Using Virtual Reality to Analyze Sports Performance

Improving performance in sports requires a better understanding of the perception-action loop employed by athletes. Because of its inherent limitations, video playback doesn't permit this type of in-depth analysis. Interactive, immersive virtual reality can overcome these limitations and foster a better understanding of sports performance.

Anxiety, ego depletion, and sports performance

In the present article, we analyzed the role of self-control strength and state anxiety in sports performance. We tested the hypothesis that self-control strength and state anxiety interact in predicting sports performance on the basis of two studies, each using a different sports task (Study 1: performance in a basketball free throw task, N = 64; Study 2: performance in a dart task, N = 79). The patterns of results were as expected in both studies: Participants with depleted self-control strength performed worse in the specific tasks as their anxiety increased, whereas there was no significant relation for participants with fully available self-control strength. Furthermore, different degrees of available self-control strength did not predict performance in participants who were low in state anxiety, but did in participants who were high in state anxiety. Thus increasing self-control strength could reduce the negative anxiety effects in sports and improve athletes' performance under pressure.

Vision-based tracking for sports performance analysis

With the world of professional sports shifting towards employing better sport analytics, the demand for vision-based performance analysis is growing increasingly in recent years. In addition, the nature of many sports does not allow the use of any kind of sensors or other wearable markers attached to players for monitoring their performances during competitions. This provides a potential application of systematic observations such as tracking information of the players to help coaches to develop their visual skills and perceptual awareness needed to make decisions about team strategy or training plans. My PhD project is part of a bigger ongoing project between sport scientists and computer scientists involving also industry partners and sports organisations. The overall idea is to investigate the contribution technology can make to the analysis of sports performance on the example of team sports such as rugby, football or hockey. A particular focus is on vision-based tracking, so that information about the location and dynamics of the players can be gained without any additional sensors on the players. To start with, prior approaches on visual tracking are extensively reviewed and analysed. In this thesis, methods to deal with the difficulties in visual tracking to handle the target appearance changes caused by intrinsic (e.g. pose variation) and extrinsic factors, such as occlusion, are proposed. This analysis highlights the importance of the proposed visual tracking algorithms, which reflect these challenges and suggest robust and accurate frameworks to estimate the target state in a complex tracking scenario such as a sports scene, thereby facilitating the tracking process. Next, a framework for continuously tracking multiple targets is proposed. Compared to single target tracking, multi-target tracking such as tracking the players on a sports field, poses additional difficulties, namely data association, which needs to be addressed. Here, the aim is to locate all targets of interest, inferring their trajectories and deciding which observation corresponds to which target trajectory is. In this thesis, an efficient framework is proposed to handle this particular problem, especially in sport scenes, where the players of the same team tend to look similar and exhibit complex interactions and unpredictable movements resulting in matching ambiguity between the players. The presented approach is also evaluated on different sports datasets and shows promising results. Finally, information from the proposed tracking system is utilised as the basic input for further higher level performance analysis such as tactics and team formations, which can help coaches to design a better training plan. Due to the continuous nature of many team sports (e.g. soccer, hockey), it is not straightforward to infer the high-level team behaviours, such as players’ interaction. The proposed framework relies on two distinct levels of performance analysis: low-level performance analysis, such as identifying players positions on the play field, as well as a high-level analysis, where the aim is to estimate the density of player locations or detecting their possible interaction group. The related experiments show the proposed approach can effectively explore this high-level information, which has many potential applications.

Performance analysis in team sports : advances from an ecological dynamics approach

Capacity to produce data for performance analysis in sports has been enhanced in the last decade with substantial technological advances. However, current performance analysis methods have been criticised for the lack of a viable theoretical framework to assist on the development of fundamental principles that regulate performance achievement. Our aim in this paper is to discuss ecological dynamics as an explanatory framework for improving analysis and understanding of competitive performance behaviours. We argue that integration of ideas from ecological dynamics into previous approaches to performance analysis advances current understanding of how sport performance emerges from continuous interactions between individual players and teams. Exemplar data from previous studies in association football are presented to illustrate this novel perspective on performance analysis. Limitations of current ecological dynamics research and challenges for future research are discussed in order to improve the meaningfulness of information presented to coaches and managers.

