Date of Graduation


Document Type


Degree Name

Master of Science in Kinesiology (MS)

Degree Level



Health, Human Performance and Recreation


Stavros A. Kavouras

Committee Member

Matthew Ganio

Second Committee Member

Brendon P. Mcdermott


Health and environmental sciences, Friendliness, Gender, Hydration, Hypohydration, Mood, Vigor


Previous research has shown that acute dehydration can result in changes in mood. These changes have been reported in less than a 1% loss in total body water. However, the effect of hypohydration (i.e., reflected through high urine concentration) on mood in free-living conditions has not been studied. PURPOSE: The present study was designed to determine if hydration status is associated with mood within the general population under free-living conditions. METHODS: A group of 103 apparently healthy subjects (49 male, 54 female, 41±14 y, 1.7±0.1 m, 76.1±16.9 kg) completed three visits separated by a week. Mood was assessed by the Profile of Mood States (POMS) questionnaire during each visit. Participants were familiarized to the POMS questionnaire on their first visit. Hydration was assessed via urine osmolality (uOsm), urine specific gravity (USG), and urine color (UC) done on both spot and twenty four hour (24-h) urine samples taken during the 2nd and 3rd visits. Urine indices and POMS data from the 2nd and 3rd visit were averaged to attain measurements for analyses. RESULTS: Overall USG displayed significance in predicting changes in Vigor/Acuity (P = 0.031). UOsm (P = 0.006) and USG (P = 0.012), as well as 24-h uOsm (P < 0.001) and USG (P < 0.001) showed significance in predicting Vigor/Acuity in females. 24-h uOsm (P = 0.012) and USG (P = 0.004) were a significant predictor of a female's feelings of friendliness. No significant relationships were found for the male subjects. CONCLUSION: These data suggested that hydration status affects mood specifically in free-living females but not in males.