Effects of Metered Versus Bolus Water Consumption on Urine Production and Rehydration

• Autores: Eric J. Jones, Phillip A. Bishop, James Mathew Green, Mark T. Richardson
• Localización: International journal of sport nutrition and exercise metabolism, ISSN 1526-484X, ISSN-e 1543-2742, Vol. 20, Nº. 2, 2010, págs. 139-144
• Idioma: inglés
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• Resumen

  • This study compared the effects of a rapid bolus and a slower metered water-consumption rate on urine production and postexercise rehydration. Participants (n = 8) dehydrated by 2% body weight through moderate exercise in an environmentally controlled chamber (35°C, 55% relative humidity). Breakfast and lunch were standardized for all participants during each 8-hr data-collection period. Rehydration was performed using a volume of water equal to that lost during exercise either as bolus consumption (100% of volume consumed in 1hr; BOL) or metered consumption (12.5% of volume every 30 min for 4 hr; MET). Urine volume was used to assess hydration efficiency (water retained vs. water lost) and net fluid balance at 8 hr. Mean urine outputs were 420 ml (MET) and 700 ml (BOL). A paired-samples t test showed that hydration efficiency was greater for MET (75%) than for BOL (55%; p = .018). These data suggest that metered administration was more effective in maintaining fluid balance. These findings suggest that rehydration rate is a factor in fluid-balance response. For situations in which available fluid volume is restricted, greater hydration efficiency is highly desirable.