RESUMO
This study aimed to compare the effects of different velocities of eccentric muscle actions on acute blood lactate and serum growth hormone (GH) concentrations following free weight bench press exercises performed by resistance-trained men. Sixteen healthy men were divided into two groups: slow eccentric velocity (SEV; n = 8) and fast eccentric velocity (FEV; n = 8). Both groups performed four sets of eight eccentric repetitions at an intensity of 70% of their one repetition maximum eccentric (1RMecc) test, with 2-minute rest intervals between sets. The eccentric velocity was controlled to 3 seconds per range of motion for SEV and 0.5 seconds for the FEV group. There was a significant difference (P < 0.001) in the kinetics of blood lactate removal (at 3, 6, 9, 15, and 20 min) and higher mean values for peak blood lactate (P = 0.001) for the SEV group (9.1 ± 0.5 mM) compared to the FEV group (6.1 ± 0.4 mM). Additionally, serum GH concentrations were significantly higher (P < 0.001) at 15 minutes after bench press exercise in the SEV group (1.7 ± 0.6 ng · mL(-1)) relative to the FEV group (0.1 ± 0.0 ng · mL(-1)). In conclusion, the velocity of eccentric muscle action influences acute responses following bench press exercises performed by resistance-trained men using a slow velocity resulting in a greater metabolic stress and hormone response.
RESUMO
Objetivo. Comparar la influencia de las velocidades de contracción lenta y rápida en el volumen total de carga levantada en una sesión de entrenamiento de resistencia con ejercicios de pesos libres para miembros superiores, y analizar el tiempo de recuperación de la fuerza máxima del músculo después del ejercicio en la resistencia de hombres entrenados. Métodos. Dieciséis hombres jóvenes que tenían experiencia en el entrenamiento de la resistencia fueron divididos aleatoriamente en dos grupos: la velocidad de contracción rápida (FCV - n = 8) y la velocidad de contracción lenta (SCV - n = 8). Ambos grupos realizaron el ejercicio de press de banca y press banca inclinado (pesos libres) con 4 series de 12 repeticiones máximo; y un intervalo de 50 segundos de descanso entre cada serie y 2 minutos entre los ejercicios. La velocidad de contracción fue de 6 segundos para el grupo SCV y 1,5 segundos para el grupo de FCV. El volumen total de carga fue anotado durante la sesión de ejercicio; y una repetición máxima (1RM) fue evaluada antes (basal) y durante 96 horas después del ejercicio para medir la función neuromuscular. Resultados. Los resultados demostraron que el grupo de FCV proporcionó un mayor (p < 0,05) volumen de carga levantada durante la sesión de ejercicio, y tuvo una disminución significativa (p < 0,05) en el rendimiento neuromuscular después del ejercicio, en comparación con el grupo SCV. Conclusión. Estos datos sugieren que además de la velocidad de contracción, el volumen total de carga elevada determina la disminución de la función neuromuscular después del ejercicio en la resistencia de hombres entrenados(AU)
Objective. To compare the influence of slow and fast contraction velocities in the total volume of load lifted in a resistance training bout with free weights exercises for upper limbs, and analyze the recovery time of the maximum muscle strength post-exercise in resistance-trained men. Methods. Sixteen young men, who were experienced in resistance training were randomly divided into two groups: fast contraction velocity (FCV - n = 8) and slow contraction velocity (SCV - n = 8). Both groups performed bench press and incline bench press exercises (free weights) with 4 sets of 12 repetitions maximum. There was a 50 seconds rest interval between each set, and 2 minutes interval between the exercises. The contraction velocity was 6 seconds for the SCV group and 1.5 seconds for the FCV group. The total volume of load was recorded during the exercise bout, and the one repetition maximum (1RM) was evaluated before (baseline) and for 96 hours after exercise to measure the neuromuscular function. Results. The results demonstrated that the FCV group provide a higher (p < 0.05) volume of load lifted during the exercise bout, and had a significant decline (p < 0.05) in the neuromuscular performance post-exercise, when compared to the SCV group. Conclusion. These data suggest that besides the contraction velocity, the total volume of load lifted determines the decline of neuromuscular function post-exercise in resistance-trained men(AU)
