Exercise-associated hyponatremia

Exercise-associated hyponatremia is a potentially fatal metabolic condition occurring up to 24 hours after prolonged exertion.[1] It has been observed increasingly since 1981 (Ibid) at endurance athletic events (like marathons and triathlons)[2] and in expedition and wilderness settings.[3] There is at least one report of the condition arising following a strenuous but routine workout.[4] At least 12 athletes or soldiers have died from exercise-associated hyponatremic encephalopathy, caused when low blood sodium levels draw excess fluid into the brain, making the brain cells swell.[5]

Mechanism and prevalence

The American College of Sports Medicine states that "Overdrinking hypotonic fluid is the mechanism that leads to exercise-associated hyponatremia ..."[6] A study conducted by the Massachusetts Medical Society on participants of the 2002 Boston Marathon found that thirteen percent finished the race with hyponatremia. The study concluded that the strongest predictor of hyponatremia was weight gain while racing, and that hyponatremia was just as likely to occur in runners who chose sports drinks as those who chose water.[7]

References

  1. ↑ Rosner, Mitchell H.; Justin Kirven (January 2007). "Exercise-Associated Hyponatremia". CJASN 2 (1): 151–161.
  2. ↑ Williams, Jonathan (April 2012). "Exercise associated hyponatremia: Drinking oneself to death". Guest blog. Clinical Journal of Sport Medicine. Retrieved 6 January 2014.
  3. ↑ http://www.expeditionmedicine.co.uk/index.php/advice/resource/r-0022.html
  4. ↑ Schucany, William G. (October 2007). "Exercise-associated hyponatremia" (Journal). Proc (Bayl Univ Med Cent). pp. 398–401. Retrieved 6 January 2014.
  5. ↑ Noakes, MD, DSc, Tim (May 1, 2012). Waterlogged. Human Kinetics. p. 109. ISBN 145042497X.
  6. ↑ Lupash, Emily, ed. (2014). ACSM’s Guidelines for Exercise Testing and Prescription. American College of Sports Medicine. p. 218.
  7. ↑ Almond CS, Shin AY, Fortescue EB, et al. (April 2005). "Hyponatremia among runners in the Boston Marathon". N. Engl. J. Med. 352 (15): 1550–6. doi:10.1056/NEJMoa043901. PMID 15829535.