Perhaps you should think twice before brewing your morning cup of joe right after you wake up.
Why? First of all, you're dehydrated. While you're sleeping, "you breathe out a tremendous amount of water vapor," explained Michael Breus, a clinical psychologist known as "The Sleep Doctor."
Coffee's possible diuretic affects are negligible in those who regularly drink it, but still, water is better when your system is dehydrated. Breus recommends starting your day with a glass of tap water instead. Not only will it help you rehydrate, it could help get your metabolism going, he said.
What's more, sleep expert Els van der Helm explained in the video above that early morning grogginess, called "sleep inertia," makes caffeine ineffective for the first 30 minutes after you wake up anyway. No point in wasting all that joe while your body is still in a sleep state.
Check out the video above for more information on healthy caffeine habits. This post was updated with clarifying language about coffee's diuretic affects.