Table 4

Dehydration defined by urine specific gravity (USG) whereas dehydration is any USG ≥1.020, while adequately hydrated is any USG <1.020

VariableDehydrated
mean±SD n=85
Hydrated
mean±SD n=233
Serum [Na+]
(mmol/L)
139.9±2.2139.9±2.1
Serum [K+]
(mmol/L)
4.4±0.44.4±0.3
Serum osmolality
(mOsmol/kgH2O)
280.6±8.3280.6±8.8
Urine osmolality
(mOsmol/kgH2O)
893.4±189.7605.8±299.0***
Urine specific gravity1.022±0.0031.011±0.004***
Thirst rating (0–10)4.3±1.84.4±1.8
  • By this definition, 27% of the athletes were dehydrated.

  • *P<0.05; **P<0.01; ***P<0.001 between dehydrated versus hydrated.

  • serum [K+], potassium concentration; serum [Na+], sodium concentration.