How much salt do you need while running?

Are salt tablets needed when running 2+ hour events? This is a question that I ask myself often. In my first & only marathon in April 2014 (high heat and humidity), I suffered major leg cramps around mile 18, and had to power through to finish the marathon. I remember seeing some of the aid stations handing out salt tablets, but I had no experience with them, so I didn’t take any. I’m currently training for my 2nd marathon in November 2015 (hopefully cool and low humidity), and my salt tablet curiosity is back. I came across an article on Active.com that was pretty interesting. The research article provides several reasons why a typical sports drink contains all the salt intake you need and that salt tablets, high sodium drinks, etc. provide no additional benefits. Read more here.