A glass of ice tea.

Staying hydrated regulates body temperature, allows your heart to work more efficiently, prevents headaches and muscle fatigue, aids digestion, and even boosts your mood. But in the heat of summer, it’s easy to become dehydrated without realizing it.

You might be tempted to try one of the many sports drinks or flavored waters on supermarket shelves, thinking they’re a step up from plain old H₂0.

What’s the truth? CR’s nutri­tion­ists took a closer look at the types of hydration drinks on the market. Here’s their verdict.

Sports Drinks
These were originally developed for hard-core athletes to replenish electrolytes, such as sodium and potassium, that are lost in sweat, plus carbohydrates that muscles use for fuel. “The average exerciser needs to replace water, not electrolytes,” says Amy Keating, R.D., a CR nutritionist.

Worse, sports drinks could offset the calorie-burning benefits of exercise. “A person who weighs 150 pounds will burn around 150 calories in 30 minutes of brisk walking, but sports drinks can have about 100 calories in 16 ounces,” Keating says. Zero-calorie and low-calorie sports drinks might not have any sugar (or as much) but may have artificial sweeteners. And both types might have artificial colors or other added ingredients.

Water With Added Vitamins
There’s no need to replenish vitamins just because it’s hot out or you went for a run. And if you drink a lot of these, you run the risk of overloading on vitamins, especially if you take a multivitamin and/or eat vitamin-fortified foods, such as certain cereals. Also, read labels; some products are full of sugars.

Plant Waters
Labeling on certain coconut, maple, cactus, and other trendy plant waters suggests that these drinks are more hydrating than water or a more natural alternative to sports drinks. There’s not much truth to the hydration claims, but they are lower in sugars. Coconut water has about 40 to 65 calories and 9 to 14 grams of sugars in 8 ounces; cactus and maple have about 25 calories and 5 grams of sugars in 8 ounces.

More on Healthy Drinking

Ice Tea
Brewed tea has negligible calories and contains antioxidants that may improve heart health and lower the risk of cognitive decline and type 2 diabetes.

But when it comes in a bottle, tea might not have any of these benefits.

Many bottled ice teas are nutritionally on a par with soda—containing loads of sugars. Diet ice teas will be low in sugars and calories, but they may have artificial sweeteners, such as aspartame and sucralose.

Instead, look for ice teas labeled “unsweetened.” “You can add a teaspoon of sugar or agave syrup and get far less sugars than in many presweetened versions,” Keating says.

If you want antioxidants, brew up a pitcher. “Bottled teas are very low in antioxidants compared to freshly brewed tea,” says Joe Vinson, Ph.D., a professor emeritus of chemistry at the University of Scranton, whose lab has analyzed a variety of teas. But the antioxidants dissipate over time. “We found that once brewed, the antioxidant content went down about 10 percent a day,” Vinson says. So don’t make a bigger batch than you can drink in a day or two.

Homemade Alternatives
Do-it-yourself flavored waters are a healthy and tasty alternative to bottled drinks. Start with a large pitcher of ice water and add sliced fruit. Or try the idea below from Chad Luethje, executive chef at the Red Mountain Resort in southwest Utah.


Ginger-Peach Cooler

Add 2 quartered peaches (or another stone fruit) and about 2 inches of peeled ginger root, thinly sliced. Fill a pitcher with water and stir gently. Add fresh lemon verbena leaves or lemongrass stalks, if desired.

Editor's Note: This article also appeared in the September 2018 issue of Consumer Reports magazine.