It turns out there can be too much of a good thing.
Sodium (an electrolyte) is critical for running performance—but even if you sweat on the regular, you could still be getting more than you need. One sign? Too much of the salty stuff could be giving you a headache.
Research from Johns Hopkins University found cutting daily salt intake from 9 to 3 grams decreased pounding noggins by 31 percent. One easy idea? Check your bread. The Centers for Disease Control and Prevention lists processed bread and cereals as big culprits for hidden salt. Look for a low-sodium loaf (and peanut butter) if you suffer from painful thumping.