Bruno Travassos
Universidade da Beira Interior, Sport Sciences, Faculty Member
- Perception-Action, Motor Control, Performance Analysis, Human Perception and Performance, Decision Making, Human Movement Science, and 8 moreEcological Psychology, Sports Performance, Judgment and decision making, Team Sports, Game Analysis, Decision-Making in Team Sports, Visuomotor control of interceptive actions, and Sport Scienceedit
The aim of this thesis was to investigate the informational constraints that guide performance of individuals and teams in sport. An initial meta-analysis of the effects of expertise on decision-making revealed stronger effects with more... more
The aim of this thesis was to investigate the informational constraints that guide performance of individuals and teams in sport. An initial meta-analysis of the effects of expertise on decision-making revealed stronger effects with more homogeneous results in performance contexts and when individuals were allowed to perform sport actions. Based on this conclusion, all of our empirical experiments were developed using a specific sub-phase of competitive futsal games. Analysis of ball passing performance revealed that the decision to pass a ball to a teammate was regulated by spatial constraints through the coupling of interpersonal distance values between players at the moment of pass initiation. Furthermore, the success of the pass was well predicted by a proposed variable defined as Time to Ball Interception. In order to understand how ball dynamics and goal position constrained interpersonal relations between players we also investigated how patterns of interpersonal coordination between players emerged during different sub-phases of the game. It was observed that the ball and the goal represent key performance constraints which shape the emergent patterns of coordination between players and teams. Different coordination dynamics for defenders and attackers were observed, which was consistent with different team objectives In conclusion, all the studies contributed to a better understanding of how individual players or teams adapted their behaviors to the changing conditions of the performance environment, in order to successfully perform.
The aim of this study was to investigate how elite Futsal coaches use match analysis tools. Six elite coaches from the top Portuguese Futsal League participated. Interviews were conducted and data were analysed through content analysis... more
The aim of this study was to investigate how elite Futsal coaches use match analysis tools. Six elite coaches from the top Portuguese Futsal League participated. Interviews were conducted and data were analysed through content analysis using QSR NVivo10 software. All coaches prepared for games in a systematic way using the observational process. Thus, they carefully selected a highly skilled analyst, and defined a list of indicators to be observed/analysed in games. Coaches stated that the most important aspects to observe in the game are: i) the global dynamics; ii) the key moments of the game; iii) set pieces; iv) individual characteristics of players. Although coaches use both quantitative/qualitative data, they primary focus their attention using qualitative analysis of the game. Coaches evaluate both their own team and that of the opposition by focusing on strengths/weaknesses/opportunities and follow a specific logic of prioritisating this in team meetings throughout the week....
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The main aims of the present study were: a) to evaluate speed and technical skills, and b) to examine the relationship between those measures. Thirty-seven junior soccer players under 19 years of age from three amateur soccer teams were... more
The main aims of the present study were: a) to evaluate speed and technical skills, and b) to examine the relationship between those measures. Thirty-seven junior soccer players under 19 years of age from three amateur soccer teams were evaluated using vertical and horizontal jump tests, 30m sprint speed test, change of direction test, dribble test and the kicking speed test. The significant correlations found help to understand this population's performance.
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Endogenous hormones are essential on the control of physiological reactions and adaptations during sport performance. This study aims to compare the mood state and the salivary levels of cortisol and testosterone during an official female... more
Endogenous hormones are essential on the control of physiological reactions and adaptations during sport performance. This study aims to compare the mood state and the salivary levels of cortisol and testosterone during an official female association football tournament. Twenty female football players (22.85 ± 4.2 yrs) from the Portuguese women's national team were included in the study. Mood, salivary cortisol and testosterone levels were examined in five moments over the championship (M1, neutral measures; M2-M5, on every match day). Saliva samples were collected before breakfast and immediately after each match. Mood was measured by the profile of mood states questionnaire (POMS); hormone levels were measure by immunoassay methods. Iceberg Profiles of POMS were observed during all the moments of evaluation (M2-M5), showing a decrease in vigor and an increase in tension and depression in both team defeats (M2 and M5). There is no relationship between the hormones levels and th...
