PUBLISHED 10/05/2006
When you peel off a sweat-drenched shirt after a hard effort on a warm day, you know you need to rehydrate. The salty lines on your hat or shorts, however, paint a fuzzier picture. You may have a hankering for pretzels or potato chips, but if you're like many runners, you pause in front of the pantry wondering if you should indulge the craving.
It's hard not to feel conflicted about sodium. After all, too much salt is linked to high blood pressure. Even runners who avoid such salt bombs as packaged and fast foods still get all the NaCl they need without trying. The recommended daily allowance is just 2,300 milligrams (mg), and if you eat cereal for breakfast, a turkey sandwich for lunch, and a midday handful of pretzels, your sodium intake would be at 1,600 mg--before dinner.
On the other hand, if it's hot or if you're training hard, you can sweat out a lot of salt--as much as 3,000 mg in an hour. Losing that much sodium may be bad news since it is essential to hydration. "Sodium helps regulate the body's fluid levels," says Bob Seebohar, R.D., director of sports nutrition at the University of Florida. The loss of salt is also connected to other running problems, including cramping and hyponatremia, a rare and potentially fatal condition in which overhydration leads to low blood-sodium levels. So how much salt should runners ingest?
