title: Biochemical and hematological changes following the 120-km open-water marathon swim.
abstract: Data on physiological effects and potential risks of a ultraendurance swimming are scarce. This report presents the unique case of a 61-year old athlete who completed a non-stop open-water 120-km ultramarathon swim on the Warta River, Poland. Pre-swimming examinations revealed favorable conditions (blood pressure, 110/70 mmHg; rest heart rate, 54 beats/minute, ejection fraction, 60%, 20.2 metabolic equivalents in a maximal exercise test). The swimming time and distance covered were 27 h 33 min and 120 km, respectively. Blood samples for hematological and biochemical parameters were collected 30 min, 4 hrs, 10 hrs and 8 days after the swim. The body temperature of the swimmer was 36.7°C before and 35.1°C after the swim. The hematological parameters remained within the reference range in the postexercise period except for leucocytes (17.5 and 10.6 x G/l noted 30 minutes and 4 hours after the swim, respectively). Serum urea, aspartate aminotransferase and C-reactive protein increased above the reference range reaching 11.3 mmol/l, 1054 nmol/l/s and 25.9 mg/l, respectively. Symptomatic hyponatremia was not observed. Although the results demonstrate that an experienced athlete is able to complete an ultra-marathon swim without negative health consequences, further studies addressing the potential risks of marathon swimming are required. Key pointsData on biochemical changes due to long-distance swimming are scarce.This report presents the unique case of a 61-year old athlete who completed a non-stop open-water 120-km ultramarathon swim.An experienced athlete is able to complete an ultra-marathon swim without serious health consequences.Regarding the growing popularity of marathon swimming further studies addressing the potential risks of such exhaustive exercise are required.
authors.affiliation: Department of Social and Preventive Medicine Medical University of Lodz , Lodz, Poland ; Department of Epidemiology, Cardiovascular Prevention and Health Promotion, National Institute of Cardiology , Warsaw, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Drygas
authors.affiliation: Department of Social and Preventive Medicine Medical University of Lodz , Lodz, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Rębowska
authors.affiliation: Department of Clinical Biochemistry, Jagiellonian University Medical College Krakow , Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Stępień
authors.affiliation: Department of Haemostasis and Haemostatic Disorders, Medical University of Lodz , Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Golański
authors.affiliation: Department of Social and Preventive Medicine Medical University of Lodz , Lodz, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kwaśniewska
keywords: Marathon swim; biochemical; men; ultraendurance exercise