Experimental sessions
hip-width, midfoot, apartThe
In a randomized and counterbalanced order, the participants performed 4 different testing conditions, one week apart: (i) 5 sets of 30 s calf raises on the platform but without vibration (CTRL); (ii) 5 sets of 30 s calf raises on the vibration platform with 30 s rest interval between sets (WBV); (iii) set of 6 drop jumps (DJ); (iv) 5 sets of 30 s calf raises on the vibration platform with a 30 s rest interval between sets followed by a set of 6 drop jumps (WBV + DJ). To assess changes in jumping variables, single sets of 2 repetitions of the CMJ were performed before and 3 min after the conditioning activity as well as immediately after a 3 km run.The whole-body vibration was performed on a commercial machine (LADY 1 Pro, New Life Balance GMBH production, Germany). Briefly, the device provides a rotational type of vibration and is 50 cm in width and 25 cm in height above the floor. The vibration frequency and peak-to-peak displacement were respectively set at 20 Hz and 5 mm, and it was constant throughout the intervention. The device was placed on the ground, and a handrail was mounted to facilitate balance control during interventions. The participant stood parallel barefoot, on midfoot in a semi-squat position with their feet hip-width distance apartThe drop jumps were performed from a 51-cm high box. The participant started in the standing position with hands placed on the hips. To initiate the drop action, the participants were instructed to: “step off” the box one foot at a time and “jump up as fast as possible after contact with the ground, making sure that the jump is the highest possible”. The jumps were interspersed by approximately 15-s intervals.The selection of warm-up variables was based on previous studies that showed their effectiveness in inducing performance enhancement