Unless you want your long run to turn into a struggle-fest, hydrating before – and during – a workout is key. “When your body is dehydrated, you don’t have the proper muscle power, accuracy, and balance you need,” says resident nutritionist at Miraval Resort & Spa, Angela Onsgard.

But what you put in your body pre-workout definitely matters. Columbia University’s health professionals advise drinking 600ml of water two hours before a workout, another 240ml during warmup, and an additional 600ml every 10 to 20 minutes depending on the amount of sweat you’re producing. That’s a lot of liquid – so you best be sure you’re sipping the right stuff.

Here what you should never chug before a workout.

Milk-Based Energy Drinks

Sure, many runners love chocolate milk as a recovery drink, but if the thought of downing dairy before a run induces images of Will Ferrell’s character in Anchorman screaming, “Milk was a bad choice,” you’ve got the right idea.

“Dairy-containing beverages are much better to consume post-workout as opposed to before or during,” says Onsgard. Since milk contains protein, carbohydrates, and fat, it takes a lot of time to digest, she says. And that’s not a good thing when you’re trying to bang out intervals.

Sugary Fruit Drinks

As a kid, you might have loved those squeezable drink packs, but they’re just about the worse thing you can fill up on before a workout. “Most of these fruity drinks are loaded with high-fructose corn syrup (HFCS), a sweetener that’s been shown to initiate liver dysfunction, metabolic syndrome, and obesity,” says Onsgard. Instead, liven up your water bottle with fresh citrus fruits, berries, mint, or basil.

Booze

This one might sound like a given, as, unless you’re trying to complete a beer mile, you’re not likely to charge up for a workout with a round of cold ones, but a drink even several hours before a run isn’t very good for you. “Alcohol is dehydrating, inflammatory, and negatively impacts balance and decision-making,” says Onsgard. Not ideal. “If you need a pick-me-up, have some coffee of the dark roast variety (which has less caffeine than lighter roasts” Onsgard says. “[It] can increase alertness and improve exercise performance.”

Carbonated Beverages

Fizzy drinks like soda and seltzer can cause bloating, abdominal pain, and gas. “Instead of soda, go for an iced-cold green tea drink,” says Onsgard. “It’s naturally high in antioxidants and is shown to reduce the risk of several types of cancer.”

Coconut Milk

Though unsweetened coconut water can be a good pre-run (and post-run) drink, it’s important to read labels carefully, and not mix up your liquids. Coconut milk is much different than the water. It’s made with both the juice from the coconut and freshly grated coconut meat – and it is not a good choice pre-workout.

“Coconut milk is higher in fat and lower in carbohydrates than coconut water,” says Amy Cantor, R.D., and nutrition fellow at Boston Children’s Hospital. “Fat is the macronutrient that takes the longest to digest. This may leave you feeling sluggish and full even if you wait a reasonable 30 minutes before you hit the road; not a way anyone wants to start a run.”

Anything With Sorbitol

While sports drinks can be a good choice for replacing electrolytes, especially for long runs, you want to avoid anything with the low-calorie sugar replacement sorbitol.

“Sorbitol, when consumed in high quantities, is known to have a laxative effect,” says Cantor. “In lower doses, it has been linked to gastrointestinal disturbances such as bloating and flatulence.” In fact, Cantor explains, the ingredient works as a low-calorie sugar replacement precisely because your body has a hard time digesting it. So normally, it’ll pass right through. iIf you’re drinking a lot (say, because you’re replacing a lot of fluids from exercise), well, it could make you end that run early.

Cantor suggests avoiding anything with it listed in the ingredients, as well as fruit juices that can be naturally high in sorbitol, such as pear or apple juice. Stick to water, or traditional energy drinks instead.

The article 5 Things to NEVER Drink Before a Workout originally appeared on Women’s Health

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