The acute effects of whole-body vibration exercise on cortical activation in young adults: An fNIRS study

Whole-body vibration (WBV) training has emerged as an alternative exercise modality for individuals unable to participate in regular physical activity. While previous studies demonstrated positive effects of WBV on physical outcomes, its impact on cognition remains relatively unexplored, despite studies suggesting cognitive benefits. This study aims to investigate the cortical activation patterns in the primary somatosensory cortex (S1) and dorsolateral prefrontal cortex (DLPFC) during WBV and a subsequent cognitive task.

Oxygenated hemoglobin (HbO2) levels in the brain were measured using functional near-infrared spectroscopy (fNIRS). Cognitive functioning was assessed using the Stroop Color-Word Interference (CWIT) and Color-Block test (CBT). Twenty-four participants (21.50 ± 1.59 years, 11 female) were randomly assigned to one of twelve balanced orders, involving different frequencies (24 Hz, 12 Hz, control) and postures (sitting or standing) on a side-alternating vibration plate.

HbO2 levels were lower at 12 and 24 Hz versus control, most prominently in the left DLPFC. During the CWIT, HbO2 levels tended to be higher after WBV versus control. CWIT performance significantly improved after WBV versus control at 12 Hz in sitting posture, and at 12 and 24 Hz in standing posture.

Our results point towards decreased cortical activation during WBV, especially in the left DLPFC, but beneficial effects as a consequence of WBV expressed in increased activation during the CWIT and improved cognitive performance, indicating cognitive readiness. These results underscore the potential efficacy of WBV as a cognitive-enhancing therapy. Replicating these findings in older adults would enhance the study's generalizability and practical implications.