A Sodium Drink Enhances Fluid Retention During 3 Hours of Post-Exercise Recovery When Ingested With a Standard Meal

Int J Sport Nutr Exerc Metab. 2017 Aug;27(4):344-350. doi: 10.1123/ijsnem.2016-0196. Epub 2017 Mar 2.


The purpose of this study was to examine the efficacy of water and a 50 mmol/L NaCl solution on postexercise rehydration when a standard meal was consumed during rehydration. Eight healthy participants took part in two experimental trials during which they lost 1.5 ± 0.4% of initial body mass via intermittent exercise in the heat. Participants then rehydrated over a 60-min period with water or a 50 mmol/L NaCl solution in a volume equivalent to 150% of their body mass loss during exercise. In addition, a standard meal was ingested during this time which was equivalent to 30% of participants predicted daily energy expenditure. Urine samples were collected before and after exercise and for 3 hr after rehydration. Cumulative urine volume (981 ± 458 ml and 577 ± 345 mL; p = .035) was greater, while percentage fluid retained (50 ± 20% and 70 ± 21%; p = .017) was lower during the water compared with the NaCl trial respectively. A high degree of variability in results was observed with one participant producing 28% more urine and others ranging from 18-83% reduction in urine output during the NaCl trial. The results of this study suggest that after exercise induced dehydration, the ingestion of a 50 mmol/L NaCl solution leads to greater fluid retention compared with water, even when a meal is consumed postexercise. Furthermore, ingestion of plain water may be effective for maintenance of fluid balance when food is consumed in the rehydration period.

Keywords: hypohydration; net fluid balance; recovery.

MeSH terms

  • Beverages*
  • Dehydration
  • Eating
  • Exercise
  • Female
  • Fluid Therapy*
  • Hot Temperature
  • Humans
  • Male
  • Rehydration Solutions / administration & dosage
  • Sodium / administration & dosage*
  • Sodium / urine
  • Sports Nutritional Physiological Phenomena*
  • Sweating
  • Water / administration & dosage*
  • Water-Electrolyte Balance*
  • Young Adult


  • Rehydration Solutions
  • Water
  • Sodium