Exercise-associated hyponatremia and hydration status in 161-km ultramarathoners
Abstract
PURPOSE: This work combines and reanalyzes 5 yr of exercise-associated hyponatremia (EAH) research at 161-km ultramarathons in northern California with primary purposes to define the relationship between postrace blood sodium concentration ([Na]) and change in body weight; to examine the interactions among EAH incidence, ambient temperature, and hydration state; and to explore the effect of hydration status on performance. METHODS: Prerace and postrace body weight and finish time data were obtained on 887 finishers, and postrace [Na] was also obtained on a subset of 669 finishers. RESULTS: EAH incidence was 15.1% overall (range, 4.6%-51.0% by year) and had a significant positive relationship with ambient temperature. Of the runners with EAH, 23.8% were classified as overhydrated (weight change, ≥0), 40.6% were euhydrated (weight change, <0% to -3%), and 35.6% were dehydrated (weight change, <-3%) at the finish. There was a weak significant relationship (r = 0.17, P < 0.0001) between postrace [Na] and change in body weight such that a lower [Na] was more common with increased weight loss. Considering all finishers examined, 18.5% were dehydrated and 34.9% were overhydrated at the finish. There was a weak significant relationship (r = 0.092, P = 0.006) between change in body weight and performance in that faster runners tended to lose more weight. Top finishers varied in body weight change from ∼1% gain to ∼6% loss. CONCLUSIONS: EAH incidence can be high in 161-km ultramarathons in northern California. In this environment, EAH is more common with dehydration than overhydration and is more common in hotter ambient temperature conditions. Because weight loss >3% does not seem to have an adverse effect on performance, excessive sodium supplementation and aggressive fluid ingestion beyond the dictates of thirst are ill advised.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
EAH can be related to the environmental conditions that occur at the time of the competition, since at high temperature or humidity a greater loss of sodium can occur in sweat.
“According to the results considered in this review, EAH can be also related to the environmental conditions that occur at the time of the competition, since at high temperature or humidity a greater loss of sodium can occur, in sweat [31].”
From Nutrition-Related Adverse Outcomes in Endurance Sports Competitions: A Review of Incidence and Practical Recommendations (2020) · cites this paper as [31]
Cites
1 retracted
Women Hydrate More Than Men During a Marathon Race
Hew, T. D. (2005) · Clinical Journal of Sport Medicine · doi:10.1097/01.jsm.0000157652.47572.56 · Cited by 45 · see citing works
RetractedHyponatremia among runners in the Boston Marathon.
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., et al. (2005) · New England Journal of Medicine · doi:10.1056/nejmoa043901 · Cited by 553 · see citing works
Noakes, T. D., Sharwood, K. A., Speedy, D. B., Hew, T. D., Reid, S., Dugas, J. P., Almond, C. S. D., WHARAM, P. C., & Weschler, L. B. (2005) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0509096102 · Cited by 330 · see citing works
Hyponatremia and Inflammation: The Emerging Role of Interleukin-6 in Osmoregulation
Swart, R. M., Hoorn, E. J., Betjes, M. G. H., & Zietse, R. (2010) · Nephron Physiology · doi:10.1159/000322238 · Cited by 244 · see citing works
Hew‐Butler, T., Ayus, J. C., Kipps, C., Maughan, R. J., Mettler, S., Meeuwisse, W. H., Page, A., Reid, S. A., Rehrer, N. J., Roberts, W. O., et al. (2008) · Clinical Journal of Sport Medicine · doi:10.1097/jsm.0b013e318168ff31 · Cited by 223 · see citing works
Self-citationNoakes, T. D., GOODWIN, N., RAYNER, B. L., BRANKEN, T., & Taylor, R. K. N. (1985) · Medicine & Science in Sports & Exercise · doi:10.1249/00005768-198506000-00012 · Cited by 197 · see citing works
Weight changes, medical complications, and performance during an Ironman triathlon
Sharwood, K. A., Collins, M., Goedecke, J. H., Wilson, G., & Noakes, T. D. (2004) · British Journal of Sports Medicine · doi:10.1136/bjsm.2003.007187 · Cited by 179 · see citing works
NSAID Use Increases the Risk of Developing Hyponatremia during an Ironman Triathlon
WHARAM, P. C., Speedy, D. B., Noakes, T. D., Thompson, J., REID, S. A., & Holtzhausen, L. (2006) · Medicine & Science in Sports & Exercise · doi:10.1249/01.mss.0000210209.40694.09 · Cited by 153 · see citing works
Weight Changes, Sodium Levels, and Performance in the South African Ironman Triathlon