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Introduction: In the last years, sports performance analysis has benefited from an ecological dynamics rational, aimed to comprehend how patterns of coordinated behaviour arise between performers (e.g., Vilar, Araújo, Davids, & Button,... more
Introduction: In the last years, sports performance analysis has benefited from an ecological dynamics rational, aimed to comprehend how patterns of coordinated behaviour arise between performers (e.g., Vilar, Araújo, Davids, & Button, 2012). Despite of recent significant contributions (Malta & Travassos, 2014), there is still a gap concerning the characterization of offensive patterns of play of futsal top level teams according to its outcome. Methods: Six (n=6) video recorded matches from European Futsal Championship 2014, were analysed. Offensive sequences of play were selected upon the type of outcome: i) success (goal scored) and ii) unsuccess (shot on target). In order to notate ball movements over the pitch, the Futsal pitch was divided in 14 different areas of performance. A total of 35 sequences of play (success = 12, and unsucess = 23) were considered for network analysis (SocNeV 0.81). This software allowed to compute the following variables: i) density (%DE); ii) between...
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Similar to other complex systems in nature (e.g., a hunting pack, flocks of birds), sports teams have been modeled as social neurobiological systems in which interpersonal coordination tendencies of agents underpin team swarming... more
Similar to other complex systems in nature (e.g., a hunting pack, flocks of birds), sports teams have been modeled as social neurobiological systems in which interpersonal coordination tendencies of agents underpin team swarming behaviors. Swarming is seen as the result of agent co-adaptation to ecological constraints of performance environments by collectively perceiving specific possibilities for action (affordances for self and shared affordances). A major principle of invasion team sports assumed to promote effective performance is to outnumber the opposition (creation of numerical overloads) during different performance phases (attack and defense) in spatial regions adjacent to the ball. Such performance principles are assimilated by system agents through manipulation of numerical relations between teams during training in order to create artificially asymmetrical performance contexts to simulate overloaded and underloaded situations. Here we evaluated effects of different nume...
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... Quero igualmente agradecer ao Conselho Directivo da ESGHT e, especialmente ao Professor Doutor Ludgero Sequeira que criou condições para a minha dispensa de ... técnicas de Recursos Humanos, Paula, São e Sónia, à estagiária Mafalda e... more
... Quero igualmente agradecer ao Conselho Directivo da ESGHT e, especialmente ao Professor Doutor Ludgero Sequeira que criou condições para a minha dispensa de ... técnicas de Recursos Humanos, Paula, São e Sónia, à estagiária Mafalda e à D. Filipa ...
This study investigated the influence of interpersonal coordination tendencies on performance outcomes of 1-vs-1 sub-phases in youth soccer. Eight male developing soccer players (age: 11.8 ± 0.4 years; training experience: 3.6 ± 1.1... more
This study investigated the influence of interpersonal coordination tendencies on performance outcomes of 1-vs-1 sub-phases in youth soccer. Eight male developing soccer players (age: 11.8 ± 0.4 years; training experience: 3.6 ± 1.1 years) performed an in situ simulation of a 1-vs-1 sub-phase of soccer. Data from 82 trials were obtained with motion-analysis techniques, and relative phase used to measure the space-time coordination tendencies of attacker-defender dyads. Approximate entropy (ApEn) was then used to quantify the unpredictability of interpersonal interactions over trials. Results revealed how different modes of interpersonal coordination emerging from attacker-defender dyads influenced the 1-vs-1 performance outcomes. High levels of space-time synchronisation (47%) and unpredictability in interpersonal coordination processes (ApEn: 0.91 ± 0.34) were identified as key features of an attacking player's success. A lead-lag relation attributed to a defending player (34% around −30° values) and a more predictable coordination mode (ApEn: 0.65 ± 0.27, P < 0.001), demonstrated the coordination tendencies underlying the success of defending players in 1-vs-1 sub-phases. These findings revealed how the mutual influence of each player on the behaviour of dyadic systems shaped emergent performance outcomes. More specifically, the findings showed that attacking players should be constrained to exploit the space-time synchrony with defenders in an unpredictable and creative way, while defenders should be encouraged to adopt postures and behaviours that actively constrain the attacker's actions.
