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BackgroundPsychological factors such as personality characteristics are influential factors of the goalkeeping performance in football (soccer). Not only for individualized treatment in practice, also from a scientific point of view, profiling goalkeepers is a relevant part of understanding athletes. The aim of this study was to investigate personality traits of goalkeepers of different expertise, age, and sex.MethodsUsing the Five Factor Model of personality we assessed personality traits of 132 male and female football goalkeepers ranging from youth to senior and low to elite level. A series of analysis investigated differences between the groups focusing on expertise, age, and sex.ResultsSignificant differences in the personality trait agreeableness between groups of different expertise and sex could be detected. Although a significant difference in neuroticism levels of males and females could be shown.ConclusionThis study was a first step of profiling football goalkeepers of different expertise, age, and sex. The study calls for more replication in this specific field of football and goalkeeping in general to understand the influence of personality characteristics on sport performance.

IntroductionThis paper deals with the question on how sport performances may be influenced by internal, emotional processes, which stem from outside feedback.MethodsIn 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.ResultsFindings 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.DiscussionThese 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.

Abstract Collecting large datasets for investigations into human locomotion is an expensive and labor-intensive process. Methods for 3D human pose estimation in the wild are becoming increasingly accurate and could soon be sufficient to assist with the collection of datasets for analysis into running kinematics from TV broadcast data. In the domain of biomechanical research, small differences in 3D angles play an important role. More precisely, the error margins of the data collection process need to be smaller than the expected variation between athletes. In this work, we propose a method to infer the global geometry of track and field stadium recordings using lane demarcations. By projecting estimated 3D skeletons back into the image using this global geometry, we show that current state-of-the-art 3D human pose estimation methods are not (yet) accurate enough to be used in kinematics research.

IntroductionThe wingwave® method combining a muscular test and elements of eye movement desensitization and reprocessing has been found to successfully reduce anxiety and improve relaxation in people. However, it is still unclear how exactly its application improves individual wellbeing (though it is assumed to be related to changes in gaze patterns) and if it works for team sport athletes.MethodTo test both, team sport athletes who had reported a problem with a team sport aspect were randomly assigned to an experimental group and a control group. The experimental group members were individually coached by a wingwave® coach once while the other participants watched a tennis match instead.ResultsResults showed that athletes in the wingwave® group benefited from the coaching as their individual perception of their problems improved. These improvements were associated with a decrease of catch-up saccades in a visual object-tracking task conducted before and immediately after coaching.DiscussionThis points to wingwave® interventions affecting gaze behavior and consequently wellbeing of team sport athletes.

Previous research has indicated that social interactions and gaze behavior analyses in a group setting could be essential tools in accomplishing group objectives. However, only a few studies have examined the impact of social interactions on group dynamics in team sports and their influence on team performance. This study aimed to investigate the effects of game performance pressure on the gaze behavior within social interactions between beach volleyball players during game-like situations. Therefore, 18 expert beach volleyball players conducted a high and a low game performance pressure condition while wearing an eye tracking system. The results indicate that higher game performance pressure leads to more and longer fixation on teammates’ faces. A higher need for communication without misunderstandings could explain this adaptation. The longer and more frequent look at the face could improve the receiving of verbal and non-verbal information of the teammate’s face. Further, players showed inter-individual strategies to cope with high game performance pressure regarding their gaze behavior, for example, increasing the number of fixations and the fixation duration on the teammate’s face. Thereby, this study opens a new avenue for research on social interaction and how it is influenced in/through sport.

Goalkeeping in handball puts special demands on the athletes. Whereas on-court strain and conditional demands of the goalkeeper position are already intensively investigated, research on handball goalkeepers’ personality traits is still lacking. In this study, the sport specific personality structure of male handball goalkeepers (N = 81) on competitive and leisure sport level was assessed for the first time, using a version of the BFI-10 adapted to the sport context. In comparison to the normal population, handball goalkeepers proved to be more conscientious, more neurotic, and less open for new experiences. A relation of the trait conscientiousness and the performance level became visible; goalkeepers on higher performance levels showed higher conscientiousness values. The current investigation presents a sport specific personality profile of handball goalkeepers for the first time, whereby derivations, for example, for the construction of talent diagnostic have to be seen more critical. The results of the current study provide the basis for further research which should, amongst others, especially focus on the comparison of the personality structure of goalkeepers and field players.

