Abstract
BACKGROUND: The application of whole body vibration (WBV) as a warm-up scheme has been receiving an increasing interest among practitioners. OBJECTIVES: The aim of this study was to determine the effect of loaded and unloaded WBV on countermovement jump, speed and agility. PATIENTS AND METHODS: Twenty-one healthy male college football players (age: 20.14 ± 1.65 years; body height: 179.9 ± 8.34 cm; body mass: 74.4 ± 13.0 kg; % body fat: 9.45 ± 4.8) underwent randomized controlled trials that involved standing in a half squat position (ST), ST with 30% of bodyweight (ST + 30%), whole body vibration at f = 50 Hz, A = 4 mm (WBV), and WBV with 30% bodyweight (WBV + 30% BW) after a standardized warm-up. Post measures of countermovement jump, 15-m sprint, and modified t-test were utilized for analyses. RESULTS: One way repeated measures ANOVA revealed a significant difference in the countermovement jump performance, F (3, 60 = 9.06, η2 = 2.21, P = 0.000. Post-hoc showed that WBV + 30% BW posted significant difference compared to (P = 0.008), ST + 30% BW (P = 0.000) and WBV (P = 0.000). There was also a significant difference in the sprint times among interventions, F (3, 60) = 23.0, η2 = 0.865, P = 0.000. Post hoc showed that WBV + 30% BW displayed significantly lower time values than ST (P = 0.000), ST + 30% BW (P = 0.000) and WBV (P = 0.000). Lastly, there was a significant difference in the agility performance across experimental conditions at F(2.01, 40.1) = 21.0, η2 = 0.954, P = 0.000. Post hoc demonstrated that WBV have lower times than ST (P = 0.013). Also, WBV + 30% BW posted lower times compared to ST (P = 0.000), ST + 30% (P = 0.000) and WBV (P = 0.003). CONCLUSIONS: Additional external load of 30% bodyweight under WBV posted superior gains in countermovement jump, speed and agility compared to unloaded WBV, loaded non-WBV and unloaded non-WBV interventions.