Jennifer Brown starts each morning by downing a 16-ounce glass of water mixed with a squeeze of lemon. Although this morning ritual is an Ayurvedic practice that promises to rev the digestion system, Brown says it’s also hydration insurance—something that anyone who lives near Phoenix, as she does, shouldn’t take lightly. “In the summer, our temperatures top 110° pretty often. Even at 9 p.m., they're still up around 100°,” says Brown, a registered dietitian who also teaches yoga at the Wellness Center in Goodyear, Arizona.
Aside from her morning practice, Brown doesn’t keep track of how much water she consumes each day. Instead, she’s proactive about keeping a quick swig within reach. “I usually carry a water bottle—and I have a glass of water by my bed at night—so I’m hydrating all the time,” she says. And Brown tells her clients that the “eight glasses of water a day” rule isn’t really a rule at all. “There isn’t much science behind that old recommendation,” she says. Instead, she urges clients to think more broadly about hydration: “Water is great, but hydration is the key—and that can come from fluid-rich foods, too.”
That’s right, a lot of things we put in our bodies contribute to our liquid needs—even caffeinated or alcoholic beverages (though you may want to avoid them for other health or personal reasons). In fact, most people chew a considerable amount of their fluid requirements, says Kelly Pritchett, PhD, RD, assistant professor in nutrition and exercise science at Central Washington University in Ellensburg, Washington. “It’s not unusual for you to get four cups of fluid from foods with high water content, such as fruits and vegetables,” she says.
So how close does that get us to our total daily needs? The Health and Medicine Division at the National Academies of Sciences recommends that most women consume about 91 ounces of fluid each day (a little more than 11 cups), while men need about 125 ounces (nearly 16 cups). But body weight, rather than gender, is actually a better guide, according to Brown. Male or female, we should consume half an ounce to an ounce of fluid per pound of body weight, with a few caveats: Pregnant and breastfeeding women, people who work or live in warm or high-altitude environments, and athletes—including many yogis—may require more. Most people who take Hatha, flow, or especially hot-yoga classes that last an hour or longer need to drink or eat after class, regardless of where they live. “Whatever you sweat out, you should replace,” Brown says.
Of course, how much to replenish is another puzzle to solve, since sweat rates can vary widely, according to a 2oo7 study in the Journal of the American College of Nutrition. Some people can perspire up to 1oo ounces during intense exercise in a hot environment (think Bikram or hot yoga), though those people tend to be the intense, need-a-mop-for-that-yoga-mat sweaters. Most of us who take even a tough class won’t sweat to the point of dehydration, which Pritchett defines as losing 2 percent of your body weight—enough to tax your heart and central nervous system. Still, even half that loss can cause side effects: One study from Central Washington University revealed that the average sweat loss for hot-yoga participants was about 1 percent of body mass, which researchers say may result in lethargy or impaired decision making. To determine what you lose during practice, weigh yourself before yoga class, don’t drink anything during the class, and then weigh yourself again afterward—the difference in ounces is your rehydration goal.
And remember that it’s not just water that needs to be replaced, says Brown. Electrolytes, such as sodium, calcium, potassium, and bicarbonate, also need to be restocked; they help repair body tissue and regulate nerve and muscle function, blood pressure, and hydration. “Try coconut water—it replaces fluids and is a natural source of electrolytes,” suggests Brown. Or, grab a healthy meal. Fruit and veggie-rich dishes are ideal post-workout rechargers because they’re hydrating and contain electrolytes, vitamins, and minerals—without the added sugar of some mass-market sports drinks. Another perk: When water is bound to food, it slows absorption and lasts longer in our bellies, making us feel satiated longer.
Seeking a little hydration inspiration? The refreshing recipes below will quench your thirst plus satisfy your cravings for something summery and delicious.
See also Sip Tips to Keep You Hydrated