Spot Urine Concentrations Should Not be Used for Hydration Assessment: A Methodology Review

Int J Sport Nutr Exerc Metab. 2015 Jun;25(3):293-7. doi: 10.1123/ijsnem.2014-0138. Epub 2014 Nov 10.


A common practice in sports science is to assess hydration status using the concentration of a single spot urine collection taken at any time of day for comparison against concentration (specific gravity, osmolality, color) thresholds established from first morning voids. There is strong evidence that this practice can be confounded by fluid intake, diet, and exercise, among other factors, leading to false positive/negative assessments. Thus, the purpose of this paper is to provide a simple explanation as to why this practice leads to erroneous conclusions and should be curtailed in favor of consensus hydration assessment recommendations.

Publication types

  • Review

MeSH terms

  • Dehydration / urine*
  • Drinking
  • Exercise
  • False Positive Reactions
  • Humans
  • Osmolar Concentration
  • Specific Gravity
  • Urine Specimen Collection / methods*
  • Urine Specimen Collection / standards
  • Water-Electrolyte Balance