There is growing interest in the use of whole body vibration (WBV) for physical training and rehabilitation applications. Subjecting the body to prolonged periods of high-frequency vibration have long been known to be potential injurious, whereas lower frequencies and durations of exposure may have potentially beneficial effects (Rittweger, 2010). Neuromuscular activation appears to be highest in the frequency range 15-20 Hz (Wakeling et al., 2002). WBV has been reported to increase local muscular blood flow (Kerschan-Schindl et al., 2001) but there are no data reporting any systemic effects of WBV on blood flow. Vibration induced shear stress is of interest for its angiogenesis inducing potential. The aim of this study was to investigate the potential shear stress effects of WBV, its effect on skeletal muscle blood flow distal (forearm) to the main site (lower limbs) of muscle activation was investigated. Ten (8 male) healthy young adults aged (mean±SD) 20±1 years, height 1.76± 0.08 m, body mass (BM) 76.1±6.8 kg undertook bouts of squatting exercise under four separate conditions, completing 60 squats in two minutes at a constant rate. The conditions were unloaded, loaded with a mass added to a back pack equivalent to 15 %BM and with and without WBV (30 Hz, 3 mm amplitude). A latin square design was used and subjects undertook two exercise conditions separated by 30 minutes in each of two separate sessions on different days. Immediately after completing each exercise bout, subjects moved to a supine position on an examination couch. Forearm blood flow (FBF) was measured in triplicate using venous occlusion plethysmography pre-exercise commencing 1½ minutes post-exercise and at 3 minutes intervals thereafter until 23 minutes had elapsed. Blood pressure was measured using an automated monitor on the opposite arm. Data were analysed using repeated measures ANOVA. Overall there were no significant differences in the post-exercise FBF (Fig 1) or mean arterial pressure (MAP) (Fig 2) between the various conditions. However, there was a trend towards differences in FBF at the first post-exercise time point (2 minutes) where FBF appears to increase in the unloaded condition. In contrast, with 15 %BM loading this increase in FBF was absent, most likely due to a selective reduction in lower limb peripheral resistance in response to the increased metabolic load which was associated with a trend towards a lower MAP (Fig 2). However, with the addition of WBV, it appears that this partially restored the observed increase in FBF. One tentative explanation consistent with this observation is that WBV induced shear stress resulted in a general systemic vasodilatory effect that partially counteracted the increased lower limb vasodilatation. These results should be considered preliminary, but indicate that the potential systemic effect of WBV induced shear stress warrant further investigation.