The oral ingestion of glycerol can be used to facilitate better retention of ingested fluids, which may be of benefit to athletes in sports where hydration status may be compromised due to prolonged and/ or intense exercise in thermally challenging environments and/ or when fluid access may be restricted.1 Consumed simultaneously with a substantial volume of fluid, glycerol contributes to the osmotic pressure of body fluids and causes a temporary retention of fluid and expansion of body fluid compartments beyond normal fluctuations.2,3