The best time of day to drink coffee is actually 9 a.m., or just after.

By Melissa Dahl, Science of Us
May 29, 2015

The best time to drink coffee, in my mind, is immediately upon waking, preferably before speaking with anyone. But the guys at AsapSCIENCE beg to differ. Based on research mapping out human biological rhythms throughout the day, they argue in a new video that the best time of day to drink coffee is actually 9 a.m., or just after.

Your level of alertness — largely driven by spikes in the hormone cortisol — peaks a few times throughout the day; in the morning, this tends to happen between 8 and 9 a.m. It would seem like a cup of coffee during this hour would help make you even more alert, but that's probably not what happens. As the narrator explains, research has shown that "consuming coffee or energy drinks during peak cortisol production greatly diminishes the caffeine's effects."

And because these ups and downs  in your cortisol are driven by your body's circadian rhythm — which, in turn, is mostly guided by sunlight — your personal sleep schedule doesn't make much of a difference. It's very nice and everything to get a glimpse of the biology behind my caffeine habit, but I think it's probably best for everyone if I stick with the system I've currently got going.

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