Had a crappy night of sleep? Try drinking more water

Getting a good night of sleep is basically as important to your health as Zayn Malik was to One Direction—without it, everything eventually falls apart.

And now there may be even more reason to prioritize getting those sweet zzz’s. A new study published in the journal SLEEP found a connection between poor sleep and dehydration—specifically, that people who slept for six hours were more likely to be dehydrated than those who slept for eight hours.

Here’s how it worked: The study looked at three existing data sets gathered from over 20,000 healthy adults in both the US and China. The people who participated in these data sets had previously reported how much sleep they got per night on average, and had also provided urine samples. Researchers determined the hydration levels of the participants (by looking at levels of two different urinary biomarkers in the participants’ urine samples) and compared that with how much sleep the participants said they got.

For people who reported sleeping six hours a night, their odds of being “inadequately hydrated” were 16-59 percent higher than those who reported sleeping eight hours. (There was no correlation between sleeping more than nine hours and dehydration.)

“This study suggests that if you’re not getting enough sleep, and you feel bad or tired the next day, drink extra water.” —Asher Rosinger, PhD, lead researcher

The reason why they’re not as hydrated is not fully clear—but researchers have some ideas. Namely, that you don’t get as many benefits from a hydration-related hormone called vasopressin if you don’t get enough sleep.

“Vasopressin, or anti-diuretic hormone, responds to the body’s internal hydration status,” says lead author Asher Rosinger, assistant professor of biobehavioral health and anthropology at Penn State in a press statement about the study. It basically helps regulate your body’s hydration levels, and is released while you sleep. “So, if you’re waking up earlier, you might miss that window in which more of the hormone is released, causing a disruption in the body’s hydration,” Rosinger says.

But before you start chugging water in the morning, remember that this study just found an association between dehydration and less sleep—it’s not proven that one causes the other. And researchers didn’t specifically measure vasopressin in their sample groups, but rather hypothesized that when someone gets less sleep they don’t get the full benefits of vasopressin. (So, we need more research for a concrete answer.)

That said, the info could still help your recovery game plan after a particularly sleepless night. “This study suggests that if you’re not getting enough sleep, and you feel bad or tired the next day, drink extra water,” says Rosinger.

Water, for better health? Groundbreaking. But in this instance, it could be worth filling up your S’well bottle an extra time.

If you’re having trouble catching zzzs, magnesium may be the supplement you need in your life. Or, maybe try a big cup of barley tea instead?