Research Interests: Soccer, Motion Analysis, Sport, Sports, Performance Analysis, and 13 moreHumans, Child, Behaviour, Male, Space Time, Interpersonal Relations, Approximate Entropy, Interpersonal Interaction, Sports Sciences, Curriculum and Pedagogy, Athletic performance, Task Performance and Analysis, and Psychomotor Performance
In this study, we examined the effects of relative positioning of attacker–defender dyads to the basket on interpersonal coordination tendencies in basketball. To achieve this aim, four right-hand dominant basketball players performed in... more
In this study, we examined the effects of relative positioning of attacker–defender dyads to the basket on interpersonal coordination tendencies in basketball. To achieve this aim, four right-hand dominant basketball players performed in a 1 vs. 1 sub-phase, at nine different playing locations relative to the basket (from 0° to 180°, in 20° increments). Performers’ movement displacement trajectories were video-recorded and digitized in 162 trials. Results showed that interpersonal coordination tendencies changed according to the scaling of the relative position of performers to the basket.Stable in-phase modes of coordination were observed between performers’ longitudinal and lateral displacements (50.47% and 43.02%) on the left side of the court. On the right side of the court, a shift in the dominant mode of coordination was observed to a defender lead-lag of −30°, both for longitudinal and lateral displacements (30.51% and 32.65%). These results suggest how information about dribbler hand dominance and relative position to the basket may have constrained attacker–defender coordination tendencies in 1 vs. 1 sub-phases of basketball.
Research Interests: Adolescent, Team Sports, Information, Performance Analysis, Humans, and 12 moreMovement, Male, Basketball, Interpersonal Relations, Sports Sciences, Curriculum and Pedagogy, Athletic performance, Task Performance and Analysis, Right Handed, Video Recording, Relative Position, and Functional Laterality
Abstract Team sports represent complex systems: players interact continuously during a game, and exhibit intricate patterns of interaction, which can be identified and investigated at both individual and collective levels. We used Voronoi... more
Abstract Team sports represent complex systems: players interact continuously during a game, and exhibit intricate patterns of interaction, which can be identified and investigated at both individual and collective levels. We used Voronoi diagrams to identify and investigate the spatial dynamics of players' behavior in Futsal. Using this tool, we examined 19 plays of a sub-phase of a Futsal game played in a reduced area (20 m 2) from which we extracted the trajectories of all players.
In this paper we investigated how interpersonal coordination tendencies of players in Futsal constrained performance of passing actions. To achieve this aim, we digitized 24 digital video film clips of attacking phases in competitive... more
In this paper we investigated how interpersonal coordination tendencies of players in Futsal constrained performance of passing actions. To achieve this aim, we digitized 24 digital video film clips of attacking phases in competitive Futsal games. Values of interpersonal distance between players were recorded from the moment at which a teammate performed the pass to the ball carrier, to the moment of pass initiation by the ball carrier. Our results revealed that performance of passing actions was constrained by a convergence in interpersonal distance values between players. Pass efficacy seemed to be constrained by changes in interpersonal distance values between the ball carrier and the 2nd defender without a correspondent adaptation in ball velocity. Based on our results we suggest three training phases for developing passing performance in Futsal by manipulating key constraints in the performance environment relative to the interpersonal distance values between players.
Objectives: A quantitative review of the effects of requisite responses and methods of stimulus presentation for assessing decision-making expertise in sport was undertaken. Design: An electronic literature search was conducted in the... more
Objectives: A quantitative review of the effects of requisite responses and methods of stimulus presentation for assessing decision-making expertise in sport was undertaken.
Design: An electronic literature search was conducted in the online databases: SPORTDiscus with Full Text and ISI Web Knowledge All Databases. Articles for analysis were selected according to prior defined criteria.