In recent years, research has shown a positive correlation between sport-specific cognitive abilities and the performance of referees in different sports. However, it is still uncertain how much of the expertise exhibited by referees results from acquired sport-specific skills versus pre-existing general abilities. This study aimed to determine if the relationship between sport-specific abilities and expertise previously observed also applies to general visual abilities. In cooperation with the German basketball federation, basketball referees were recruited for the study, resulting in the final sample of 86 participants who were grouped as elite basketball referees, amateur referees, or novices. These participants completed five tests within the Vienna Test System: time and spatial anticipation, perceptual speed, visual orientation, and spatial working memory. Five separate ANOVAs reported a significant effect of the factor expertise on the performance in spatial anticipation. Post hoc tests revealed that elite referees performed significantly better than amateur referees and novices in spatial anticipation. The superior performance of elite referees in spatial anticipation tasks suggests that their expertise may not be solely limited to acquired skills in basketball but may also be partly attributed to better general spatial anticipatory abilities that might reflect a required skill for refereeing.

Running power is a popular measure to gauge objective intensity. It has recently been shown, though, that foot-worn sensors alone cannot reflect variations in the exerted energy that stems from changes in the running economy. In order to support long-term improvement in running, these changes need to be taken into account. We propose leveraging the presence of two additional sensors worn by the most ambitious recreational runners for improved measurement: a watch and a heart rate chest strap. Using these accelerometers, which are already present and distributed over the athlete’s body, carries more information about metabolic demand than a single foot-worn sensor. In this work, we demonstrate the mutual information between acceleration data and the metabolic demand of running by leveraging the information bottleneck of a constrained convolutional neural network. We perform lab measurements on 29 ambitious recreational runners (age = 28 ± 7 years, weekly running distance = 50 ± 25 km, V˙O2max = 60.3 ± 7.4 mL · min−1·kg−1). We show that information about the metabolic demand of running is contained in kinetic data. Additionally, we prove that the combination of three sensors (foot, torso, and lower arm) carries significantly more information than a single foot-worn sensor. We advocate for the development of running power systems that incorporate the sensors in watches and chest straps to improve the validity of running power and, thereby, long-term training planning.

Testing and application of suitable learning tools and methods can facilitate learning environments conducive to skill acquisition for the target group. This also applies to sports education at school level, including extracurricular activities. On the one hand, traditional learning methods are still effective in sports education; on the other hand, keeping up with societal and technological developments, new learning strategies are continuously being researched to complement existing pedagogical tools. An innovative tool that has been increasingly used in various fields of application in recent years is Virtual Reality (VR) as part of the Extended Reality (XR) domain. It enables learning in immersive and specifically designed learning environments and is particularly suitable for learning in (sports-)motor contexts due to its flexible use. In our study, we test a VR-based rotation task in an extracurricular dance class with the objective of supporting the crucial didactic, collaborative, and perceptual components of dance training in educational contexts. We conducted feedback sessions with the students and used direct observation to examine their behavioural actions. Based on the qualitative content analysis of the written feedback and the overview from the observations, we can identify integrative potentials of this innovative tool in sports education, especially extracurricular dance classes.

(1) Background: Computer-based analyses have been widely used to study aspects of various team and racket sports. However, such analyses have so far eluded table tennis, except in special competition forms, under fixed laboratory conditions or have only tracked the ball. The aim was to detect a basic, global, positional behavior, independent of the score. (2) Methods: We investigated the player position of professional male table tennis players with respect to handedness (right/left), playing system (offensive/defensive) and racket holding (shakehand/penholder) to determine the applicability of automated analysis systems. We used existing video data of competitive matches (N = 198 sets; 2006–2020) and transliterated them into an x–y coordinate system. From this, we were able to conduct a heatmap analysis for different types of players. (3) Results: The comparison between right- and left-handed players resulted in a significant difference in the positioning of the x coordinate (D = 0.5663; p = 0.001). Both groups positioned themselves on average in their own backhanded half of the table (Re: x = −0.22 m, Li: x = 0.39 m). (4) Conclusions: Our results have yielded valuable insights into the importance of analyzing positional behavior in a differentiated manner depending on handedness, playing strategy and racket holding posture.

