title: Body composition, energy, and fluid turnover in a five-day multistage ultratriathlon: a case study.
abstract: A multistage ultraendurance triathlon over five times the Ironman distance within five consecutive days leads in one ultraendurance triathlete to minimal changes in body mass (BM; -0.3 kg), fat mass (FM; -1.9 kg), skeletal muscle mass (SM; no change), and total body water (TBW; +1.5 l). This might be explained by the continuously slower race times throughout the race every day and the positive energy balance (8,095 kcal), although he suffered an average energy deficit of -1,848 kcal per Ironman distance. The increase of TBW might be explained by the increase of plasma volume (PV) in the first 3 days. The increase of PV and TBW could be a result of an increase of sodium, which was increased after every stage. We presume that this could be the result of an increased activity of aldosterone.
authors.affiliation: Gesundheitszentrum St. Gallen, St. Gallen, Switzerland. beat.knechtle@hispeed.ch
authors.forename: Beat
authors.initials: B
authors.lastname: Knechtle
authors.forename: Patrizia
authors.initials: P
authors.lastname: Knechtle
authors.forename: Jorge Luis
authors.initials: JL
authors.lastname: Andonie
authors.forename: Gotz
authors.initials: G
authors.lastname: Kohler
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood; D001642:Bicycling / Q000502:physiology*; D001823:Body Composition / Q000502:physiology; D050218:Body Fat Distribution; D015992:Body Mass Index; D001834:Body Water / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D010953:Plasma Volume / Q000502:physiology; D012420:Running / Q000502:physiology*; D012885:Skinfold Thickness; D012964:Sodium / Q000097:blood; D013550:Swimming / Q000502:physiology*; D013997:Time Factors; D014508:Urea / Q000097:blood / Q000652:urine
chemical_list: D000450:Aldosterone; D014508:Urea; D012964:Sodium