You don’t need to open your eyes to know last night was a mistake. Because while it might take your body and brain a while to make sense of what’s happening, your wrist is already hours ahead of you… with a “tsk tsk tsk” waiting.

Before your head even has time to regret, WHOOP has logged the receipts. Your heart rate variability tanked, your resting heart rate spiked, and by the time you check your phone to realize that you sent a text that you shouldn’t have sent, there’s an ugly little number waiting for you called Recovery.

WHOOP, the viral wearable that’s suddenly everywhere (right?), is offering a free trial right now of its PEAK membership, which includes a 5.0 WHOOP device (with charger) and new Jet Black CoreKnit band.

Try WHOOP free for a month and pick your membership before your trial ends—because there’s no way you’re giving up access to these vital stats.

Science Time: How Whoop Knows You’re Hungover

Here’s what actually happened while you were out there making those… misguided(?) decisions. 

Per WHOOP’s own aggregated member data, even a single drink drops average HRV by about 7 milliseconds and pushes resting heart rate up roughly 3 beats per minute overnight. Those two numbers, plus your sleep and respiratory rate, are what gets put into your daily Recovery score, and WHOOP’s data shows Recovery runs about 8% lower on average the morning after members log a drink the night before. Interestingly, that’s the average whether it was one glass of wine or the whole bottle.

All of that traces back to your autonomic nervous system, which is the part of your body running fight-or-flight versus rest-and-digest without you making that decision. Alcohol tilts that balance toward fight-or-flight while you sleep, which is the actual mechanism behind the drop in HRV and the spike in resting heart rate. 

I know… a bit science-speaky. I gotchu: That means your body isn’t relaxing overnight. It’s actually working overtime, and Recovery is just the receipt it hands you in the morning.

What sucks even more is that your body doesn’t let it go after one night. In a WHOOP-tracked study of collegiate athletes, the majority still had suppressed Recovery the day after drinking, and a chunk of them were still dragging two, three, even four or five days out. So that, “I’m fine now” you told yourself at brunch on day two might just be your ego talking, not your nervous system. Now, I don’t need a study to tell me that a night of beer and shots will leave me in a fog for a few days… but I’m glad I’m not alone. We’re in this together, fellow degenerate!

Not here to judge

There is one move that softens the blow, though, at least according to WHOOP’s own numbers… and that comes with hydration. Members who logged both alcohol and enough water intake woke up with noticeably better Recovery scores than the ones who skipped it. Groundbreaking information, I know. But I guess I did learn something from college when I made it my habit to absolutely chug a giant glass of water before passing out. Pro-Tip: Bookend your sleep with a LiquidIV. That’s some 40-year-old wisdom for ya.

None of this requires you to change your ways. YOLO, am I right? Is that still a thing? 

But WHOOP isn’t a sobriety app. It just sits on your wrist and tells you, in cold hard data, exactly how much your Saturday cost your Sunday (and Monday), then lets you decide what to do with that information. That may be nothing more than a shoulder shrug, and that’s your business.

Ready to start taking stock of exactly how hungover you are at all times? Right now you can try WHOOP free for a month. Four-ish weekend binges is more than enough time to watch it call you out in real time. Memberships start at $199 per year after that. Consider it the most ride-or-die-yet-honest roommate you’ve ever had.

Who knows? It might just drive you to actually start making better decisions.