Abstract
Exercise-associated hyponatremia (EAH) is defined as a plasma sodium concentration of <135 mmol/L during or after endurance and ultra-endurance performance and was first described by Timothy Noakes when observed in ultra-marathoners competing in the Comrades Marathon in South Africa in the mid-1980s. It is well-established that a decrease in plasma sodium concentration <135 mmol/L occurs with excessive fluid intake. Clinically, a mild hyponatremia will lead to no or very unspecific symptoms. A pronounced hyponatremia (<120 mmol/L) will lead to central nervous symptoms due to cerebral edema, and respiratory failure can lead to death when plasma sodium concentration reaches values of <110–115 mmol/L. The objective of this narrative review is to present new findings about the aspects of sex, race location, sports discipline, and length of performance. The prevalence of EAH depends on the duration of an endurance performance (i.e., low in marathon running, high to very high in ultra-marathon running), the sports discipline (i.e., rather rare in cycling, more frequent in running and triathlon, and very frequent in swimming), sex (i.e., increased in women with several reported deaths), the ambient temperature (i.e., very high in hot temperatures) and the country where competition takes place (i.e., very common in the USA, very little in Europe, practically never in Africa, Asia, and Oceania). A possible explanation for the increased prevalence of EAH in women could be the so-called Varon–Ayus syndrome with severe hyponatremia, lung and cerebral edema, which was first observed in marathon runners. Regarding the race location, races in Europe seemed to be held under rather moderate conditions whereas races held in the USA were often performed under thermally stressing conditions (i.e., greater heat or greater cold).
Highlights
Exercise-associated hyponatremia (EAH) has been well-known among endurance and ultra-endurance athletes
A possible explanation for the increased prevalence of exercise-associated hyponatremia (EAH) in women could be the so-called Varon–Ayus syndrome with severe hyponatremia, lung and cerebral edema, which was first observed in marathon runners
Races in Europe seemed to be held under rather moderate conditions whereas races held in the USA were often performed under thermally stressing conditions
Summary
Exercise-associated hyponatremia (EAH) has been well-known among endurance and ultra-endurance athletes. Considering the increased number of endurance and ultra-endurance races, and of finishers in these races during the last years, comprehensive knowledge about EAH would be of great practical importance for athletes and professionals (e.g., coaches, nutritionists, practitioners, exercise physiologists) working with them. It would be of interest to examine the variation of EAH by parameters such as sex, sport discipline, race distance and environmental conditions. The purpose of this review was to present new aspects regarding sex, race location, discipline and length of performance as risk factors in developing EAH. A further aspect was to present data on the prevalence and severity of EAH regarding the discipline, environmental conditions, and length of the performance
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.