Focusing of visual attention at rest and during physical exercise in soccer players

In this study, we investigated the focus of visual attention in expert soccer players together with the effects of acute bouts of physical exercise on performance. In two discriminative reaction time experiments, which were performed both at rest and under submaximal physical workload, visual attention was cued by means of spatial cues of different size followed by compound stimuli with local and global target features. Soccer players were slower than non-athletes in reacting to local compared with global targets, but were faster in switching from local to global attending. Thus, soccer players appear to be less skilled in local attending, but better able than non-athletes to rapidly "zoom out" the focus of attention. Non-athletes generally showed faster performance under physical load, as expected according to the hypothesis of exercise-induced increases in arousal and/or activation and in resource allocation. In contrast, soccer players showed a more differentiated pattern of exercise-induced facilitation that selectively affects specific components of the attentional performance and is interpreted by referring to the role played by individual expertise and cognitive effort.     

Oculomotor dynamics in skilled soccer players: The effects of sport expertise and strenuous physical effort

The ability to quickly locate objects within the visual field has a significant influence on athletic performance. Saccades are conjugate eye movements responsible for the rapid shift that brings a new part of the visual field into foveal vision. The aim of this study was to investigate the effects of sport expertise and intense physical effort on saccade dynamics during a free-viewing visual search task in skilled soccer players. Two groups of male subjects participated in this study: 18 soccer players and 18 non-athletes as the control group. Two sessions of visual search tasks without a sport-specific design were employed. Eye movements during the visual search tasks were recorded binocularly. Between pre- and post-test sessions, athletes performed a maximal incremental treadmill test. Cardiorespiratory parameters were measured continuously. Capillary lactate samples were collected. Pre-test findings indicated that athletes, in comparison to non-athletes, achieve higher values of the following characteristics of saccades (1) average acceleration, (2) acceleration peak, (3) deceleration peak, and (4) average velocity. An increase in post-test saccade duration and a decrease in post-test saccade velocity was observed in athletes due to the strenuous physical effort in relation to the pre-test state. Athletes may transfer high saccadic function efficiency to non-specific visual stimuli. The findings partially confirm that physical exertion can reduce oculomotor efficiency in athletes.     

Centre of pressure sway characteristics during static one-legged stance of athletes from different sports

Abstract

The frequency of one-legged stance and two-legged stance differs considerably among sports. We therefore expect the balance ability of athletes from different sports to vary. This study compared the sway characteristics during a static one-legged stance of soccer players, basketball players, swimmers, and non-athletes. The centre of pressure sway during one-legged stance of ten male participants representing each of the four groups was measured using a stabilometer. Centre of pressure sway was assessed by four sway factors: sway velocity, anterior-posterior sway, horizontal sway, and high-frequency sway. None of the four groups of participants showed significant differences in body sway between standing on the dominant leg and standing on the non-dominant leg. The soccer players had more high-frequency sway and less anterior-posterior sway and horizontal sway than the basketball players, swimmers, and non-athletes. These results suggest that soccer players have superior ability to maintain a stable one-legged stance. Further study is required to determine how much of the superior balance ability in soccer players is innate and how much is developed through training, as well as to determine the relationship between balance ability and playing performance.     

Prevalence of disordered eating in elite female athletes in team sports in Greece

ABSTRACT

The purpose of the study was to assess (a) the prevalence of disordered eating (DE) in elite female team sports players compared to non-athletes and (b) to compare DE prevalence in elite female players in basketball, volleyball and water polo. One hundred and seventy-five females were recruited (age 23.10?±?5.4, BMI 21.85?±?2.3?kg/m²), 53 were elite basketball players, 42 were elite volleyball players, 34 were elite water polo players and 46 were non-athletes. Participants completed the Eating Disorders Questionnaire (EDE-Q) and a physical activity questionnaire. The EDE-Q incorporates 36 statements which relate to the occurrence and frequency of key behaviours of eating disorders, under the following four subscales: Restraint, eating concern, shape concern and weight concern and a global score of disordered eating. No differences were found in the EDE-Q subscale score and global score between athletes and non-athletes. Only 6.2% of the total number of participants exhibited DE using the global score >2.3. Water polo players had significantly higher scores in the ‘eating concern’ subscale and in the frequency of key behavioural features of DE such as binge eating episodes and objective and subjective bulimic episodes, compared to volleyball and basketball players. In conclusion, team sport elite female players do not exhibit greater prevalence of DE compared to non-athletes. Water polo, a sport that emphasises leanness and control of body weight for international distinctions, is associated with a higher tendency to exhibit DE, when compared to other team sports.     

