title: Alterations in Body Fluid Balance During Fin Swimming in 29 °C Water in a Population of Special Forces Divers.
abstract: Highly trained "combat swimmers" encounter physiological difficulties when performing missions in warm water. The aim of this study was to assess the respective roles of immersion and physical activity in perturbing fluid balance of military divers on duty in warm water. 12 trained divers performed 2 dives each (2 h, 3 m depth) in fresh water at 29 °C. Divers either remained Static or swam continuously (Fin) during the dive. In the Fin condition, oxygen consumption and heart rate were 2-fold greater than during the Static dive. Core and skin temperatures were also higher (Fin: 38.5±0.4 °C and 36.2±0.3 °C and Static: 37.2±0.3 °C and 34.3±0.3 °C; respectively p=0.0002 and p=0.0003). During the Fin dive, the average mass loss was 989 g (39% urine loss, 41% sweating and 20% insensible water loss and blood sampling); Static divers lost 720 g (84% urine loss, 2% sweating and 14% insensible water loss and blood sampling) (p=0.003). In the Fin condition, a greater decrease in total body mass and greater sweating occurred, without effects on circulating renin and aldosterone concentrations; diuresis was reduced, and plasma volume decreased more than in the Static condition.
authors.affiliation: Military Biomedical Research Institute (IRBA), Underwater Research Team (ERRSO), Toulon Cedex, France.
authors.forename: O
authors.initials: O
authors.lastname: Castagna
authors.affiliation: Military Biomedical Research Institute (IRBA), Underwater Research Team (ERRSO), Toulon, France.
authors.forename: A V
authors.initials: AV
authors.lastname: Desruelle
authors.affiliation: Department of Hyperbaric and Diving Medicine, Ste Anne's Military Hospital, Toulon Armées, France.
authors.forename: J E
authors.initials: JE
authors.lastname: Blatteau
authors.affiliation: Military Biomedical Research Institute (IRBA), Underwater Research Team (ERRSO), Toulon Armées, France.
authors.forename: B
authors.initials: B
authors.lastname: Schmid
authors.affiliation: Université de Franche-comte, Besancon, France.
authors.forename: G
authors.initials: G
authors.lastname: Dumoulin
authors.affiliation: Université de Franche-comte, Besancon, France.
authors.forename: J
authors.initials: J
authors.lastname: Regnard
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood; D001833:Body Temperature Regulation; D003681:Dehydration / Q000209:etiology; D004734:Energy Metabolism; D006339:Heart Rate; D006801:Humans; D008889:Military Personnel; D009318:Natriuresis; D010101:Oxygen Consumption; D010953:Plasma Volume; D011188:Potassium / Q000097:blood; D012083:Renin / Q000097:blood; D013550:Swimming / Q000502:physiology*; D013696:Temperature; D014867:Water; D014882:Water-Electrolyte Balance
chemical_list: D014867:Water; D000450:Aldosterone; D012083:Renin; D011188:Potassium