Ad libitum water consumption prevents exercise-associated hyponatremia and protects against dehydration in soldiers performing a 40-km route-march

ConclusionsAd libitum drinking resulted in 4% body mass loss with a 2  mmol/L serum [Na+] reduction in conjunction with high urine osmolality (>  1000 mOsmol/kg H2O) and plasma AVP. No single hydration strategy likely prevents EAH, but hypernatremia (cellular dehydration) was not seen despite>  2% body mass losses and high urine osmolality.
Source: Military Medical Research - Category: International Medicine & Public Health Source Type: research