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I read this article on a triathalon training site. I thought you guys may enjoy it. Especially those who spend lots on those nifty sports waters that are coming out these days. --TT
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Iam writing in response to an article recently published in the Toronto Star regarding hyponatremia and overhydration in runners. For those who have not read the article, the content suggests that overhydration is a common problem in distance runners and the resultant relative sodium depletion can cause serious consequences including death! The article also suggests that heart attacks occurring in runners are really not heart attacks but hyponatremia episodes.
Over the years, I have treated over 5,000 running injuries (I believe that’s the largest number of running injuries by any individual physician in Canada) and have only seen one documented case of hyponatremia, but have seen many cases of problems related to dehydration and also related to heart
difficulties. In the one instance of hyponatremia, the athlete drank huge amounts of water for at least three days prior to running the marathon and then drank a litre of water almost every mile throughout the marathon. Shortly after the marathon, he became dizzy, then very nauseated, vomited, and finally, he convulsed. He was treated in hospital correctly because appropriate tests revealed the resultant electrolyte (sodium, potassium, and chlorides) imbalance.
Hyponatremia is, in both my experience with Canadian class elite athletes as well as amateur athletes, and in the studies I have read, extremely uncommon. I am certain that athletes are in much greater danger if they try to avoid overhydration rather than dehydration. In the twenty years I have dealt with endurance athletes, I have counseled the use of water as the
ideal fluid for rehydration. Our average diet provides all the salt
replenishment athletes need. Cold water at refrigerator temperature is the ideal rehydrating beverage for the perspiring athlete.
The following is a direct quote from a chapter in the textbook Sports Medicine by Richard Strauss, M.D. The chapter is written by Nathan Smith, M.D.: “Perspiring athletes are keenly aware that salt and other electrolytes are lost along with the water of sweat. The athlete is a vulnerable target for the commercial promotion of a variety of salt and electrolyte mixtures
as tablets, powders, ‘athletic drinks,’ and even special foods that are alleged to be needed to replenish the electrolyte and nutrient losses in sweat. Such products are useless for the healthy, well-nourished athlete and will only contribute to further increasing the concentration of electrolytes in the extracellular fluid of the dehydrated athlete. The unique taste and the satiety-producing effect of many of these mixtures and beverages may actually discourage much needed water intakes. Athletes should know that sweat is a VERY HYPOTONIC body fluid, and in the well–conditioned and acclimatized athlete, sweat is particularly dilute. The sweat of athletes contains much more water than electrolytes in contrast to other body fluids..
A diet sufficient in amount to meet the energy needs of the active athlete will provide an abundant replacement of all the nutrient substances lost in the sweat of the most vigorously exercising athlete. Sodium, chloride, and potassium losses have been measured in the sweat of ten distance runners performing in very warm weather. They ran a sufficient distance to lose 3 per cent of their body weight as body water each day for 5 consecutive days..
The electrolytes were measured in their self–selected ad libitum diets. There was a markedly positive balance of each of the three electrolytes measured. Under these study circumstances, there was an abundance of sodium, potassium, and chloride in the typical American diet to replace all sweat losses. A generous diet and normal functioning kidneys will ensure that all
of the needs for electrolyte replacement are being met even in the most vigorously exercising athletes. Salt mixtures and salt tablets particularly, are not to be used. In the hands of the uninformed or credulous athlete, salt intakes may be dangerous.”
This well–documented and respected text expresses my beliefs as well. I feel the article in the Toronto Star might create much more harm than good if followed by endurance athletes.
Harvey H. Sternberg, M.D.
_____________________________________________
Iam writing in response to an article recently published in the Toronto Star regarding hyponatremia and overhydration in runners. For those who have not read the article, the content suggests that overhydration is a common problem in distance runners and the resultant relative sodium depletion can cause serious consequences including death! The article also suggests that heart attacks occurring in runners are really not heart attacks but hyponatremia episodes.
Over the years, I have treated over 5,000 running injuries (I believe that’s the largest number of running injuries by any individual physician in Canada) and have only seen one documented case of hyponatremia, but have seen many cases of problems related to dehydration and also related to heart
difficulties. In the one instance of hyponatremia, the athlete drank huge amounts of water for at least three days prior to running the marathon and then drank a litre of water almost every mile throughout the marathon. Shortly after the marathon, he became dizzy, then very nauseated, vomited, and finally, he convulsed. He was treated in hospital correctly because appropriate tests revealed the resultant electrolyte (sodium, potassium, and chlorides) imbalance.
Hyponatremia is, in both my experience with Canadian class elite athletes as well as amateur athletes, and in the studies I have read, extremely uncommon. I am certain that athletes are in much greater danger if they try to avoid overhydration rather than dehydration. In the twenty years I have dealt with endurance athletes, I have counseled the use of water as the
ideal fluid for rehydration. Our average diet provides all the salt
replenishment athletes need. Cold water at refrigerator temperature is the ideal rehydrating beverage for the perspiring athlete.
The following is a direct quote from a chapter in the textbook Sports Medicine by Richard Strauss, M.D. The chapter is written by Nathan Smith, M.D.: “Perspiring athletes are keenly aware that salt and other electrolytes are lost along with the water of sweat. The athlete is a vulnerable target for the commercial promotion of a variety of salt and electrolyte mixtures
as tablets, powders, ‘athletic drinks,’ and even special foods that are alleged to be needed to replenish the electrolyte and nutrient losses in sweat. Such products are useless for the healthy, well-nourished athlete and will only contribute to further increasing the concentration of electrolytes in the extracellular fluid of the dehydrated athlete. The unique taste and the satiety-producing effect of many of these mixtures and beverages may actually discourage much needed water intakes. Athletes should know that sweat is a VERY HYPOTONIC body fluid, and in the well–conditioned and acclimatized athlete, sweat is particularly dilute. The sweat of athletes contains much more water than electrolytes in contrast to other body fluids..
A diet sufficient in amount to meet the energy needs of the active athlete will provide an abundant replacement of all the nutrient substances lost in the sweat of the most vigorously exercising athlete. Sodium, chloride, and potassium losses have been measured in the sweat of ten distance runners performing in very warm weather. They ran a sufficient distance to lose 3 per cent of their body weight as body water each day for 5 consecutive days..
The electrolytes were measured in their self–selected ad libitum diets. There was a markedly positive balance of each of the three electrolytes measured. Under these study circumstances, there was an abundance of sodium, potassium, and chloride in the typical American diet to replace all sweat losses. A generous diet and normal functioning kidneys will ensure that all
of the needs for electrolyte replacement are being met even in the most vigorously exercising athletes. Salt mixtures and salt tablets particularly, are not to be used. In the hands of the uninformed or credulous athlete, salt intakes may be dangerous.”
This well–documented and respected text expresses my beliefs as well. I feel the article in the Toronto Star might create much more harm than good if followed by endurance athletes.
Harvey H. Sternberg, M.D.
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