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Cited by 553Electrolyte and hormonal disordersThermoregulation and physiological responsesCardiovascular Effects of Exercise

Hyponatremia among runners in the Boston Marathon.

Open access
Almond, Christopher S.D., Shin, Andrew Y., Fortescue, Elizabeth B., Mannix, Rebekah C., Wypij, David, Binstadt, Bryce A., Duncan, Christine N., Olson, David P. +3 more·2005·New England Journal of Medicine
DOI 10.1056/nejmoa043901
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Abstract

BACKGROUND: Hyponatremia has emerged as an important cause of race-related death and life-threatening illness among marathon runners. We studied a cohort of marathon runners to estimate the incidence of hyponatremia and to identify the principal risk factors. METHODS: Participants in the 2002 Boston Marathon were recruited one or two days before the race. Subjects completed a survey describing demographic information and training history. After the race, runners provided a blood sample and completed a questionnaire detailing their fluid consumption and urine output during the race. Prerace and postrace weights were recorded. Multivariate regression analyses were performed to identify risk factors associated with hyponatremia. RESULTS: Of 766 runners enrolled, 488 runners (64 percent) provided a usable blood sample at the finish line. Thirteen percent had hyponatremia (a serum sodium concentration of 135 mmol per liter or less); 0.6 percent had critical hyponatremia (120 mmol per liter or less). On univariate analyses, hyponatremia was associated with substantial weight gain, consumption of more than 3 liters of fluids during the race, consumption of fluids every mile, a racing time of >4:00 hours, female sex, and low body-mass index. On multivariate analysis, hyponatremia was associated with weight gain (odds ratio, 4.2; 95 percent confidence interval, 2.2 to 8.2), a racing time of >4:00 hours (odds ratio for the comparison with a time of <3:30 hours, 7.4; 95 percent confidence interval, 2.9 to 23.1), and body-mass-index extremes. CONCLUSIONS: Hyponatremia occurs in a substantial fraction of nonelite marathon runners and can be severe. Considerable weight gain while running, a long racing time, and body-mass-index extremes were associated with hyponatremia, whereas female sex, composition of fluids ingested, and use of nonsteroidal antiinflammatory drugs were not.

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  • Exercise-associated hyponatremia can be a result of solute (primarily sodium) loss and/or excess fluid load.

    “This can be a result of solute (primarily sodium) loss and/or excess fluid load [275].”

    From International society of sports nutrition position stand: nutritional concerns of the female athlete (2023) · cites this paper as [275]

  • Sex hormone effects on body fluid and sodium regulation have important implications for several syndromes that affect women, including orthostatic hypotension, insulin resistance, polycystic ovary syndrome, and neurological consequences of postoperative and exercise-associated hyponatremia.

    “Moreover, the impact of sex hormones on body fluid and sodium regulation has important implications for a number of syndromes for which women are at risk, including orthostatic hypotension, insulin resistance, polycystic ovary syndrome, and neurological consequences from postoperative (8) and exercise-associated hyponatremia (1).”

    From Sex Hormone Effects on Body Fluid Regulation (2008) · cites this paper as [1]

  • Recreational competitors may drink in volumes exceeding their sweat rates.

    “A personalized drinking plan can be adjusted to all levels of runners, including recreational competitors who may drink in volumes exceeding their sweat rates and who should be warned about the dangers of developing hyponatremia (Almond et al., 2005).”

    From Contemporary Nutrition Strategies to Optimize Performance in Distance Runners and Race Walkers (2019) · cites this paper as Almond et al., 2005

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Authors
Almond, C. S. D., Shin, A. Y., Fortescue, E. B., Mannix, R. C., Wypij, D., Binstadt, B. A., Duncan, C. N., Olson, D. P., Salerno, A. E., Newburger, J. W., & Greenes, D. S.
Affiliations
  • Boston Children's Hospital (US)
  • Harvard University (US)
ORCID
Venue
New England Journal of Medicine
Publisher
Massachusetts Medical Society
Published
2005-04-14
Volume
352
Issue
15
Pages
1550-1556
ISSN
  • 0028-4793 (ISSN-L)
  • 1533-4406
DOI
10.1056/nejmoa043901
OpenAlex
W2020799520
Cited by
553
References
23
Citations by year
2026: 8 · 2025: 7 · 2024: 13 · 2023: 13 · 2022: 15 · 2021: 20 · 2020: 17 · 2019: 29 · 2018: 20 · 2017: 18 · 2016: 29 · 2015: 30 · 2014: 38 · 2013: 27 · 2012: 42
FWCI
34.28
Type
journal article
Language
en
Open access
Locations
  • New England Journal of Medicine (publishedVersion)
  • PubMed (publishedVersion)
Funders
National Center for Research Resources (M01RR002172, RR02172)
Topics
  • Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Electrolyte and hormonal disorders
  • Health Sciences › Medicine › Physiology › Thermoregulation and physiological responses
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiovascular Effects of Exercise
Keywords
hyponatremia, marathon runners, Boston Marathon, fluid intake, body mass index, race time, risk factors, nonsteroidal anti-inflammatory drugs, female sex
MeSH terms
Analysis of Variance, Beverages, Drinking, Female, Humans, Hyponatremia, Male, Risk Factors, Running, Sex Factors, Sodium, Time Factors, Urine, Water, Cohort Studies, Weight Gain, Body Mass Index, Logistic Models

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