A person on the internet agrees with me. I am vindicated.

Because I have hiking on the brain, I looked up information this morning about sodium needs of athletes.  And then endurance athletes.  And then ultra endurance athletes.  Because it turns out that a thruhiker is an ultra endurance athlete (defined, where I was looking, as someone who exercises at high intensity for 12 or more hours at a time.  Which, maybe not so much if you're on the ridgeline.  But if you're going up a mountain quickish-like?  Pretty high intensity.)  And the ultra endurance athletes mentioned in the article weren't doing it every day.

Then on the radio while I was driving to work I heard a piece about a guy who ran a marathon a day for a year, just to see what would happen (or to prove it could be done).  He was feeling pretty proud of himself.  I'd like to introduce him to thruhikers who hike a marathon a day (though not for a year - and I am definitely not in the marathon a day crowd) with no support team like he had.  And over mountains, on uneven footing.  Carrying a backpack.  Of course, most of them aren't running.

Anyway, the salt issue.  Here's one of the pages I found: 
http://sportsmedicine.about.com/od/hydrationandfluid/a/Sodium_Salt.htm

An interesting tidbit from the article is that the athletes can lose 1-2 grams of salt per liter of sweat.  And they are losing a liter or more of sweat an hour.  So that is a *lot* of salt.  (I totally believe it, too.  You should see the salt crusted onto people's shirts, shorts, and hats.  Gross.)  The recommended daily intake of sodium in the diet is only 2.4 grams per day.  If you followed that recommendation while being very active in the summer, you would be in the danger zone for hyponatremia pretty quickly.

Anyway, my personal feeling has generally been that people hiking all day in the summer need more than the USDA recommendation for salt, and I think the article backs me up. 

More interesting (to me) details, plus the advice to get the salt from food rather than tablets:

http://www.rice.edu/~jenky/sports/salt.html

Also, it says, avoid aspirin, ibuprofen, and other NSAIDs during the exercise because they inhibit kidney function and may contribute to development of hyponatremia.  Which is advice most thruhikers will laugh at.  Not because they don't believe it, but because after a few hundred or a thousand miles they don't function well without anti-inflammatories.  Not YOU, of course.  I'm not talking about YOU.  I'm talking about the rest of us with less than perfect physiques, joints, and ligaments.

So, to sum up, I am happy to have found random unsubstantiated pages on the Internet which back up my own beliefs.  It's always nice when people agree with you.

Also?  Pretty sure I'm buying a 2.5 oz Tracfone for my trek this summer.  There's a good chance my iphone won't work pretty much anywhere in Maine.  The Tracfone, which uses whichever network is handy, should at least let me text JD from mountaintops.