You can never have too much of a good thing- said no one ever. You may have heard about the countless benefits of water and how hydrating adequately can help you achieve improved skin, digestion, mood, and so on and so forth. I’m here not to discredit the scientific research done to validate its health benefits nor the legitimate dangers of dehydration. Rather, I am here to tell you a bit about what mainstream media isn’t covering and what my professors at the University of Toronto want YOU to hear about- overhydration.
“Every year, more athletes are injured by hyponatremia [i.e. overhydration] than dehydration” (Dreyfuss, 2015).
In 1996 the American College of Sports Medicine released a statement, “during exercise, athletes should start drinking early and at regular intervals in attempt to consume fluids at a rate sufficient to replace all the water lost through sweating (i.e. body weight loss), or consume the maximal amount that can be tolerated” (Convertino VA et al., 1996). Now let me be clear that drinking the maximal amount of water possible is not the thing same as drinking to thirst as many of us do on a hot summer day. Our kidneys are only able to generate 1L of urine per hour so, if the kidneys are overrun with an abundance of fluid and not able to “pee it out” what kind of effect would that have on the body? Well, not a good one. The fluid around your cells needs sodium (good old salt) and if you continue to overhydrate the amount of sodium surrounding your cells becomes lower and lower. Yes, just like a watered down drink. When there isn’t enough sodium surrounding your body’s cells, water begins to move INTO them which causes a list of dangerous symptoms including:
· Fatigue
· Lethargy
· Disorientation
· Confusion
· Headache
· Nausea
· Vomiting
· Cerebral edema
· Encephalopathy
· Seizures
· Noncardiogenic pulmonary edema
· In extreme cases, coma and death
Which essentially means, too much water IS a bad thing. If your blood sodium level reaches below 135 mmol/L you can be clinically diagnosed with EAH exercise associated hyponatremia or EIH exercise induced hyponatremia. Which are both fancy words for excessive water intake to the body or overhydration. Now you may be wondering, am I at risk? How can I avoid hyponatremia? Well, hyponatremia mainly occurs in athletes who participate in endurance events such as marathons, triathlons, and long distance racing. Others say it is most common in women who compete at a slow, sustained pace. In fact during the 2002 Boston Marathon one study found that 13% of the runners they sampled had hyponatremia and studies of other endurance events have seen this rate go up to 29%. Some articles even claim that hyponatremia is one of the most common medical complications of long-distance racing but few members of the public even know it exists.
“The single most important risk factor is sustained, excessive fluid (water, sport drink, or other hypotonic fluids) intake in volumes greater than loss through sweat, respiratory, and renal water excretion so that a positive fluid balance accrues over time” (Hew-Butler T et al., 2015).
The dangers of water intoxication are well known amongst sports physicians but EAH doesn’t always present with symptoms right away. Actually, most athletes are asymptomatic (present with no symptoms whatsoever) so when it is detected there may be severe consequences i.e. seizures. This would require a rapid IV infusion of concentration saline solution (salt water) to move water out of your brain cells, and in severe cases, it may cause irreversible brain damage.
Without a doubt, awareness surrounding hyponatremia has gained traction within the sports medicine community but its recognition must supersede beyond this. Sports drink companies and wellness magazines, to name a few, are still proposing outdated ideas that stress the need for all athletes to drink as much as they can to prevent dehydration. Though, in actuality, every year more athletes are injured by overhydration than dehydration. Publicizing this reality whilst stressing the need for judicious fluid intake during exercise is our first step in the right direction as well as our first step towards hydrating adequately.
References:
Convertino VA et al. American College of Sports Medicine position stand. Exercise and fluid replacement. 1996
Dreyfuss, J. H. (2015, April 14). Every Year, More Athletes Are Injured By Hyponatremia than Dehydration. Retrieved August 20, 2020, from https://www.mdalert.com/article/every- year-more-athletes-are-injured-by-hyponatremia-than-dehydration
Hew-Butler T et al. Statement of the 3rd International Exercise-Associated Hyponatremia Consensus Development Conference. Br J Sports Med 2015;49:1432–1446
Rosner, M. H., & Kirven, J. (2006). Exercise-Associated Hyponatremia. Clinical Journal of the American Society of Nephrology, 2(1), 151-161. doi:10.2215/cjn.02730806
Whitfield A. H. (2006). Too much of a good thing? The danger of water intoxication in endurance sports. The British journal of general practice : the journal of the Royal College of General Practitioners, 56(528), 542–545.
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