Centre of pressure sway characteristics during static one-legged stance of athletes from different sports

The frequency of one-legged stance and two-legged stance differs considerably among sports. We therefore expect the balance ability of athletes from different sports to vary. This study compared the sway characteristics during a static one-legged stance of soccer players, basketball players, swimmers, and non-athletes. The centre of pressure sway during one-legged stance of ten male participants representing each of the four groups was measured using a stabilometer. Centre of pressure sway was assessed by four sway factors: sway velocity, anterior-posterior sway, horizontal sway, and high-frequency sway. None of the four groups of participants showed significant differences in body sway between standing on the dominant leg and standing on the non-dominant leg. The soccer players had more high-frequency sway and less anterior-posterior sway and horizontal sway than the basketball players, swimmers, and non-athletes. These results suggest that soccer players have superior ability to maintain a stable one-legged stance. Further study is required to determine how much of the superior balance ability in soccer players is innate and how much is developed through training, as well as to determine the relationship between balance ability and playing performance.     

Do cognitive training strategies improve motor and positive psychological skills development in soccer players? Insights from a systematic review

ABSTRACT

Soccer players are required to have well-developed physical, technical and cognitive abilities. The present systematic review, adhering to Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines, examined the effects of cognitive training strategies on motor and positive psychological skills development in soccer performance and identified the potential moderators of the “cognitive training–soccer performance” relationship. Thirteen databases were systematically searched using keywords related to psychological or cognitive training in soccer players. The review is based on 18 studies, employing 584 soccer players aged 7–39 years. Cognitive strategies, particularly imagery, appear to improve sports performance in soccer players. Regarding imagery, the combination of two different types of cognitive imagery training (i.e., cognitive general and cognitive specific) has a positive influence on soccer performance during training, whereas motivational imagery (i.e., motivational general-arousal, motivational general-mastery and motivational specific) enhance competition performance. Younger soccer players employ cognitive general and cognitive specific imagery techniques to a greater extent than older soccer players. Combined cognitive training strategies were more beneficial than a single cognitive strategy relative to motor skills enhancement in elite (particularly midfielders) and amateur (i.e., when practising complex and specific soccer skills in precompetitive period) soccer players. In conclusion, it appears that there are differences in cognitive/psychological training interventions, and their efficacy, according to whether they are directed towards training or competition, and the age, standard and playing position of the players.     

足球运动员视觉搜索策略研究

足球是一项攻防转换速度非常快的运动项目,良好的预测能力对足球运动员非常重要。足球比赛中,运动员比非运动员有更好的预测能力,这种差异可能是因为在视觉搜索过程中,运动员注意到了关键线索,而非运动员根本没有注视到。本研究通过不同时间阻断点、放映速度的足球罚点球视频分析不同水平运动员的预测能力和中枢资源占用程度,发现在触球瞬间,运动员组预测准确率较非运动组高。通过眼动仪分析视觉停留区域时间序列特征,发现运动员组采用了有规律的视觉搜索模式提取有效特征值进行预测。本研究认为运动员可以通过反复观看和分析不同场景下的比赛过程,提高视觉搜索能力,进而提高预测能力,结果对运动训练实践有一定的现实指导意义。     

Preservation of visual attention in older expert orienteers at rest and under physical effort

This study investigated the visual attention of older expert orienteers and older adults not practicing activities with high attentional and psychomotor demands, and considered whether prolonged practice of orienteering may counteract the age-related deterioration of visual attentional performance both at rest and under acute exercise. In two discriminative reaction time experiments, performed both at rest and under submaximal physical workload, visual attention was cued by means of spatial cues of different sizes followed, at different stimulus-onset asynchronies, by compound stimuli with local and global target features. Orienteers, as compared to nonathletes, showed a faster reaction speed and a complex pattern of attentional differences depending on the time constraints of the attentional task, the demands on endogenous attentional control, and the presence or absence of a concomitant effortful motor task. Results suggest that older expert orienteers have developed attentional skills that outweigh, at least at rest, the age-related deficits of visual attentional focusing.     

