Life is full of daily challenges. Staying hydrated shouldn't be one of them. If you struggle to make sense of the seemingly ever-changing advice on what, when and how much to drink, especially while on the run, join the club. But it's not impossible to sort the facts from fiction. Base your hydration habits on research-based guidelines--not these four common hydration myths—and you'll stay fueled and run strong.
Myth #1: You must drink eight glasses of water a day.
In reality, fluid needs vary widely, both for individuals and on a day-to-day basis. For women, the Institute of Medicines' Food and Nutrition Board's general recommendation is 91 ounces (about 11 cups) of total water daily, which can come from beverages (including caffeinated drinks) and food sources. On average, water and other drinks fulfill 80 percent of our total daily water needs and food supplies 20 percent.
Female runners should include nutrient-rich beverages such as 100 percent fruit and vegetable juices, herbal tea and low-fat milk for calcium, vitamin D and protein. Delivering energy, nutrients and electrolytes, meal replacement beverages and electrolyte replacement drinks are a good option before, during and after prolonged or intense exercise.
Myth #2: It's best to drink like your fast running buddy.
One-size-fits-all rules for drinking during exercise are out. Sweat rates vary greatly among runners, especially during prolonged exercise or in hot weather. How much you need to drink depends on how much fluid you need to replace, regardless of well-intentioned group guidelines. In fact, major authorities like the American College of Sports Medicine (ACSM) and the American Medical Athletic Association (AMAA) have moved away from giving definitive formulas to runners, especially marathoners, about how much to drink while running.
Take responsibility for yourself. Daily hydration needs are influenced by your physiology, fitness level, running speed, the clothing you wear and the weather. A good rule of thumb: Pay attention to the color of your urine throughout the day. If it's dark yellow, you're not drinking enough.
Your bathroom scale can also help. Weigh yourself before and after a run (in the nude is best). If you routinely drop more than two percent of your body weight on a single run (for example, about 2.5 pounds if you weigh 130 pounds), you need to do a better job meeting your fluid needs while running. To find your hourly sweat weight, add the weight lost during a one-hour run with the ounces you drank. The total number of ounces is what you should consume during each hour of running to avoid dehydration.