In recent years, the postulation that deception is necessary for placebos to have an effect on pain relief or increased well-being has come into question. Latest studies have shown that an openly administered mock drug works just as well as a deceptively administered placebo on certain complaints. This open-label placebo effect has primarily been used in the area of pain treatment so far. This study is the first to examine the effect of such placebos on healthy individuals with the use of drinking water. In two experiments, participants were required to use certain specified water bottles for their daily drinking water consumption. At the beginning of Experiment 1, all participants (N = 68) received one bottle of water, which they were asked to refill themselves each day during a 2-week intervention period. In Experiment 2, participants (N = 75) received a new sealed water bottle every day. In both experiments, participants were randomly assigned to one of four groups: no treatment (control group CG), open-label placebo without rationale (OPR–), open-label placebo with rationale (OPR+), and open-label placebo with additional rationale in a suggested relaxed state (group OPR++). We conducted baseline and post-treatment measurements of the subjective perceived physical and mental well-being of the participants. In Experiment 1, only the OPR++ group reported enhanced vitality at the post-treatment level compared to the other groups. In Experiment 2, post-treatment measurements showed improvements for the OPR++ group in the Physical Performance Capability, Mental Performance Capability, Emotional Balance, Overall Recovery, Negative Emotional State, and Overall Stress categories compared to the other groups. Our results support the idea that placebos with an additional rationale in a suggestive relaxed state are more effective than with just a rationale in a normal state. Furthermore, our study shows the tendency that OLP++ in the form of water with health claims may be more effective when the water is given in several sealed bottles separately than in one sealed but refillable bottle.

The current study was designed to assess the personality traits and emotion regulation styles of elite beach volleyball players. Intra-team differences were examined with three primary objectives: (i) to create a personality profile of elite beach volleyball players, (ii) to examine the relationship of this profile in relation to performance and satisfaction levels, and (iii) to highlight the similarities in personalities of members of successful teams. A total of 82 elite beach volleyball players were asked to fill out the Big Five Inventory, the Personality Adjective Scale, and the Affective Style Questionnaire. In addition to these, the overall satisfaction and performance level of these athletes were measured. Results indicated a higher manifestation of warmth, liveliness, emotional stability and reasoning, along with lower levels of neuroticism in successful athletes. The players used a variety of emotional regulation styles and reported being moderately to highly satisfied with their team. A repeated-measures MANCOVA revealed no significant differences in personality traits between the team members. This study generates valuable insights into the personality of elite beach volleyball players and can be useful for coaches, sport psychologists, and academics for practical application and further scientific research.

The current study aimed to examine the effects of spatial separation and working memory capacity on selective visual attention. We investigated differences in the ability to identify the two covertly attended stimuli that appeared either along one of the meridians (e.g., both along the horizontal) or along two of the meridians (e.g., one along the horizontal and one along the vertical) in the attention-window task. Two visual stimuli in the periphery could be perceived along wider extents of the attentional focus’ meridians (horizontal, vertical, and diagonal) when they were located along the same meridian (e.g., horizontal) compared to two different ones (e.g., horizontal and vertical). Subjects with high working memory capacity outperformed subjects with lower working memory capacity in both conditions and stimuli presented on two meridians were less accurately perceived. The findings support the proposal that individual differences in working memory capacity are important for selective spatial visual attention.

In recent years, studies have increasingly dealt with the interaction of gaze behavior and decision making of team sports athletes. However, there is still a variety of important game situations, for example, in the case of penalty corners in field hockey, in which this interaction has not been investigated in detail yet. Penalty corners present a meaningful goal scoring opportunity by providing a relatively free shot. This paper considers two studies. The first study investigated a possible connection between the gaze behavior and the quality of decisions of experienced field hockey players and evaluated the level of success of different gaze strategies. A preliminary study (Study 1) was designed as a survey questionnaire with the aim of preparing for the main study by obtaining subjective assessments of the individual gaze behavior and decision making of professional athletes. In the second and the main study (Study 2), the gaze behavior of experienced field hockey players was recorded using mobile eye-tracking systems to analyze different strategical approaches in associated gaze behavior and decision making. Study 1 showed that players consider reacting to the defenders' behavior during a penalty corner a promising avenue for improving success at penalty corner attempts. It also indicated that such defense-dependent strategies are currently only rarely employed. Study 2 demonstrated how gaze behavior differs between different strategical approaches of the offense. It was shown that the gaze direction on the ball, the stopper, and the goal area is important to allow for a more optimal adaptation to the tactical behavior of defense. It can be concluded that adaptive decision making (i.e., choosing which variation will be carried out just after the “injection” of the ball) seems promising but requires further training to improve the success rate of penalty corner.

