Is the Prevalence of Exercise-Associated Hyponatremia Higher in Female than in Male 100-KM Ultra-Marathoners?
Purpose. The prevalence of exercise-associated hyponatremia (EAH) has mainly been investigated in male endurance athletes. The aim of the present study was to investigate the prevalence of EAH in female 100-km ultra-marathoners and to compare them to male ultra-runners since females are considered more at risk of EAH. Methods. Changes in body mass, hematocrit, [Na+] and [K+] levels in both plasma and urine, plasma volume, urine specific gravity, and the intake of energy, fluids and electrolytes was determined in 24 male and 19 female 100-km ultra-marathoners. Results. Three male (11%) and one female (5%) ultra-marathoners developed asymptomatic EAH. Body mass decreased, while plasma [Na+], plasma [K+] and hematocrit remained stable in either gender. Plasma volume, urine specific gravity and the potassium-to-sodium ratio in urine increased in either gender. In males, fluid intake was related to running speed (r = 0.50, p = 0.0081), but not to the change in body mass, in post-race plasma [Na+], in the change in hematocrit and in the change in plasma volume. Also in males, the change in hematocrit was related to both the change in plasma [Na+] (r = 0.45, p = 0.0187) and the change in the potassium-to-sodium ratio in urine (r = 0.39, p = 0.044). Sodium intake was neither related to post-race plasma [Na+] nor to the change in plasma volume. Conclusions. The prevalence of EAH was not higher in female compared to male 100-km ultra-marathoners. Plasma volume and plasma [Na+] were maintained and not related to fluid intake, most probably due to an activation of the reninangiotensin-aldosterone-system.
Noakes T. D., Goodwin N., Rayner B. L., Branken T., Taylor R. K., Water intoxication: a possible complication during endurance exercise. Med Sci Sports Exerc, 1985, 17 (3), 370-375.
Almond C. S., Shin A. Y., Fortescue E. B., Mannix R. C., Wypij D., Binstadt B. A. et al., Hyponatremia among runners in the Boston Marathon. N Engl J Med, 2005, 352 (15), 1550-1556.
Chorley J., Cianca J., Divine J., Risk factors for exercise-associated hyponatremia in non-elite marathon-runners. Clin J Sport Med, 2007, 17 (6), 471-477, doi: 10.1097/JSM.0b013e3181588790.
Hew T. D., Chorley J. N., Cianca J. C., Divine J. G., The incidence, risk factors and clinical manifestations of hyponatremia in marathon runners. Clin J Sport Med, 2003, 13 (1), 41-47.
Kipps C., Sharma S., Tunstall-Pedoe D. S., The incidence of exercise-associated hyponatremia in the London Marathon. Br J Sports Med, 2011, 45, 14-19, doi: 10.1136/bjsm.2009.059535.
Mettler S., Rusch C., Frey W. O., Bestmann L., Wenk C., Colombani P. C., Hyponatremia among runners in the Zurich Marathon. Clin J Sport Med, 2008, 18 (4), 344-349, doi: 10.1097/JSM.0b013e31817e3515.
Davis D. P., Videen J. S., Marino A., Vilke G. M., Dunford J. V., Van Camp S. P. et al., Exercise-associated hyponatremia in marathon runners: A two-year experience. J Emerg Med, 2001, 21, 47-57.
Goudie A. M., Tunstall-Pedoe D. S., Kerins M., Terris J., Exercise-associated hyponatraemia after a marathon: case series. J R Soc Med, 2006, 99 (7), 363-367, doi: 10.1258/jrsm.99.7.363.
Fallon K. E., Sivyer G., Sivyer K., Dare A., The biochemistry of runners in a 1600 km ultramarathon. Br J Sports Med, 1999, 33, 264-269, doi: 10.1136/bjsm.33.4.264.
Page A. J., Reid S. A., Speedy D. B., Mulligan G. P., Thompson J., Exercise-associated hyponatremia, renal function, and nonsteroidal anti-inflammatory drug use in an ultra-endurance mountain run. Clin J Sport Med, 2007, 17 (1), 43-48, doi: 10.1097/JSM.0b013e31802b5be9.
Reid S. A., King M. J., Serum biochemistry and morbidity among runners presenting for medical care after an Australian mountain ultramarathon. Clin J Sport Med, 2007, 17 (4), 307-310, doi: 10.1097/JSM.0b013e31804c77da.
Stuempfle K. J., Lehmann D. R., Case H. S., Hughes S. L., Evans D., Change in serum sodium concentration during a cold weather ultradistance race. Clin J Sport Med, 2003, 13 (3), 171-175.
Noakes T. D., 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 USA, 2005, 102 (51), 18550-18555, doi: 10.1073/pnas.0509096102.
Kao W. F., Shyu C. L., Yang X. W., Hsu T. F., Chen J. J., Kao W. C. et al., Athletic performance and serial weight changes during 12- and 24-hour ultra-marathons. Clin J Sport Med, 2008, 18 (2), 155-158, doi: 10.1097/JSM.0b013e31815cdd37.
