ArticleEuropean journal of applied physiology2010
Effects of athletes' muscle mass on urinary markers of hydration status.
Article in European journal of applied physiology, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 28 papers, 1 of them a synthesis that pooled it.
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Who cites it
28 citing papers in PubMed, 1 synthesis or guideline pooled it, 83 citations in OpenAlex.
- Fluid balance and hydration status in combat sport Olympic athletes: a systematic review with meta-analysis of controlled and uncontrolled studies.European journal of nutrition · 2019Pooled it
- Trial
- Longitudinal assessment of kidney function in migrant farm workers.Environmental research · 2021Trial
- Relevance of individual characteristics for thermoregulation during exercise in a hot-dry environment.European journal of applied physiology · 2011Trial
- Creatinine Normalization Over-Corrects Urinary Electrolytes but Not Protein: Implications for Hydration Monitoring in Athletes.Metabolites · 2026Article
- Time of urine sampling may influence the association between urine specific gravity and body composition.PloS one · 2025Observational
- Fat-Free Mass Is Positively Associated With Urine Specific Gravity in Athletes and Active Adults: A Quantitative Review.Translational sports medicine · 2024Review
- Fluid balance of female para hockey players during simulated competition.Frontiers in sports and active living · 2024Article
- In-Season Longitudinal Hydration/Body Cell Mass Ratio Changes in Elite Rugby Players.Sports (Basel, Switzerland) · 2023Article
- Automated Urinal-Based Specific Gravity Measurement Device for Real-Time Hydration Monitoring in Male Athletes.Frontiers in sports and active living · 2022Article
- Article
- A Portable Biodevice to Monitor Salivary Conductivity for the Rapid Assessment of Fluid Status.Journal of personalized medicine · 2021Article
- Gender Differences in Neuromuscular, Haematological and Urinary Responses during Padel Matches.International journal of environmental research and public health · 2021Article
- Evaluation and review of body fluids saliva, sweat and tear compared to biochemical hydration assessment markers within blood and urine.European journal of clinical nutrition · 2018Review
- Arsenic and Obesity: A Comparison of Urine Dilution Adjustment Methods.Environmental health perspectives · 2017Article
- Validity of Urine Specific Gravity When Compared With Plasma Osmolality as a Measure of Hydration Status in Male and Female NCAA Collegiate Athletes.Journal of strength and conditioning research · 2016Article
- Influence of Physical Activity and Ambient Temperature on Hydration: The European Hydration Research Study (EHRS).Nutrients · 2016Article
- Validation of a urine color scale for assessment of urine osmolality in healthy children.European journal of nutrition · 2016Article
- Fluid Balance During Training in Elite Young Athletes of Different Sports.Journal of strength and conditioning research · 2015Article
- Hydration Status and Fluid Balance of Elite European Youth Soccer Players during Consecutive Training Sessions.Journal of sports science & medicine · 2014Article
Corrections and comments
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Authors and funding
4 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
To determine if athletes' muscle mass affects the usefulness of urine specific gravity (U(sg)) as a hydration index. Nine rugby players and nine endurance runners differing in the amount of muscle mass (42 +/- 6 vs. 32 +/- 3 kg, respectively; P = 0.0002) were recruited. At waking during six consecutive days, urine was collected for U (sg) analysis, urine osmolality (U(osm)), electrolytes (U[Na+], U[K+] and U[Cl-]) and protein metabolites (U([Creatinine]), U([Urea]) and U([Uric acid])) concentrations. In addition, fasting blood serum osmolality (S(osm)) was measured on the sixth day. As averaged during 6 days, U(sg) (1.021 +/- 0.002 vs. 1.016 +/- 0.001), U(osm) (702 +/- 56 vs. 554 +/- 41 mOsmol kg(-1) H(2)O), U([Urea]) (405 +/- 36 vs. 302 +/- 23 mmol L(-1)) and U([Uric acid]) (2.7 +/- 0.3 vs. 1.7 +/- 0.2 mmol L(-1)) were higher in rugby players than runners (P < 0.05). However, urine electrolyte concentrations were not different between groups. A higher percentage of rugby players than runners (56 vs. 11%; P = 0.03) could be cataloged as hypohydrated by U(sg) (i.e., >1.020) despite S (osm) being below 290 mOsmol kg(-1) H(2)O in all participants. A positive correlation was found between muscle mass and urine protein metabolites (r = 0.47; P = 0.04) and between urine protein metabolites and U(sg) (r = 0.92; P < 0.0001). In summary, U(sg) specificity to detect hypohydration was reduced in athletes with large muscle mass. Our data suggest that athletes with large muscle mass (i.e., rugby players) are prone to be incorrectly classified as hypohydrated based on U(sg).
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