title: [Hyponatremia in ultraendurance exercises. Effects on health and performance].
abstract: Dehydration is one of the main problems associated to endurance sports. In order to avoid the negative effects of dehydration athletes tend to drink well above their current needs. The negative effect of drinking too much fluid is hyponatremia. Hyponatremia is defined as a plasma sodium concentration lower than 135 mmol/L. Hyponatremia is the first cause of severe illness in ultraendurance sports and has been associated with sudden death. In this article, we analyze the causes, consequences, associated factors, therapeutic treatment and prevention of ultraendurance sports-associated hyponatremia. It is concluded that an adequate fluid ingestion is the best method to avoid hyponatremia. There is not conclusive data about the amount and necessity of sodium supplementation to avoid hyponatremia. However, it might be that it is not necessary to ingest additional sodium to prevent the development of hyponatremia in athletes who only partially replace their fluid losses during prolonged exercise.
authors.affiliation: Unidad de Fisiología del Ejercicio y Evaluación de la Forma Física, Departamento de Fisiología Médica, Facultad de Medicina, Universidad de Granada, Granada, España.
authors.forename: Francisco B
authors.initials: FB
authors.lastname: Ortega Porcel
authors.forename: Jonatan
authors.initials: J
authors.lastname: Ruiz Ruiz
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Castillo Garzón
authors.forename: Angel
authors.initials: A
authors.lastname: Gutiérrez Sainz
mesh_terms: D004326:Drinking; D015444:Exercise / Q000502:physiology*; D005260:Female; D017408:Guidelines as Topic; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D012964:Sodium / Q000008:administration & dosage / Q000172:deficiency; D013177:Sports / Q000502:physiology
chemical_list: D012964:Sodium