Üzleti teljesítménymérés a sportban = Business performance evaluation in sports associations

A sportszervezetek, sportvállalkozások esetében is kulcsfontosságú a teljesítménymérés. Annak ellenére, hogy a teljesítménymérés sok esetben elsősorban a sportteljesítményre koncentrál, egyre többen foglalkoznak az üzleti teljesítménymérés relevanciájával is. A nyugati társadalmakban a szűkös erőforrások és a növekvő társadalmi kontroll igénye erősíti ezt a folyamatot. A szakirodalom ezen a téren még viszonylag szűk körű. Jelen tanulmány célja, hogy egy olyan szakirodalmi áttekintést adjon, ami elindíthatja a jelenlegi és potenciális jövőbeli vezetők gondolkodását az üzleti teljesítménymérés fontosságának irányába. A tanulmány először áttekinti a pénzügyi teljesítménymérés lehetőségeit, foglalkozik a költségfelosztás problémakörével, kiemelt szerepet szán a stratégiai gondolkodás és a több szempontú megközelítés érvényesítésének. Részletesen összehasonlítja a sportszervezeteknél javasolt kiegyensúlyozott stratégiai mutatószámrendszer (BSC) adaptációkat. A tanulmány kiinduló pontot jelenthet nemcsak a szakirodalom feldolgozásához, de a gyakorlati megvalósításhoz is. _____ Performance measurement is crucial in sports associations. Although sports performance is in the spotlight, more and more researchers and experts deal with the business perspective of performance evaluation. This trend is strengthened by the scarcity of resources and a rising demand for social control in Western societies. The literature in this field is relatively limited. The aim of this study is to provide a literature review, which can motivate experts and managers to shift towards business thinking, and realize the importance of business performance evaluation. The study presents the opportunities of financial performance measurement, deals with the issues of cost allocation, and focuses on the role of strategic thinking and multi-dimension approach. Finally it compares the proposed balanced scorecard adaptations for sports associations. The study can be a starting point for literature review as well as for practical implementation.

