Sleep debt: can you catch up on sleep? We ask an expert

Woman sat up, rubbing her eyes and looking tired, with a mug in her hand
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Sleep debt, also known as sleep deficit, is the difference between the amount of sleep a person needs and the amount they’re actually getting. As we all know, sleep is essential to our health so if we’re not getting enough, it can have ongoing effects. A lack of sleep can lead to a multitude of problems and can interfere in all aspects of your life.

It’s easy to get into sleep debt, but it’s harder to get back out of it. Sleep debt can occur very quickly so it’s a good idea to try and establish healthy sleep and lifestyle patterns to help you get the best night’s sleep in the first place. Make sure your bedroom environment is conducive to sleep – our guide to the best mattress and best pillows will help you update your bed if it’s not giving you a restful night.

What is sleep debt?

A person reaching for the snooze button on their alarm clock

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As we mentioned above, sleep debt is when you sleep fewer hours than your body needs. Also known as sleep deficit, it’s cumulative, meaning that the less sleep you get, the more your sleep debt builds up.

Just going to bed 20 minutes later each night for a few days can build up your sleep debt. For example, if you go to bed 20 minutes late each night for a week (seven days) you’ll have built up a sleep debt of 140 minutes, which is over two hours. Taking this further, say you only sleep six hours a night instead of eight, you’ll be building up a sleep debt of two hours a night. Over seven days this translates to 14 hours. You can see from the maths that, although it might not seem like a lot of sleep debt individually, taken cumulatively it quickly mounts up to a lot and can impact your sleep cycles and affect your circadian rhythms. 

What are the effects of sleep debt?

“Sleep debt can have a real, serious impact on both your overall health”, explains Rumeet Patel, independent Prescribing Pharmacist at LloydsPharmacy Online Doctor. “Research has found that, even if you feel you can adjust to reduced sleep, your body will begin to show physical and mental performance declines.”

Studies have also shown that sleep debt can cause weight gain. Rumeet explains that, “There is a link between sleep and weight loss. Recurrent insufficient sleep has been shown to cause metabolic dysregulation, which means that your late nights and early mornings during the working week could be the reason you’re struggling to shift some weight, even if you’re trying to make it up with sleeping in on the weekends.

“Another alarming side effect of sleep debt is its effect on cardiovascular and age-related illnesses. Sleep deprivation has been linked to coronary artery disease, hypertension, arrhythmias, diabetes and obesity, so it’s important to take your sleep seriously, especially if there is a history of heart disease in your family.”

Sleep debt can also lead to neurocognitive consequences. “Accumulated sleep debt can also be a contributing factor in poor mental health”, says Rumeet. “Studies have found that prolonged periods of sleep restriction can exacerbate symptoms of anxiety, depression.”

And sleep debt is also associated with disease related sleep fragmentation, such as sleep apnoea and restless legs syndrome.  

“An important factor to note is that it is incredibly difficult to repay your sleep debt”, reiterates Rumeet. “It can take your body a full week to properly recover from ten days of sleep debt, so it’s best to avoid sleep debt in the first place.”

How to get yourself out of sleep debt

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“If you’ve had some late nights or early starts, there are ways you can alleviate the effects of sleep debt”, says Rumeet. Here are his tips:

  • Naps -Taking naps can be a very useful way to combat the common side-effects of fatigue and mental drain. Just a short 10-20-minute nap can improve memory and learning.”
  • Sleep journals - “Keeping a sleep journal can help you track your sleeping habits. By knowing your current sleep pattern, you can begin altering it and work on becoming more consistent.”
  • Get professional help - “If you’re really struggling with your sleep, then it may be important to talk to your doctor. By seeking out personalised professional advice you can discuss other health factors which may be affecting your quality of sleep and potentially speak about issues such as insomnia.”

Rumeet reminds us that, “While these tips can be useful, the best way to improve your sleep debt is to avoid falling into it in the first place.” Knowing how to find your sleep window can be really helpful when it comes to adopting healthier sleep habits.

Tips for avoiding sleep debt

“The best way you can avoid sleep debt is to develop a healthy sleep schedule”, says Rumeet. “Developing a nightly routine can ensure that you are getting enough sleep every night.

There are lots of habits you can include in your personal nightly routine to help you get a better quality of sleep. Budgeting 30-minutes of your night to wind down and unplug from technology can be a useful way to relax and prevent mental stimulation before bed.

Avoiding screens and dimming your lights can also help you fall asleep easier. Looking at bright lights can hinder your body’s production of melatonin, one of your body’s sleep hormones, making it more difficult for you to get to sleep.

Not everyone is able to maintain such a regular bedtime and wake-time, for example, shift workers may have to alter their sleep schedules significantly around their job. For these people, it is important that you are still getting a solid eight hours of sleep per night to ensure optimal mental and physical health.”

And if you know you have some nights of disrupted sleep coming up, avoid falling into sleep debt by practicing sleep banking. Sleep banking relies on the same cumulative effect as sleep debt, but in the opposite direction – it's about building up a reserve of sleep to draw from when you miss out on rest.

Recovering from sleep debt

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You can’t always avoid losing sleep. A late night out with friends, working long hours or simply struggling to sleep can all lead to sleep debt. Having a plan to recover from sleep debt is important. Here are some tips:

  • Take a nap to help you feel more refreshed during the day.
  • Sleep in on the weekends – it’s unclear as to whether this compensates for sleep debt, but it will help the body return to normal sleeping patterns.
  • Don’t think of sleep as a chore, see it as a way for your body to prevent illness and keep you healthy.
  • Give it time. It can take days to recover from sleep debt, so don’t expect to feel better overnight.
Rumeet Patel
Rumeet Patel

Rumeet Patel qualified as an Independent Prescribing Pharmacist in 2018, specialising in minor illness and chronic condition management. In October 2019, Rumeet joined the Clinical Team at LloydsPharmacy Online Doctor.

Jo Plumridge

Jo Plumridge is a freelance writer and photographer with over 20 years of experience writing for a variety of magazines, books and websites. She writes, perhaps unsurprisingly, about photography but also extensively on all things sleep and interior design related, alongside home and tech product reviews. She’s lived in the middle of a nature reserve in Botswana and written a guidebook to New Zealand, but now spends a lot of time trying to photograph the cats she and her husband foster for a local charity - without a doubt the most challenging subjects on earth!