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1.
Pediatr Exerc Sci ; 31(4): 473-478, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31330502

RESUMO

PURPOSE: The aim of this study was to determine the effects of an 8-week program of resistance training (RT) or suspension training (ST) on explosive strength in prepubescent boys. METHODS: Fifty-seven boys aged 10-11 years were assigned to 2 training groups, RT or ST or a control group (no training program). Boys trained twice weekly for 8 weeks. RESULTS: A significant interaction was reported with a large (P < .001, ηp2=.463), medium (P < .001, ηp2=.395), and small effect sized (P ≤ .001, ηp2=.218) in the 1-kg ball throw, 3-kg ball throw, and time-at-20-m test, respectively. There was no significant interaction in the countermovement vertical jump or the standing long jump. Changes from preintervention to postintervention for the 1-kg ball throw were 5.94% and 5.82% for the ST and RT, respectively, and 8.82% and 8.14% in the 3-kg ball throw for the ST and RT, respectively. The improvement in the 20-m sprint was 1.19% for the ST and 2.33% for the RT. CONCLUSION: Traditional RT and ST seem to be effective methods for improving explosive strength in prepubescent boys. ST could be considered as an alternative modality to optimize explosive strength training in school-based programs.


Assuntos
Desempenho Atlético/fisiologia , Força Muscular/fisiologia , Educação Física e Treinamento/métodos , Treinamento Resistido/métodos , Criança , Humanos , Masculino
2.
J Sports Sci ; 34(16): 1557-63, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26667896

RESUMO

This study aimed to analyse how youth basketball players explored numerical overloads during shot attempts by measuring their space occupation across specific court areas. Four process-tracing variables measured how the number of attackers (NA), number of defenders (ND), interpersonal distance between attacker and the closest defender (ID) and distance between attacker and the basket (DBkt) impacted on the performance outcome (converted shot; missed shot; ball possession lost). Ten competitive games involving 13 U14 teams were video recorded and players' displacements were digitised. The associations between performance outcomes and the process-tracing measures were assessed using standardised mean differences and a cross-correlation function. A multinomial logistic regression was used to calculate the odds ratio (OR) for each of the three possible outcomes. Results revealed that when shot attempts occurred at larger ID and at smaller DBkt, the possibilities to obtain a converted shot increased. The numerical overload of defenders near the scoring target was predominantly associated with offensive success. Also, the possibility of attackers to lead the spatial relation of movements with the defenders, near the scoring target, appeared as a prominent strategy to succeed. In sum, basketball teams that exhibit potential to adapt their collective behaviours to local changes in the environment might be closer to achieving successful outcomes.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Destreza Motora/fisiologia , Adolescente , Comportamento Competitivo/fisiologia , Humanos , Estudos de Tempo e Movimento , Gravação em Vídeo
3.
Res Q Exerc Sport ; : 1-10, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38980761

RESUMO

Handball is a body-contact Olympic ball sport that is characterized by fast-paced defensive and offensive actions. Players must coordinate explosive movements (e.g. changing of direction) and handball-specific skills (e.g. passing). Maximizing performance requires a systematic approach to training that includes physical, psychological, technical, and tactical preparation. Purpose: The aim of this study is to determine the effects of movement-based (MOV; unspecific sport stimulus) or game-based (GAM; sport-specific stimulus) flywheel resistance training intervention in highly trained youth handball players. Method:Twenty-five highly trained youth male handball players completed two sessions per week of flywheel resistance training (MOV, n = 12; GAM, n = 13) over the 7-week intervention period. Change-of-direction tests (180º change-of-direction speed test of both legs and test) and handball-throwing test were conducted before and after the intervention. Results: Both groups significantly improved V-cut, and 180º Change-of-direction speed test performance (p < .05; d = 0.79-2.05). Notwithstanding, the GAM group demonstrated greater improvements in V-cut and COD180ASY compared with the MOV group (p < .05) with small effect. Handball throwing speed performance remained unchanged independently of training condition (p > .05). Conclusions: These findings provide further support for the training principle of "specificity" and highlight the importance of including a game-based training stimulus during resistance training. This is a key consideration for coaches wanting to enhance physical performance in youth handball players.

4.
PLoS One ; 18(9): e0291917, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37733773

RESUMO

The purpose of this study was to understand the contribution of each performance indicator to evaluate match performance of football referees. Thirty-four elite Referee Match Observers (RMOs) from the Portuguese FA participated voluntarily in the study. From the official assessment sheet of each game, the referee's game score was categorized in two groups according to referee's game score: i) Referees with a Low Score (LFS) and ii) Referees with High Score (HFS). A multivariable binary logistic regression model was used to assess the relationship between the Performance Indicators (PIs) of the dimensions i) game difficulty and game intervention and ii) disciplinary actions and game management in relation to the referee's match assessment score. The model proposed revealed that only the PIs negative application of the laws of the game and referee teamwork, from the dimension disciplinary actions and game management, significantly defined the final game referee's assessment score. This study suggests that the PIs scored by the RMOs contributed in a different way to the referee's game score. The model explains 60.4% of the referee's game score based on the variables referee teamwork and negative application of the laws of the game.


