Let’s say it’s Friday night, and you’ve made it through another hectic workweek filled with meetings and tasks. (You go, Glen Coco!) You have the whole weekend ahead of you—but while you’ve been looking forward to your social plans since Monday morning, you now feel like your energy gas tank is on “E.” You’re tired. Like, really tired to the point where you’d rather stay in than do anything that requires you to put on real clothes. So… what gives? Why are you so tired on your days off? After all, it just seems wildly unfair that the second you have some downtime to yourself, all you want (no, need) to do is sleep.

According to board-certified behavioral sleep medicine specialist Jade Wu, PhD, sleep expert at sleep tech company Hatch and author of Hello Sleep, a case of the weekend sleepies can often be attributed to your workweek rest habits (or, ahem, lack thereof). Sure, a rogue all-nighter can disrupt your energy levels in the short-term, but if you’re always feeling tired on your weekends or days off, it may be high time to do an audit of your workweek sleep practices.

Below, Dr. Wu shares some of the most common workday habits that can lead to tiredness on days off, plus simple ways to avoid these tendencies. Read on, and a weekend warrior you’ll soon be.

4 reasons why you’re so tired on your days off (and what to do about each)

1. You’re overstimulated during the workweek

When your week is a flurry of to-do lists, non-negotiable meetings, and high-stakes deadlines, your body can get caught in fight-or-flight mode, or a physiological response to stress that floods the body with adrenaline, resulting in symptoms like a rapid breathing rate and heart rate, and heightened anxiety. These changes are a natural response to danger, designed to keep us safe—but because the brain can’t tell the difference between an actually life-threatening scenario and a difficult day at work, it tends to throw us into fight-or-flight mode in response to even the slightest signs of stress.

“When we don’t have a crisis on our hands anymore—AKA, the weekend—our bodies can finally let go and relax, and not be on guard anymore.” —Jade Wu, PhD, behavioral sleep medicine specialist

“Our fight-or-flight system can be overused during the week,” explains Dr. Wu. “Eventually, when we don’t have a crisis on our hands anymore—AKA, the weekend—our bodies can finally let go and relax, and not be on guard anymore.” The result can be a rush of tiredness, as the brain finally feels safe enough to turn off the adrenaline pump. “By that point, we may have been scraping the bottom of the barrel in terms of our energy, which means the exhaustion will finally catch up with us,” says Dr. Wu.

Overstimulation from back-to-back tasks and constant exposure to screens can also thrust us into mental burnout, says Dr. Wu. “Historically, before social media, before all the screens, we had lots of time to just [let our] mind wander and twiddle our thumbs and be kind of bored,” says Dr. Wu. This served as a restful reset for our brain—which we no longer have, for the most part. “It makes a lot of sense that by the weekend, we’re so exhausted by the stimulation from all the screens, all the decisions, all the planning, all the strategizing, and all the learning, and we just don’t want to think about yet another thing,” she says.

How to fix it:

Feeling constantly stressed or overstimulated during the workweek could point to impending burnout. If your plate is indeed overflowing, consider asking your boss or colleagues for help re-distributing your work tasks or leaning on a roommate or significant other for support with household chores. Setting up clear boundaries at work can also help keep those work responsibilities from creeping into your off hours in the evenings.

You can also practice calming breathwork, meditation, or vent writing to manage mounting levels of stress and anxiety. Monitor your screen time, and try to unplug at least an hour before you hit the hay to optimize your sleep during the workweek (which can also reduce your tiredness on your days off). To do so, it might help to remember that not all texts, social media messages, or work emails are emergencies—chances are, it can wait until tomorrow.

2. You have major sleep debt

If you’re getting less sleep than your body needs throughout the week (whether for work or social reasons), you’re essentially stealing sleep from yourself, and at some point, you’ll need to pay it back. That’s the concept of sleep debt, which accumulates every time you come up short on sleep. When you finally have a few extra hours to spare on your days off, your body may seek to repay that debt, leading you to feel sleepier than usual—hence the tendency to sleep in on weekends.

Unfortunately, it’s nearly impossible to fully catch up on sleep debt with just one or two days of extra zzzs. According to Dr. Wu, attempting to do so by sleeping in for several hours can actually make you even more tired than you were to begin with.

“It’s kind of ironic because you think that by catching up on sleep, you’ll be less tired, but our circadian rhythm—the body’s clock—loves to be stable from day to day,” says Dr. Wu. “When it gets unstable, it gets really confused. It’s not sure what time it is anymore, and that makes us feel more fatigued.”

