Table 1.
Changes (mean ± SD, range, 95% confidence interval) in haematocrit (Hct), haemoglobin (Hb) and osmolality, serum concentration of sodium, potassium magnesium and chloride before (Pre), and immediately (0) and 65 min following downhill running (DHR) for the spring water (Water) and electrolyte water (OS-1) intake during DHR and 40 min after DHR. *: significant (P < 0.05) difference from the pre-value, #: significant (P < 0.05) difference between conditions
| Condition | Pre | 0 | 65 | ANOVA | |
|---|---|---|---|---|---|
|
Hct (%) |
Water | 45.7 ± 2.5 | 45.2 ± 2.5 | 45.5 ± 2.5 |
F = 2.92 P = 0.08 |
| (42.0–48.3) | (41.3–48.0) | (41.3–48.0) | |||
| 44.2–47.2 | 43.7–46.7 | 43.9–47.1 | |||
| OS-1 | 47.6 ± 4.0 | 45.7 ± 1.8 | 45.3 ± 1.5* | ||
| (42.6–50.0) | (42.6–48.3) | (43.3–48.0) | |||
| 45.1–50.1 | 44.6–46.8 | 44.4–46.3 | |||
|
Hb (g/dl) |
Water | 15.5 ± 1.2 | 15.4 ± 1.3 | 15.4 ± 1.2 |
F = 1.51 P = 0.24 |
| (13.8–16.9) | (13.7–17.3) | (13.7–16.9) | |||
| 14.8–16.2 | 14.6–16.2 | 14.6–16.1 | |||
| OS-1 | 15.6 ± 1.1 | 15.2 ± 0.9 | 15.1 ± 0.9* | ||
| (14.0–17.0) | (14.2–16.5) | (13.5–16.4) | |||
| 14.8–16.3 | 14.6–15.8 | 14.5–15.8 | |||
|
Osmolality (mOsm/kg H2O) |
Water | 291.1 ± 4.9 | 285.3 ± 6.8* | 288.6 ± 6.1 |
F = 5.27 P = 0.016# |
| (282–300) | (277–300) | (281–301) | |||
| 288.0–294.1 | 281.1–289.5 | 284.8–292.4 | |||
| OS-1 | 293.3 ± 6.2 | 294.2 ± 7.5 | 289.7 ± 3.8* | ||
| (282–301) | (285–307) | (285–296) | |||
| 289.5–297.1 | 289.5–298.9 | 287.3–292.1 | |||
|
Sodium (mmol/L) |
Water | 140.2 ± 1.9 | 137.9 ± 2.2* | 138.8 ± 1.9 |
F = 0.92 P = 0.42 |
| (137–143) | (135–142) | (137–140) | |||
| 139.0–141.3 | 136.6–139.3 | 137.6–140.0 | |||
| OS-1 | 140.7 ± 2.9 | 139.3 ± 4.6 | 139.1 ± 2.3* | ||
| (136–145) | (138–146) | (136–144) | |||
| 138.9–142.5 | 136.5–142.1 | 137.6–140.6 | |||
|
Potassium (mmol/L) |
Water | 4.6 ± 0.4 | 4.5 ± 0.4 | 4.2 ± 0.5* |
F = 1.0 P = 3.87 |
| (4.0–5.3) | (4.1–5.1) | (3.5–4.9) | |||
| 4.3–4.8 | 4.2–4.8 | 3.8–4.5 | |||
| OS-1 | 4.7 ± 0.6 | 4.7 ± 0.6 | 4.4 ± 0.6* | ||
| (4.1–5.8) | (4.0–5.9) | (3.8–5.4) | |||
| 4.3–5.1 | 4.3–5.1 | 4.0–4.8 | |||
|
Magnesium (mmol/L) |
Water | 0.85 ± 0.04 | 0.82 ± 0.05* | 0.84 ± 0.06 |
F = 1.85 P = 0.19 |
| (0.78–0.91) | (0.71–0.89) | (0.70–0.94) | |||
| 0.83–0.87 | 0.78–0.85 | 0.80–0.88 | |||
| OS-1 | 0.89 ± 0.04 | 0.83 ± 0.04* | 0.86 ± 0.05* | ||
| (0.83–0.96) | (0.77–0.92) | (0.78–0.93) | |||
| 0.86–0.92 | 0.81–0.86 | 0.83–0.90 | |||
|
Chloride (mmol/L) |
Water | 101.9 ± 2.0 | 100.0 ± 2.4* | 100.3 ± 2.6 |
F = 16.8 P = 0.001# |
| (99–105) | (96–104) | (97–104) | |||
| 100.6–103.2 | 98.5–101.5 | 98.7–101.9 | |||
| OS-1 | 101.6 ± 2.7 | 102.7 ± 2.7 | 102.4 ± 2.0 | ||
| (99–106) | (99–107) | (100–106) | |||
| 99.9–103.3 | 101.0–104.4 | 101.2–103.6 |