Sharwood, K. A., Collins, M., Goedecke, J. H., Wilson, G., & Noakes, T. D. (2002) · Clinical Journal of Sport Medicine · doi:10.1097/00042752-200211000-00012 · Cited by 131 · see citing works
Food Intake and Electrolyte Status of Ultramarathoners Competing in Extreme Heat
Glace, B. W., Murphy, C. A., & McHugh, M. P. (2002) · Journal of the American College of Nutrition · doi:10.1080/07315724.2002.10719254 · Cited by 97 · see citing works
Increasing Creatine Kinase Concentrations at the 161-km Western States Endurance Run
Hoffman, M. D., Ingwerson, J. L., Rogers, I. R., Hew‐Butler, T., & Stuempfle, K. J. (2012) · Wilderness and Environmental Medicine · doi:10.1016/j.wem.2011.11.001 · Cited by 94 · see citing works
Self-citationHyponatremia and Weight Changes in an Ultradistance Triathlon
Speedy, D. B., Faris, J. G., Hamlin, M., Gallagher, P. G., & Campbell, R. G. (1997) · Clinical Journal of Sport Medicine · doi:10.1097/00042752-199707000-00005 · Cited by 93 · see citing works
Hew‐Butler, T., Sharwood, K. A., Collins, M., Speedy, D. B., & Noakes, T. D. (2006) · British Journal of Sports Medicine · doi:10.1136/bjsm.2005.022418 · Cited by 93 · see citing works
Self-citationRace Diet of Finishers and Non-Finishers in a 100 Mile (161 km) Mountain Footrace
Stuempfle, K. J., Hoffman, M. D., Weschler, L. B., Rogers, I. R., & Hew-Butler, T. (2011) · Journal of the American College of Nutrition · doi:10.1080/07315724.2011.10719999 · Cited by 86 · see citing works
Self-citationBruso, J. R., Hoffman, M. D., Rogers, I. R., Lee, L., Towle, G., & Hew-Butler, T. (2010) · Wilderness & Environmental Medicine · doi:10.1016/j.wem.2010.06.012 · Cited by 82 · see citing works
Self-citationInfluence of Temperature and Performance Level on Pacing a 161 km Trail Ultramarathon
Parise, C. A., & Hoffman, M. D. (2011) · International Journal of Sports Physiology and Performance · doi:10.1123/ijspp.6.2.243 · Cited by 73 · see citing works
Self-citationEvaluation of i-STAT portable clinical analyzer in a neonatal and pediatric intensive care unit
Murthy, J. N., Hicks, J. M., & Soldin, S. J. (1997) · Clinical Biochemistry · doi:10.1016/s0009-9120(97)00046-5 · Cited by 67 · see citing works
Hyponatremia in the 2009 161-km Western States Endurance Run
Hoffman, M. D., Stuempfle, K. J., Rogers, I. R., Weschler, L. B., & Hew-Butler, T. (2012) · International Journal of Sports Physiology and Performance · doi:10.1123/ijspp.7.1.6 · Cited by 67 · see citing works
Self-citationHoffman, M. D., Stuempfle, K. J., Fogard, K., Hew‐Butler, T., Winger, J. M., & Weiss, R. H. (2012) · Journal of Sports Sciences · doi:10.1080/02640414.2012.720705 · Cited by 60 · see citing works
Self-citationBürge, J., Knechtle, B., Knechtle, P., Gnädinger, M. P., Rüst, A., & Rosemann, T. J. (2011) · Hormone and Metabolic Research · doi:10.1055/s-0031-1284352 · Cited by 48 · see citing works
Biochemical parameters in athletes before and after having run 160 kilometres.
Noakes, T. D., & Jw, C. (1976) · PubMed · Cited by 43 · see citing works
Knechtle, B., Knechtle, P., & Rosemann, T. J. (2010) · The Physician and Sportsmedicine · doi:10.3810/psm.2010.12.1831 · Cited by 30 · see citing works
Rüst, C. A., Knechtle, B., Knechtle, P., & Rosemann, T. J. (2011) · European Journal of Applied Physiology · doi:10.1007/s00421-011-2024-y · Cited by 29 · see citing works
Hyponatremia is Associated With Higher NT-proBNP Than Normonatremia After Prolonged Exercise
Harris, G., Reid, S., Sikaris, K. A., & McCrory, P. R. (2012) · Clinical Journal of Sport Medicine · doi:10.1097/jsm.0b013e3182580ce8 · Cited by 23 · see citing works
Flagged first, then by citations
Cited by
Sorted by citations
Hew-Butler, T., Rosner, M. H., Fowkes-Godek, S., Dugas, J. P., Hoffman, M. D., Lewis, D. P., Maughan, R. J., Miller, K. C., Montain, S. J., Rehrer, N. J., et al. (2015) · Clinical Journal of Sport Medicine · doi:10.1097/jsm.0000000000000221 · Cited by 205 · see citing works
Self-citationDrinking Strategies: Planned Drinking Versus Drinking to Thirst
Kenefick, R. W. (2018) · Sports Medicine · doi:10.1007/s40279-017-0844-6 · Cited by 142 · see citing works
Costa, R. J. S., Gill, S. K., Hankey, J., Wright, A., & Marczak, S. (2014) · British Journal of Nutrition · doi:10.1017/s0007114514000907 · Cited by 99 · see citing works
Nutritional implications for ultra-endurance walking and running events
Williamson, E. (2016) · Extreme Physiology & Medicine · doi:10.1186/s13728-016-0054-0 · Cited by 53 · see citing works
“Common GI challenges that hinder intake include nausea, abdominal cramping, bloating, diarrhea, vomiting, flatulence, and belching [26, 36].”
