Acute Effects of Vibration Versus High-Intensity Resistance Conditioning on Neuromuscular Performance

Overview

The purpose of this randomized crossover study was to compare the immediate effects of high-intensity resistance conditioning and whole-body vibration conditioning on lower- and upper-body neuromuscular performance in recreationally resistance-trained young adults. Twenty participants were enrolled, and 19 completed both experimental conditions. After a preliminary assessment and familiarization session, participants completed the resistance-conditioning and vibration-conditioning protocols in a randomized order during two experimental sessions separated by 24 hours. The resistance-conditioning protocol included three squat repetitions at 90% of estimated one-repetition maximum before countermovement jump testing and three bench-press repetitions at 90% of estimated one-repetition maximum before an isometric push-up assessment. The vibration-conditioning protocol included lower- and upper-body vibration exercises performed on a vibration platform before the corresponding performance assessments. Lower-body performance was assessed using countermovement jump height, flight time-to-contraction time ratio, and relative peak power. Upper-body performance was assessed using peak force during an isometric push-up. All performance outcomes were measured using dual force desks.

Acute conditioning activities are commonly included in pre-performance routines to influence subsequent force- and power-related performance. High-intensity resistance exercise and whole-body vibration represent mechanically different conditioning strategies, but direct comparisons of their immediate effects, particularly across both lower- and upper-body outcomes in the same participants, remain limited. This study used a randomized, two-treatment, two-period, two-sequence crossover design. Twenty recreationally resistance-trained students from the Faculty of Sport Sciences were enrolled. One participant withdrew during preliminary testing and did not proceed to the experimental crossover sessions. The remaining 19 participants completed both conditioning conditions. Participants were assigned to either a resistance-conditioning followed by vibration-conditioning sequence or a vibration-conditioning followed by resistance-conditioning sequence using a computer-generated random-number sequence. The study included one preliminary assessment session and two experimental sessions. During the preliminary session, demographic and training-history information, anthropometric and body-composition measurements, estimated squat and bench-press one-repetition maximum values, familiarization trials, and a common pre-experimental performance assessment were completed. A 48-hour recovery interval was provided between the preliminary session and the first experimental session. The two experimental sessions were separated by 24 hours. During the high-intensity resistance-conditioning condition, participants performed three squat repetitions at 90% of estimated one-repetition maximum. After 9 minutes of passive recovery, countermovement jump performance was assessed. Following the jump assessment, participants rested for 15 minutes and then performed three bench-press repetitions at 90% of estimated one-repetition maximum. Isometric push-up performance was assessed 9 minutes after the bench-press conditioning activity. During the vibration-conditioning condition, participants completed four 30-second lower-body vibration bouts at 28 Hz and 4 mm displacement, with 30 seconds of passive recovery between bouts. Countermovement jump performance was assessed after 5 minutes of recovery. Following the jump assessment and a 7-minute passive recovery period, participants completed two 30-second upper-body vibration bouts using extended- and flexed-elbow push-up positions. Isometric push-up performance was assessed 9 minutes after completion of the upper-body vibration protocol. The four primary outcomes were countermovement jump height, flight time-to-contraction time ratio, relative peak power, and isometric push-up peak force. Outcomes were obtained using a dual force-plate system. The common pre-experimental assessment was used descriptively because it was performed once before both crossover conditions and was not a period-specific baseline. The primary comparison evaluated the period-adjusted within-participant difference between the complete resistance-conditioning and vibration-conditioning protocols.