These simple strategies will ensure you stay healthy, happy, and energized all winter long

By Mirel Ketchiff
January 06, 2015

When we're doing intervals in the heat and humidity of mid-August, you can bet our water bottles are never far from our sides. But in the winter, we're more worried about warming up than cooling down. As a result, our H2O intake often falls by the wayside.

That's a major mistake, though, because water helps rev your metabolism, protect your heart, and improve your focus-and even mild dehydration can seriously hamper your energy and mood. (Learn more about Your Brain On: Dehydration.)

But even though we all grew up hearing the old "eight glasses of water a day rule" over and over, experts now say that the actual amount you need varies depending on body type, activity level, and more-which makes knowing how much water you should drink a day even more confusing. So we asked Carly Day, M.D., orthopaedic surgeon and member of the American Medical Society for Sports medicine, how to be sure you stay hydrated all winter long.

Not Sweating? Keep Sipping

Just because you're not a sweaty mess doesn't mean you're not losing water. It also seeps out when you breath, and when you're sucking in cold, dry air on a winter run you lose even more H2O via respiration than you typically would, says Day. What's more, she adds, research shows that you feel 40 percent less thirsty in the cold than when you're warm-so you can't count on body cues to tell you when to drink. Set your watch or phone alarm to ding every 15 to 30 minutes, and evaluate your thirst levels; if you're even a little parched, knock back a couple ounces. And keep an eye out for these 3 Signs You're Dehydrated During a Workout.

Think Beyond the Bottle

When you think hydration, you think liquid-sports drinks, coconut water, and, of course, plain old H2O. But that's missing out on a major hydrator: your diet. "Food counts for 20 to 30 percent of our water intake, and eating helps stimulate your thirst response," explains Day. In addition to guzzling aqua, eat water-rich fruits and vegetables like grapefruit, pineapple, or eggplant.

Peek at your Pee

You've probably heard that clear to light yellow urine is a sign that you're drinking enough. True, confirms Day, but to get the most accurate indicator of how hydrated you are, take a look at your first pee of the day. After eight hours without water, it'll likely be a bit yellower than ideal-but if it's veering into amber territory, up your intake throughout the day. (Decode 6 other Things Your Pee is Trying to Tell You.)

Don't Overdo It

Yes, it is possible to overdose on water, resulting in a condition called water intoxication that can trigger headaches, confusion, drowsiness, and in extreme cases, even death. Endurance athletes are at increased risk: In 2002, 13 percent of Boston marathon finishers had hyponatremia, or low sodium concentration in the blood caused by over-hydration (from water and sports drinks alike). If you're at your limit, don't force down more water, and if you start feeling bloated or heavy stop exercising and get to a doctor stat. (We Asked the Diet Doctor: Do I Drink Too Much Water?)