Changes

The Science Of Hydration

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|Sweat of acclimated, fit||40||0.9||0.4||1.1
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===Sodium Source Table===
{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Source'''
| align="center" style="background:#f0f0f0;"|'''Sodium - mmol per liter'''
| align="center" style="background:#f0f0f0;"|'''Sodium - grams per liter'''
| align="center" style="background:#f0f0f0;"|'''Sodium - grams per pint'''
| align="center" style="background:#f0f0f0;"|'''Salt - grams per pint'''
|-
|Gatorade||18||0.4||0.2||0.5
|}
*Note: S-Caps does not specify the amount of fluid to take with each capsule, but does mention 'at least one cup', so this ratio is used. The per-pint and per-liter equivalents assumes a constant ratio of one capsule per 8oz of water.
===Examples===
== More on Hyponatremia ==
[[Hyponatremia ]] is where the sodium (salt) levels becomes too dilute. Initial symptoms tend to be a gain in weight and a general swelling and 'puffiness', most noticeable in the hands. More severe symptoms are caused by a swelling of the brain (cerebral edema) including nausea, vomiting, headache and malaise <ref name="ref10"/>. The cause of Hyponatremia is poorly understood, but believed to be related to excessive water intake <ref name="ref1"/>. (I believe that this is excessive fluid intake in the absence of sufficient electrolytes.) Hyponatremia can be common in endurance athletes. In a 1997 Ironman triathlon, almost 4% of competitors received attention for Hyponatremia <ref name="ref4"/>. In a study of the 2002 Boston Marathon, 13% of finishers had some level of Hyponatremia, and 0.6% had critical Hyponatremia <ref name="ref2"/>. The study revealed that the risk factors for Hyponatremia include a slow finish time (&gt;4 hour) and consumption of &gt;6 pints (3 liters) of water during the race; BAA suggests a 'slight build' is also a risk factor<ref name="ref12"/>. Healthy kidneys can excrete about 2 pints (1 liter) of fluid per hour, but this may be reduced by exertion or illness <ref name="ref3"/>. So drinking &gt;6 pints in 4 hours could easily exceed the kidneys capacity to cope. The recent rise in Hyponatremia may be due to earlier advice to athletes to "drink as much as possible" <ref name="ref13"/>, combined with a general concern about salt intake.
== HypERnatremia - the opposite of HypOnatremia ==
<ref name="SYMPT">Sensitivity and specificity of clinical signs for assessment of dehydration in endurance athletes
http://bjsm.bmj.com/content/early/2010/04/22/bjsm.2008.053249.abstract
</ref>
 
<ref name="ref1">Exercise-Associated Hyponatremia
[http://cjasn.asnjournals.org/cgi/content/abstract/2/1/151 http://cjasn.asnjournals.org/cgi/content/abstract/2/1/151]
</ref>
 
<ref name="ref2">Hyponatremia among Runners in the Boston Marathon
[http://content.nejm.org/cgi/content/abstract/352/15/1550 http://content.nejm.org/cgi/content/abstract/352/15/1550]
</ref>
 
<ref name="ref3">Water Intoxication
[http://en.wikipedia.org/wiki/Water_intoxication http://en.wikipedia.org/wiki/Water_intoxication]
</ref>
 
<ref name="ref4">Micronutrient Information Center - Sodium
[http://lpi.oregonstate.edu/infocenter/minerals/sodium/ http://lpi.oregonstate.edu/infocenter/minerals/sodium/]
</ref>
</ref>
<ref name="ref12">BAA - HYDRATION, DEHYDRATION AND HYPONATREMIA
[http://www.bostonmarathon.org/BostonMarathon/WelcomeBooklet.asp#hydration http://www.bostonmarathon.org/BostonMarathon/WelcomeBooklet.asp#hydration]
</ref>
<ref name="ref13">USATF Announces Major Changes in Hydration Guidelines for Long Distance Runners
[http://www.rrm.com/archive03/042803n2.htm http://www.rrm.com/archive03/042803n2.htm]
</ref>
<ref name="ref14">Metabolic and exercise endurance effects of coffee and caffeine ingestion
<ref name="acsm">http://journals.lww.com/acsm-msse/_layouts/oaks.journals/ImageView.aspx?k=acsm-msse:2007:02000:00022&i=TT2
</ref>
 
<ref name="ref4">Micronutrient Information Center - Sodium
[http://lpi.oregonstate.edu/infocenter/minerals/sodium/ http://lpi.oregonstate.edu/infocenter/minerals/sodium/]
</ref>
</references>