BACKGROUND AND AIMS: This study was undertaken to assess the comparability of body water compartment estimates in healthy volunteers using single and dual frequency bioelectrical impedance analysis (BIA) with established reference methods of tritium and NaBr dilution. METHODS: Total body water (TBW) was estimated in 10 healthy volunteers using single frequency (50 kHz) BIA (Bodystat [...]

Age-related changes in the proportions of intracellular or extra-cellular water to total body water and in the ratio of total body water to fat-free mass are debatable. These are important issues both for medical reasons (dehydration is a threat in the diseased elderly) and for methodological reasons (most techniques for assessing of body composition assume [...]

BACKGROUND: As a reduction of water spaces is expected in the elderly because of fat-free mass loss, disease is often associated with increased hydration. The present study compared water spaces and cellular hydration in adults, healthy and diseased aged patients. METHODS: An open study was conducted in 6 geriatric wards and a nutrition laboratory involving [...]

The present study was performed to determine how equilibrated fluctuations in hydration affected the validity of bioelectrical impedance analysis (BIA) for body composition assessment. Total body water (TBW) expansion was induced by a 4 d endurance trial and the subsequent water loss was obtained over the recovery period. Twelve healthy men exercised on a cycle [...]

PURPOSE: The purpose of this study was to determine a quick and easy method for assessment of day-to-day hydration status in athletes in the heat. METHODS: Measurement of the osmolality of the first urine sample of the day collected after wakening but before breakfast established a standardized collection procedure to allow day-to-day comparisons of individuals. [...]

No abstract available.

Twenty women underwent body density (DB) measurements using underwater weighing with correction of residual lung volume by nitrogen dilution and total body water (TBW) using isotope dilution of 18O to estimate body composition at 30 wk of gestation. DB and TBW were used as independent variables in the same equation. The hydration constant (HC) of [...]

No abstract available.

PURPOSE: This study examined the utility of bioimpedance spectroscopy (BIS) for assessing total body water (TBW) changes associated with moderate (6-7% TBW), hypertonic (HH), and isotonic (IH) hypohydration. METHODS: The TBW of nine men was measured using BIS (TBWBIS) when euhydrated (EU) and during HH and IH. These measurements were compared with TBW measurements obtained [...]

No abstract available.