Salt isn’t the only electrolyte. You have potassium, magnesium, phosphorous, just to name a few. Personally, I’m with you on salt (sodium) being one of the most important when it comes to racing, but I think other electrolytes play an important role in performing at the top of your game in endurance events. When I sweat a lot on a race, I’ll supplement with endurolyte capsules as well as salt tablets, just to make sure I get enough sodium. Different people have different needs though.