Description of Three Female 24-h Ultra-Endurance Race Winners in Various Weather Conditions and Disciplines

Abstract

A The incidence of exercise-associated hyponatremia (EAH) is higher in women than in men. We present three cases of a very mild post-race EAH in female winners of three 24-h ultra races in various weather conditions and disciplines with post-race plasma sodium [Na] levels of 134 mM (Case 1), 133 mM (Case 2) and 134 mM (Case 3). Moreover, Case 1 and Case 2 showed elevated creatine kinase concentrations of >10,000 U/l with an absence of renal function abnormality. The common characteristics were female sex, veteran recreational category, long race experience in the particular sports discipline, excellent race performance, similar total weekly training hours and the presence of luteal phase of the menstrual cycle during the race. Hematocrit and hemoglobin decreased and post-race K/Na ratio in urine increased in all three cases. In addition, an increased body mass and a decreased urine specific gravity and urine osmolality suggested over-drinking in Case 1. A decrease in the glomerular filtration rate and creatine clearance accompanied by an increase in urine [Na] may contribute to fluid overload in Cases 2 and 3. Furthermore, urine osmolality reached a level indicating antidiuretic hormone secretion in all the present cases. Therefore, we recommend that race medical personnel should not forget to look for EAH even in fast and experienced female athletes and during races in different environmental conditions.

Ultra-Cycling– Past, Present, Future: A Narrative Review

“…Based on the existing literature incorporating the characteristics of ultra-cyclists, it appears that they are predominantly male and typically between 35 and 45 years old. Moreover, Swiss, German, and Scandinavian nationals dominate in European races, whereas North American cyclists are predominant in the RAAM [ 8 , 31 , 33 , 40 , 41 , 154 ]. Compared to other individual ultra-disciplines like running or swimming, ultra-cyclists are slightly younger, have a slightly higher body mass index (BMI), and focus more on training volume than training intensity [ 44 , 45 ].…”

Exercise-Associated Hyponatremia in Endurance and Ultra-Endurance Performance–Aspects of Sex, Race Location, Ambient Temperature, Sports Discipline, and Length of Performance: A Narrative Review

“…However, there are also less dramatic situations of EAH in women [187]. Women can perform well despite developing EAH.…”

“…In one case description, three women were described as winning 24-h races in different conditions and disciplines ahead of all men. In all three cases, mild and asymptomatic EAH was found [187]. A possible explanation for the increased prevalence of EAH in women could be Varon–Ayus syndrome [188].…”

“…In another group of the 26 ultra-runners running seven marathons in seven consecutive days, the prevalence of EAH was 3.8% [194]. During a 24-h ultra-marathon held in winter, hydration status was maintained [173], with one athlete presenting mild EAH (4.8%) [187].…”