Methods: We considered 111 effect sizes in studies involving 882 expert and non-expert participants. Effect sizes were calculated for six common protocols for measures responses: verbalized knowledge, eye movement measures, decision time, response accuracy, movement accuracy, and movement time. Two moderator variables were also considered to assess effects of research protocols on the dependent variables: “the requisite response” and “stimulus presentation”. A random effect model was used to calculate effect sizes.
Results: Analysis of moderator variables suggested that expertise effects were more apparent for “requisite responses” when participants were required to actually perform sporting actions and for “stimulus presentation” under in situ task constraints than for other conditions.
Conclusions: Future empirical work on expertise and decision-making needs to consider task representativeness in considering requisite responses of participants in simulating performance environment conditions. Use of representative task constraints with performers required to perform sport actions in in situ conditions appeared the most functional empirical protocols to enhance validity of data.
Design: An electronic literature search was conducted in the online databases: SPORTDiscus with Full Text and ISI Web Knowledge All Databases. Articles for analysis were selected according to prior defined criteria.
Methods: We considered 111 effect sizes in studies involving 882 expert and non-expert participants. Effect sizes were calculated for six common protocols for measures responses: verbalized knowledge, eye movement measures, decision time, response accuracy, movement accuracy, and movement time. Two moderator variables were also considered to assess effects of research protocols on the dependent variables: “the requisite response” and “stimulus presentation”. A random effect model was used to calculate effect sizes.
Results: Analysis of moderator variables suggested that expertise effects were more apparent for “requisite responses” when participants were required to actually perform sporting actions and for “stimulus presentation” under in situ task constraints than for other conditions.
Conclusions: Future empirical work on expertise and decision-making needs to consider task representativeness in considering requisite responses of participants in simulating performance environment conditions. Use of representative task constraints with performers required to perform sport actions in in situ conditions appeared the most functional empirical protocols to enhance validity of data.
This study investigated effects of manipulating the number of action possibilities in a futsal passing task to understand the representativeness of practice tasks designs. Eight male senior futsal players performed a passing task in which... more
This study investigated effects of manipulating the number of action possibilities in a futsal passing task to understand the representativeness of practice tasks designs. Eight male senior futsal players performed a passing task in which uncertainty on passing direction for the player in possession of the ball was increased in four conditions and compared with passing data from a competitive match. Performance during a passing task and competitive futsal performance was compared using ball speed and passing accuracy data. Ball speed data were analysed by approximate entropy (ApEn) to capture their regularity in each of the four conditions and during competitive performance. Significantly high levels of regularity were observed in predetermined passes in comparison with emergent passes (i.e., passes with high number of possibilities for action). Similar results for ball speed regularity were observed between practice tasks with a high number of possibilities for action (i.e., emergent passes) and competitive performance. Similar results were observed for passing accuracy in practice tasks with a high number of possibilities for action compared to competitive performance. Increases in the number of action possibilities during practice improved action fidelity of tasks in relation to competitive performance.
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Here, we report an investigation of the patterned movement behavior of players for a specific sub-phase of the game of futsal, namely when the goalkeeper for the attacking team is substituted with an extra outfield player. The movement... more
Here, we report an investigation of the patterned movement
behavior of players for a specific sub-phase of the game of futsal,
namely when the goalkeeper for the attacking team is substituted
with an extra outfield player. The movement trajectories of the ball
and players were recorded in both lateral and longitudinal direc-
tions and investigated using relative phase analysis. Some differ-
ences in phase relations between different playing dyads were
noted, indicating specificity of phase attractions, or otherwise, for
certain players. In general terms, the defenders demonstrated
strong in-phase attractions with the ball and with each other,
whereas weaker phase attractions, indicated by increased relative
phase variability, were observed for the attackers and ball, as well
as between attackers themselves. These results demonstrate differ-
ent coordination dynamics for the defending and attacking dyads,
from which we interpret evidence for different playing sub-sys-
tems consistent with different team objectives linked together in
an overarching game structure. In keeping with dynamical systems
theory for complex systems, we view this sub-phase of futsal as
being characterized by coordinated behavior patterns that emerge
as a result of self-organizing processes. These dynamic patterns are
generated within functional constraints, with players and teams
exerting mutual influence on each other.
