The impact of internal and external loads in the neuromuscular and mechanical properties of hamstring muscles in football players
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2018-12-19
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O conhecimento atual do rendimento humano está ainda longe de perceber como parâmetros físicos como as acelerações, desacelerações e saltos podem influenciar o rendimento de um jogador e em particular a funcionalidade muscular. Objetivos: O objetivo deste estudo foi analisar as relações entre as cargas internas e externas nas propriedades mecânicas e neuromusculares dos músculos isquiotibiais em jogadores de futebol. Em paralelo, esta investigação pretendeu caracterizar, por tipo de sessão de treino e em diferentes posições no campo, perfis específicos deste tipo de componentes físicas. Métodos: A amostra utilizada foi composta por jogadores de futebol (n=11) de um clube Lituano que compete na principal divisão do país, A Lyga. Os jogadores foram testados usando o aparelho Biodex System 3 no laboratório da LSU. Os mesmos jogadores foram reavaliados quatro semanas após a avaliação inicial enquanto que entre ambos os testes, a carga aplicada foi monitorizada diariamente com unidades GPS OptimEye S5 da Catapult Sports - Australia (carga externa) e com a PSE (carga interna) sendo mais tarde correlacionadas com os testes laboratoriais. Resultados: Os eventos de acelerações de baixa e moderada intensidade foram estatisticamente correlacionados de forma negativa (p =0.005; r =- 0.773 e p =0.011; r=-0728, respetivamente) com o aumento da tensão involuntária dos músculos isquiotibiais. Nos jogos oficiais verificaram-se valores significativamente mais elevados em parâmetros físicos como a carga individual do jogador, PSE e desacelerações. Relativamente as sessões de cariz físico, equipararam-se nas acelerações, pois nenhum resultado estatisticamente relevante foi obtido, enquanto que no total dos saltos existiu a probabilidade de o número de eventos ocorrer com mais frequência que em jogos. Os resultados obtidos em função da posição em campo, nomeadamente os defesas em comparação com os médios apresentaram um maior número de eventos em acelerações e saltos de baixa intensidade. Entre médios e avançados, foi identificada uma diminuição na perceção subjetiva de esforço e no número de eventos de aceleração de baixa e moderada intensidade. Os saltos baixos e médios ocorrem com mais frequência em avançados. Conclusão: Este estudo confirma que diferentes componentes físicas deverão ser consideradas nas diferentes sessões de treino. Ajudando a prescrever estímulos de treino semelhantes ao jogo tendo em conta a posição em campo e a preocupação pelo estado muscular, enriquecendo assim o rendimento individual e coletivo.
Current human performance knowledge is still far from understand how physical workloads such as acceleration, decelerations and jumps can influence performance and in particularly muscle functionality. Aims: The aim of this study was to examine the relationships between internal and external workload in the neuromuscular and mechanical properties of hamstring muscles in football players. In parallel, this study aimed to profile markers of these sort of loads for training formats and players’ positions. Methods: Sample used included football players (n=11) from one club which competes in A Lyga (Lithuania 1st division). The players were evaluated Using Biodex System 3 under laboratories condition at LSU. The retest of this protocol was done after four weeks while in between these assessments, the workload of the same players was monitored daily with GPS units from OptimEye S5, Catapult Sports - Australia (external load) and with RPE (internal load) having been later correlated with the laboratory tests. Results: Low and moderate accelerations events were negative correlated (p =0.005; r =-0.773 and p =0.011; r=- 0.728, respectively) with increase of hamstring muscle stiffness. In official matches were identified statiscally greater values than the remaining training sessions in physical parameters as player load, RPE and decelerations. Regarding physical sessions were similar in acceleration because no differences were found, while total jumps had a greater probability to occur more often in comparison with matches. Concerning the results obtained by players’ positions, namely defenders in comparison with midfielders presented a greater number of events in terms of low accelerations and jumps. Between midfielders and forwards, it was identified a decrease on RPE as well as low and moderate accelerations. Low and moderate jumps occurred often in forwards. Conclusion: This study confirmed that different physical loads must be considered to different formats. Helping to prescribe and replicate similar stimulus to the matches by player positions and should be aware about the muscle functionality with an aim to enrich the team and the individual performance.
Current human performance knowledge is still far from understand how physical workloads such as acceleration, decelerations and jumps can influence performance and in particularly muscle functionality. Aims: The aim of this study was to examine the relationships between internal and external workload in the neuromuscular and mechanical properties of hamstring muscles in football players. In parallel, this study aimed to profile markers of these sort of loads for training formats and players’ positions. Methods: Sample used included football players (n=11) from one club which competes in A Lyga (Lithuania 1st division). The players were evaluated Using Biodex System 3 under laboratories condition at LSU. The retest of this protocol was done after four weeks while in between these assessments, the workload of the same players was monitored daily with GPS units from OptimEye S5, Catapult Sports - Australia (external load) and with RPE (internal load) having been later correlated with the laboratory tests. Results: Low and moderate accelerations events were negative correlated (p =0.005; r =-0.773 and p =0.011; r=- 0.728, respectively) with increase of hamstring muscle stiffness. In official matches were identified statiscally greater values than the remaining training sessions in physical parameters as player load, RPE and decelerations. Regarding physical sessions were similar in acceleration because no differences were found, while total jumps had a greater probability to occur more often in comparison with matches. Concerning the results obtained by players’ positions, namely defenders in comparison with midfielders presented a greater number of events in terms of low accelerations and jumps. Between midfielders and forwards, it was identified a decrease on RPE as well as low and moderate accelerations. Low and moderate jumps occurred often in forwards. Conclusion: This study confirmed that different physical loads must be considered to different formats. Helping to prescribe and replicate similar stimulus to the matches by player positions and should be aware about the muscle functionality with an aim to enrich the team and the individual performance.
Descrição
Master Thesis International Master in Performance Analysis of Sport
Palavras-chave
Rendimento , Monitorização , Avaliação Muscular , GPS , PSE , Tipo de Sessões de Treino , Posições Específicas