Purpose: To determine if metabolic, ventilatory, or cardiovascular response to isometric squats with or without external load was enhanced by the addition of a whole body vibration (WBV). Methods: Fifteen subjects (28.4±6.5y; 173.7±8.6 cm; 75.5±20.8 kg) underwent four exercise sessions with three days’ rest between sessions. The sample included 7 males and 8 females. Subject performed 10-sets of one-minute isometrics squats with 45 degrees of knee flexion standing on a WBV platform under four conditions: Unloaded, Unloaded Vibration, Loaded, and Loaded Vibration. Each condition was performed on a separate day; the session order was presented at random. One-minute recovery was given between sets. During the vibration conditions, the plate vibrated at 4mm peak-to-peak displacement and 30Hz. Loaded sessions were performed with a barbell equal to 30% body weight across the subjects shoulder. Oxygen consumption (VO2) and ventilation (VE) were measured using a metabolic cart and heart rate was obtained using polar chest straps. A 2x2 ANOVA was used to evaluate main effects for vibration (vibration vs. no vibration), load (loaded vs. unloaded), and interactions. Results: There were significant vibration (p = 0.02) and load (p = 0.003) main effects for VO2. VO2 during vibration (9.2±3.3 mL.kg-1.min-1) was significantly greater than no vibration (7.9±1.2 mL.kg-1.min-1); VO2 was also greater during the loaded (9.6 ± 3.1 mL . kg-1 . min-1) condition compared to unloaded (7.5±1.1 mL.kg-1.min-1). There were significant vibration (p=0.01) and load (p=0.01) main effects for VE. VE during vibration (20.8±10.0 L.min-1) was greater than no vibration (17.8±4.8 L.min-1); VE was greater during loaded (21.5±9.4 L.min-1) conditions compared to unloaded (17.7±5.5 L.min-1). There were significant vibration (p=0.02) and load (p=0.008) main effects for HR. HR during vibration (97.0±20.3 beats . min-1) was greater than no vibration (86.8 ± 25.7 beats . min-1); HR was also greater during loaded (101.3±20.8 beats . min-1) conditions compared to unloaded (90.8±12.6 beats.min-1). No interaction effects were detected for VO2 (p= 0.16), VE (p=0.14), or HR (p=0.84). Conclusion: Significant differences were observed in VO2, VE, and HR while exercising with WBV. Differences were similar across loaded and unloaded conditions. It is unclear if these small differences would be sufficient to induce enhanced long-term training adaptations. Future research should investigate similar physiological responses during dynamic exercise with a range of loads. Further, research is also needed to determine if these responses are enhanced or diminished by the amplitude, frequency, or duration of the vibration stimulus.



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