Exercise-Associated Hyponatremia in Endurance Athletes: Recognition, Prevention and Clinical Management – A Narrative Review
DOI:
https://doi.org/10.12775/QS.2026.69.74453Keywords
exercise-associated hyponatremia, endurance athletes, endurance exercise, hydration, sport medicineAbstract
Background: Exercise-associated hyponatremia (EAH) is a potentially life-threatening electrolyte disorder occurring during or within 24 hours after prolonged endurance exercise. Despite increasing awareness, EAH remains underrecognized because its clinical presentation frequently overlaps with dehydration and other exercise-related conditions.
Aim: This narrative review aims to summarize current evidence regarding the epidemiology, pathophysiology, risk factors, clinical presentation, diagnosis, management, and prevention of exercise-associated hyponatremia in endurance athletes.
Materials and Methods: A narrative review of the literature was conducted using peer-reviewed publications retrieved from PubMed and Google Scholar. Original studies, review articles, international consensus statements, and clinical practice guidelines addressing exercise-associated hyponatremia in endurance athletes were analyzed and synthesized to provide a comprehensive overview of current knowledge.
Results: Current evidence indicates that EAH primarily results from excessive hypotonic fluid intake combined with impaired renal free water excretion due to persistent arginine vasopressin secretion. Individualized hydration strategies based on physiological thirst represent the most effective preventive approach, whereas prompt administration of intravenous 3% hypertonic saline remains the treatment of choice in severe symptomatic cases.
Conclusions: Early recognition, appropriate differential diagnosis, and evidence-based management are essential for preventing severe neurological complications associated with EAH. Improved education of athletes, coaches, and healthcare professionals may further reduce the incidence and clinical consequences of this condition.
References
1. Bennett BL, Hew-Butler T, Rosner MH, Myers T, Lipman GS. Wilderness Medical Society clinical practice guidelines for the management of exercise-associated hyponatremia: 2019 update. Wilderness Environ Med. 2020;31(1):50-62. doi:10.1016/j.wem.2019.11.003.
2. Hew-Butler T, Rosner MH, Fowkes-Godek S, Dugas JP, Hoffman MD, Lewis DP, et al. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015. Clin J Sport Med. 2015;25(4):303-320.
3. Rosner MH. Exercise-associated hyponatremia. Trans Am Clin Climatol Assoc. 2019;130:76-87.
4. Altieri B, Aini I, Cannavale G, Magnelli C, Mancini C, Zamponi V, et al. Pathophysiology and treatment of exercise-associated hyponatremia. J Endocrinol Invest. 2025. doi:10.1007/s40618-025-02673-7.
5. Hew-Butler T, Loi V, Pani A, Rosner MH. Exercise-associated hyponatremia: 2017 update. Front Med (Lausanne). 2017;4:21. doi:10.3389/fmed.2017.00021.
6. Rosner MH, Kirven J. Exercise-associated hyponatremia. Clin J Am Soc Nephrol. 2007;2(1):151-161. doi:10.2215/CJN.02730806.
7. Rogers IR, Hew-Butler T. Exercise-associated hyponatremia: overzealous fluid consumption. Wilderness Environ Med. 2009;20(2):139-143. doi:10.1580/08-WEME- CON-231R2.1.
8. Almond CS, Shin AY, Fortescue EB, Mannix RC, Wypij D, Binstadt BA, et al. Hyponatremia among runners in the Boston Marathon. N Engl J Med. 2005;352(15):1550-1556. doi:10.1056/NEJMoa043901.
9. Noakes TD, Sharwood K, Speedy D, Hew T, Reid S, Dugas J, et al. Three independent biological mechanisms cause exercise-associated hyponatremia: evidence from 2,135 weighed competitive athletic performances. Proc Natl Acad Sci U S A. 2005;102(51):18550-18555. doi:10.1073/pnas.0509096102.
