BACKGROUNDThe consumption of carbohydrate-electrolyte beverages (CEs) has been known to be more effective than plain water for recovery from dehydration. This phenomenon suggests that the ingestion of CEs after dehydration is better than water for maintaining body fluid and plasma volume, and for the recovery from hemoconcentration and high blood viscosity as well. High blood viscosity causes infarction and other cardiovascular events. In this study, CE was compared with water and tea for the ability to reduce increased blood viscosity after dehydration.

METHODSA crossover random control study was conducted to assess the effectiveness of three beverages for rehydration and decreasing of blood viscosity. Following exercise-induced dehydration of 2.2% of body weight in a permanent warm environment, 10 male subjects rested in a thermoneutral environment for 3 hours (rehydration period, REP). The subjects ingested test beverages equal to their body weight loss during the first 20 minutes in REP. Blood and urine samples were obtained throughout the experiments to assess the rehydration effect.

RESULTSThe change in blood viscosity at a shear rate of 5/s was significantly lower in CE ((-1.66 ± 0.21) mPa×s) in comparison to water ((-0.95 ± 0.26) mPa×s) or tea ((-0.92 ± 0.14) mPa×s) at 60th minute during the REP. The fluid retention rate was significantly greater for CE ((77.0 ± 3.9)%) than water ((61.2 ± 3.4)%) and tea ((60.5 ± 3.7)%) for 3 hours of rest in REP.

CONCLUSIONSThe recovery from high blood viscosity induced by dehydration was higher with CE consumption than with water or tea. These results suggest that CE is useful for normalizing increased blood viscosity due to exercise-induced dehydration.