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What Is Sleep Debt?

Medically Reviewed by Dan Brennan, MD on June 05, 2021

Sleep debt, also known as sleep deficit, is the difference between how much sleep you need and how much you actually get. When you sleep fewer hours than your body needs, you have a sleep debt.

Sleep debt adds up over time and can negatively impact your health. Read on to learn about sleep debt, the consequences of not sleeping enough, and more.

What Is Sleep Debt?

Sleep debt is when you sleep fewer hours than your body needs. It’s cumulative, meaning that if you regularly get less sleep than you should, you’re going to have more sleep debt.

For instance, if you get four hours of sleep when you should be getting eight, you’ll have a sleep debt of four hours. If you do this for the next seven days, you’ll end up with a sleep debt of 28 hours.

In the same vein, if you go to sleep 20 minutes or 40 minutes later than usual for a few days, that can quickly add up your sleep debt — even though it doesn’t seem like you’re losing a lot of sleep. Accordingly, you should watch your late-night habits and make sure you’re not missing sleep by commuting, relaxing, working, studying, or watching shows.

Consequences of Sleep Debt

Sleep debt can negatively impact your health, since getting enough sleep is important for your health. 

If don’t get enough sleep on a regular basis, you might:

  • Feel tired throughout the day
  • Lose your ability to remain focused and efficient during the day
  • Weaken your immune system
  • Make it more difficult for your brain to process and store new information

However, you may not always feel tired if you have a sleep debt. Research has shown that you can adapt to chronic sleep restriction. This means that even if you don’t feel sleepy, your body may already have significant declines in mental and physical performance.

You’ll also be at a higher risk for the following conditions if you don’t sleep as much as you should:

  • Hypertension (high blood pressure)
  • Diabetes mellitus ( diabetes)
  • Coronary heart diseases
  • Obesity
  • Cardiovascular diseases

How To Avoid Sleep Debt

To avoid the consequences of sleep debt, you need to learn how much sleep your body needs and improve your sleep hygiene. Keeping a sleep diary, developing a nighttime routine, reconsidering your daytime schedule, and making your bedroom more sleep-friendly will all help avoid sleep debt.

Find out how much sleep you need. The first step to avoiding sleep debt is to learn how much sleep you need. This varies from person to person.

Most adults need seven to nine hours of sleep per night according to the National Sleep Foundation, while teens and children need even more sleep. Specifically, it’s recommended for children to get nine to 11 hours of sleep while teenagers should get eight to 10 hours of sleep each night. 

Keep a sleep diary. Keep a diary or schedule where you can set a sleep schedule. This will allow you to prioritize sleep and make sure you’re getting the rest you need. If you want to change your sleep schedule, you should do it slowly through 30-minute or 60-minute increments.

Develop a nighttime routine. Think about what relaxes you before you go to sleep so you can get quality rest. For example, you can turn off your electronics, stop studying or working, and dim the lights half an hour before you go to sleep.

Reconsider daytime schedule. See if there’s anything you do during the day that may contribute to your lack of sleep. If you find something that limits your sleep, try and avoid it or find an alternative.

Things you can try may include:

  • Avoid caffeine after sunset.
  • Get more exercise during the day so you’re tired enough to get quality sleep.
  • Use your bed only for sleeping and sex.

Making your bedroom more sleep-friendly. You can make sure that your bedroom is a good place to sleep if you:

  • Get rid of sources of distraction, such as objects that make noises or lights that can keep you awake. This includes electronics.
  • Replace your sheets, pillow, or mattress if they’re uncomfortable.
  • Keep the temperature of the bedroom good for sleeping (around 65 degrees Fahrenheit or 18 degrees Celsius).

How To Recover From Sleep Debt

When losing sleep sometimes is unavoidable due to life circumstances, you should make up for lost sleep by taking naps, sleeping more on the weekends, and most importantly, reconsidering your relationship with sleep.

Take naps. If you’re underslept, you should take a 10-minute to 20-minute nap. This will help you feel more refreshed and capable of taking on various tasks throughout the day.

Naps offer the following benefits for people with sleep debt:

  • Lessens fatigue
  • Boosts energy
  • Improves cognitive performance
  • Makes you feel less sleepy

However, you can’t rely on napping to make up for lost sleep. Naps can help relieve sleepiness and make you more energetic, but they shouldn’t interfere with your sleeping schedule.

Sleep more on the weekends. You can also sleep more by sleeping in during the weekends to make up for your sleep debt. However, it’s not clear how much sleeping in can make up for sleep loss. 

One study has shown that sleeping in on weekends can’t reverse the potential weight gain and metabolic dysregulation that can come with regular sleep loss.

Reconsider your relationship with sleep. To recover and avoid falling into sleep debt, you need to reconsider your relationship with sleep. 

Instead of thinking of sleep as another chore, think of it as preventative medicine. Remember, sleep can reduce illness and boost your health. You should start seeing sleep as a vital part of your life and overall well-being.

WebMD Medical Reference

Sources

SOURCES:

Current Biology: “Ad libitum Weekend Recovery Sleep Fails to Prevent Metabolic Dysregulation during a Repeating Pattern of Insufficient Sleep and Weekend Recovery Sleep.”

Harvard Health Publishing: Harvard Medical School: “Weekend catch-up sleep won’t fix the effects of sleep deprivation on your waistline.”

Sleep: “A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative?” “The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation.”

Sleep Foundation: “Sleep Debt and Catching up on Sleep.”

Sleep Health: “National Sleep Foundation’s sleep time duration recommendations: methodology and results summary.”

Sleep Medicine: “Short sleep duration and health outcomes: a systematic review, meta-analysis, and meta-regression.”

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