10. Speedy DB, Noakes TD, Schneider C. Exercise-associated hyponatremia: a review. Emerg Med (Fremantle). 2001;13(1):17-27. doi:10.1046/j.1442-2026.2001.00173.x.
11. Klingert M, Nikolaidis PT, Weiss K, Thuany M, Chlíbková D, Knechtle B. Exercise- associated hyponatremia in marathon runners. J Clin Med. 2022;11(22):6775. doi:10.3390/jcm11226775.
12. Johnson KB, Connolly CP, Cho SP, Miller TK, Sallis RE, Hiller WDB. Clinical presentation of exercise-associated hyponatremia in male and female IRONMAN triathletes over three decades. Scand J Med Sci Sports. 2023;33:1841-1849. doi:10.1111/sms.14401.
13. Hew-Butler T. Exercise-associated hyponatremia. Front Horm Res. 2019;52:178-189. doi:10.1159/000493247.
14. Jonas CE, Arnold MJ. Exercise-associated hyponatremia: updated guidelines from the Wilderness Medical Society. Am Fam Physician. 2021;103(4):252-253.
15. Buck E, McAllister R, Schroeder JD. Exercise-associated hyponatremia. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023.
16. Noakes TD. Hyponatremia in distance runners: fluid and sodium balance during exercise. Curr Sports Med Rep. 2002;1(4):197-207. doi:10.1249/00149619-200208000- 00003.
17. Hew-Butler TD, Sharwood K, Collins M, Speedy D, Noakes T. Sodium supplementation is not required to maintain serum sodium concentrations during an Ironman triathlon. Br J Sports Med. 2006;40(3):255-259. doi:10.1136/bjsm.2005.022418.
18. Seal AD, Kavouras SA. A review of risk factors and prevention strategies for exercise- associated hyponatremia. Auton Neurosci. 2022;238:102930. doi:10.1016/j.autneu.2021.102930.
19. Ayus JC, Varon J, Arieff AI. Hyponatremia, cerebral edema, and noncardiogenic pulmonary edema in marathon runners. Ann Intern Med. 2000;132(9):711-714. doi:10.7326/0003-4819-132-9-200005020-00005.
20. Hoffman MD, Hew-Butler T, Stuempfle KJ. Exercise-associated hyponatremia and hydration status in 161-km ultramarathoners. Med Sci Sports Exerc. 2013;45(4):784- 791. doi:10.1249/MSS.0b013e31827985a8.
21. Hoffman MD, Fogard K, Winger J, Hew-Butler T, Stuempfle KJ. Characteristics of 161-km ultramarathon finishers developing exercise-associated hyponatremia. Res Sports Med. 2013;21(2):164-175.
22. Winger JM, Dugas JP, Dugas LR. Beliefs about hydration and physiology drive drinking behaviours in runners. Br J Sports Med. 2011;45(8):646-649.
23. Rogers IR, Hook G, Stuempfle KJ, Hoffman MD, Hew-Butler T. An intervention study of oral versus intravenous hypertonic saline administration in ultramarathon runners with exercise-associated hyponatremia: a preliminary randomized trial. Clin J Sport Med. 2011;21(3):200-203. doi:10.1097/JSM.0b013e31821a6450.
24. Adrogué HJ, Madias NE. Hyponatremia. N Engl J Med. 2000;342(21):1581-1589. doi:10.1056/NEJM200005253422107.
25. Verbalis JG, Goldsmith SR, Greenberg A, Korzelius C, Schrier RW, Sterns RH, et al. Diagnosis, evaluation, and treatment of hyponatremia: expert panel recommendations. Am J Med. 2013;126(10 Suppl 1):S1-S42. doi:10.1016/j.amjmed.2013.07.006.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Piotr Ziajka, Agnieszka Zwolińska, Aleksandra Gaudynek-Sowała, Monika Łapot, Gabriela Szczepanek, Anna Matyas, Hubert Lurka, Anna Zyskowska, Michał Starczewski, Adam Tomczak, Izabela Filar
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Stats
Number of views and downloads: 168
Number of citations: 0
