How to Catch up on Sleep the Right Way, According to Experts

On the not-so-unlikely chance that you’re parsing this paragraph through stinging, bloodshot eyes, I’ll spare you the suspense: Whether you’re looking to bounce back from an all-nighter or claw your way out of a deep deficit, you can catch up on sleep. Regardless, however, it’s going to take more than one night of solid shut-eye—and you’d better believe your body is keeping count. “Sleep debt is a very real thing,” says Eric Zhou, Ph.D., associate professor in the Division of Sleep Medicine at Harvard Medical School. Here’s what that actually means, along with some expert advice to help you zero out your bedtime balance as quickly as possible.What is sleep debt?The amount of sleep you actually need differs from person to person, but the National Sleep Foundation recommends adults aim for 7–9 hours per night—give or take an hour on either end to account for genetics and activity level. Think of those restorative hours in bed as the price you pay each night for being a conscious, functioning human during the preceding day. “That's your body settling a bill,” says Joanna Fong-Isariyawongse, MD, FAES, FAAN, associate professor of neurology at the University of Pittsburgh and consultant to the UPMC Sleep Medicine Center.A key factor in how sleep debt actually works is a chemical called adenosine, which steadily accumulates in the brain during the time you spend awake, gradually increasing what experts call sleep pressure. “That buildup is what makes you feel sleepy,” says Dr. Fong-Isariyawongse. (Adenosine also inhibits electrical impulses in the brain, which is one reason why you don’t feel as sharp when you’re tired as you do when you’re well rested.) Each night, while you sleep, your brain clears out the adenosine from the previous day, and the cycle resets when you wake up. When you deny your body the time it needs to carry out this process completely—in other words, when you fail to pay your bill in full—your body carries the balance to the next day, and subsequent overages get added to a running tab.Now, here’s the really important bit. Just like your credit card company charges a fee for carrying a balance, sleep debt comes with a cost of its own—and it’s a steep one. In addition to clearing adenosine while you sleep, your brain also flushes out a range of potentially harmful molecules that, according to a 2020 review published in Biomed Research International, are linked to cognitive decline, neurodegenerative diseases like Alzheimer’s and Parkinson’s, and more. “Sleep debt doesn't just make you tired; it changes your physiology,” says Dr. Fong-Isariyawongse. “When that bill goes unpaid long enough, it starts to affect things such as blood sugar regulation, thyroid function, cortisol, and testosterone—all in the wrong direction.”“We can see the impact of sleep debt in many health domains, ranging from traffic accidents and workplace errors to cardiovascular, metabolic, and mental health outcomes,” says Dr. Zhou. “It’s also important to note that the data suggests the impact of sleep deprivation is cumulative. It just keeps building and building over time. So you want to do your best to avoid consistent insufficient sleep at all costs.”You’re going to need more than one night of good sleepSleep debt may come with a frighteningly high interest rate. “One estimate suggests that for every hour of sleep debt you rack up, you can expect to need about four days of extra sleep to fully pay it back,” says Dr. Fong-Isariyawongse. In a 2021 study, published in the journal PLOS One, a group of well-rested adults were subjected to 10 consecutive nights of reduced sleep—roughly 70% of their individual sleep needs—followed by a seven-day recovery period of unrestricted sleep. “The study found that a full week of recovery wasn't enough,” says Dr. Fong-Isariyawongse, who notes that subjects’ reaction time was the only measure to have normalized by the end of the study. Attention, cognitive efficiency, and memory all continued to lag.“If your sleep deprivation is a one-off, then it’s perfectly reasonable to catch up on sleep however you can—no rules apply—but If your sleep deficit is long-term, you’re better off planning for how you can recuperate,” says Dr. Zhou. “Give yourself a more extended period of time to consistently get a little more sleep than usual, rather than trying to catch it all up in one go.”In other words, weekends won’t save you. In fact, trying to repay your sleep debt in one lump sum could end up doing more harm than good. “Irregular weekend catch-up sleep itself causes circadian misalignment, or ‘social jet lag,’ that can offset some of the benefit,” says Dr. Fong-Isariyawongse. According to Dr. Zhou, getting caught up in a weekly cycle of incurring and paying off sleep debt could even lead you to develop insomnia. “An all-too-common phenomenon is people who end up getting insufficient sleep during the week, and then trying to catch up on weekends,” he says. “This erratic pattern creates a confused circadian rhythm, and can result in the body learning to sleep in bits and pieces through the night.”Your body will let you know when you’re squareSo, how will you know when you’re officially debt-free? “In terms of how someone knows they've caught back up, it is when they notice themselves waking up consistently in the morning at around the same time, feeling rested and able to tackle their day,” says Dr. Zhou. Until then, unless you’ve made a sustained effort to catch up on sleep over several nights and genuinely think you might be back to baseline, don’t expect any loan forgiveness.“The scariest part is that we are a terrible judge of our own fatigue,” says Dr. Fong-Isariyawongse. In a 2003 clinical trial published in the journal Sleep, as sleep restriction continued day after day, people's own sense of how sleepy they felt leveled off, even while their actual cognitive performance kept getting worse and worse.“I think the bottom line is that catch-up works, but only partially, and takes days to weeks—not a weekend,” Dr. Fong-Isariyawongse says. As Dr. Zhou puts it, “approach the sleep debt you owe your body the same way that a bank might approach money that you owe them: relentlessly, until they are made whole.”