Kavouras S. A., Assessing hydration status. Curr Opin Clin Nutr Metab Care, 2002, 5 (5), 519-524.
Shireffs S. M., Markers of hydration status. Eur J Clin Nutr, 2003, 57 (suppl. 2), S6-S9, doi: 10.1038/sj.ejcn.1601895.
Speedy D. B., Faris J. G., Hamlin M., Gallagher P. G., Campbell R. G., Hyponatremia and weight changes in an ultradistance triathlon. Clin J Sport Med, 1997, 7 (3), 180-184.
Speedy D. B., Noakes T. D., Kimber N. E., Rogers I. R., Thompson J. M., Boswell D. R. et al., Fluid balance during and after an Ironman triathlon. Clin J Sport Med, 2001, 11 (1), 44-50.
Hew-Butler T., Ayus J. C., Kipps C., Maughan R. J., Mettler S., Meeuwisse W. H. et al., Statement of the Second International Exercise-Associated Hyponatremia Consensus Development Conference, New Zealand, 2007. Clin J Sport Med, 2008, 18 (2), 111-121, doi: 10.1097/JSM.0b013e318168ff31.
Glace B. W., Murphy C. A., McHugh M. P., Food intake and electrolyte status of ultramarathoners competing in extreme heat. J Am Coll Nutr, 2002, 21 (6), 553-559.
Knechtle B., Duff B., Schulze I., Rosemann T., Senn O., Anthropometry and pre-race experience of finishers and non-finishers in a multistage ultra-endurance run - Deutschlandlauf 2007. Percept Mot Skills, 2009, 109 (1), 105-118, doi: 10.2466/pms.109.1.105-118.
Beaumont van W., Evaluation of hemoconcentration from hematocrit measurements. J Appl Physiol, 1972, 32 (5), 712-713.
Kirchhoff E., Online-Publication of the German Food Composition Table ‘Souci-Fachmann-Kraut’ on the Internet. J Food Comp Anal, 2002, 15, 465-472, doi: 10.1006/jfca.2002.1091.
Williams M. H., Nutrition for Fitness and Sport. 4th ed. Brown & Benchmark Publishers, USA, 1995.
Knechtle B., Wirth A., Knechtle P., Rosemann T., Training volume and personal best time in marathon, not anthropometric parameters, are associated with performance in male 100-km ultrarunners. J Strength Cond Res, 2010, 24 (3), 604-609, doi: 10.1519/JSC.0b013e3181c7b406.
Knechtle B., Knechtle P., Rosemann T., Senn O., What is associated with race performance in male 100 km ultramarathoners: Anthropometry, training or marathon best time. J Sports Sci, 2011, 29 (6), 571-577, doi: 10.1080/02640414.2010.541272.
Knechtle B., Knechtle P., Rosemann T., Lepers R., Predictor variables for a 100-km race time in male ultra-marathoners. Percept Mot Skills, 2010, 111 (3), 681-693, doi: 10.2466/05.25.PMS.111.6.681-693.
Gisolfi C. V., Duchman S. M., Guidelines for optimal replacement beverages for different athletic events. Med Sci Sports Exerc, 1992, 24 (6), 679-687.
Noakes T., Fluid replacement during marathon running. Clin J Sport Med, 2003, 13 (5), 309-318.
Casa D., Proper hydration for distance running: identifying individual fluid needs. Track Coach, 2004, 5321-5328.
Armstrong L. E., Casa D. J., Millard-Stafford M., Moran D. S., Pyne S. W., Roberts W. O., American College of Sports Medicine Position Stand. Exertional heat illness during training and competition. Med Sci Sports Exerc, 2007, 39(3), 556-572, doi: 10.1249/MSS.0b013e31802fa199.
Sawka M. N., Burke L. M., Eichner E. R., Maughan R. J., Montain S. J., Stachenfeld N. S., American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc, 2007, 39 (2), 377-390, doi: 10.1249/mss.0b013e31802ca597.
Fellmann N., Ritz P., Ribeyre J., Beaufrère B., Delaître M., Coudert J., Intracellular hyperhydration induced by a 7-day endurance race. Eur J Appl Physiol, 1999, 80 (4), 353-359, doi: 10.1007/s004210050603.
Freund B. J., Shizuru E. M., Hashiro G. M., Claybaugh J. R., Hormonal, electrolyte, and renal responses to exercise are intensity dependent. J Appl Physiol, 1991, 70 (2), 900-906.
Wade C. E., Dressendorfer R. H., O'Brien J. C., Claybaugh J. R., Renal function, aldosterone, and vasopressin excretion following repeated long-distance running. J Appl Physiol, 1981, 50 (4), 709-712.
Bürge J., Knechtle B., Knechtle P., Gnädinger M., Rüst A. C., Rosemann T., Maintained serum sodium in male ultra-marathoners - the role of fluid intake, vasopressin, and aldosterone in fluid and electrolyte regulation. Horm Metab Res, 2011, 43 (9), 646-652, doi: 10.1055/s-0031-1284352.