From the August 2004 issue of Runner's World
Fresh Is Best
Since potassium plays such a key role in hydration, runners might be worried about taking in enough. Relax. Potassium is found in so many common foods that supplementation is rarely necessary to meet the Daily Value of 3,500 milligrams. High-mileage runners may want to take in closer to 4,700 milligrams (you can safely ingest three times that per day), but these amounts are easy to attain by eating a varied diet that consists of lots of fresh, unprocessed foods. That's because potassium is abundant in all living plant and animal cells. The cells remain intact--along with their potassium content--until food is processed, making whole foods the best source. "Just one regular carrot, or six baby carrots, has about 300 milligrams," says Bonci. "What I tell athletes who are already paying extra attention to their carbohydrate and protein intake, is to simply choose carbs and proteins that are also rich in potassium." Bonci's five favorite potassium sources are: a four-inch-long baked potato, which contains about 800 milligrams; a banana (500 milligrams), eight ounces of milk (450 milligrams), eight ounces of yogurt (400 milligrams), and a nectarine (300 milligrams).
While it's hard to become potassium deficient, it's not impossible. Dorfman cautions that some college athletes who train consistently in hot, humid weather and who eat a typical college diet--lots of fast foods that are high in sodium and low in potassium--have exhibited signs of potassium deficiency such as pronounced muscle fatigue. So it's best to concentrate on eating a wide variety of whole foods every day to keep your potassium levels optimal. That and eating that banana in the recovery tent.
