutes played were modelled as selected contextual factors hypothesized to have associations with the WCS. Linear mixed effects models were used to account for cross-sectional observations and repeated measures. Unexplained variance remained high (total distance R2 = 0.53, high-speed running R2 = 0.53 and sprinting R2 = 0.40). Intra-individual variability was also high (total distance CV = 4.6–8.2%; high-speed CV = 15.6–37.8% and Sprinting CV = 21.1–76.4%). The WCS defined as the maximal physical load in a given time-window, produces unstable metrics lacking context, with high variability. Furthermore, training drills targetting this metric concurrently across players may not have representative designs and may underprepare athletes for complete match demands and multifaceted WCS scenarios. Using WCS as benchmarks (reproducing similar physical activity for training purposes) is conceptually questionable.

Staying on the ball during COVID-19 pandemic: impact on training modalities in football players.

COVID-19 pandemic has affected worldwide sports competitions and training in both amateur and professional leagues. We thus aimed to investigate changes in different training modalities in elite and amateur football players following COVID-19 lockdown in March 2020. In this cross-sectional study, we applied a Likert Scale-based questionnaire with 20 items to quantify and classify time spent at standard training methods in 47 professional and 54 amateur football players from 12 Austrian clubs before and during lockdown. Additionally, McLean Score was calculated to assess perceived training fatigue. Weekly amount of training time at endurance exercises (cycling) increased in both professional (37.5 [IQR 46.5] min/week vs. 187.5 [IQR 127.5] min/week, P<0.001), and amateur players (0.0 [IQR 45.0] min/week vs. 37.5 [IQR 112.5] min/week, P=0.015) during COVID-19 lockdown. Time on diverse muscle strengthening workouts was significantly elevated in both cohorts. Total training time at ball declined for professionals (from 472.5 [IQR 150] min/week to 15.0 [IQR 112.5] min/week, P<0.001) and amateurs (from 337.5 [IQR 285] min/week to 0.0 [IQR 37.5] min/week, P<0.001). Video-guided training was intensified in both groups (P<0.001 each). Location shifted from football fields and gyms to home and outdoors. Overall McLean Score remained unchanged in amateurs (P=0.42) while elite players showed a trend towards an increase (P=0.056). COVID-19 lockdown compromised football training, especially training concepts with ball. Consequently, resulting changes in exercise loads and muscular burden might impact susceptibility for injuries and impair performances especially in amateur players, especially as they lacked training supervision and professional training plans. Minimum effective dose of training workload to maintain endurance- and neuromuscular-related performance parameters should be prescribed.

Relationship between sport and financial performance in top European football clubs

The Champions League has been the most elite football competition in Europe for several decades. Achieving sports successes makes it much easier for football clubs participating in the Champions League games to have very good financial results, which allow them to spend significant amounts on the purchase of players and their salaries. The total market value of the players in some teams exceeded 1 billion EUR in the 2018/2019 season. In the article the relationship between financial results and sports results in national and international competitions in the seasons 2014/2015–2018/2019 is verified. The efficiency of the football clubs under investigation is verified using a model developed by the author of the article. In addition, dynamics of changes in profits, expenditure on salaries and operating activities as well as the market value of selected European football clubs is presented. The results of the analysis allow to identify football clubs whose activities are characterized by the highest efficiency. Both the market value of the players and the expenses on their salaries have a significant, positive impact on sports performance. However, among the leading European football clubs one can distinguish those that functioned much more effectively than their competitors. Sports successes contribute to increasing the market value of players, but also involve the need to allocate larger amounts to players’ wages.

The Effect of Reactive Strength Index on Some Parameters of Young Elite Football Players

Aim: The aim of this study is to determine the relationship between the reactive strength index of young athletes and the parameters of agility, sprint and eccentric usage rate. The current research is expected to raise awareness for trainers, conditioners and researchers working in this field in terms of reactive power. Methods: A total of 21 players from the Beşiktaş Football Team's U15 team participated in the study in the 2019-2020 season. While height, weight and body mass index measurements were used to determine the physical parameters of the players, reactive strength index-drop jump test, pro agility test and maximal sprint speed-acceleration test were used as performance tests. SPSS 24.0 licensed package program was used for statistical analysis of the obtained data. Data; presented as the arithmetic mean, standard deviation, minimum value and maximum value. Pearson correlation test was used to control the relationship between variables. Results: While a significant relationship was found between young football players' reactive strength index and their changing direction performance (r = 0.619; p 0.05). Conclusion: The findings of this study show that there is a high correlation between reactive strength and agility in young football players. According to these results, it can be suggested to consider the reactive force index parameter in the strength and agility assessment process of young football players. Also, it was seen in the study that reactive force was not related to sprint performance components. This is thought to be because speed and agility are different physical qualities.