Préconditionnement ischémique et exercice : de la réadaptation à la performance

La pratique d’activité physique fait partie intégrante des recommandations médicales pour prévenir et traiter les maladies coronariennes. Suivant un programme d’entraînement structuré, serait-il possible d’améliorer la réponse à l’exercice tout en offrant une protection cardiaque au patient? C’est ce que semblent démontrer certaines études sur le préconditionnement ischémique (PCI) induit par un test d’effort maximal. Les mêmes mécanismes physiologiques induits par le PCI sont également observés lorsqu’un brassard est utilisé pour créer des cycles d’ischémie/reperfusion sur un muscle squelettique. Cette méthode est connue sous l’appellation : préconditionnement ischémique à distance (PCID). À l’autre extrémité du spectre de l’activité physique, des sportifs ont utilisé le PCDI durant leur échauffement afin d’améliorer leurs performances. C’est dans l’objectif d’étudier ces prémisses que se sont construits les projets de recherches suivants. La première étude porte sur les effets du PCID sur des efforts supra maximaux de courte durée. Les sujets (N=16) ont exécuté un test alactique (6 * 6 sec. supra maximales) suivi d’un test lactique (30 secondes supra maximales) sur ergocycle. Les sujets avaient été aléatoirement assignés à une intervention PCID ou à une intervention contrôle (CON) avant d’entreprendre les efforts. La procédure PCID consiste à effectuer quatre cycles d’ischémie de cinq minutes à l’aide d’un brassard insufflé à 50 mm Hg de plus que la pression artérielle systolique sur le bras. Les résultats de ce projet démontrent que l’intervention PCID n’a pas d’effets significatifs sur l’amélioration de performance provenant classiquement du « système anaérobie », malgré une légère hausse de la puissance maximal en faveur du PCID sur le test de Wingate de trente secondes (795 W vs 777 W) et sur le test de force-vitesse de six secondes (856 W vs 847 W). Le deuxième essai clinique avait pour objectif d’étudier les effets du PCID, selon la méthode élaborée dans le premier projet, lors d’un effort modéré de huit minutes (75 % du seuil ventilatoire) et un effort intense de huit minutes (115 % du seuil ventilatoire) sur les cinétiques de consommation d’oxygène. Nos résultats démontrent une accélération significative des cinétiques de consommation d’oxygène lors de l’intervention PCID par rapport au CON aux deux intensités d’effort (valeur de τ1 à effort modéré : 27,2 ± 4,6 secondes par rapport à 33,7 ± 6,2, p < 0,01 et intense : 29,9 ± 4,9 secondes par rapport à 33,5 ± 4,1, p < 0,001) chez les sportifs amateurs (N=15). Cela se traduit par une réduction du déficit d’oxygène en début d’effort et une atteinte plus rapide de l’état stable. Le troisième projet consistait à effectuer une revue systématique et une méta-analyse sur la thématique du préconditionnement ischémique (PCI) induit par un test d’effort chez les patients coronariens utilisant les variables provenant de l’électrocardiogramme et des paramètres d’un test d’effort. Notre recherche bibliographique a identifié 309 articles, dont 34 qui ont été inclus dans la méta-analyse, qui représente un lot de 1 053 patients. Nos analyses statistiques démontrent que dans un effort subséquent, les patients augmentent leur temps avant d’atteindre 1 mm de sous-décalage du segment ST de 91 secondes (p < 0,001); le sous-décalage maximal diminue de 0,38 mm (p < 0,01); le double produit à 1 mm de sous-décalage du segment ST augmente de 1,80 x 103 mm Hg (p < 0,001) et le temps total d’effort augmente de 50 secondes (p < 0,001). Nos projets de recherches ont favorisé l’avancement des connaissances en sciences de l’activité physique quant à l’utilisation d’un brassard comme stimulus au PCID avant un effort physique. Nous avons évalué l’effet du PCID sur différentes voies métaboliques à l’effort pour conclure que la méthode pourrait accélérer les cinétiques de consommation d’oxygène et ainsi réduire la plage du déficit d’oxygène. Nos découvertes apportent donc un éclaircissement quant à l’amélioration des performances de type contre-la-montre étudié par d’autres auteurs. De plus, nous avons établi des paramètres cliniques permettant d’évaluer le PCI induit par un test d’effort chez les patients coronariens.

Listening to music in the first, but not the last 1.5 km of a 5-km running trial alters pacing strategy and improves performance

We examined the effects of listening to music on attentional focus, rating of perceived exertion (RPE), pacing strategy and performance during a simulated 5-km running race. 15 participants performed 2 controlled trials to establish their best baseline time, followed by 2 counterbalanced experimental trials during which they listened to music during the first (M-start) or the last (M-finish) 1.5 km. The mean running velocity during the first 1.5 km was significantly higher in M-start than in the fastest control condition (p < 0.05), but there was no difference in velocity between conditions during the last 1.5 km (p > 0.05). The faster first 1.5 m in M-start was accompanied by a reduction in associative thoughts compared with the fastest control condition. There were no significant differences in RPE between conditions (p > 0.05). These results suggest that listening to music at the beginning of a trial may draw the attentional focus away from internal sensations of fatigue to thoughts about the external environment. However, along with the reduction in associative thoughts and the increase in running velocity while listening to music, the RPE increased linearly and similarly under all conditions, suggesting that the change in velocity throughout the race may be to maintain the same rate of RPE increase.

