How did you perform? Investigating football players' perception of self-regulated passing performances under auditory noise environments.

Introduction: This paper deals with the question on how sport performances may be influenced by internal, emotional processes, which stem from outside feedback. Methods: In terms of methods, players' subjective performance ratings for four experimental auditory cue conditions were examined; these included both 'positive' and 'negative' stadium noise, 'no (auditory) conditions,' and a control/'baseline' condition. This resulted in a qualitative-analytic data set that was obtained succeeding each auditory cue condition using a unique football training machine (i.e., known as 'Footbonaut'). Without having received any coaching/performance feedback, players were asked to rate and individually comment on their perceived performance ratings for each experimental auditory condition. Results: Findings indicate stronger and more significant correlations between auditory conditions and subjective ratings compared to the non-auditory condition and its subjective rating. Furthermore, data provides initial insight into players' emotional experiences during each of the practice conditions. Discussion: These noteworthy findings on players' abilities to accurately judge their performances based on selfmonitoring and intrinsic feedback are discussed from an Ecological Dynamics perspective, linked to a Nonlinear Pedagogy for coaching. Here, representative and affective learning designs for skill learning and performance preparation are presented. Finally, a hypothetical catalyst effect of auditory stadium noise on subjective performance rating is proposed.

Advancing and critical appraisal of an integrative load monitoring approach in microcycles in professional soccer.

Despite load monitoring being considered an integral part of targeted performance management, including injury and illness prevention, there is currently no consensus of an effective monitoring system in professional soccer. Thus, the aims were to apply an integrative load monitoring approach, previously established in rink-hockey, in professional soccer; extend this approach with further data (Short Recovery and Stress Scale); assess this (extended) approach, thereby further evaluating the relationship between the used external load (EL) measures (total distance, distance above 55% and 70% of individual maximal speed, number of accelerations and decelerations > 4 m/s2, total loading) and the internal load (IL) measure session rate of perceived exertion training load (sRPE-TL) as well as between the used EL measures and sRPE. This retrospective observational cohort study analyzed data from a Swiss team collected over a 14 week-period during the 2021/22 season. Based on our findings, the integrative approach tested proved to be an applicable load monitoring tool in professional soccer, placing players on a fitness-fatigue continuum throughout the different microcycle sessions without using tests, thus providing relevant information to individually tailor training programs. sRPE-TL (ρ [95% CI] = .55 [.51 to .59] to .87 [.85 to .88]; all p < .001) better reflected the EL experienced by players than sRPE (ρ [95% CI] = .45 [.40 to .50] to .71 [.69 to .75]; all p < .001) supporting the definition of sRPE-TL as a measure of IL. However, for even stronger relevance of the tested tool, further research is warranted, especially to ascertain its sensitivity and determine an optimal selection of EL and IL measures. In sum, the present data clearly demonstrate the importance of load management taking place at an individual level, even within team structures, thereby analyzing a set of both EL and IL measures.

Air pollution, a worthy opponent? How pollution levels impair athlete performance across physical, technical, and cognitive domains.

INTRODUCTION: Air pollution is a global issue known to effect on human health and performance. In the context of highly skilled athletes, the influence of air pollution on players' physical and technical abilities are established, yet its effects on cognitive performance have received little consideration. This study aims to address this research gap by comprehensively examining the influence of air pollution on the performance of highly skilled athletes using a holistic approach, including both the athlete's brain and body. METHODS: Between 2016 and 2022, a total of 799 soccer players (578 males, 221 females) belonging to a German professional first division club were measured on a battery of performance assessments, including physical, technical, and cognitive tests. The performance data were combined with the average daily concentration of three pollutants: PM10, O3 and NO2. RESULTS: Increased levels of PM10 and O3 were primarily associated with decreased physical and technical performance, including slower sprinting times, impaired change of direction and worse speed and accuracy in the technical assessment. For instance, if the assessment test was held when PM10 levels were at 20 µg/m3, players ran an average 22 ms slower on the 30 m sprint test, 36 ms slower on the change of direction test and showed a 1 % decrease in accuracy on the technical assessment (p < .001). Furthermore, higher concentrations of NO2 negatively impacted cognitive performance across four separate tests of athletes' executive functions (p < .05). CONCLUSION: By encompassing physical, technical, and cognitive assessments, this study highlights the multifaceted nature of performance impairments resulting from air pollution exposure in a population characterized by have exceptional abilities across all three domains. These findings underscore the widespread impact of pollution on a diverse sample of athletes and emphasize the need to consider air pollution in the broader context of its effects on human health and the environment.

Air pollution and elite adolescent soccer players' performance and well-being; an observational study.