Surveillance for COVID-19 in the English Football League 2019-2020

ABSTRACT Medical surveillance and risk mitigation protocols to reduce viral transmission have underpinned the return of elite football during the COVID-19 pandemic. This article describes the evidence-informed approach and surveillance findings from the English Football League across a 9-week period at the end of the 2019–20 season. Protocols were devised by the lead EFL Medical Advisor with specialist occupational medicine input. Isolation requirements for cases and contacts were in-line with UK Government regulations, with external contact tracing conducted by local public health authorities. Quantitative PCR testing was conducted twice weekly and within 72 hours of fixtures. Forty-three individuals, including 18 players returned positive tests. No positive results were returned after week 5 (round 10). Our findings support those from other leagues that with appropriate compliance, elite football can continue safely during this pandemic. We recommend that protocols and compliance should be revised as necessary according to community prevalence and changes in viral transmission dynamics.

Physical performance and loading for six playing positions in elite female football: full-game, end-game, and peak periods.

The present study investigated the position-specific match demands and heart rate response of female elite footballers, with special focus on the full-game, end-game, and peak-intensity periods. In total, 217 match observations were performed in 94 players from all eight teams of the best Danish Women's League, that is, goalkeepers (GK, n=10), central defenders (CD, n=23), full-backs (FB, n=18), central midfielders (CM, n=28), external midfielders (EM, n=18), and forwards (FW, n=11). Positional data (GPS; 10Hz Polar Team Pro) and HR responses were collected. HRmean and HRpeak were 87%-89% and 98%-99% of HRmax , for outfield players, with no positional differences. CM, EM, and FB covered 8%-14% greater (P<.001) match distances than CD. EM, FW, FB, and CM performed 40%-64% more (P<.05) high-speed running and 41%-95% more (P<.01) very-high-speed running (VHSR) than CD. From the first to the last 15-minute period, total distance, except for FW, number of VHSR, except FB, peak speed and sum of accelerations and sum of decelerations decreased (P<.05) for all outfield positions. In the most intense 5-minute period, EM, FB, and CM performed 25%-34% more (P<.01) HSR than CD, whereas EM, FW, and FB performed 36%-49% more (P<.01) VHSR than CD. In conclusion, competitive elite female matches impose high physical demands on all outfield playing positions, with high aerobic loading throughout matches and marked declines in high-speed running and intense accelerations and decelerations toward the end of games. Overall physical match demands are much lower for central defenders than for the other outfield playing positions, albeit this difference is minimized in peak-intensity periods.

The Self-Regulation of Learning - Self-Report Scale for Sport Practice: Validation of an Italian Version for Football.

Self-regulation of learning (SRL) is a key psychological factor that supports young athletes aiming to reach the elite level by promoting their involvement in deliberate practice. We contributed to the validation of the Italian version of the Bartulovic et al. (2017) Self-Regulation of Learning – Self-Report Scale for Sport Practice by testing its factorial structure, reliability, and measurement invariance among elite and non-elite football players, involving 415 male professional, semi-professional, and amateur youth academy players (Mage = 16.2, SD = 1.51). The original six-factor structure (planning, reflection, effort, self-efficacy, self-monitoring, and evaluation) did not fit the data well and a five-factor solution (where self-monitoring and evaluation items load on the same factor, named “self-supervision”) was a better fit. This five-factor solution was measurement invariant across groups of elite and non-elite athletes. We found that elite athletes scored significantly higher than non-elite ones in each SRL subprocess. Implications for future validation studies and for the use of this tool are discussed.

Is there meaningful influence from situational and environmental factors on the physical and technical activity of elite football players? Evidence from the data of 5 consecutive seasons of the German Bundesliga.

The study aimed to identify the effects of situational (match location, match outcome and strength of team/opponent team) and environmental (ambient temperature, relative humidity, WBGT, ground and weather condition) factors on the physical and technical activity of elite football on individual playing positions. Physical and technical activity were collected from 779 football players competing in the German Bundesliga during 5 domestic seasons, from 2014/2015 to 2018/2019, totalling 1530 matches. The data on players' physical and technical activity was taken from the IMPIRE AG system. Based on the available data, 11 variables were selected to quantify the match activity profiles of players. The results showed that situational variables had major effects on the technical performance (especially number of passes performed) but minor effects on physical performance. In turn, among the analysed environmental factors, temperature is the most sensitive, which affects the Total Distance and Sprint Efforts of players in all five positions. This investigation demonstrated that, given that passing is a key technical activity in modern football, players and training staff should be particularly aware that passing maybe affected by situational variables. Professional players are able to react and adapt to various environmental conditions, modifying physical activity depending on the needs in German Bundesliga. These results could help coaches and analysts to better understand the influences of situational and environmental variables on individual playing positions during the evaluation of players' physical and technical performance.