Effects of Diets Supplemented with Branched-Chain Amino Acids on the Performance and Fatigue Mechanisms of Rats Submitted to Prolonged Physical Exercise

This study aimed to determine the effects of diets chronically supplemented with branched-chain amino acids (BCAA) on the fatigue mechanisms of trained rats. Thirty-six adult Wistar rats were trained for six weeks. The training protocol consisted of bouts of swimming exercise (one hour a day, five times a week, for six weeks). The animals received a control diet (C) (n = 12), a diet supplemented with 3.57% BCAA (S1) (n = 12), or a diet supplemented with 4.76% BCAA (S2) (n = 12). On the last day of the training protocol, half the animals in each group were sacrificed after one hour of swimming (1H), and the other half after a swimming exhaustion test (EX). Swimming time until exhaustion was increased by 37% in group S1 and reduced by 43% in group S2 compared to group C. Results indicate that the S1 diet had a beneficial effect on performance by sparing glycogen in the soleus muscle (p < 0.05) and by inducing a lower concentration of plasma ammonia, whereas the S2 diet had a negative effect on performance due to hyperammonemia (p < 0.05). The hypothalamic concentration of serotonin was not significantly different between the 1H and EX conditions. In conclusion, chronic BCAA supplementation led to increased performance in rats subjected to a swimming test to exhaustion. However, this is a dose-dependent effect, since chronic ingestion of elevated quantities of BCAA led to a reduction in performance.

The analysis of the basketball coach speech during the moments of game and pause in relation to the performance in competition

In the area of the professional competition, the coach is a fundamental part in the management of a team and more concretely in the game planning. During the competition, the management of the times of pause and times out as well as the conduct of the coach during the same ones is an aspect to analyze in the sports performance. It is for this that it becomes necessary to know some of the behaviors that turn out to be more frequent by the coach and that are more related to a positive performance of his players. For it there has been realized a study of 7 cases of expert coaches in those that his verbal behavior has observed during 4 games. It has focused on the content of the information only to verbal level, on his meaning. The information that have been obtained in the study shows a major quantity of information elaborated during the pauses of the games and a major tactical content with regard to the moments of game. On the other hand, a relation exists between a major number of questions and a minor number of psychological instructions when the score is adverse, whereas in case of victory, a direct relation does not exist with any category. The rest of categories of the speech do not meet influenced directly for the result, for what it is not possible to consider a direct and immediate relation between the coach verbal behavior during the pauses and the result of the game, except in punctual moments.

Performance Factors in Women's Team Handball: Physical and Physiological Aspects—A Review

Team handball is an Olympic sport played professionally in many European countries. Nevertheless, a scientific knowledge regarding women's elite team handball demands is limited. Thus, the purpose of this article was to review a series of studies (n = 33) on physical characteristics, physiological attributes, physical attributes, throwing velocity, and on-court performances of women's team handball players. Such empirical and practical information is essential to design and implement successful short-term and long-term training programs for women's team handball players. Our review revealed that (a) players that have a higher skill level are taller and have a higher fat-free mass; (b) players who are more aerobically resistant are at an advantage in international level women team handball; (c) strength and power exercises should be emphasized in conditioning programs, because they are associated with both sprint performance and throwing velocity; (d) speed drills should also be implemented in conditioning programs but after a decrease in physical training volume; (e) a time-motion analysis is an effective method of quantifying the demands of team handball and provides a conceptual framework for the specific physical preparation of players. According to our results, there are only few studies on on-court performance and time-motion analysis for women's team handball players, especially concerning acceleration profiles. More studies are needed to examine the effectiveness of different training programs of women's team handball players' physiological and physical attributes.

Tradução e validação do questionário de Oslo Sports Trauma Research Center para lesões causadas pelo esforço-sobrecarga e a sua aplicação, numa equipa portuguesa de atletismo

