Efeito da duração do intervalo em saltos verticais: relações entre trabalho realizado e duração até a exaustão
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Data
2004-03-30
Autores
Pereira, Gleber [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi verificar se o modelo da potência crítica se ajusta para saltos verticais. Após a determinação da altura máxima de salto vertical, dez participantes realizaram saltos verticais, com movimento semelhante ao bloqueio no voleibol com contra-movimento, até a exaustão em três intervalos de tempo diferentes (entre 4 e 7 s). No 5º, 6º e 7º dias foram executados saltos verticais na intensidade correspondente ao intervalo crítico ( tc) e 5% abaixo e acima. O teste era interrompido quando o participante não pôde mais alcançar uma altura pré-estabelecida por três vezes consecutivas, e em seguida medida a concentração de lactato sangüíneo, freqüência cardíaca, tempo até a exaustão e número de saltos verticais realizados. Uma plataforma de força foi utilizada para captar a força de reação do solo vertical, possibilitando posteriormente o cálculo do impulso concêntrico e da altura do salto vertical. Foi assumido que o trabalho externo total para elevar o centro de massa nos saltos verticais poderia ser expresso pela somatória dos impulsos concêntricos ( I) ou pelo número de saltos verticais multiplicados pela altura do salto vertical pré-fixada ( H). Os dados foram ajustados com os procedimentos de regressão linear e não linear para resolver as equações do modelo da potência crítica (PCrit) e determinar as estimativas da PCrit, da capacidade de trabalho anaeróbio e do tc para cada modelo matemático (não linear potência-tempo, linear trabalho-tempo e linear potência-1/tempo) e método ( I e H). Os resultados indicaram que (a)as sessões utilizadas para determinar o tc foram exaustivas e similares; (b)houve relação entre trabalho externo realizado em saltos verticais medido pela plataforma de força e pelo número de saltos verticais em diferentes intervalos com a duração do exercício até a exaustão... .
The aim of this study was to verify if the critical power (CP) model fits to vertical jump. The maximum jump height of ten subjects were determined. During following days, the subjects performed vertical jumps until exhaustion, simulating volleyball block with countermovement, with three different time intervals between jumps (between 4 and 7 seconds). In 5º, 6º and 7º days the subjects performed jumps at ?tc (critical interval) and 5% below and above it, until they could not reach pre-established height for three consecutive times. Blood lactate, heart rate, time to exhaustion and number of jump performed at the end of exercise were measured. The concentric impulse and jump height were measured by vertical ground reaction force at force platform. It was assumed that the total external work to elevate body center of mass, would be expressed as the somatory of the concentric impulses ( I) or the total jumps performed multiplied by the pre-established jump height ( H). The data were fitted to the three mathematics equations of the CP model (non-linear power-time, linear work-time and linear power-1/time). The results indicated that (a)the sessions used to determine tc were exhaustive and similar; (b)there was relationship between the total external work in vertical jump measured in both methods (force platform and number of vertical jump performed under different intervals) with the time to exhaustion; (c)the tc values estimated by the two methods were similar and; (d)the physiologic of responses to vertical jumps performed at tc intensity were similar to that observed in continuous exercise performed at CP intensity. Therefore, it was concluded that the critical power model fits to vertical jump.
The aim of this study was to verify if the critical power (CP) model fits to vertical jump. The maximum jump height of ten subjects were determined. During following days, the subjects performed vertical jumps until exhaustion, simulating volleyball block with countermovement, with three different time intervals between jumps (between 4 and 7 seconds). In 5º, 6º and 7º days the subjects performed jumps at ?tc (critical interval) and 5% below and above it, until they could not reach pre-established height for three consecutive times. Blood lactate, heart rate, time to exhaustion and number of jump performed at the end of exercise were measured. The concentric impulse and jump height were measured by vertical ground reaction force at force platform. It was assumed that the total external work to elevate body center of mass, would be expressed as the somatory of the concentric impulses ( I) or the total jumps performed multiplied by the pre-established jump height ( H). The data were fitted to the three mathematics equations of the CP model (non-linear power-time, linear work-time and linear power-1/time). The results indicated that (a)the sessions used to determine tc were exhaustive and similar; (b)there was relationship between the total external work in vertical jump measured in both methods (force platform and number of vertical jump performed under different intervals) with the time to exhaustion; (c)the tc values estimated by the two methods were similar and; (d)the physiologic of responses to vertical jumps performed at tc intensity were similar to that observed in continuous exercise performed at CP intensity. Therefore, it was concluded that the critical power model fits to vertical jump.
Descrição
Palavras-chave
Treinamento desportivo, Variabilidade do batimento cardíaco, Modelo da potência crítica, Lctato sangüíneo
Como citar
PEREIRA, Gleber. Efeito da duração do intervalo em saltos verticais: relações entre trabalho realizado e duração até a exaustão. 2004. xvi, 134 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2004.