How do you pay back a short-term sleep debt that you have accumulated during the previous week? Short answer: it all depends on how much sleep debt you have accumulated over the past week.
Repaying Your Sleep Debt
In general, your body is incredibly good at making up for a short-term sleep loss, if you just have one night of short sleep. If you get only got 4,5 hours of sleep on one night, your body can fully recover the next night if you sleep for a solid 9 hours. That night you will not only sleep longer, you will also spend more time in high quality non-REM and REM sleep to make up for the previous night. And even if you only get 7,5 hours of sleep that night, chances are high that you will make up for the night before, simply because the amount and type of sleep you get (both non-REM and REM) are influenced by the sleep you got the previous night.
However, when you accumulate a sleep debt over the course of the week your body and brain will not be able to fully recover without extra hours of sleep during the weekend.
Minor Sleep Debts
If the total sleep debt that you have accumulated over the precious week is less than three hours, the easiest way to repay it, is to sleep in for 90 minutes on both days of the weekend. Alternatively, you can get up at your regular time and choose to have a siesta of 90 minutes after lunch on both days of the weekend.
If your sleep debt was more than three hours you will need to build in more time for sleep during the weekend.
For instance, if the total sleep debt that you have accumulated over of the precious week is three to six hours, the easiest way is to repay it, is to sleep in for 90 minutes on both days of the weekend and have a siesta of 90 minutes on both days of the weekend.
N.B. Don’t think that sleeping in longer than 90 minutes will help you to repay more of your sleep debt. While sleeping longer will increase your chances of getting some extra REM sleep, it will not help you get more restorative deep sleep. Furthermore, especially when you sleep in on both days of the weekend, it may shift your biological clock backwards which can make it much harder to fall asleep at your regular bedtime on Sunday evening; depriving you of the much-needed sleep before the work week begins.
In short: sleeping in is good, but don’t overdo it!
Major Sleep Debts
If you have accumulated a sleep debt of six to nine hours it’s good to realize that you have missed an entire night of sleep, and that this will have had significant impact on your performance during the previous week. To make up for this kind of sleep debt you will need to top-prioritize sleep on the weekend. The only way you will be able to fully repay your outstanding sleep debt is by combining different strategies. Ideally you (1) go to bed earlier, (2) sleep in longer than you normally do and (3) take restorative naps. Maybe this sounds too much and chances are that you simply won’t be able to do all of it, but it’s good to realize that this is what you would actually need to fully repay your outstanding sleep debt and start with a fresh body and brain the next week.
Finally, when you have accumulated a sleep debt of more than nine hours in the previous week, you will have to accept that you will NOT be able too fully recover on the weekend. You simply need more time to do so. While sleep efficiency varies significantly between individuals, you will probably need to sleep at least three extra hours on both days of the weekend and an extra hour on the first days of the next week (or an extra half hour on all days of the week). This may seem highly impractical, but is what you need if you want to perform at your best ability.
The Power of Naps
There are two types of naps, power naps and restorative naps. Power naps can be highly beneficial to your mood and executive functions, boosting your focus and creativity for a few hours. However, they are not effective at repaying an outstanding sleep debt. Longer naps, which are called restorative naps (90 minutes) will help you catch up on missed sleep.
By combining restorative naps in the early afternoon with sleeping in for a max of 90 minutes on both days of the weekend, it’s possible to repay more than six hours of an outstanding sleep debt in one weekend. Maybe not enough, if you structurally sleep too little, but in many cases an effective strategy to recover sufficiently and start fresh the next week.
How long you need exactly to repay a sleep debt that you accumulated in the previous week also depends on what you are doing throughout the day. Many things, such as consumption of alcohol or caffeine can have a negative influence on time and quality of your sleep and thus make it much harder to catch up on missed sleep. Other behaviors will have a positive impact on your sleep; exercise for example can help you to get more deep sleep and repay your sleep debt faster!
Beware: If you continue to sleep too little during the week and catch up in the weekends, you might have repaid your debt. However, because you keep falling short during the week, your health (credit rating) will suffer in the long run.
Making up for a Long-Term Sleep Debt
When you haven’t been getting the sleep you need for a longer period of time (weeks, months or years), your body and brain suffer in a variety of ways, which without a doubt will have a negative impact on your performance, as well as your Wellbeing. The good news is that you will not have to make up for each and every one of those hours to repay your sleep debt. It will however take much longer to fully recover; think weeks, not days. Many people who sleep too little during the year recognize this when they go on a long vacation in the summer. After two weeks of sleeping without an alarm clock, often sleeping for ten or more hours per night, they finally start to wake up fully rested. The trick here is obviously to avoid backsliding into a new sleep debt cycle.
Calculate Your Sleep Debt
In order to calculate your sleep debt, you first need to know how much sleep you need. While the vast majority of people need between 7 – 9 hours, it may be less or more for you. To figure out how much sleep your body needs, I offer the ‘vacation solution’. Allow yourself to wake up naturally for two weeks, in a relaxed period of time; you can then calculate your baseline sleep need.
Improve the Quality of Your Sleep
Once you know how much sleep you need to wake up fully refreshed, then prioritize it and factor it into your daily schedule. And if you need any tips on how to get the most out of your time spent in bed, then check out the advice on ‘How to Sleep Like a Baby‘.