behavior of players for a specific sub-phase of the game of futsal,
namely when the goalkeeper for the attacking team is substituted
with an extra outfield player. The movement trajectories of the ball
and players were recorded in both lateral and longitudinal direc-
tions and investigated using relative phase analysis. Some differ-
ences in phase relations between different playing dyads were
noted, indicating specificity of phase attractions, or otherwise, for
certain players. In general terms, the defenders demonstrated
strong in-phase attractions with the ball and with each other,
whereas weaker phase attractions, indicated by increased relative
phase variability, were observed for the attackers and ball, as well
as between attackers themselves. These results demonstrate differ-
ent coordination dynamics for the defending and attacking dyads,
from which we interpret evidence for different playing sub-sys-
tems consistent with different team objectives linked together in
an overarching game structure. In keeping with dynamical systems
theory for complex systems, we view this sub-phase of futsal as
being characterized by coordinated behavior patterns that emerge
as a result of self-organizing processes. These dynamic patterns are
generated within functional constraints, with players and teams
exerting mutual influence on each other.
Research Interests:
The main goal of performance analysis in team sports has been the identification of data frequencies or sequences of actions in a temporal line, based on the assemblage of numerous discrete variables. This focus may be deemed as not... more
The main goal of performance analysis in team sports has been the identification of data frequencies or sequences of actions in a temporal line, based on the assemblage of numerous discrete variables. This focus may be
deemed as not displaying the foremost team sport feature, i.e., the dynamics of the interaction between two teams. In order to better understand the dynamic patterns of the game, the methods commonly applied must be furthered in a functional perspective. Underpinned in the Ecological Dynamics approach to decision making in sport, this paper regards performance analysis as a process of synthesis and parsimonious explanation of game’s functional nature. Accordingly, we argue the importance of the following three aspects: i) game must be viewed considering different levels of analysis;
ii) there is a functional role of variability in players’ behaviour that must be included in the analysis; iii) human behaviour is better understood if we consider how the dynamics reflects individual and collective perceptual-action couplings.
deemed as not displaying the foremost team sport feature, i.e., the dynamics of the interaction between two teams. In order to better understand the dynamic patterns of the game, the methods commonly applied must be furthered in a functional perspective. Underpinned in the Ecological Dynamics approach to decision making in sport, this paper regards performance analysis as a process of synthesis and parsimonious explanation of game’s functional nature. Accordingly, we argue the importance of the following three aspects: i) game must be viewed considering different levels of analysis;
ii) there is a functional role of variability in players’ behaviour that must be included in the analysis; iii) human behaviour is better understood if we consider how the dynamics reflects individual and collective perceptual-action couplings.
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This report investigated the behavioural dynamics of teams in futsal game practice when the goalkeeper of the attacking team is substituted for an extra outfield player. To this end, the lateral and longitudinal displacements of the ball... more
This report investigated the behavioural dynamics of teams in futsal game practice when the goalkeeper of the attacking team is substituted for an extra outfield player. To this end, the lateral and longitudinal displacements of the ball and both teams, as well as their kinematics expressed in angles and radial distances from the centre of goal, were obtained and subjected to relative phase analysis. The results demonstrated (a) stronger phase relations with the ball for the defending team than the attacking team for both coordinate systems, (b) phase relations between each team and ball, and, to a lesser extent, between teams themselves, produced greater stabilities in the lateral (side-to-side) direction than the longitudinal (forward-backward) direction, and (c) phase attractions were most pronounced for the defending team and ball when using angles as a measure of association, indicating ball position and goal location as key informational constraints for futsal game behaviour. These findings advance understanding of self-organizing sports game dynamics with implications for sports practice.
