SALT

This is by far one of the most important topics in the nutrition section; salt intake is critical during all endurance events and can make the difference between optimum performance and a trip to the medical tent...

Sweat generally contains approximately 10 to 70 meq/L of sodium. As the sweating rate increases, for example warmer weather or increased intensity, so does the concentration of sodium in the sweat.

Including 500 to 700 mg of sodium per liter of rehydration fluids during exercise lasting over one hour improves water absorption from the gastrointestinal tract as well as water retention. Including sodium in rehydration fluids has also been shown to decrease muscle cramps.