INTRODUCTION: Exercising outdoors may inadvertently lead to individuals inhaling levels of air pollution that may be detrimental to their health and activity-related performance. Endurance athletes are a particularly susceptible subgroup due to their high ventilation rates sustained over prolonged periods of time coupled with high training loads that often occur outdoors. In this study, we estimate the effects of air pollution on a series of athletic performance parameters in an elite adolescent soccer team. METHODS: External, internal, and subjective loads and wellness questionnaires were recorded for the 26 matches and 197 training sessions carried out during the 2018-19 season for a U19 team competing in Germany. Each session was combined with hourly information on the concentration of PM10, O3 and NO2 in spatial proximity to each playing field for the duration of training or playing. RESULTS: Increases in PM10 and O3 had significant (p <.001) associations with decreasing total distance (m) ran per session. Furthermore, increases in O3 and NO2 concentrations were related to an increase in average heart rate (p <.05). Moreover, increases in PM10 concentration was associated with increased rating of perceived exertion (p <.001). Last, the total inhaled dose of O3 and NO2 over one session was linked to significant (p <.05) decreases in athletes' wellness scores on the following morning. DISCUSSION: We find supporting evidence of the negative effects of air pollution in elite adolescent soccer players in both matches and training. The negative impacts observed on several aspects of performance are present within an elite team that regularly trained in pollution levels well within the normal ranges of what the World Health Organisation (WHO) reports to be suitable air quality. Therefore, mitigation strategies such as monitoring the air quality at the training pitch are recommended to reduce athlete exposure to air pollution even when exercising in moderate air quality.

The relationship of personality and executive functions in high-level soccer athletes: expertise-and gender-specific differences.

Background: Psycho-cognitive factors such as personality and executive functions (EFs) are influential parameters when it comes to examining expertise in high-level soccer. Therefore, the profiles of those athletes are relevant both from a practical and scientific point of view. The aim of this study was to investigate the relationship between personality traits and executive functions with age group as an influential factor in high-level male and female soccer players. Methods: Personality traits and executive functions of 138 high-level male and female soccer athletes from the U17-Pros teams were assessed using the big-five paradigm. A series of linear regressions investigated contributions of personality on EF assessments and team, respectively. Results: Linear regression models showed both negative and positive relationships between various personality traits, executive function performance and the influence of expertise and gender. Together, a maximum of 23% (R2 = 6%-23%) of the variance between EFs with personality and various teams, demonstrating that many unaccounted-for variables remain at play. Conclusion: The results of this study demonstrate the inconsistent relationship between personality traits and executive functions. The study calls for more replication studies to help strengthen the understanding of relationships between psycho-cognitive factors in high-level team sport athletes.

Longitudinal development of physical, perceptual-cognitive and skill predictors of talent in academy and professional female football players.

Existing literature on talent development predominantly focuses on male athletes, with limited representation of female athletes. This study aims to address this gap by examining the long-term development of female football players in an elite club. Routine lab-based assessments were conducted on 238 athletes across six teams for 7 years to determine how physical, perceptual-cognitive, and skill performance predictors fluctuated with player age and developmental stage (sampling 9-11y, specializing 12-14y, investment 15-18y, and performance +18y). The developmental stage was a significant predictor of improved performance for each talent indicator (p < .001), with each consecutive stage significantly outperforming the previous stage in all domains with moderate to large effect sizes (0.07-0.40 ηp2). Improvement rate was higher in young adolescence (<15) and slower approaching adulthood (>18y). Playing position influenced performance scores on several physical and technical skill predictors (p ≤ .001), but not perceptual-cognitive ones (p ≥ .11). Players progressed continuously from the sampling to the performance stage, contradicting previously reported plateaus observed when athletes reached the investment stage. Benchmark data are provided across age and playing position to better understand what is required for successful participation at an elite level at varying age groups in female soccer.

Personality in Soccer: Investigation of the Five-Factor Model of Personality in High-Level Athletes.

Background: In high-level sports, rapid screening and diagnostic instruments are necessary considering limited access that researchers have to these athletes. In the area of sport psychological diagnostics, the NEO-FFI is a promising tool to gain information about an athlete's personality traits. The current study investigated the NEO-FFI's scientific quality criteria and general application to elite-level soccer. Methods: Personality traits of 378 elite-level soccer athletes were assessed using the NEO-FFI. Analysis focused on internal consistency, factor structure and gender differences. Additionally, a second measurement with a 6-week interval was conducted with a sub-sample of 86 athletes to analyse test-retest reliability. Results: Overall, the results are in line with previous findings outside high-level sports. For the total sample, alpha-levels from 0.68 to 0.84 and intraclass correlation coefficients (ICC) for test-retest measures from 0.86 to 0.91 could be found. Item-level principal component analysis using both oblimin and oblique rotation showed better stability in neuroticism (N) and conscientiousness (C) than in extraversion (E), openness (O), and agreeableness (A). Gender differences could be found in values of internal consistency, ICC and NEO-FFI traits. Conclusion: The results of this study demonstrate good transferability of the NEO-FFI from settings outside high-level sports into this specific niche of sport psychological assessment. However, the same weaknesses of the applied instrument in general populations were also replicated in the sporting population.

