Table 2 Sweat and performance variables according to sweat electrolyte concentration. Data is mean ± SD for each group
From: Interindividual variability in sweat electrolyte concentration in marathoners
Variable (units) | Low-salt sweat | Typical Sweat | Salty sweat | P value |
|---|---|---|---|---|
<30 mmol·L−1 [sweat Na+] | 30–60 mmol·L−1 [sweat Na+] | >60 mmol·L−1 [sweat Na+] | ||
Number/Frequency | 42/27 % | 84/54 % | 31/20 % | - |
Men/women | 37/5 | 73/11 | 31/0 | 0.11 |
Sweat Na+ concentration (mmol·l−1) | 21.4 ± 6.4* | 43.2 ± 8.8 | 71.0 ± 9.0*† | <0.01 |
Sweat Cl− concentration (mmol·l−1) | 16.4 ± 4.3* | 31.9 ± 9.9 | 54.4 ± 10.7*† | <0.01 |
Sweat K+ concentration (mmol·l−1) | 5.9 ± 0.9 | 5.9 ± 0.9 | 6.2 ± 0.6 | 0.26 |
Sweat osmolality (mOsm·kg H2O−1) | 100.8 ± 38.9* | 150.4 ± 42.1 | 206.3 ± 40.3*† | <0.01 |
Sweat rate (L·h−1) | 0.9 ± 0.2 | 0.9 ± 0.3 | 1.0 ± 0.2 | 0.76 |
Sweat NaCl loss (g L−1) | 1.1 ± 0.3* | 2.1 ± 0.5 | 3.5 ± 0.6*† | <0.01 |
Fluid intake (L·h−1) | 0.32 ± 0.18 | 0.31 ± 0.17 | 0.33 ± 0.15 | 0.85 |
Na+ intake (mmol) | 12.3 ± 8.1 | 11.9 ± 9.9 | 14.6 ± 16.6 | 0.81 |
Cl− intake (mmol) | 21.3 ± 13.0 | 20.8 ± 15.0 | 24.0 ± 25.0 | 0.72 |
K+ intake (mmol) | 5.1 ± 6.0 | 4.7 ± 7.9 | 6.0 ± 5.6 | 0.85 |
Running pace (m·s−1) | 3.0 ± 0.4 | 3.1 ± 0.5 | 3.2 ± 0.5 | 0.18 |
Average training distance·week−1 (km) | 65.1 ± 32.0 | 60.5 ± 26.7 | 64.2 ± 24.1 | 0.65 |