Is sleep debt a real thing - and can you actually catch up on lost shuteye?

We’ve all heard of the concept of sleep debt, but what exactly is it and is it possible to make up for lost sleep? We asked three experts.

Here are their answers:

DR ALISON BENTLEY

General practitioner, researcher and expert on sleep disorders

There is definitely such a thing as sleep debt. When you wake up in the morning you start spending on a credit card which needs to be paid off every night when you sleep. If you don't sleep enough then you are in sleep debt when you start the next day. Sleep debt is very much like credit card debt - it can only be paid off by sleep (as in money for credit card). No amount of meditating/resting will pay off the debt.

Also, even when in massive debt the brain can really only take 14 hours of sleep as a maximum, but the sleep debt may not be paid. You have had your usual eight hours and then paid back an extra six hours which may not be enough. Many people have accidents after this first long sleep because they think they paid it all back.

The jury is out on whether you need to pay back hour-for-hour, because when in debt your sleep does become more efficient. Plan on catching up every hour you are behind.

DR IRSHAAD EBRAHIM

Specialist neuropsychiatrist in sleep disorders at the Constantia Sleep Centre

Sleep is not like a bank where you can go into overdraft mode. If you are sleep deprived your brain will first make up the deep sleep you lost and then the REM (rapid eye movement) sleep will kick in. You need to prioritise making up the deep sleep you lost.

If you’re chronically sleep deprived you will feel the impact of this, whether it’s physical or psychological.

The short answer is yes, in the very short term you’ll make up the sleep you lost, but if you are sleep deprived in the long term you’ll feel the impact of this, and you won’t be able to make up this sleep.

DR MAUREEN ALLEM 

Founder and medical director of Sleep Renewal

Thinking that one can make up for lost sleep at the weekend after a week of late nights and early mornings is a myth. Keeping a consistent schedule is best for the body, as chronobiologist Till Roenneberg so adequately explains in his book, Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired. 

The fact is that you can actually throw your body off even more by trying to catch up on sleep at the weekends, which can create a vicious cycle as it is then harder to sleep during the week.

If you, however, really are sleep deprived, do try to get in a few extra hours when you can. But this is not a long-term solution and establishing a routine of getting enough deep sleep is highly recommended.