Takeaway: One of the best things you can do after you wake up: drink at least 16oz (500mL) of water. Water fires up your metabolism, hydrates you, helps your body flush out toxins, gives your brain fuel, and may even make you eat less. : One of the best things you can do after you wake up: drink at least 16oz (500mL) of water. Water fires up your metabolism, hydrates you, helps your body flush out toxins, gives your brain fuel, and may even make you eat less. Estimated Reading Time: 2 minutes, 3s.

If you like this article you might also dig this productivity experiment I just finished up: The top 10 things I learned drinking only water for a month

Imagine not drinking any water, tea, or any other liquids for the next eight hours.

Well, that’s essentially what you do while you sleep. While you sleep, your body slowly becomes dehydrated because it needs fluid to operate. Naturally, you don’t drink water while you sleep because, well, you’re sleeping!

I’m reducing my body fat from 17% to 10% for a productivity experiment, and drinking a huge glass of water right after I wake up is something both my personal trainer and dietician recommended to reduce my body fat. Especially this week, when I’m being a complete slob in the name of productivity, it’s helping my energy levels a ton.

Most sources I’ve read recommend drinking 16oz of water right after you wake up, and I’d recommend even more (depending on your weight; I drink 1-2L every morning and weigh 173 pounds). Here are five solid reasons to drink a big glass of water right when you wake up.

It fires up your metabolism. Drinking a large, cool glass of water after you wake up has been shown to fire up your metabolism by a whopping 24% for 90 minutes ! 1

Drinking a large, cool glass of water after you wake up has been shown to fire up your metabolism by a whopping ! You’re dehydrated when you wake up. You just went 7-8 hours without drinking any water! Even if your body isn’t telling you that it’s thirsty, it probably is.

You just went 7-8 hours without drinking any water! Even if your body isn’t telling you that it’s thirsty, it probably is. Water helps your body flush out toxins. “Your kidneys do an amazing job of cleansing and ridding your body of toxins as long as your intake of fluids is adequate”, according to Kenneth Ellner, an Atlanta-based dermatologist. Getting fluids into your body right after your wake up will help your body flush out toxins first thing in the morning. 2

“Your kidneys do an amazing job of cleansing and ridding your body of toxins as long as your intake of fluids is adequate”, according to Kenneth Ellner, an Atlanta-based dermatologist. Getting fluids into your body right after your wake up will help your body flush out toxins first thing in the morning. Your brain tissue is 75% water. When you’re not properly hydrated, your brain operates on less fuel, and you can feel drained, or experience fatigue or mood fluctuations. 3

When you’re not properly hydrated, your brain operates on less fuel, and you can feel drained, or experience fatigue or mood fluctuations. You’ll eat less. One study showed that people who drink a glass of water before every meal lost 4.5 pounds over a three-month period, because “it fills up the stomach with a substance that has zero calories”, and people “feel full as a result”.4 Especially after I’ve eaten a big breakfast, drinking a lot of water in the morning has also helped me avoid the temptation of snacking before lunch.

Your body is 72% water, and you don’t have enough water in you when you wake up. Drinking a big glass of water first thing in the morning is a great way to rehydrate, and start kicking ass from the moment you wake up.

A great tip by S.J. Scott in the comments: if you’re not a fan of drinking water right after you wake up, reward yourself after you drink the water (like with tea) to make the habit stick!