Research in penalty kicking has primarily focused on spatial decision making, while temporal decision making has largely been neglected, even though it is as critical for success. Temporal decision making concerns goalkeepers choosing when to initiate their jump to the ball during the penalty taker's run-up (i.e., jump early or wait long), and penalty takers deciding where to kick the ball, either prior to the run-up or after the goalkeeper has committed to one side. We analyzed penalty takers' and goalkeepers' behavior during penalty shoot-outs at FIFA World Cups and UEFA European Championships to scrutinize if temporal aspects of decision making have an impact on penalty kick success. Results indicate that the likelihood of a penalty kick being scored depends on the combination of penalty takers' and goalkeepers' temporal decision-making strategies. Hence, moving early more often seems fruitful for goalkeepers, while penalty takers should consider varying penalty kick strategy between attempts.

The performance and the success of a group working as a team on a common goal depends on the individuals’ skills and the collective coordination of their abilities. On a perceptual level, individual gaze behavior is reasonably well investigated. However, the coordination of visual skills in a team has been investigated only in laboratory studies and the practical examination and knowledge transfer to field studies or the applicability in real-life situations have so far been neglected. This is mainly due to the fact that a methodological approach along with a suitable evaluation procedure to analyze the gaze coordination within a team in highly dynamic events outside the lab, is still missing. Thus, this study was conducted to develop a tool to investigate the coordinated gaze behavior within a team of three human beings acting with a common goal in a dynamic real-world scenario. This team was a (three-person) basketball referee team adjudicating a game. Using mobile eye-tracking devices and an indigenously designed software tool for the simultaneous analysis of the gaze data of three participants, allowed, for the first time, the simultaneous investigation of the coordinated gaze behavior of three people in a highly dynamic setting. Overall, the study provides a new and innovative method to investigate the coordinated gaze behavior of a three-person team in specific tasks. This method is also applicable to investigate research questions about teams in dynamic real-world scenarios and get a deeper look at interactions and behavior patterns of human beings in group settings (for example, in team sports).

Visual attentional processes have been an important topic in psychological research for years. Over the last few decades, new methods have been developed, aiming to explore the characteristics of the focus of attention in more detail. Studies that applied the “Attention-Window Task” (AWT) quantified the maximum extent of the “Attention Window” (AW) along its horizontal, vertical, and diagonal meridians, when subjects were required to perceive two peripheral stimuli simultaneously. In three experiments using the AWT, we investigated the effects of cue validity (Experiment 1), stimulus-onset asynchrony (SOA) (i.e., the interval between the onset of the cues and the onset of the target stimuli), and target stimuli complexity (Experiment 3) on the size and shape of the AW. Results showed that the AW was greater under valid cue conditions compared to invalid conditions, when the locations of cue and target stimuli differed. Furthermore, the AW decreased when the SOA between the cue and targets was reduced and also when the task complexity was higher and more objects within the target stimuli had to be classified. Overall, it can be stated that the AWT with its possible task changes and adjustments can be considered as a potential standard tool to measure the maximum spread and shape of the spatial AW.

It has been evidenced that in attention-window tasks, the participants fixate on the center of a screen while inspecting two stimuli that appear at the same time in parafoveal vision. Such tasks have successfully been used to estimate a person's breadth of attention under various conditions. While behavioral investigations of visual attention have often made use of response accuracy, recent research has shown that the pupil size can also be used to track shifts of attention to the periphery. The main finding of previous studies is that the harder the evaluation of the stimuli becomes, e.g., because they appear farther away from the central fixation point, the stronger the pupils dilate. In this paper, we present experimental data suggesting that in an attention-window task, the pupil size can also be used to assess whether the participants attend to static, non-moving, or dynamic, moving stimuli. That is, regression models containing information on presentation mode (static vs. dynamic) and the visual angle between spatially separated stimuli better predict accuracy of perception and pupil dilation than model without these sources of information. This finding is useful for researchers who aim at understanding the human attentional system, including potential differences in its sensitivity to static and dynamic objects.

In specialist sports coaching, the type and manner of augmented information that the coach chooses to use in communicating and training with individual athletes can have a significant impact on skill development and performance. Informed by insights from psychology, pedagogy, and sport science, this position paper presents a practitioner-based approach in response to the overarching question: When, why, and how could coaches provide information to athletes during coaching interventions? In an ecological dynamics rationale, practice is seen as a search for functional performance solutions, and augmented feedback is outlined as instructional constraints to guide athletes’ self-regulation of action in practice. Using the exemplar of team sports, we present a Skill Training Communication Model for practical application in the context of the role of a specialist coach, using a constraints-led approach (CLA). Further based on principles of a non-linear pedagogy and using the recently introduced Periodization of Skill Training (PoST) framework, the proposed model aims to support practitioners’ understanding of the pedagogical constraints of feedback and instruction during practice. In detail, the PoST framework’s three skill development and training stages work to (1) directly impact constraint manipulations in practice designs and (2) indirectly affect coaches’ choices of external (coach-induced) information. In turn, these guide practitioners on how and when to apply different verbal instruction methodologies and aim to support the design of effective skill learning environments. Finally, several practical guidelines in regard to sports coaches’ feedback and instruction processes are proposed.