The Development of Executive Functions in High-Level Female Soccer Players.

Executive functions (EFs) are higher-level cognitive functions that help keep an individual's goal-oriented thoughts and actions aligned. While many studies have shown the importance of EFs in sport, a limitation in this literature is that female participants have been underrepresented. In this mixed-longitudinal study, we examined the development of EFs in a cohort of high performing female athletes. We collected data over five seasons in a large sample of 175 female soccer players (aged 12-29 years old) from the U14 - senior age groups of a professional German soccer club. Players undertook a large battery of cognitive tasks aimed at measuring higher-level cognitive functioning: a sustained attention task, a stop-signal task, a Go-No-go test, an N-Back Test, and both a 180°- and 360°-multiple-object tracking task. We used linear and non-linear mixed effect regressions to examine the relationship between age and EFs. Second order polynomial curves explained many of these relationships between age and EFs compared to their linear relationships. Negatively accelerated curves reveal that these players' cognitive abilities mainly developed before players reached early adulthood, with a performance plateau evident at around 21 years of age. Age explained low to moderate proportions of the variance in EFs (<1-50%), while cognitive development across playing positions was not a strong contributor to this variance (M = 2.1, SD = 2.1%). We concluded that age has a negatively accelerated relationship with EFs in female soccer players that does not differ between playing positions. These data support the idea that athletes require only a reasonable level of EF ability to perform at the highest level of their sport. Our research raises new questions regarding the validity of current EF measurement methods for inferring information about in-game use of these cognitive abilities.

Match-related physical performance in professional soccer: Position or player specific?

The purpose of this study was to examine to what extent the physical match performance of professional soccer players is both position and player specific. First, official match data from the 2019/20 German Bundesliga season was used to search for players that met the inclusion criteria of playing a minimum of four entire matches in at least two different playing positions. Overall, 25 players met the criteria prior to the COVID-19 induced break, playing a minimum of eight matches. Second, the physical match performance of these players was analyzed separately for each position they played. The following four parameters were captured: total distance, high-intensity distance, sprinting distance, and accelerations. Third, the 25 players' physical match performance data was then compared to normative data for each position they played to understand whether players adapted their physical performance (position dependent), or maintained their performance regardless of which position they were assigned to (position independent). When switching the position, the change in physical match performance of the respective players could be explained by 44-58% through the normative positional data. Moreover, there existed large individual differences in the way players adapted or maintained their performance when acting in different positions. Coaches and practitioners should be aware that some professional soccer players will likely incur differences in the composition of physical match performance when switching positions and therefore should pay special consideration for such differences in the training and recovery process of these players.

The effect of stroboscopic vision on performance in a football specific assessment.

Purpose: This study aimed to investigate how restricted visual feedback affects performance in a football-specific skills assessment that incorporates the coupling of football a-specific perceptual information with football-specific motor actions. Methods: The Footbonaut is a 14x14m cage equipped with 8 ball dispensers and 64 targets measuring passing accuracy and time to complete each pass. Eighty-four amateur male participants (19.5 ± 5.4 years old; 13.1 ± 6.0 years experience) completed two sessions under two different visual conditions: stroboscopic and normal vision. Results: A linear regression revealed that performance under normal conditions was significantly associated (p < 0.001) with the performance decrement under stroboscopic vision conditions. Players were then subdivided into skilled (S; top 25%) and less-skilled (LS; bottom 25%) groups. Restricting visual feedback impacted the average time required to complete the passes in both S and LS groups equally (S: +0.18 s; LS: + 0.12 s; p = 0.385), yet S athletes' accuracy (-11.1%) was more heavily reduced under restricted visual conditions compared to their Normal condition; whereas the LS athletes' accuracy remained relatively unchanged (-1.9%). Conclusion: Therefore, stroboscopic vision may be used to induce performance errors during practice to stimulate larger training effects, particularly in more skilled players.

A Longitudinal Analysis of the Executive Functions in High-Level Soccer Players.

INTRODUCTION: Assessments of executive functions (EFs) with varying levels of perceptual information or action fidelity are common talent-diagnostic tools in soccer, yet their validity still has to be established. Therefore, a longitudinal development of EFs in high-level players to understand their relationship with increased exposure to training is required. METHODS: A total of 304 high-performing male youth soccer players (10-21 years old) in Germany were assessed across three seasons on various sport-specific and non-sport-specific cognitive functioning assessments. RESULTS: The posterior means (90% highest posterior density) of random slopes indicated that both abilities predominantly developed between 10 and 15 years of age. A plateau was apparent for domain-specific abilities during adolescence, whereas domain-generic abilities improved into young adulthood. CONCLUSION: The developmental trajectories of soccer players' EFs follow the general populations' despite long-term exposure to soccer-specific training and game play. This brings into question the relationship between high-level experience and EFs and renders including EFs in talent identification questionable.