High-intensity endurance capacity assessment as a tool for talent identification in elite youth female soccer

ABSTRACT

Talent identification and development programmes have received broad attention in the last decades, yet evidence regarding the predictive utility of physical performance in female soccer players is limited. Using a retrospective design, we appraised the predictive value of performance-related measures in a sample of 228 youth female soccer players previously involved in residential Elite Performance Camps (age range: 12.7–15.3 years). With 10-m sprinting, 30-m sprinting, counter-movement jump height, and Yo-Yo Intermittent Recovery Test Level 1 (IR1) distance as primary predictor variables, the Akaike Information Criterion (AIC) assessed the relative quality of four penalised logistic regression models for determining future competitive international squads U17–U20 level selection. The model including Yo-Yo IR1 was the best for predicting career outcome. Predicted probabilities of future selection to the international squad increased with higher Yo-Yo IR1 distances, from 4.5% (95% confidence interval, 0.8 to 8.2%) for a distance lower than 440 m to 64.7% (95% confidence interval, 47.3 to 82.1%) for a score of 2040 m. The present study highlights the predictive utility of high-intensity endurance capacity for informing career progression in elite youth female soccer and provides reference values for staff involved in the talent development of elite youth female soccer players.     

Relative Age Effect,Biological Maturation,and Coaches’ Efficacy Expectations in Young Male Soccer Players

Purpose: The talent identification and selection process in young male soccer players is mainly focused on anthropometrics and physical performance, but social factors are also considered in this process. The purpose of this study was to test the existence of the relative age effect and its possible influence on anthropometrics and physical performance and to analyze coaches’ efficacy expectations. Method: Data for 564 young male soccer players (M_age = 13.7 ± 1.5 years; M_weight = 53.7 ± 11.6 kg; M_height = 160.2 ± 11.6 cm) included their birth quartile, maturity status, anthropometrics, a physical test battery, and coaches’ efficacy expectations. Results: Early-born players were overrepresented (p < .05). Early-born players were not statistically taller, heavier, or better at physical performance (p > .05) when maturation and chronological age were controlled as confounding factors. However, coaches expected more from early-born players (p < .05), and the inferential analysis showed likely to very likely worthwhile differences between the coaches’ expectations for players born in the first quartile of the year and those born in the fourth quartile of the year. Conclusions: Anthropometrical and physical performance variables were not affected by birth quartile, and coaches’ efficacy expectations were related to the relative age effect.     

The effect of progressively increased physical efforts on visual evoked potentials in volleyball players and non-athletes

We assessed the effect of physical effort with increasing intensity on neural activity in the visual pathway in volleyball players (n = 10) and non-athletes (n = 10). Participants performed three 10-min tests of increasing intensity on a cycle ergometer. Each participant was assigned individual workloads below the lactate threshold (40% [Vdot]O(2max)), at the lactate threshold (65-75% [Vdot]O(2max)), and above the lactate threshold (80% [Vdot]O(2max)). Four recordings of visual evoked potentials were made: pre-exercise and immediately after each of the three subsequent tests. We assessed neural activity of the visual pathway by examining the amplitude and latency of the N75, P100, and N135 components of the visual evoked potentials waveform. Pre-exercise P100 wave latency was shorter (P < 0.05) in volleyball players than in non-athletes. In non-athletes, the latency of P100 following the first and second effort (40% and 65-75% [Vdot]O(2max)) was reduced compared with pre-exercise (P < 0.01). However, P100 latency increased and P100 amplitude decreased after the third test (80% [Vdot]O(2max)) in non-athletes. In contrast, no significant changes in the latency or amplitude of visual evoked potentials were observed in the athletes in the three tests. Neural conductivity in the visual pathway after exercise might be at least partially dependent on the individual's personal training adaptation status.     

Estimation of body density based on hydrostatic weighing without head submersion in young Japanese adults

Abstract

The aim of this study was to evaluate the effect of a soccer-training season on the anthropometric and performance characteristics of elite youth soccer players.

