The Truth about Water: Avoiding Hyponatremia

If you told me after my first marathon that it is possible to drink too much water I would have laughed long and hard. But as of 2008, while training for the Philadelphia marathon, I learned the hard way how easy it is to overdose on water, even in the hottest conditions.

Sometimes I wonder if every new problem (disaster?) is age-related, because I never had problems with water consumption while training for marathons in my 30s. But beginning last year, every time I ran for over 2.5 hours and drank only water, I found myself vomiting in the last mile. At first I thought it had something to do with overexertion because it almost always happened after running up a steep hill. But the more I thought about it, the culprit seemed more likely to be too much water - for several reasons:

• There was a LOT of water still in my stomach (!) at that point, and I was desperately thirsty even after drinking at regular intervals that day
• It didn't happen on runs when I took electrolytes, Gu Roctane (my newest favorite gel, thanks to Bill at Second Sole), Gatorade, or Hammer Nutrition's Heed during or before the run
• I noticed excess salt stains on my skin and clothing when the sweat dried (don't ask me how or why I take note of these things)
  

So, yes, it does make me wonder: does the need for electrolyte supplementation increase with age? Am just more depleted after my long bike rides the day before? Am I trying to ingest too much water each time I drink?

Whatever the cause, one thing is certain - focusing on the task at hand (i.e., my run) is something I need to pay more attention to. Before my run on Sunday I was worrying about so many things, but nutrition wasn't one of them: new shoes, a budding pain in my lower left leg, the wind direction, and trails with soft surfaces (and I know for a fact that none of THESE things
have ever caused vomiting - in the past). I did not stop to grab a Gu or Endurolyte on my way out the door (I'm even embarrassed to say I might have gave it less than a second's thought and brushed it off thinking "there's water fountains on my route").

So, Sunday's run was mostly a live & learn lesson all in itself. I should be looking at these long sessions as practice for the Ironman RACE. Which includes getting the nutrition thing nailed down for each leg and practicing it whenever I get the chance. I've been doing it religiously on the bike every weekend. But, doing everything right on the bike is completely useless if I throw logic out the window on the run. And I won't get a second chance if I do it wrong in Couer d'Alene on June 21.