Assuntos
Futebol , Humanos , Etnicidade , Modelos Logísticos
5.
J Sports Sci ; 30(12): 1285-93, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22852826

RESUMO

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.


Assuntos
Desempenho Atlético , Basquetebol , Comportamento Competitivo , Lateralidade Funcional , Movimento , Análise e Desempenho de Tarefas , Adolescente , Humanos , Relações Interpessoais , Masculino
6.
Front Psychol ; 13: 885765, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35712138

RESUMO

We examined the effect of physiological workload on gaze behaviour during defensive performance in 2 vs. 1 +goalkeeper game situations in football. Twenty-two players were assigned to either a high- or low-performing group based on a validated measure of tactical performance. A total of 12 game sequences (trials) were presented under high- and low-workload conditions. At the end of each sequence, participants were asked to indicate their perceived exertion using the Rating Scale of Mental Effort and the Borg Scale. The low- and high-workload conditions were defined when the players achieved 60 and 90% of their maximal heart rate, respectively, as per their performance in the Yo-Yo Intermittent Recovery Test. Visual search behaviours were recorded using Tobii Pro eye-movement registration glasses. Players reported higher rates of perceived exertion on the high- compared to low-workload condition. Participants in the low-performing group increased their average fixation duration and decreased the number of fixations and number of fixation locations from the low- to high-workload conditions. The low- and high-performing groups displayed different visual search strategies with regards the areas of interest fixated upon. Participants in the high-performing group focused on the SpaceFrontPlayer, followed by Ball, and AnotherOpponent. The low-performing group spent more time focusing on the SpaceFrontPlayer and SpacePlayer than Ball and AnotherOpponent. It appears that physiological workload and tactical expertise interact in constraining visual search behaviours in football players. Coaches and practitioners should consider ways to manipulate individual and task constraints while attending to the close interplay between physiological workload, visual behaviour, and tactical performance during practise.

7.
Eur J Sport Sci ; 21(1): 26-35, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32172667

RESUMO

Teams experiencing highly competitive densities may be particularly exposed to performance breakdown and injury risk. The aim of this study was to analyse the association between fixture congestion cycles (playing back-to-back games, playing on one day's rest, playing on two day's rest, playing on three or more day's rest) and performance of NBA basketball teams. A total of 82 games from all teams participating in NBA 2016/2017 regular season were considered. Game-related statistics by fixture congestion cycles and game outcome were examined using the Pearson's Chi-Square test, Discriminant Analysis and Binary logistic regression. The results revealed that the likelihood of winning a game increased significantly from playing back-to-back games to having one day rest in between. Shooting efficacy-related statistics presented a considerable discriminatory power of the different fixture congestion cycles. In conclusion, fixture congestion cycles showed a significant impact on the game outcome and team performance. The findings may add value in the re-design of game schedules in the NBA as well as inform coaches to critically manage training load in order to enhance performance and reduce the risk of injury.


Assuntos
Desempenho Atlético/estatística & dados numéricos , Basquetebol/estatística & dados numéricos , Descanso , Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Distribuição de Qui-Quadrado , Intervalos de Confiança , Análise Discriminante , Humanos , Modelos Logísticos , Masculino , Razão de Chances , Esportes de Equipe , Fatores de Tempo
8.
Hum Mov Sci ; 40: 264-72, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25625811

RESUMO

This study examined the continuous interpersonal interactions of performers in dyadic systems in team sports, as a function of changing information constraints. As a task vehicle, we investigated how attackers attained success in 1v1 sub-phases of basketball by exploring angular relations with immediate opponents and the basket. We hypothesized that angular relations would convey information for the attackers to dribble past defenders. Four basketball players performed as an attacker and defender in 1v1 sub-phases of basketball, in which the co-positioning and orientation of participants relative to the basket was manipulated. After video recording performance behaviors, we digitized participant movement displacement trajectories and categorized trials as successful or unsuccessful (from the attackers' viewpoint). Results revealed that, to successfully dribble past a defender, attackers tended to explore the left hand side of the space by defenders by increasing their angular velocity and decreasing their angular variability, especially in the center of the court. Interpersonal interactions and goal-achievement in attacker-defender dyads appear to have been constrained by the angular relations sustained between participants relative to the scoring target. Results revealed the functionality of exploratory behaviors of participants attempting re-align spatial relations with an opponent in 1v1 sub-phases of team games.


Assuntos
Atletas , Relações Interpessoais , Movimento , Esportes/psicologia , Adolescente , Basquetebol , Comportamento Competitivo , Humanos , Masculino , Desempenho Psicomotor , Comportamento Social , Gravação em Vídeo
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