Two groups (age: 14.4 years) participated in this study: 1) 24 soccer players training 8 to 10 hours per week and 2) 26 non-athletic boys used as controls. Anthropometric measurements, aerobic (Yo-Yo Intermittent Recovery test level 1) and anaerobic (counter-movement-jump (CMJ), squat-jump (SqJ), five-jump-test (5JT), and speed (T5m, 10 m, 30 m)) performances were assessed twice during 8 months (T0: October; T1: May) of the competitive season.

Data showed significant differences in height and weight at T0 between the two groups (P < 0.05), while no difference in the percentage of body fat (%BF) was observed. However, the soccer players were significantly taller and had lower %BF than age-matched controls at T1.

Compared to the controls, the soccer players attained better results in the physical fitness test (P < 0.05) at T0 and T1 except in (T5m) sprinting speed. Hence, significant improvements (P < 0.05) in physical parameters were observed between T0 and T1 only in soccer players.

The results demonstrate that soccer-training season was able to provide maturation free improvement in anthropometric and performance characteristics in young soccer players during the training season.     

Report of Committee on Criteria for Evaluation of Articles Submitted for Publication in the Research Quarterly April 1950

The aim of this study was to determine what visual information expert soccer players encode when they are asked to make a decision. We used a repetition-priming paradigm to test the hypothesis that experts encode a soccer pattern's structure independently of the players' physical characteristics (i.e., posture and morphology). The participants were given either realistic (digital photos) or abstract (three-dimensional schematic representations) soccer game patterns. The results showed that the experts benefited from priming effects regardless of how abstract the stimuli were. This suggests that an abstract representation of a realistic pattern (i.e., one that does not include visual information related to the players' physical characteristics) is sufficient to activate experts' specific knowledge during decision making. These results seem to show that expert soccer players encode and store abstract representations of visual patterns in memory.     

Premier League academy soccer players’ experiences of competing in a tournament bio-banded for biological maturation

Individual differences in the growth and maturation have been shown to impact player performance and development in youth soccer. This study investigated Premier League academy players’ experiences of participating in a tournament bio-banded for biological maturation. Players (N = 66) from four professional soccer clubs aged 11 and 14 years and between 85–90% of adult stature participated in a tournament. Players competed in three 11 vs 11 games on a full size pitch with 25-min halves. Sixteen players participated in four 15-min focus groups and were asked to describe their experiences of participating in the bio-banded tournament in comparison to age group competition. All players described their experience as positive and recommended the Premier League integrate bio-banding into the existing games programme. In comparison to age-group competitions, early maturing players described the bio-banded games more physically challenging, and found that they had to adapt their style of play placing a greater emphasis on technique and tactics. Late maturing players considered the games to be less physically challenging, yet appreciated the having more opportunity to use, develop and demonstrate their technical, physical, and psychological competencies. Bio-banding strategies appear to contribute positively towards the holistic development of young soccer players.     

Academic performance and self-regulatory skills in elite youth soccer players

Abstract

Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self-efficacy) of elite youth soccer players aged 12–16 years (n = 128) with those of 164 age-matched controls (typical students). The results demonstrate that the elite youth soccer players are more often enrolled in the pre-university academic system, which means that they are high academic achievers, compared with the typical student. The elite players also report an increased use of self-regulatory skills, in particular self-monitoring, evaluation, reflection, and effort. In addition, control students in the pre-university system had more highly developed self-regulatory skills than those in the pre-vocational system, whereas no difference was observed within the soccer population. This suggests that the relatively stronger self-regulatory skills reported by the elite youth soccer players may be essential for performance at the highest levels of sport competition and in academia.     

Body composition of English Premier League soccer players: Influence of playing position,international status,and ethnicity

Abstract

Body composition is a key consideration in the physical make-up of professional soccer players. The aims of the present study were to determine whether the body composition of professional soccer players varied according to playing position, international status or ethnicity, and to establish which variables best distinguished the soccer players from a reference group. Body composition was assessed using dual-energy X-ray absorptiometry in 64 male professional soccer players. Measured variables included bone mineral density and the relative amounts of lean and fat mass. Data were analysed using analysis of variance and stepwise discriminant function. The soccer players recorded better values than a reference group (n = 24) for all body composition compartments. Percent lean mass and bone mineral density were the variables best able to identify the soccer players (95.5% correctly classified). Differences in body composition were evident between goalkeepers and outfield players, but not between outfield playing positions. No differences were found on the basis of international status. The non-Caucasian players demonstrated significantly lower percent body fat (9.2 ± 2.0%) than the Caucasian players (10.7 ± 1.8%). It was concluded that body composition is important for elite soccer players, but that homogeneity between players at top professional clubs results in little variation between individuals.     

