Post-Exercise Voluntary Drinking Cessation Is Associated with the Normalization of Plasma Osmolality and Thirst Perception, but Not of Urine Indicators or Net Fluid Balance.

Post-exercise rehydration has been widely studied, with particular emphasis on retention of ingested fluid; comparatively little research has been conducted on why we drink more or less. To identify physiological values corresponding to voluntary drinking cessation (VDC), nine males exercised intermittently at 70−80% HRmax in the heat (WBGT = 28.1 ± 0.

Awareness of Fluid Losses Does Not Impact Thirst during Exercise in the Heat: A Double-Blind, Cross-Over Study.

Background: Thirst has been used as an indicator of dehydration; however, as a perception, we hypothesized that it could be affected by received information related to fluid losses. The purpose of this study was to identify whether awareness of water loss can impact thirst perception during exercise in the heat.

Methods: Eleven males participated in two sessions in random order, receiving true or false information about their fluid losses every 30 min.

Validity and Reliability of a Water Frequency Questionnaire to Estimate Daily Total Water Intake in Adults.

The purpose of this investigation was to assess the validity and reliability of a seven-day water frequency questionnaire (TWI-FQ) to estimate daily total water intake (TWI) in comparison to a water turnover objective reference value via deuterium oxide (DO). Data collection occurred over 3 weeks, with a wash-out period during week two. Healthy adults ( = 98; 52% female; 41 ± 14 y; BMI, 26.

Combining urine color and void number to assess hydration in adults and children.

Background/objectives: To test the diagnostic ability of two combined practical markers for elevated urine osmolality (underhydration) in free-living adults and children.

Subjects/methods: One hundred and one healthy adults (females n = 52, 40 ± 14 y, 1.70 ± 0.

Urine Reagent Strips Are Inaccurate for Assessing Hypohydration: A Brief Report.

Objective: To assess the diagnostic ability of urine reagent strips to identify hypohydration based on urine specific gravity (USG).

Design: This study examined the agreement of USG between strips and refractometry with Bland-Altman, whereas the diagnostic ability of the strips to assess hypohydration was performed by receiver operating characteristic analysis.

Setting: Arkansas high school football preseason practice.

Validation Testing Demonstrates Efficacy of a 7-Day Fluid Record to Estimate Daily Water Intake in Adult Men and Women When Compared with Total Body Water Turnover Measurement.

Mean daily water intake from fluids (WATER-FL) has proven to be difficult to measure because of a range of nonvalidated data collection techniques. Few questionnaires have been validated to estimate WATER-FL against self-reported diaries or urinary hydration markers, which may limit their objectivity. The goals of this investigation were ) to assess the validity of a 7-d fluid record (7dFLR) to measure WATER-FL (WATER-FL-7dFLR) through comparison with WATER-FL as calculated by measuring deuterium oxide (DO) disappearance (WATER-FL-DO), and ) to evaluate the reliability of the 7dFLR in measuring WATER-FL.

The Effect of Storing Temperature and Duration on Urinary Hydration Markers.

The purpose of this investigation was to quantify the effects of storage temperature, duration, and the urinary sediment on urinary hydration markers. Thirty-six human urine samples were analyzed fresh and then the remaining sample was separated into 24 separate vials, six in each of the following four temperatures: 22 °C, 7 °C, -20 °C, and -80 °C. Two of each sample stored in any given temperature, were analyzed after 1, 2, and 7 days either following vortexing or centrifugation.