Understanding Sleep Debt And How To Pay It Off

Don’t let the word debt scare you off, this is one you can do something about with the right routine or support. While it’s not uncommon to miss out on a bit of sleep from time to time, did you know a constant lack of sleep actually adds up? 

Sleep debt, also known as sleep deficit, is the total amount of sleep you’ve lost, accumulating over time. For example, if you go to bed an hour later from Monday to Friday without adjusting your wake-up time, you’ll have built up a sleep debt of 5 hours in just one week¹.

There’s also a phenomenon caused by changing schedules known as social jetlag. This is where your circadian rhythm conflicts with work and social schedules, leading to less sleep during the week and longer weekend sleeps to catch up². Ever had one of those hectic weeks where you just want to sleep all weekend?

So, how exactly does it work? And how do you fix it? Let’s take a deep dive into sleep debt. 

What is sleep debt?

Put simply, sleep debt is the difference between how much sleep you need and how much sleep you actually get. It adds up over time, meaning if you regularly don’t get enough sleep, your debt will continue to grow³. 

As sleep is an important way for your body and mind to rest and restore, sleep debt can have a negative impact on your health³, especially if it builds to a large amount over time. However, learning how to catch up on missed sleep can help you in the long run, so there are ways to beat the debt. 

Is sleep debt real?

You might have heard you can train your body to get used to not sleeping as much, leading people to ask, is sleep debt a thing? The short answer is yes, sleep debt is real. In fact, there’s evidence to suggest the cumulative long-term impact of sleep loss and sleep disorders are linked with a variety of potential health impacts4. This is why knowing how to catch up on sleep debt is so important.

How can you tell if you’re sleep deprived?

Most people can feel when they’ve had a bad night’s sleep (or from taking one look in the mirror). But while a bit of missed sleep here and there might not seem like a big deal, you may notice other long-term issues with your physical or mental performance after years of sleep debt 

Lack of sleep symptoms 

Key symptoms that stem from a lack of sleep include⁵:

• Trouble focusing
• Memory issues
• Slower thinking
• Poor coordination
• Increased hunger for high-calorie foods
• Caffeine cravings 
• Persistent fatigue
• Irritability
• Mood changes like depression, anxiety, stress or low motivation

How much sleep debt do I have?

So, how much do you owe? You might be wondering how to work out your sleep debt. While everyone’s sleep needs vary, experts typically recommend adults aged 18 and over aim for 7–8 hours of quality sleep each night⁶. To work out your sleep debt, consider how much sleep you normally get and subtract how much sleep you’re actually getting. 

Let’s say you’ve been going to bed 2 hours later each night. Over a 7-day period, your sleep debt will add up to 14 hours. Keep in mind that sleep debt is cumulative, and over the course of a few days or weeks, an hour or two of lost sleep each day can quickly accumulate. 

How to catch up on sleep

When it comes to your sleep, the ultimate goal should be to get enough quality sleep each night. That said, there are a few steps you can take in terms of sleep debt recovery to help get yourself back on track. Here’s how to catch up on sleep debt:

• Take a nap: If you lose out on a few hours of sleep here and there, you might find that taking a nap can help boost your mental alertness and performance over the short term¹. 
  
• Play catch up: Try catching up on sleep on your days off. That said, sleeping more on your day off could be a sign that you’re not getting enough sleep during the week. While getting a few hours of extra sleep might help you feel better in the short run, it could actually throw your circadian rhythm out of whack, further affecting your long-term sleep patterns¹.
  
• Create a consistent sleep routine: It can take days to recover from sleep debt, so rather than try to nap it off or play catch up, it can be worth focusing your effort on creating healthy sleep practices and implementing a consistent sleep routine⁶. 

While these methods can help you if you lose sleep here and there, it can take time to recover from sleep debt. The best long-term strategy is to make sure you’re getting consistent sleeps each night. If you find you’re regularly missing sleep without reason, it might be time to visit the GP.

Do naps help with sleep debt?

A nap can be a great way to quickly boost mental alertness and help feel refreshed¹. For some, a mid-afternoon nap in particular can improve memory, learning and mental clarity for several hours⁶.

That said, a nap isn’t a magical substitute for a good night’s rest, and it certainly doesn’t come with all the benefits of overnight sleep¹.

Can you bank sleep if you know you’ll be in debt later on?

If you have an inkling you'll be losing sleep soon, try adding extra hours to your "sleep bank". While experts once thought you couldn’t catch up on sleep⁷, recent studies show sleep banking can help you handle short-term sleep loss^{8, 9, 10}. However, more research is needed to understand its long-term effects.

Even though there are ways to fight sleep deprivation, the best approach is sticking to healthy sleep habits and a consistent routine. 

Need help creating your own sleep habits? Check out the Swisse Wellness Hub for more information on sleep, such as five ways to improve your sleep.  


References:

1. How much sleep is enough | NHLBI, NIH. (2022, March 24). NHLBI, NIH. https://www.nhlbi.nih.gov/health/sleep-deprivation/how-much-sleep#:~:text=If%20you%20regularly%20lose%20sleep,nap%20to%20deal%20with%20sleepiness 
   
2. Spaeth, A. M., Goel, N., & Dinges, D. F. (2012b). Managing neurobehavioral capability when social expediency trumps biological imperatives. Progress in Brain Research, 377–398. https://doi.org/10.1016/b978-0-444-59427-3.00021-6
   
3. What is sleep debt? (2023, July 17). WebMD. https://www.webmd.com/sleep-disorders/what-is-sleep-debt   
   
4. Institute of Medicine (US) Committee on Sleep Medicine and Research; Colten HR, Altevogt BM, editors. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Washington (DC): National Academies Press (US); 2006. 3, Extent and Health Consequences of Chronic Sleep Loss and Sleep Disorders. Available from: https://www.ncbi.nlm.nih.gov/books/NBK19961/ 
   
5. Department of Health & Human Services. (n.d.-b). Sleep deprivation. Better Health Channel. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/sleep-deprivation   
   
6. Sleep Foundation. (2024, January 16). Sleep debt: the hidden cost of insufficient rest. https://www.sleepfoundation.org/how-sleep-works/sleep-debt-and-catch-up-sleep 
   
7. Clinic, C. (2024, June 27). Good news: you can make up for lost sleep over the weekend (Kind of). Cleveland Clinic. https://health.clevelandclinic.org/insomnia-can-you-make-up-for-lost-sleep-on-weekends 
   
8. Rupp, T. L., Wesensten, N. J., Bliese, P. D., & Balkin, T. J. (2009). Banking sleep: realization of benefits during subsequent sleep restriction and recovery. Sleep, 32(3), 311–321. https://doi.org/10.1093/sleep/32.3.311
   
9. Axelsson, J., & Vyazovskiy, V. V. (2015). Banking Sleep and Biological Sleep Need. Sleep, 38(12), 1843–1845. https://doi.org/10.5665/sleep.5222
   
10. Arnal, P. J., Sauvet, F., Leger, D., van Beers, P., Bayon, V., Bougard, C., Rabat, A., Millet, G. Y., & Chennaoui, M. (2015). Benefits of Sleep Extension on Sustained Attention and Sleep Pressure Before and During Total Sleep Deprivation and Recovery. Sleep, 38(12), 1935–1943. https://doi.org/10.5665/sleep.5244