How to fix it:

The only sustainable fix for the tiredness that can come with sleep debt, says Dr. Wu, is to consistently make sure you get enough sleep (on average, seven hours per night) throughout your workweek—not *just* on your days off. It can be tempting to engage in revenge bedtime procrastination, or stay up late on workdays to do the things you want to do after spending the day working. But that just eats away at the energy you’ll have left for fun activities on the weekend.

There’s no escaping it: “The only answer is to sleep enough,” says Dr. Wu. “I think a lot of people count on the weekends as their catch-up time [for sleep] instead of just investing in good sleep every day, but it’s a myth that we can just catch up on sleep debt like that.”

To collect better quality shut-eye during the week, create a bedtime routine that’ll foster sleepiness with continued practice: Avoid screens leading up to bedtime, partake in a relaxing nighttime activity, and maintain a sleep environment that’s dark, cozy, and clean.

Another simple way to build a healthier, more consistent sleep schedule during the week, says Dr. Wu, is to set an alarm for about an hour before your bedtime that will signal to you that it’s time to settle down. “Sleep is not an on-off switch; it’s more like a dimmer or a down ramp,” says Dr. Wu. Cues like an alarm can help us remember to get on that ramp with time to spare, she says. This way, “it’s easier to slide down peacefully, rather than fight ourselves to get to sleep immediately.”

3. You’re experiencing social jet lag—and it’s thrown your circadian rhythm for a loop

You probably already know what jet lag is, but have you ever heard of social jet lag? It’s the exhaustion that tends to follow a change in sleep schedule prompted by nighttime social activities (rather than a change in timezone).

It typically goes like this: You decide to stay out late on a Saturday night—say, for cocktails with friends—and then wind up sleeping in on Sunday way later than usual in an effort to get a full night’s rest. This throws off your circadian rhythm, leading you to struggle to fall asleep on Sunday night, only to wind up getting insufficient sleep and feeling tired as the week begins. Though you could get back to your regular sleep pattern before the weekend arrives, the change in schedule can lead to residual tiredness (even if you’re technically clocking enough hours of sleep).

“We all talk about how much sleep we should get, but people don’t tend to talk enough about consistency,” says Dr. Wu. “If you’re getting close to the right amount of sleep, but you’re still feeling really tired, look at your timing.” Even a couple hours difference in your wake-up time on weekends versus workdays can throw things off. Just consider that if you get up at 6:00 a.m. on weekdays and 9:00 a.m. on weekends, “that’s like traveling from New York to Los Angeles and back every weekend,” says Dr. Wu. In that case, it’s no wonder you’d feel exhausted.

How to fix it:

The prospect of sleeping in until lunchtime on your days off may sound appealing, but Dr. Wu suggests only sleeping in for about an hour or two (max) past your usual workday wake-up time. This way, you’ll avoid disrupting your circadian rhythm. “There’s going to be exceptions here and there, but generally speaking, we should be keeping roughly the same sleep schedule from day to day,” she says.

4. You’re tired, sure—but it has nothing to do with your sleep

According to Dr. Wu, you could be tired on your days off for reasons that aren’t sleep-related, too. “We often talk about ‘tired’ and ‘sleepy’ as if they are the exact same thing, but actually, they’re different,” says Dr. Wu. “‘Sleepy’ is when you are about to fall asleep, but ‘tired’ doesn’t necessarily have anything to do with sleep itself.”

Maybe you’re dehydrated, or you’re bored, or you haven’t moved your body for a while, or you haven’t eaten enough. All of these things could be true if you tend to throw your weekday wellness habits to the wind come Friday night. “There are all sorts of different reasons for being tired, and they tend to commingle on the weekends, when your schedule may be thrown off,” says Dr. Wu.

How to fix it:

Do a self check-in to determine what your mind and body really need. When was the last time you had a glass of water? Have you moved today? Exactly how many hours have you been binge-watching 90-Day Fiancé without taking a break? (No shade—just looking out for you.)

It’s great to use your weekends to take a load off, but be conscientious about whether your relaxing activities are rejuvenating, too. No one’s saying you can’t veg out on the couch for a few hours, but be sure to fuel and hydrate your body, and move a bit, too, to avoid the tiredness that can keep you from enjoying the things you actually want to do on your weekends.