for this study. All of the participants were well-trained athletes, members of a university team, participants of a university technical training programme, and were all fully informed of the research procedures, which were approved by the University of Alicante Ethics . On the first day of intervention, the subjects completed a questionnaire about their state of health. None of the athletes had to be excluded from participation in the study due to health conditions. A pre-test/post-test equivalent-group design was used to investigate whether traditional strength training combined WBV can enhance the strength and jumping performance of trained athletes compared with the results of traditional strength training alone for 6 weeks. Players were randomly assigned to the training combined with WBV (WBV; n=12 players, 6 VB and 6 BVB) and the control with isolated strength training (CON; n=11 players, 6 VB and 5 BVB) groups. The physical characteristics of the participants of each group are shown in Table 1. The independent variables were training, WBV use and discipline kind.Training protocol
The four groups completed the 6-week training programme in the same weight-training room, performing the following 4 lower limb exercises: leg press, alternative lunge, squat and front squat for 4 sets x 12 repetitions at 70% of repetition maximum (RM).