BackgroundIndividuals are able to perform goal-directed behaviors thanks to executive functions. According to the neurovisceral integration model, executive functions are upregulated by brain areas such as the prefrontal and cingulate cortices, which are also crucially involved in controlling cardiac vagal activity. An array of neuroimaging studies already showed that these same brain areas are activated by transcutaneous vagus nerve stimulation (tVNS). Despite evidence toward effects of tVNS on specific executive functions such as inhibitory control, there have been no studies investigating what type of inhibition is improved by tVNS by systematically addressing them within the same experiment. Furthermore, the effect of tVNS on another core executive function, cognitive flexibility, has not yet been investigated.ObjectiveWe investigated the effects of tVNS on core executive functions such as inhibitory control and cognitive flexibility.MethodsThirty-two participants (nine women, Mage = 23.17) took part in this study. Vagally mediated heart rate variability parameters (root mean square of successive differences, RMSSD, and high frequency, HF) were measured while participants performed four different cognitive tasks that mainly rely on different aspects of both the aforementioned executive functions.ResultsDespite clear conflict effects in the four tasks, only performance on the task used to measure set-shifting paradigm was improved by tVNS, with switch costs being lower during tVNS than during sham stimulation. Furthermore, HF increased during each of the cognitive flexibility tasks, although HF during tVNS did not differ from HF during sham stimulation.ConclusionThe results indicate for the first time (a) that tVNS can increase cognitive flexibility in a set-shifting paradigm, and (b) that tVNS may exert a stronger effect on cognitive flexibility than inhibition. The present study provides only partial evidence for the neurovisceral integration model. Future studies should address further paradigms that demand cognitive flexibility, thus investigating this new hypothesis on the specificity of the tVNS effects on cognitive flexibility.

(1) Background: For nearly 20 years, the wingwave® method, which combines elements of eye movement desensitization and reprocessing (EMDR) and a muscular strength test, has been used to reduce anxiety and improve relaxation in subjects. Past studies have scientifically evaluated this method in various contexts and have found it to be effective. In this study, we investigated the effects of short-term wingwave® coaching on specific anxiety parameters regarding school, concentration ability, and subjective feelings towards two self-chosen themes in schoolchildren. (2) Methods: A group of 53 schoolchildren aged 11 to 12 years were randomly divided between an experimental and a control group. The experimental group received an intervention of three wingwave® coaching sessions (one hour each). In these sessions, past and present negative feelings towards school as well as psychological resources to face future tasks in school were focused on and utilized. (3) Results: The results showed that the overall text anxiety, manifested anxiety, and dislike of school decreased significantly in the experimental group after the three coaching sessions compared to the control group. Furthermore, both concentration ability and the subjective feeling towards self-chosen subjects improved significantly in the experimental group compared to the control group. (4) Conclusions: Our results indicate that the wingwave® method is an appropriate and effective instrument to reduce school anxiety and to improve concentration performance in schoolchildren—at least in the short and medium term.

Professional football players, coaches, and researchers have discussed additional substitutions in football to reduce player load for a while. However, the effects of additional substitutions on the game have not yet been investigated in detail. The aim of this paper is to determine whether an additional substitution in (1) extra time and (2) regular time would be beneficial and would lead to (a) greater tactical influence of coaches on the match, (b) load reduction during one match, and (c) load reduction during one season. The methodological approach adopted includes two studies, both of which involve data analysis of substitution times (Study 1: n = 3060; Study 2: n = 1153) as well as a survey of football coaches (Study 1: n = 37; Study 2: n = 25). For assessing the effect of an additional substitution in regular time and in extra time, the substitutions made in the Bundesliga, U19-Bundesliga West, DFB-Cup, and 2018 World Cup were evaluated. The findings of this research clearly indicate the potential of an additional substitution by enabling almost 50% of additional load reduction in regular time and 27% in extra time. However, in practice, the findings showed the limits of an additional substitution in extra time on long-term load reduction.

