I trained for and ran my first marathon last year, with the help of a coach and training group. I'm glad she talked about this with us because I never heard of it until then. Actually I had the opposite problem....during the marathon I couldn't drink enough water/Powerade to compensate my fluid loss through sweating. I ended up pretty dehydrated and nearly fainting at the finish line. One of the medical people saw me and got me to the med tent for an IV, and also gave me beef broth to drink. Except for the really sore leg muscles I felt good as new!
I thought that fainting was the normal physiological reaction to just having run a marathon.
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