The calcium-binding protein S100B is produced primarily by astrocytes and exerts concentration-dependentparacrine and autocrine effects on neurons and glia. The numerous findings of a correlation between S100B andtraumatic brain injury (TBI) have resulted in the employment of this protein as a clinical biomarker for such injury.Our present aim was to determine whether cycling with (V) or without (NV) vibration alters serum concentrations ofS100B. Twelve healthy, male non-smokers (age: 25.3±1.6 yrs, body mass: 74.2±5.9 kg, body height: 181.0±3.7 cm,VO2peak: 56.9±5.1 ml·min-1·kg-1(means ± SD)) completed in random order two separate trials to exhaustion on avibrating bicycle (amplitude 4 mm and frequency 20 Hz) connected to an ergometer. The initial workload of 100 W waselevated by 50 W every 5 min and the mean maximal period of exercise was 25:27±1:30 min. The S100B in venousblood taken at rest, immediately after the test, and 30, 60 and 240 min post-exercise exhibited no significant differences(p>0.05), suggesting that cycling with and without vibration does not influence this parameter.