The effects of short-term resistance program on vertical jump ability in elite male volleyball players during the competition season

The aim of this study was to describe the effects of 6 weeks of combined strength and jump training which incorporated moderate loads and high intensity contractions on the vertical jump ability (VJ), loaded jumps and velocity of execution in full squat in a group of professional male volleyball players during the competition season. It was hypothesized that the VJ improved by cross combined strength and jump training both characterized by high velocity of execution (>1m/s). The participants in this study were twelve players who competed in the first national division of the Spanish National League during the 2011-2012 season. The neuromuscular performance was estimated by unloaded (CMJ) and loaded countermovement jumps (CMJloaded) height (cm); and by velocity of displacement in the concentric phase of full squat (FS) (m/s). There was a significant increase in CMJ and CMJloaded after 6-week of training (5%, p1m/s). El rendimiento neuromuscular fue estimado por la altura (cm) del salto sin cargas (CMJ), salto con cargas (CMJloaded), y por la velocidad (m/s) de desplazamiento en la fase concéntrica en la sentadilla completa (FS). Tuvo lugar un incremento significativo en CMJ y CMJloaded después de 6 semanas de entrenamientos (5%, p<0.01; y 5.7%, p<0.05; respectivamente). Estos cambios fueron acompañados por un valor de Tamaño del Efecto pequeño y moderado (0.47, and 0.67; respectivamente). No se observaron diferencias significativas en la velocidad de desplazamiento en FS. El análisis de correlación lineal mostró una correlación moderada estadísticamente significativa entre los cambios en CMJ-CMJloaded y CMJ-FS (r=0.62; y r=0.59, p