The longer you doze, the better you retain water.
THE SCIENCE
The amount of sleep you get each night affects your hydration levels the next morning, reports a new study in the journal Sleep.
Researchers found that adults who usually log six or fewer hours of shut-eye are up to 59 percent more likely to be dehydrated than those who get eight hours or more. The study looked at each person's average nightly sleep, so it’s unclear if you’d be dehydrated after one night of getting too little.
EXPERT INSIGHT
While you sleep, your body releases a hormone called vasopressin that helps you retain water, says lead study author Asher Yoel Rosinger, Ph.D., assistant professor of biobehavioral health at Pennsylvania State University in University Park.
Vasopressin is released at a faster rate during the later sleep stages. That means your body conserves water less efficiently the sooner you wake up, leaving you dehydrated, he explains.
THE BOTTOM LINE
Regularly skimping on sleep ups your risk of chronic dehydration, which can make you more irritable, distracted, and sluggish and slow in the gym. If you don’t log eight hours on a particular night or you notice your urine is darker than normal in the morning, drink two extra glasses of water that day to minimize the effects, Rosinger says.
Photo: Sarah Lauren Holt/thelicensingproject.com