This article was created in partnership with BODYARMOR as part of Destination Hydration.

If working out feels a lot more complicated than you remember, that’s probably because it is. Gone are the days of hitting the pavement without a plan and calling it exercise. We want to know which exercise we should do first in the gym, whether incline or speed is more important, and what to eat for optimal performance and recovery and when. It’s pretty clear there’s a difference between getting it done and getting it done *right.* But there’s one crucial element you might be overlooking: hydration.

We partnered with the experts at BODYARMOR to find out the best way to hydrate for intense workouts. They make better-for-you hydration products such as BODYARMOR LYTE Sports Drink, a naturally sweetened, low-calorie (only 20 calories and 3 grams of sugar per serving!) option, and BODYARMOR SportWater, an alkaline water (pH 8+), that keep athletes like James Harden and Megan Rapinoe at the top of their game.

So how exactly do you go about hydrating for high-intensity or endurance exercise? Let’s dive right in. (Sorry, we had to.)

Why Hydration Is So Important

Staying hydrated can have a bigger impact on your workout than you might think. According to Sports Dieticians Australia, as you lose fluids, you’ll not only experience a decrease in physical and mental performance, but you’ll also feel like the exercise is harder than it actually is.

“Performance is what gives us that edge,” says celebrity fitness trainer and founder of Don-A-Matrix Training, Don Brooks. Whether you’re hitting the gym or playing a sport like professional athletes, “that performance at the beginning of the game needs to match your performance at the end of the game or workout.”

Keeping your energy and performance levels up means you’ll not only get a better workout, but you’ll also avoid potential injuries or setbacks. Not to mention dehydration can be seriously damaging to your health.

“We need adequate hydration so that our muscles can work,” says Alexis Halpern, M.D., emergency medicine physician at New York-Presbyterian/Weill Cornell Medical Center. “Muscle mass is 70 to 75 percent water. Staying hydrated properly improves both physical and cognitive performance, and without [hydration], both suffer.”

To make matters worse, dehydration is not always easy to notice.A recent study discovered that even professional athletes struggle with monitoring and maintaining their hydration levels.

“A lot of people try to go through their workouts without hydrating,” Brooks says. “That’s why we [need to] take those breaks to make sure we hydrate up.”

How to Do It Right

So what’s the secret formula for staying hydrated?

“Hydration depends on the individual,” Brooks says. “Whatever you put out, you need to put back in.” In other words, it’s highly personal. But while there isn’t a one-fits-all approach, there are some guidelines you can follow.

First, you’ll want to be hydrated before you start. The American College of Sports Medicine recommends drinking 16 to 20 ounces of water or sports drink at least four hours before exercise, then another 8 to 12 ounces 10 to 15 minutes before.

But don’t stop there: You have to keep sipping throughout your workout too. If you’re exercising for more than 60 minutes, the ACSM recommends 3 to 8 ounces every 15 to 20 minutes, while other research suggests 7 to 10 ounces every 10 to 20 minutes.

But don’t get too caught up in the numbers. The important thing is to monitor your fluid loss. Whereas you might perspire a bit during a 20-minute jog, you’re probably going to sweat a lot more in an hour-long HIIT class. Additionally, you might be losing fluids in other ways: Are you spitting frequently during a 10-mile training run? Have you taken a lot of bathroom breaks? Is your towel soaked? Were you breathing heavily the entire time? Those can all indicate you might be losing more fluids than you want.

Another way to gauge it is to step on the scale before and after your workout, since your weight change reflects water loss (sorry, guys, it’s not fat). The ACSM suggests drinking 20 to 24 fluid ounces of water or sports beverage for every one pound lost—and doing so within two hours of exercising.

One warning: It is possible to overhydrate. Just as too little fluids can lead to cramps, fatigue, and injury, Halpern says drinking too much can make you feel sick—and potentially lead to a condition called hyponatremia (more on that below). The key is to listen to your body and find that Goldilocks sweet spot.

When to Reach for Something Other Than Water

There’s a big reason water alone doesn’t always cut it after a lengthy workout: electrolytes (minerals that keep your cells hydrated and help with muscle contraction and brain function).

“If we put in too much free water without keeping up with those electrolytes, the body can go into a dangerous state where the sodium is too low,” Halpern says.

This condition, called hyponatremia, happens when your water-sodium balance is out of whack, causing nausea, vomiting, fatigue, confusion, and, in extreme cases, death.

“It’s why drinking fluids with electrolytes is great for your body during and after exercising,” Halpern says.

The other thing you have to replenish? Carbs. Your body breaks them down into glucose (a.k.a. sugar) and uses them as fuel for your muscles. During long workouts, your body burns through your glycogen stores, and if you don’t replace ’em, you’ll hit a wall.

That’s why Brooks recommends BODYARMOR LYTE Sports Drink—it contains a blend of natural sugars and electrolytes that are easily digestible and deliver nutrients to the cells faster (plus it’s only 20 calories per serving).

The Bottom Line

It all comes down to smart planning. If you’re going out for an especially sweaty sweat session, be sure to hydrate before, during, and after, and keep an eye on how many fluids you’re losing. And remember that plain water might not be enough. Anytime you’re exercising intensely for more than an hour, you need to replenish electrolyte and carb levels too.

We want to send you and a friend to L.A. to work out with celeb trainer Don-A-Matrix! Your flight, hotel, and a year’s supply of ultra-hydrating BODYARMOR LYTE and BODYARMOR SportWater are included. To enter for your chance to win, post a photo on Instagram showing how you hydrate with BODYARMOR before May 30 and tag it #DestinationHydration. The winner will be chosen the first week in June. Read the official rules here.