"Salt/electrolytesTalk about putting your money where you mouth is!
"I didn’t take any supplemental salt or electrolytes during the run. Further, the foods I consumed were generally low in sodium. None of my teammates took salt or electrolyte supplements.
"While the sports-drink industry markets the importance of electrolytes, Tim Noakes has argued that the body contains enough salt and electrolytes to last for weeks. Further, he points out that in a hot environment, the salt content of sweat and urine drops by 90-plus percent. People see white, crusty sweat on their clothes after running because their bodies are ridding themselves of the excessive salt contained in the typical western diet (Noakes 2012). Ironically, people see the salt crusts and, worrying that they are running low on electrolytes, eat more salt—when they actually may have more than they need.
If you can run 292 miles through Death Valley without supplementary salt, I think we can put that myth to bed.
Full version (from the link above) here (PDF).