This study looks at the visual scan patterns of high-class basketball referees. Using mobile eye-tracking devices, referees’ gaze behavior was analyzed during the execution of three-point shots in the official pre-season games of Germany’s men’s professional basketball league. We evaluated the extent to which the referees fulfill the tasks assigned to them, where do they look, and to what extent does their gaze behavior overlap during a three-point shot. Results indicate that referees who are far away from the ball and are, therefore, not responsible for observing the actual shot, tend to comply with their areas of responsibility less often than referees standing nearer to the ball, i.e., they appear to observe the ball more than required (ball watching) at the expense of other areas that they are required to be observing at the beginning of the shooting process. However, referees spend a very small part of a three-point shot looking at the same areas of interest. This indicates that referee teams’ allocation of gaze is rather effective, remaining in line with FIBA recommendations and is presumably not the main cause for errors in officiating.

Running power as measured by foot-worn sensors is considered to be associated with the metabolic cost of running. In this study, we show that running economy needs to be taken into account when deriving metabolic cost from accelerometer data. We administered an experiment in which 32 experienced participants (age = 28 ± 7 years, weekly running distance = 51 ± 24 km) ran at a constant speed with modified spatiotemporal gait characteristics (stride length, ground contact time, use of arms). We recorded both their metabolic costs of transportation, as well as running power, as measured by a Stryd sensor. Purposely varying the running style impacts the running economy and leads to significant differences in the metabolic cost of running (p < 0.01). At the same time, the expected rise in running power does not follow this change, and there is a significant difference in the relation between metabolic cost and power (p < 0.001). These results stand in contrast to the previously reported link between metabolic and mechanical running characteristics estimated by foot-worn sensors. This casts doubt on the feasibility of measuring running power in the field, as well as using it as a training signal.

This study used a single bout of repeated high-intensity sprint exercise as a variable to compare the performance and recovery time of handball players within a typical age range for team sport athletes. Two test groups (U20 players, n = 12, mean age = 18 years; senior players, n = 17, mean age = 27 years) were observed during and after their performance of a high-intensity interval exercise consisting of four sets of 6 × 40 m all-out change-of-direction sprints. U20 players outperformed senior players in all sprint sets. The groups’ physiological responses and perceived exertion and stress levels were measured immediately before and after the exercise and also after 24, 48, and 72 h. Repeated measures ANOVAs revealed no interaction effects between age and measurement time points on jump height, muscle soreness, and perceived stress levels after the high-intensity interval exercise. However, the U20 athletes showed marginally, but not statistically significant lower creatine kinase (CK) values than the seniors 72 h after the exercise. The vagal heart rate variability (HRV) parameter rMSSD indicated a faster recovery for the U20 athletes compared to the senior players 24 h after the sprint intervals. Overall, the results demonstrate that repeated sprint intervals do not differently affect the physical performance ability (i.e., jump height) of U20 and senior players. Single parameters related to the players’ ability to recover, such as CK and HRV values, show some variations as a function of age. Based on this, coaches may want to consider a longer recovery period after a high-intensity exercise for senior players compared to younger ones.

Over the last few decades, technical as well as cognitive skills and their relation to position-specific skill requirements have been extensively investigated as indicators for players’ performance in team sports. To explore the impact of positioning in football on inattentional blindness we employed dynamic tasks that presented an unexpected object and analyzed its noticing rates in three different experiments. In Experiment 1, amateur and expert football players performed a well-established inattentional blindness task of counting the number of times a basketball was passed between two groups while an unexpected, non-sport specific object was introduced to the situation. Noticing rates were higher for strikers compared to players of other playing positions. The findings support a position-specific advantage regarding inattentional blindness for more offensive players compared to more defensive players. Using the same inattentional blindness task, this finding was investigated in Experiment 2 in more detail, i.e., by differentiating between more playing positions. Results revealed that offensive players (in particular strikers) observed unexpected objects more frequently than defensive players. Experiment 3 used a newly developed football-specific task requiring participants to find solutions in different game situations with an unexpected free-standing player appearing in one of these situations. Defensive players again showed more inattentional blindness than offensive players (in particular offensive mid-fielders), i.e., offensive players perceived the unmarked player more often. This indicates that players not only differ in the conscious perception of unexpected objects that are irrelevant to the sport as a function of their playing position, but also show differences when the perception of the unexpected relevant object is useful for finding tactical solutions in a given game situation. Our findings provide further insight into the importance of the definition of position-specific skill requirements in team sports.