What Is Sleep Debt?
The human body must sleep. Without sleep, toxins will build up in your tissues, your nervous system will stop functioning properly, and you won’t live as long.
To get more done during the day, however, many people habitually forego sleep. Getting into sleep debt, however, could make you less efficient, and chronic lack of sleep will eat away at your health.
What does sleep debt mean?
Also known as sleep deficit, sleep debt is the difference between the number of hours you need to sleep and the number of hours you actually sleep. Sleep debt is cumulative, and it becomes increasingly damaging over time.
Here’s how sleep debt works:
- Your body needs to sleep for eight hours
- You only sleep for six hours one night
- Therefore, you have two hours of sleep debt
Sleep debt also works cumulatively, however:
- You already have a sleep debt of two hours from the night before
- Tonight, you also sleep six hours instead of the eight hours your body needs
- As a result, your sleep debt is now four hours
How do I know if I have sleep debt?
You have sleep debt if you have slept less than the number of hours your body needs to sleep to rejuvenate itself each night. Everyone is different, but according to the National Sleep Foundation, you need between seven and nine hours of sleep every night.
Since the amount of time each person needs to sleep is variable, sleep debt isn’t an exact science. If you’re getting less than seven hours of sleep every night, however, it’s guaranteed that you’ve accumulated sleep debt.
Here are some common signs of sleep debt you should watch for:
- Fatigue throughout the day
- Excessive perspiration
- Foggy thinking
- Falling asleep at inappropriate times in inappropriate places
- Digestive issues
- Poor memory
- Reduced physical strength
- Compromised immunity
- Reduced libido
Can you repay sleep debt?
Yes, it’s possible to catch up on lost sleep. You should always strive to get enough sleep every night, however.
Even losing a single night of good sleep increases oxidative stress throughout your body. Oxidative stress leads to inflammation, which is the root cause of many different diseases.
While it’s possible to catch up on lost sleep at a later date, you can’t erase the stress your body went through when you were sleep-deprived. Commonly going into sleep debt under the assumption that you can make up for lost sleep later is irreparably harmful.
With that said, it’s infinitely better to start making up for lost sleep than staying in sleep debt. Just don’t make the mistake of catching up on sleep only to go into sleep debt again.
What are some tips for catching up on lost sleep?
Chances are that you didn’t accumulate sleep debt for fun. It’s likely that your responsibilities thrust you into sleep debt in the first place, making it difficult to figure out how to dig yourself out of your hole.
There are a few simple tactics you can use, however, you get yourself out of sleep debt even if you’re strapped for time:
- Take a short nap during the early afternoon
- Rearrange your schedule to sleep longer for one or two nights in a row
- Sleep a little bit longer on the weekends
- Start going to bed progressively earlier
Let’s clearly state that catching up on sleep during the weekend isn’t a healthy long-term strategy. If you do use weekends for sleep catch-up, make sure not to sleep in any later than two hours after you usually get up during the week.
Sleeping too late on the weekends can disrupt your circadian rhythm, making it harder to get enough sleep on weekday nights. Instead of sleeping until the early afternoon on weekends and getting up at the crack of dawn on weekdays, focus on getting more sleep every night.
How long does it take to repay sleep debt?
One study from 2016 suggests that it takes up to four days to recover from just one hour of sleep debt. Getting enough sleep on two weekend nights won’t make up for a week of consecutively short nights. It won’t even help you recover sufficiently from one night of lost sleep.
How do I avoid sleep debt?
The only way to avoid sleep debt is to get enough sleep every single night. Even going one night without enough sleep is enough to harm your health, and it takes more than half a week to recover from a single hour of lost sleep.
It isn’t worth losing sleep just to work or study a little bit more. Cognitive performance is impaired by lost sleep, so you’ll actually do worse at your job or score lower on a test if you stay up too late.
Here are some tips for getting enough sleep every night:
Set a strict sleep schedule
Go to sleep and wake up around the same time every night. If you like going to bed at midnight and getting up at 8 AM, follow this schedule on both weekday and weekend nights.
With a modern smartphone, you can set a nightly sleep schedule. Check the instructions for setting up a sleep schedule on iOS and Android.
Settle into a sleep routine
Performing the same actions before sleep every night acclimates your body to your sleep schedule. Brush your teeth and get ready for bed at the same time every night.
Your sleep scheduling function on your smartphone will automatically remind you to stop using electronics before bed. It can even dim your lights for you before bedtime.
Improve your daily habits
Failing to get enough exercise or go outside during the day can negatively impact your sleep quality. Don’t drink caffeine any later than early afternoon, and practice good sleep hygiene.
Upgrade your bedroom
Your sleep gear might be preventing you from getting enough shuteye at night. Keep your bedroom cool, block outside light with blackout curtains, and consider investing in a white noise machine.
The most important factor that impacts your sleep quality is your mattress. Upgrade to a better mattress to improve your sleep debt overnight.
Is 5 hours of sleep enough?
No. Five hours of sleep is not sufficient for anyone. You will incur 2-4 hours of sleep debt if you only sleep five hours for a single night. Sleeping five hours per night consistently will significantly harm your health.
Is 7 hours of sleep enough?
For some people, seven hours of sleep per night might be sufficient. You may need more sleep, however, to stay healthy. If you habitually sleep for only seven hours per night, closely observe your physical and mental health to determine if more sleep is necessary.
What are some of the risks of staying in sleep debt?
Sleep debt not scary enough yet? Consider these risks of inconsistent sleep to incentivize yourself to get out of sleep debt once and for all:
- Weight gain and obesity
- Impaired immune functioning
- Bipolar disorder
- Cardiovascular disease
- Impaired nervous system functioning
- Memory impairment
- Oxidative stress and inflammation
What are the benefits of getting enough sleep?
Fear isn’t always the best incentive. You might be more swayed by the enticing benefits of getting enough sleep:
- Better cognitive performance
- Improved decision-making
- Increased professional performance
- Boosted financial health
- Improved metabolism
- Weight loss
- Emotional balance
- Better production of human growth hormone
- Increased antioxidant activity
Sleep debt isn’t always your fault. Upgrade your mattress or pillow if you want to experience the benefits of better sleep regardless of how much snooze time you can set aside every night.