Introdução: No atletismo existe uma prevalência de lesões e sintomas de sobrecarga, havendo a possibilidade de monitorizar o início e a evolução das mesmas. Objetivos: Traduzir, validar e aplicar o Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSTRC-O) a atletas de atletismo. Metodologia: O questionário OSTRC-O foi traduzido para português e aplicado por e-mail semanalmente (durante 7 semanas) a um grupo de atletas (n=23), verificando em que medida o esforço/sobrecarga a que estão sujeitos em duas regiões anatómicas específicas (anca e coxa) poderá afectar o seu rendimento e/ou mesmo ser alvo de lesão desportiva. Resultados/Discussão: A prevalência média de lesões de sobrecarga para todos os atletas, em qualquer área anatómica foi de 44,0% (95% IC 35-53). A prevalência média de lesões de sobrecarga substanciais, problemas que causam moderada/severa redução no volume de treino ou performance desportiva ou, completa incapacidade de participar em treino ou competição foi de 13,7% (95% IC 7-19). Não obstante os sintomas de sobrecarga serem prevalentes nas duas áreas, a prevalência semanal de problemas de sobrecarga foi maior na coxa (40%) do que na anca (15%) Conclusões: O OSTRC-O permitirá basear-nos na limitação da funcionalidade e não no tempo de paragem dos atletas, oferecendo a possibilidade de um controlo semanal mais real. Neste estudo sobre atletismo a prevalência média semanal de lesões de sobrecarga na coxa (40%) foi maior do que a prevalência semanal de lesões de sobrecarga na anca (15%).

Do the kinematics of a baulked take-off in springboard diving differ from those of a completed dive

Consistency and invariance in movements are traditionally viewed as essential features of skill acquisition and elite sports performance. This emphasis on the stabilization of action has resulted in important processes of adaptation in movement coordination during performance being overlooked in investigations of elite sport performance. Here we investigate whether differences exist between the movement kinematics displayed by five, elite springboard divers (age 17 ± 2.4 years) in the preparation phases of baulked and completed take-offs. The two-dimensional kinematic characteristics of the reverse somersault take-off phases (approach and hurdle) were recorded during normal training sessions and used for intra-individual analysis. All participants displayed observable differences in movement patterns at key events during the approach phase; however, the presence of similar global topological characteristics suggested that, overall, participants did not perform distinctly different movement patterns during completed and baulked dives. These findings provide a powerful rationale for coaches to consider assessing functional variability or adaptability of motor behaviour as a key criterion of successful performance in sports such as diving.

Esportes e lazer como instrumentos políticos da Era Vargas e governo Lula: aproximações e particularidades

Esta Tese de Doutorado foi elaborada com a pretensão de contribuir para as reflexões políticas acerca do lazer e dos esportes. A compreensão que há confusões conceituais entre eles e a convicção de que suas características favorecem o uso ideológico dessas práticas foram determinantes para o aprofundamento destes estudos. Nosso entendimento é que essas atividades se legitimam como direitos sociais e, como tal, deveriam ser contempladas no conjunto das Políticas Públicas sejam em nível federal, estadual ou municipal. Entretanto, aqui se revelam as contradições que subsidiam as análises centrais dessa Tese. É fato que o lazer e os esportes estiveram presentes nos programas das políticas sociais de diferentes governos brasileiros em distintas épocas, entretanto, o protagonismo atribuído a eles está marcado pela ideologização de suas propostas de ação. Essa hipótese pôde ser comprovada na recuperação histórica que fizemos neste trabalho. O objetivo principal da pesquisa era a análise das Políticas Públicas de Esportes e Lazer implementadas pela Era Vargas e Governo Lula para estabelecer comparações entre eles e, por esse motivo nos dedicamos a esses dois períodos históricos, emblemáticos e permeados de contradições políticas e sociais. Inquietava-nos a percepção de que, dois governos ideologicamente distintos fizessem uso dos mesmos instrumentos no diálogo com a classe trabalhadora. A contextualização dos governos dos dois líderes demarcou a analogia entre eles na utilização dos preceitos desenvolvimentistas, nacionalistas e populistas. Ainda que essas aproximações em níveis mais gerais tenham apontado coincidências relevantes, a principal constatação de nossa Tese foi a similaridade no uso ideológico do lazer e dos esportes, o que comprovou nossas intuições iniciais. Enquanto Getúlio Vargas associou as concessões de direitos trabalhistas aos programas de Recreação Operária e ao estímulo do ufanismo nacional articulado com a seleção brasileira de futebol, Lula adotou o assistencialismo explícito, incentivou a espetacularização dos esportes de rendimento e proporcionou a realização histórica dos Megaeventos Esportivos em série, no Brasil. Na Era Vargas foi possível constatar o lazer contribuindo para a domesticação dos corpos, os esportes para estabelecer uma relação harmoniosa entre dominantes e dominados e o futebol para a divulgação do regime interna e externamente. Já no Governo Lula, percebemos a retração das políticas sociais nas questões do lazer; os programas de esportes, predominantemente voltados para a descoberta de talentos e a priorização do espetáculo esportivo. A análise que fizemos não deixa dúvidas que os princípios liberais de fortalecimento do capital e aumento dos lucros, norteadores da política econômica mundial e balizadores da política macro do Governo Lula, se refletiram na definição de suas Políticas Públicas de Esportes e Lazer, que em nosso entendimento se resumiram na realização dos Megaeventos Esportivos.

