If you tend to feel sluggish during the workday, here's a surprisingly easy way to boost your productivity: Drink more water.
Water has a myriad of physical benefits, from lubricating your joints to helping flush waste from your body. But according to a recent study published in the journal PLOS One, increasing your water intake can also have positive effects on your mood and energy level.
The study, funded by Danone, set out to examine how a change in water intake would affect the moods and sensations of folks who habitually drank high volumes of water — two to four liters per day — and others who habitually drank low volumes of water — less than 1.2 liters per day.
For three days, the researchers restricted the 22 high-volume drinkers to a mere one liter of water a day. Meanwhile, they had the 30 low-volume drinkers up their water intake to 2.5 liters a day. Throughout each day, they administered a series of tests to gauge the participants' mood, sleepiness, thirst and various other sensations.
Their findings validate every parental figure who ever harped on you for not drinking enough water. (Sorry, Dad.)
Besides being really thirsty, the high-volume drinkers forced to restrict their water intake experienced a decrease in contentedness, calmness, positive emotions and vigor, according to the study. Meanwhile, the low-volume drinkers who increased their water intake reported feeling less fatigued, confused and sleepy.
"The present research results suggest that an increase or decrease in habitual water intake have, respectively, an improving or worsening effect on mood and sensations depending upon an individual's habitual drinking habits," the researchers wrote.
How much water should you really be drinking? To reach adequate hydration levels, women should consume around 2.7 liters of water per day from beverages and food, according to the Institute of Medicine of the National Academies. Men should consume around 3.7 liters. Those numbers are higher for folks who live in hot climates or do a lot of physical activity.
There are plenty of easy tricks to help you get there. The Centers for Disease Control and Prevention has a number of tips for folks not getting enough water. Try ordering water at restaurants, drinking your water with a lemon or lime to improve its taste and storing water bottles in the freezer so you can have ice-cold water on-the-go.
Smartphone apps like Apple Health and Fitbit will also let you digitally track your water intake. Smart water bottles will tell you when to take a sip. And if you don't mind lugging around a plastic water jug everywhere you go, head to social media and check out the #GallonADayChallenge.