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Complex environments require effective individual/team decision making and adaptation to environmental changes. Salas et al. (2007) consider that this process implies the development of Team Cognition. The aim of this presentation is to... more
Complex environments require effective individual/team decision making and adaptation to environmental changes. Salas et al. (2007) consider that this process implies the development of Team Cognition. The aim of this presentation is to advocate
an Eco-Dynamic approach for developing decision making in teams. Following this approach we considered team behaviour as an emergent process brought by the interaction between the individuals, environmental and task constraints rather than being controlled by individual minds. This means that team cognition should be developed as the capacity of different players to become perceptually attuned to the relevant information of the environment. Relevant means that this information specifies goal achievement. To illustrate our perspective we present an example for training the development of emergent team decision making processes.
an Eco-Dynamic approach for developing decision making in teams. Following this approach we considered team behaviour as an emergent process brought by the interaction between the individuals, environmental and task constraints rather than being controlled by individual minds. This means that team cognition should be developed as the capacity of different players to become perceptually attuned to the relevant information of the environment. Relevant means that this information specifies goal achievement. To illustrate our perspective we present an example for training the development of emergent team decision making processes.
Team sports are complex systems, where the players, interact continuously during a game, forming patterns of interaction that, once identified, can be used to analyze their behavior in an individual and/or in a collective perspective. In... more
Team sports are complex systems, where the players, interact continuously during a game, forming patterns of interaction that, once identified, can be used to analyze their behavior in an individual and/or in a collective perspective. In order to identify these interaction patterns, we considered voronoiVoronoi diagrams to describe the spatial dynamics of players’ behavior in Futsal plays. We considered 19 plays of a sub-phase of a Futsal game played in a reduced area (20 m2) from which the trajectories of all players were extracted. Results from a comparative analysis of player’s voronoiVoronoi area (dominant regionamount of space available to act) and nearest teammate distance, show that there are different patterns of interaction between attackers and defenders, at both player and team levels. Namely, we found that, in comparison with the defender team, attacker players have larger dominant action regions. In addition, these regions are more variable in size among players from the same team but, at a player level, the attackers’ dominant action regions are more regular during performance than those associated to each of the defender players. These findings support a formal description of the dynamic spatial interaction of the players, in this sub-phase of the game.
This approach may be extended to other team behaviors where the actions taken at any instant by each of the involved agents are associated with the amount of space available to act at that very time.
This approach may be extended to other team behaviors where the actions taken at any instant by each of the involved agents are associated with the amount of space available to act at that very time.
Previous research on coordination dynamics of 1 vs. 1 sub-phases in team sports has reported stable emergent patterns of coordination in the displacement trajectories of attackers and defenders. The aim of this study was to use... more
Previous research on coordination dynamics of 1 vs. 1 sub-phases in team sports has reported stable emergent patterns of coordination in the displacement trajectories of attackers and defenders. The aim of this study was to use attacker–defender interactions in competitive team match-play to investigate how the locations of the goal and ball constrain the pattern-forming dynamics of attacker–defender dyadic systems. Ten high-level futsal matches were filmed and 13 goal sequences selected for analysis. Displacements of the players and the ball were filmed and digitized from 52 attacker–defender dyadic system interactions. Results showed that, although attackers and defenders exhibited similar angular orientations to the goal, the latter always remained closer to the goal than attackers. Observations revealed that in-phase patterns of coordination emerged from changes to both the distances and angles of attackers and defenders to the goal. Attackers always remained closer to the ball than defenders, while the latter exhibited a lower angle to the ball than attackers. A pattern of in-phase coordination modes emerged between the attackers and defenders' distances and angles to the ball. This study helps us to understand interpersonal interactions in team sports by explaining how attackers and defenders use information about their relative positioning to the goal and the ball to perform successfully.
In 2009, Kannekens and colleagues evaluated the development of tactical skills of elite youth football players using a method based on verbal reports. Results showed no improvements in players’ tactical skills over the years of their... more
In 2009, Kannekens and colleagues evaluated the development of tactical skills of elite youth football players using a method based on verbal reports. Results showed no improvements in players’ tactical skills over the years of their longitudinal study. These results are based on an erroneous assumption that tactical skills and verbalizations about tactical skills are equivalent. This note comprises an explanation of why verbal reports are not a valid measure of tactical skills.