Most of us probably try to suck down our first cup of joe as soon after we wake up as possible. But a new video by AsapSscience parses the research and reveals that the best time to give your body its first caffeine boost of the day is actually not when you first wake up, but about an hour later.

Why? It has to do with our circadian rhythm, the built-in biological clock that, among other things, regulates the release of cortisol, a hormone related to alertness. Cortisol levels peak around 8 a.m. and 9 a.m., AsapScience notes, as part of our natural waking process. And if we drink coffee or other caffeinated beverages during this peak cortisol production phase, the caffeine is less effective. Plus, we build up a greater tolerance to it over time, meaning we have to drink more and more for the same pick-me-up.

This cortisol surge is regulated by sunlight, so it happens no matter what time we hit the sack or wake up. (Science has shown we have two more spikes during the day — between noon and 1 p.m. and between 5:30 p.m. and 6:30 p.m. — making those times less than ideal for a coffee break.) Cortisol levels, however, have also been found to jump by 50 percent right after we wake up no matter what time of day that is.

So what’s a caffeine lover to do? “Wait at least an hour [after you wake up] to get your cup of joe,” AsapScience advises, “and your body will be optimally ready to go.” That is, if you don’t hit the snooze button and nod off in the meantime.