Relações de gênero na imprensa esportiva

O objetivo deste documento é apresentar os artigos que compõem a tese, cuja abordagem temática circunscreve-se sobre as relações de gênero na imprensa esportiva. Em nível de organização, sentimo-nos à vontade para dividirmos esta tese em dois blocos: o de BASE e o de APROFUNDAMENTO. O Bloco base é composto pelos artigos "Os estudos de gênero e masculinidade e seus reflexos para a Educação Física" e "O olhar da imprensa sobre o vôlei feminino: quando a sombra se destaca". O Primeiro versa sobre uma reflexão sobre as identidades e os desdobramentos das masculinidades para a área da Educação Física e esportes. Nessa empreitada, pudemos inferir que os estudos sobre as temáticas Gênero e Masculinidades apontam-nos para um terreno fecundo e promissor no que diz respeito à contemporaneidade e a abrangência teórica no universo da ciência com a qual esta área de saber dialoga. Destarte, somos levados a inferir que os esportes, ao que tudo indica, vem atuando como legitimadora e reprodutora de uma ideologia hegemônica, sexista, patriarcal e machista. O segundo artigo, abordamos a história da inserção e da permanência das mulheres no universo dos esportes, utilizando a técnica da análise de imagens. Verificamos que a imprensa esportiva ainda carreia a imagem das mulheres atletas mantendo padrões ainda subordinados a uma hegemonia masculina que legisla sobre o que se quer ver. Já no segundo bloco, é composto pelos estudos "Jogos Olímpicos de Londres 2012: brasileiros e brasileiras em foco" e "Revelações dos fotógrafos esportivos brasileiros sobre relações de gênero". No primeiro estudo, ao analisarmos as imagens publicadas em jornais no período olímpico de 2012, percebemos que é evidente a quantidade e dimensão superior das imagens masculinas frente às femininas. Também, nas poucas vezes em que o homem é retratado denotando emotividade, choro ou decepção, as imagens divulgadas são de dimensões médias ou pequenas. E nas raras vezes em que a mulher é registrada durante a execução de gestos técnicos, vale-se do mesmo ocorrido no masculino: fotos médias ou pequenas e restritas ao interior do jornal. No artigo seguinte desse bloco, constatamos que o discurso dos fotógrafos para clicar atletas seguem as premissas: focam o corpo feminino belo e sensual em detrimento da representação de seu movimento no esporte, o que explica a apresentação de conotação sexual; sua performance é relegada a segundo plano. Já o corpo masculino, quando exposto sugerindo algum tipo de apelo, é representado de forma diferenciada, não vexatória ou pejorativa e sempre em posição de altivez. Verificamos que o publicado nos jornais não condiz com os discursos proferidos pelos entrevistados, uma vez que em diversos momentos afirmaram não haver discrepâncias quanto ao registro do masculino e do feminino. Nas Considerações finais, elencamos as principais impressões da composição da obra. Nesse item, pudemos confirmar que atletas masculinos e femininos têm tratamentos diferenciados e desiguais nos discursos e nas imagens exibidas pela imprensa esportiva.