BackgroundNausea is associated with endotoxemia during a 161-km ultramarathon
Stuempfle, K. J., Valentino, T., Hew-Butler, T., Hecht, F. M., & Hoffman, M. D. (2016) · Journal of Sports Sciences · doi:10.1080/02640414.2015.1130238 · Cited by 41 · see citing works
Self-citationCairns, R. S., & Hew-Butler, T. (2015) · Clinical Journal of Sport Medicine · doi:10.1097/jsm.0000000000000144 · Cited by 37 · see citing works
Self-citationWinger, J. M., Hoffman, M. D., Hew-Butler, T. D., Stuempfle, K. J., Dugas, J. P., Fogard, K., & Dugas, L. R. (2013) · International Journal of Sports Physiology and Performance · doi:10.1123/ijspp.8.5.536 · Cited by 36 · see citing works
Self-citationMartínez-Sanz, J. M., Fernández Nuñez, A., Sospedra, I., Martínez-Rodríguez, A., Domínguez, R., González-Jurado, J. A., & Sánchez-Oliver, A. J. (2020) · International Journal of Environmental Research and Public Health · doi:10.3390/ijerph17114082 · Cited by 25 · see citing works
Exercise-Associated Hyponatremia
Rosner, M. H., Bennett, B., Hew-Butler, T., & Hoffman, M. D. (2013) · Hyponatremia · doi:10.1007/978-1-4614-6645-1_10 · Cited by 15 · see citing works
Self-citationManagement of suspected fluid balance issues in participants of wilderness endurance events
Hoffman, M. D., Joslin, J., & Rogers, I. R. (2017) · Current Sports Medicine Reports · doi:10.1249/jsr.0000000000000344 · Cited by 14 · see citing works
Top 10 research questions related to preventing sudden death in sport and physical activity
Katch, R. K., Scarneo, S. E., Adams, W. M., Armstrong, L. E., Belval, L. N., Stamm, J. M., & Casa, D. J. (2017) · Research Quarterly for Exercise and Sport · doi:10.1080/02701367.2017.1342201 · Cited by 11 · see citing works
- Authors
- HOFFMAN, M. D., HEW-BUTLER, T., & STUEMPFLE, K. J.
- Affiliations
- VA Northern California Health Care System (US)
- Gettysburg College (US)
- ORCID
- HOFFMAN, MARTIN D.
- Venue
- Medicine & Science in Sports & Exercise
- Published
- 2013-04
- Volume
- 45
- Issue
- 4
- Pages
- 784-791
- ISSN
- 0195-9131 (ISSN-L)
- OpenAlex
- W1963797202
- Cited by
- 111
- References
- 24
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 1 · 2023: 1 · 2022: 4 · 2021: 9 · 2020: 11 · 2019: 9 · 2018: 12 · 2017: 8 · 2016: 11 · 2015: 15 · 2014: 17 · 2013: 9
- FWCI
- 12.04
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Medicine & Science in Sports & Exercise (publishedVersion)
- PubMed (publishedVersion)
- The Cupola: Scholarship at Gettysburg College (Gettysburg College) (submittedVersion)
- Topics
- Health Sciences › Medicine › Physiology › Thermoregulation and physiological responses
- Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Electrolyte and hormonal disorders
- Health Sciences › Medicine › Rehabilitation › Exercise and Physiological Responses
- Keywords
- exercise-associated hyponatremia, ultramarathon, hydration status, weight change, ambient temperature, dehydration, fluid overload, running performance, sodium supplementation, fluid intake
- MeSH terms
- Body Water, California, Dehydration, Humans, Hyponatremia, Physical Endurance, Running, Temperature, Time Factors, Water-Electrolyte Imbalance, Weight Loss
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
