Table 1.

Daily values (mean ± SD) for 24 h urine biomarkers and plasma osmolality during baseline fluid consumption (D1–D2, low drinkers 1.0 L/day, high drinkers 2.5 L/day) and during the intervention period (D3–D5, low drinkers 2.5 L/day, high drinkers 1.0 L/day)

	Baseline		Intervention			p value
	D1	D2	D3	D4	D5	Baseline vs. intervention
24 h UOsm (mOsm/kg)
Low	807 ± 209	875 ± 203	409 ± 97*,†	377 ± 103	389 ± 73	<0.001
High	334 ± 68	331 ± 46	652 ± 105*,†	761 ± 147	748 ± 177	<0.001
24 h USG
Low	1.021 ± 0.005	1.022 ± 0.005	1.011 ± 0.003†	1.010 ± 0.003	1.010 ± 0.002	<0.001
High	1.010 ± 0.003	1.009 ± 0.001	1.018 ± 0.003*,†	1.020 ± 0.004	1.019 ± 0.005	<0.001
24 h UCol
Low	5.5 ± 1.2	5.4 ± 1.2	3.3 ± 1.2*,†	2.8 ± 0.9	2.4 ± 0.8	<0.001
High	2.6 ± 0.7	2.5 ± 0.7	4.8 ± 1.1	5.5 ± 1.1	4.2 ± 1.4	<0.001
24 h UVol (ml)
Low	1,080 ± 364	971 ± 288	2,246 ± 554	2,414 ± 453	2,326 ± 396	<0.001
High	2,406 ± 537	2,481 ± 273	1,238 ± 238*,†	1,061 ± 220	1,031 ± 294	<0.001
0700 hours POsm (mOsm/kg)
Low	292 ± 8	291 ± 5	292 ± 5	290 ± 6	291 ± 5	NS
High	289 ± 6	287 ± 4	288 ± 9	289 ± 3	290 ± 5	NS
1800 hours POsm (mOsm/kg)
Low	291 ± 5	290 ± 5	290 ± 5	291 ± 5	293 ± 7	NS
High	290 ± 8	287 ± 4	288 ± 3	289 ± 6	291 ± 5	NS
SOsm (mOsm/kg)
Low	72 ± 20	77 ± 27	71 ± 21	73 ± 27	71 ± 23	NS
High	68 ± 22	70 ± 20	71 ± 20	74 ± 25	70 ± 17	NS

UOsm urine osmolality, USG urine specific gravity, UCol urine color, UVol urine volume, POsm plasma osmolality, SOsm saliva osmolality, Low low drinkers, High high drinkers

* D3 significantly different than D4

^†D3 significantly different than D5