In both Series I (49h) and Series II (32h) experiments, the intake of glycerol results in smaller urine volumes (a 700 ml reduction), demonstrating that glycerol is able to keep a hyperhydrated state for extended periods as long as 32 and 49 hours.
Athletic Performance Support
After administration of 1.2 g/kg glycerol in 26 ml/kg solution before exercise, time-to-fatigue is prolonged up to 24% with pre-exercise glycerol. Subjects who consumed glycerol lasted around 94 minutes, compared with 77 minutes for the placebo group. Mean heart rate decreased by 4.4 beats/min with glycerol ingestion.
Compared to pre-exercise hydration with water, exercise following glycerol-induced hyperhydration yielded significantly elevated mean sweat output of 700mL (compared with the water trial mean sweat output of 470mL), representing a 33% increase in the sweat rate.
Glycerol-induced hyperhydration also resulted in lower core temperature (decreased by 0.9°C), demonstrating that pre-exercise glycerol supplementation helps reduce the thermal burden of moderate exercise in heat.