Details

Autor(en) / Beteiligte

• Johnson, Evan C.
• Huffman, Ainsley E.
• Yoder, Hillary
• Dolci, Alberto
• Perrier, Erica T.
• Larson-Meyer, D. Enette
• Armstrong, Lawrence E.

Titel

Urinary markers of hydration during 3-day water restriction and graded rehydration

Ist Teil von

• European journal of nutrition, 2020-08, Vol.59 (5), p.2171-2181

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Purpose This investigation had three purposes: (a) to evaluate changes in hydration biomarkers in response to a graded rehydration intervention (GRHI) following 3 days of water restriction (WR), (b) assess within-day variation in urine concentrations, and (c) quantify the volume of fluid needed to return to euhydration as demonstrated by change in U col . Methods 115 adult males and females were observed during 1 week of habitual fluid intake, 3 days of fluid restriction (1000 mL day −1 ), and a fourth day in which the sample was randomized into five different GRHI groups: no additional water, CON; additional 500 mL, G +0.50 ; additional 1000 mL, G +1.00 ; additional 1500 mL, G +1.50 ; additional 2250 mL, G +2.25 . All urine was collected on 1 day of the baseline week, during the final 2 days of the WR, and during the day of GRHI, and evaluated for urine osmolality, color, and specific gravity. Results Following the GRHI, only G +1.50 and G +2.25 resulted in all urinary values being significantly different from CON. The mean volume of water increase was significantly greater for those whose U col changed from > 4 to < 4 (+ 1435 ± 812 mL) than those whose U col remained ≥ 4 (+ 667 ± 722 mL, p  < 0.001). Conclusions An additional 500 mL of water is not sufficient, while approximately 1500 mL of additional water (for a total intake between 2990 and 3515 mL day −1 ) is required to return to a urine color associated with adequate water intake, following 3 days of WR.