Using the weekend to lie in and catch up on sleep is a way of life for anyone with demanding work or social lives. But could consciously ‘banking’ extra hours of slumber over multiple nights help to counteract the effects of an upcoming period where you predict you might get less-than-stellar shuteye? The concept of ‘sleep banking’—which was first studied in 2009 as a method to help US soldiers improve alertness before missions—has been recommended by wellness leaders like neuroscientist Dr. Matthew Walker, who describes sleep banking as a ‘safety net’ when you know you’re going to be burning the candle at both ends. Longevity specialist Dr. Vassily Eliopoulos says it can aid resilience and recovery, and physical therapist Jason Silvernail recommends it for preserving mental performance when you’re jetlagged. But some researchers argue that sleep functions more like a credit card than a piggy bank—it can’t be saved up for later. We asked health experts to settle the debate once and for all.
Why sleep debt matters
Everyone has experienced the misery of slogging through a day at work after a bad night’s sleep (or several in a row), trying desperately to stop your eyelids dropping during a particularly boring meeting or keep your head from lolling onto your laptop. Not only can a sleep deficit leave you feeling exhausted and irritable, it’s also detrimental to your health.
“In addition to performance and alertness, sleep impacts your metabolic functions and cardiovascular health,” says Elizabeth Klerman, professor of neurology at Massachusetts General Hospital and Harvard Medical School. “It may be that you only need, for example, six hours of sleep to feel rested, but you might need seven and a half hours of sleep for metabolism.” Sleep deprivation is associated with a range of cognitive disorders, says Dr. Valentin Dragoi, neuroscientist at Houston Methodist and Rice University. “In the long run, it could cause Alzheimer’s and dementia, because metabolic waste that accumulates in the brain is eliminated during sleep.”
Unfortunately, the average person doesn’t always register when they’ve racked up a lot of sleep debt, says psychologist and neuroscientist Dr. Lindsay Browning, founder of Trouble Sleeping. “There was a study in 2003 where participants were given two weeks of restricted sleep, but that didn't increase how sleepy they felt, even though they were continually sleep-deprived.”
What is sleep banking?
The term sleep banking was coined in 2009 with a two-week study carried out at the Walter Reed Army Institute of Research. The experiment split 24 adults into two groups. During week one, the first group slept for their usual seven hours a night, while the second extended their time in bed to 10 hours, allowing them to bank extra sleep. During week two, both groups were only allowed to sleep for three hours a night. The results showed that the sleep banking group had better concentration and reaction times on performance tests during the sleep deprivation week, even though they didn’t feel less tired, according to self-report measures.
The theory has since been tested in a variety of other settings. A 2023 experiment found sleep banking for 30 to 60 minutes per night for a week improved performance effectiveness among doctors working night shifts at a Miami hospital, and a 2026 review of 12 studies found that ‘preemptive sleep extension’ improved alertness, reaction times, and mood.
Can you really bank extra sleep?
While studies may indicate improvements in physical and cognitive performance following sleep banking, debate exists around whether participants are actually banking sleep, or simply ‘paying off’ existing debt.
“There's no such thing as sleep banking,” says Klerman, who coauthored a paper refuting the claims of the initial 2009 study. “There's no evidence that you can bank sleep when you don't need it. All the studies that claim sleep banking is happening are actually restoring a sleep deficit, like paying off a credit card, not putting money into a savings bank.”
Browning believes there are benefits to intentionally increasing the amount of sleep you get ahead of a time when you need to be at peak performance. “A study of basketball players found that deliberately extending their sleep over a long period—five to seven weeks—was associated with better sprint times and accuracy in their shooting, and improved mood as well.” However, this study didn’t include a period of sleep deprivation, so it can’t technically be placed in the category of sleep banking. Besides, Klerman points out, going to bed earlier doesn’t automatically lead to better sleep. “Going to sleep an hour or so earlier than you usually do is difficult to do because your circadian system decides when you're able to sleep and when you're awake and your circadian system paradoxically promotes wakefulness until a few hours before your usual bedtime to enable you to remain awake for 16 hours.”
Sleep banking is more worthwhile for people who work nights, says sleep medicine and pulmonary physician Dr. Saema Tahir. “I look at sleep banking as a refresher for people who need a boost in alertness and functioning while they’re off of their normal circadian rhythm.” She believes that neither the credit card nor piggy bank analogy is accurate. “You can never really pay back that debt. Can you reset your sleep by starting from scratch and adhering to a schedule and prioritizing it? Yes. But once it's gone, it's gone.”
Should you try sleep banking?
While experts may disagree about whether sleep functions as a credit or debit system, they’re on the same page about one thing: consistently getting enough sleep is far better for your performance, productivity and mood than hatching any kind of catch-up scheme.
“People should not build up a sleep deficit in the hopes of later paying it back. They should instead obtain sufficient sleep now,” says Klerman, adding that if you have to use an alarm clock instead of waking up naturally, you’re already sleep-deprived.
According to National Sleep Foundation guidelines, adults aged 18 to 64 need seven to nine hours of sleep a night, but requirements can vary greatly between individuals. “If you're sleeping more than nine or 10 hours regularly, your bed partner says you snore or stop breathing or do a lot of kicking in bed, or you still feel tired after nine or 10 hours, you should probably see a sleep specialist,” Klerman says.
Who on earth, you might be wondering, has time to catch nine hours of Z’s? With the pressures of work, social and family commitments, not to mention sleep disruptors like pets, kids, and smartphones, getting to bed and staying asleep is a challenge at the best of times. If you work from home, or are lucky enough to have a place to snooze at work, napping could be a better way to add to your daily sleep total, experts say—with some caveats.
“I often recommend to athletes, or even people who are competing not on a professional level, that short naps earlier in the day are very good for alertness and improving functioning,” says Dr. Tahir. “Never past 3 p.m., and always less than 30 minutes, because the longer they are, the more you risk getting into a deep stage of sleep that's harder to wake up from.” The only exception is if you struggle to fall asleep at night, as napping during the day can reduce the ‘sleep pressure’ needed to drift off later.
“Even a six-minute nap will improve your performance immediately after, and there's evidence that if you close your eyes and try to relax and empty your thoughts, that is also beneficial,” says Dr. Dragoi. So in lieu of sleep, adding a nap into your schedule could be the energy boost you need to feel rested and refreshed.