Rehydration after bathing:
Comparison between a carbohydrate-electrolyte beverage and water
Tadano K, Sakurai M, Shimizu M, Noda T, Hamada K, Morimoto T, Tadano J
Medicine and Biology 2010; 154: 376-386
We studied whether an ion supply drink was more effective than water for restoring the dehydration and increased blood viscosity induced by bathing.
Twelve healthy male subjects were studied in three randomized cross-over intervention trials using an ion supply drink, water and a control condition without fluid intake. After the subjects took a bath in hot water at 41℃ for 15 min, they rested in a room at 27.8℃ ambient temperature and 38.0% relative humidity for 30 min. After resting for 30 min, they ingested test beverages equal to their body weight loss. The changes in the properties of the blood were measured after the subjects ingested the test beverages.
Approximately 800 ml of body water was lost by bathing in hot water at 41℃ for 15 min and resting for 30 min. The recovery of the plasma volume observed in the ion supply drink was significant at 60 min in comparison to the water and at 60, 120, and 240 min of the recovery period, in comparison to the no fluid intake. The blood viscosity in ion supply drink was significantly lower than that in the no fluid intake at 120 and 180 min.
The ion supply drink was more effective than water for restoring the plasma volume and also that the ingestion of an ion supply drink may suppress an increase in blood viscosity after bathing-induced dehydration.