The Yanomamo Indians eat about 100 times less salt than we do. It has been argued that their salt intake is the natural salt intake for all humans. Obviously, if the salt intake is this low, then there is no room for there to be much salt in the sweat. However, most guidelines will say that if you sweat a lot, you should replenish the salt lost via sweating. But if the natural salt intake is much lower, then we're only losing excess salt via sweat.
So, is our sweat salty only because we eat way too much salt, or are we really losing essential salt via our sweat that we must replenish?