The effects of whole-body vibration amplitude on glucose metabolism, inflammation, and skeletal muscle oxygenation

Whole-body vibration (WBV) is an exercise mimetic that elicits beneficial metabolic effects. This study aims to investigate the effects of WBV amplitude on metabolic, inflammatory, and muscle oxygenation responses. Forty women and men were assigned to a high (HI; n = 20, Age: 31 +/- 6 y) or a low-amplitude group (LO; n = 20, Age: 33 +/- 6 y). Participants engaged in 10 cycles of WBV [1 cycle =1 min of vibration followed by 30 s of rest], while gastrocnemius muscle oxygen consumption (mVO(2)) was assessed using near-infrared spectroscopy (NIRS). Blood samples were collected PRE, POST, 1H, 3Hs, and 24H post-WBV and analyzed for insulin, glucose, and IL-6. In the LO group, Homeostatic Model Assessment for Insulin Resistant (HOMA-IR) at 3 h (0.7 +/- 0.2) was significantly lower compared to PRE (1.1 +/- 0.2; p = 0.018), POST (1.3 +/- 0.3; p = 0.045), 1H (1.3 +/- 0.3; p = 0.010), and 24H (1.4 +/- 0.2; p < 0.001). In addition, at 24H, HOMA-IR was significantly lower in the LO when compared to the HI group (LO: 1.4 +/- 0.2 vs. HI: 2.2 +/- 0.4; p = 0.030). mVO(2) was higher (p = 0.003) in the LO (0.93 +/- 0.29 ml/min/100 ml) when compared to the HI group (0.63 +/- 0.28 ml/min/100 ml). IL-6 at 3H (LO: 13.2 +/- 2.7 vs. HI: 19.6 +/- 4.0 pg.ml(-1); p = 0.045) and 24H (LO: 4.2 +/- 1.1 vs. HI: 12.5 +/- 3.1 pg.ml(-1); p = 0.016) was greater in the HI compared to the LO group. These findings indicate that low-amplitude WBV provides greater metabolic benefits compared to high-amplitude WBV.