Sometimes if you're doing that much marching and doing that much sweating, you can lose a lot of the salt from your body as well. You can offset that with a little bit of Gatorade at some of the rest stops. Gatorade has a lot of salt and a lot of sugar in it. But you don't want to overload yourself too much on sugar and caffeine, as well, really.
On February 24th, 2015. See this statement in context.