Journal article
Blood and urinary measures of hydration status during progressive acute dehydration
Medicine and science in sports and exercise, Vol.33(5), pp.747-753
2001
DOI: 10.1097/00005768-200105000-00011
PMID: 11323543
Abstract
Purpose: To determine whether: a) plasma osmolarity (Posm) is sensitive to small incremental changes in hydration status, b) urine specific gravity (Usg) can accurately identify a state of euhydration, c) Usg is a sensitive indicator of a change in hydration status, and d) Usg correlates with Posm.
Methods: Euhydrated (Posm = 288 +/- 4 mOsm.L-1) subjects (N = 12) were dehydrated by 5% of their body weight via exercise in the heat (40 degrees C, 20% RH). Posm, urine osmolarity (Uosm), and Usg were measured at 1%, 3%, and 5% dehydration, and 30 and 60 min of recovery (rec). Subjects consumed water in recovery equal to their loss of body weight.
Results: Posm increased incrementally with each successive increase in percent body weight loss (%BWL). Usg was not significantly different from baseline until 3% BML. Uosm was not significantly different from baseline until 5% BWL. Usg correlated moderately (r = 0.46, P > 0.10) with Posm but reasonably well (r = 0.68, P < 0.02) with Uosm.
Conclusions: Posm accurately identifies a state of euhydration and is sensitive to changes in hydration status during acute dehydration and rehydration. Usg and Uosm are also sensitive to changes in hydration status but lag behind during periods of rapid body fluid turnover and therefore correlate only moderately with Posm during acute dehydration.
Details
- Title: Subtitle
- Blood and urinary measures of hydration status during progressive acute dehydration
- Creators
- Leroy A Popowski - Departments of Exercise Science and Psychology, University of Iowa, Iowa City, IA 52242, United StatesRobert A Oppliger - Departments of Exercise Science and Psychology, University of Iowa, Iowa City, IA 52242, United StatesG. Patrick Lambert - Departments of Exercise Science and Psychology, University of Iowa, Iowa City, IA 52242, United StatesRalph F Johnson - Departments of Exercise Science and Psychology, University of Iowa, Iowa City, IA 52242, United StatesAlan Kim Johnson - Neuroscience and PharmacologyCarl V Gisolfi - Departments of Exercise Science and Psychology, University of Iowa, Iowa City, IA 52242, United States
- Resource Type
- Journal article
- Publication Details
- Medicine and science in sports and exercise, Vol.33(5), pp.747-753
- Publisher
- Lippincott Williams & Wilkins
- DOI
- 10.1097/00005768-200105000-00011
- PMID
- 11323543
- ISSN
- 0195-9131
- eISSN
- 1530-0315
- Language
- English
- Date published
- 2001
- Academic Unit
- Psychological and Brain Sciences; Neuroscience and Pharmacology; Health and Human Physiology
- Record Identifier
- 9984213416502771
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