Evaluation of soccer players under the Moneyball concept

ABSTRACT

The recruitment of athletes with limited resources is a global problem in professional sports. In US Major League Baseball, the experience of the Oakland Athletics’ general manager in the last decade turned his “Moneyball” model into a synonym of quantitative analysis in the transfer market of baseball players. His strategy focused on hiring players with outstanding technical skills but relatively low market value. This study adapted this model to the framework of a multiple criteria decision aid (MCDA), by selecting undervalued players who have complementary abilities. The novelty here refers to the joint use of four algorithms explored by the composition of probabilistic preferences (CPP) (i.e., ranking, classification, dynamic evaluation and regularity analysis) and their application to soccer player performance evaluation. The new model analysed the recent transfer of a left-back soccer player to Europe. The results indicated 12 opportunities for better investment, among 32 left and right-back players considered. Two years later, the value of the same player was considerably lower. He played only five matches in the 2018–2019 season, without scoring or providing any assists. On the other hand, the players better classified by the CPP-MB model presented higher performances and market values.     

Perceived distributed effort in team ball sports

Abstract

In this study, we explored the multifaceted concept of perceived mental and physical effort in team sport contexts where athletes must invest individual and shared efforts to reach a common goal. Semi-structured interviews were conducted with a convenience sample of 15 Catalan professional coaches (3 women and 12 men, 3 each from the following sports: volleyball, basketball, handball, soccer, and water polo) to gain their views of three perceived effort-related dimensions: physical, psychological, and tactical. From a theoretical thematic analysis, it was found that the perception of effort is closely related to how effort is distributed within the team. Moreover, coaches viewed physical effort in relation to the frequency and intensity of the players’ involvement in the game. They identified psychological effort in situations where players pay attention to proper cues, and manage emotions under difficult circumstances. Tactical effort addressed the decision-making process of players and how they fulfilled their roles while taking into account the actions of their teammates and opponents. Based on these findings, a model of perceived distributed effort was developed, which delineates the elements that compose each of the aforementioned dimensions. Implications of perceived distributed effort in team coordination and shared mental models are discussed.     

Validity of the Yo-Yo intermittent endurance test in young soccer players

Abstract

The Yo-Yo intermittent endurance test is frequently used to assess aerobic endurance performance in young soccer players but only the logical validity of the test has been shown to date. The main ai m of this study was to assess the criterion (i.e. association with maximal aerobic capacity, [Vdot]O_2max) and construct validities of the test in young soccer players. A secondary aim was to examine possible shared variance of the Yo-Yo intermittent endurance test with other physical capacities. Sixty-two soccer players (age 13.7±0.5 years) from an Under-14 team participated. All players performed a battery of fitness tests to assess [Vdot]O_2max, aerobic endurance performance (Yo-Yo intermittent endurance test), soccer dribbling endurance performance (Hoff dribbling test), and power performance (maximal vertical jump, 30-m sprint with 10-m split time). Results showed that the Yo-Yo intermittent endurance test was strongly correlated with [Vdot]O_2max (r=0.63, P<0.001), thereby showing the test's criterion validity. Players with the best performance on the Yo-Yo intermittent endurance test had significantly higher [Vdot]O_2max (P<0.001, large effect), and significantly better soccer dribbling endurance (P<0.001, large effect) and 30-m sprint times (P<0.05, medium effect). Logistic regression (r=0.79, P=0.0001) showed that Hoff dribbling test performance (explained variance=50.4%), [Vdot]O_2max (explained variance=39.7%), and 30-m sprint time (explained variance=14.4%) were significant independent parameters contributing to performance on the Yo-Yo intermittent endurance test. Therefore, the Yo-Yo intermittent endurance test is a valid on-field aerobic endurance performance test for young soccer players, which can also be used to differentiate the maximal aerobic capacity, soccer dribbling endurance, and 30-m sprint performance of these players.