You Can Catch up on Sleep fact

Can a Person Catch up on Sleep?

Studies show you can semi-effectively catch up on short-term sleep debt over a few nights, but not long-term sleep debt accumulated over time.^[2][3]

Short-term sleep debt and long-term sleep deprivation can contribute to mood disorders and a number of other health risks.

What is Sleep Debt?

Sleep debt refers to the difference between the amount of sleep your body needs, versus the amount of sleep you actually get. As you deprive yourself of sleep (undergo sleep derivation), your total sleep deficit builds over time resulting in long-term sleep debt. Long-term sleep debt and sleep deprivation in general have negative health effects.

Example: If you get 5 hours of sleep, and needed 7, you have 2 hours of sleep debt/deficit for that day. If this happens every day of the week, you have a 14 hour sleep debt/deficit.

A video discussing how much sleep a person needs and whether or not you can catch up on it.

Short-Term Sleep Debt Versus Long-Term Sleep Debt

Short-term sleep debt and long-term sleep debt are loose terms, but generally they refer to sleep deprivation added up over a number of days:

• Short-term sleep debt refers to sleep debt over a short period of time, perhaps a week or so.
• Long-term sleep debt refers to sleep debt accumulated over weeks, months, or even years.

Sleep Debt Versus Sleep Deprivation

Sleep deprivation refers to being deprived of sleep, typically over consecutive days; sleep debt is a measure of insufficient sleep over a period of time (x hours per night). Sleep debt over time can have health risks similar to consecutive sleep deprivation.

Is Sleep Debt Cumulative?

While we can’t measure exactly how sleep debt builds up, we can measure the effects of going X amount of time with X hours of sleep debt. In general sleep debt is cumulative and can lead to health problems.

For example: about two weeks of less than 6 hours sleep a night reduces alertness and performance to a level equivalent to a full 24 hours of sleep deprivation; a week of only four hours sleep a night is equivalent to 2-3 days without any sleep; etc.^[1]

How Much Sleep Should Someone Get?

The average healthy adult needs about 7 1/2 to 9 hours of sleep, while children need more.^[6][7]

Average Sleep Needs by Age
Newborn to 2 months old	12 – 18 hrs
3 months to 1 year old	14 – 15 hrs
1 to 3 years old	12 – 14 hrs
3 to 5 years old	11 – 13 hrs
5 to 12 years old	10 – 11 hrs
12 to 18 years old	8.5 – 10 hrs
Adults (18+)	7.5 – 9 hrs

NOTE: recommended hours of sleep differ per source, and different people need different amounts of sleep. We have seen 5 – 10 and 7 -8 hours as the recommendation.^[8]

How Much Sleep Do People Actually Get?

A study from the UK showed people got an average of about 6 1/2 hours a night of sleep.^[8] This could equate to an hour or more of sleep debt a night for those who fall into the “average” category. As with any statistical analysis there will be outliers, people who need more or less than the average group.

In general, it seems to be common to get less than the ideal amount of sleep in modern western society. Consider that our ancestors probably got much more sleep than we do now due to a lack of artificial light and long hours of darkness in many regions of the world during the winter, and then got less sleep than we now during longer summer hours, particularly in areas of the world where there is a large difference in the day/night balance. In fact it’s believed that people practiced something called segmented sleep. It’s likely that many of us still require more sleep then we are getting on average.

Reasons Why People Don’t Get Enough Sleep

In the same UK study mentioned above, the number one reason for missing sleep wasn’t just long hours are watching TV, it was actually worry due to financial insecurity (i.e. money worries).^[8]

Listed below are the top five reasons that are giving Britons sleepless nights:^[8]

1. Money worries (32%)
2. Family issues (25%)
3. Work stress (18%)
4. Job security worries (17%)
5. Unfinished household chores (16%)

Health Risks of Sleep Debt and Sleep Deprivation

Research has shown that even missing a few days of lost sleep can have adverse effects including: daytime sleepiness, worsened daytime performance, an increase in molecules that are a sign of inflammation in the body, and impaired blood sugar regulation.^[2]

It is also thought that long-term sleep debt may compound issues potentially causing irreparable damage.

Sleep deprivation from sleep debt may also cause:^[4]

• aching muscles
• confusion, memory lapses or loss
• depression
• development of false memory
• hallucinations
• hand tremor
• headaches
• malaise
• stye
• periorbital puffiness, commonly known as “bags under eyes” or eye bags
• increased blood pressure
• increased stress hormone levels
• increased risk of diabetes
• increased risk of fibromyalgia
• irritability
• nystagmus (rapid involuntary rhythmic eye movement)
• obesity
• seizures
• temper tantrums in children
• yawning
• mania
• symptoms similar to:
  • attention-deficit hyperactivity disorder (ADHD)
  • psychosis

NOTE: It should be noted that getting too much sleep may have it’s own health risks, so the best advice is to simply pay attention to your body and try to fall within your own normal sleeping times.

The Study That Shows You Can Catch Up on Sleep Debt (Somewhat)

With the above in mind, Penn State University College of Medicine placed 30 volunteers on a sleep schedule that mimicked a sleep-restricted workweek followed by a weekend with extra recovery sleep.^[2][3]

• They found that sleepiness and inflammation rose with a lack of sleep, but returned after the period of recovery sleep.
• They found that stress rose with a lack of sleep, but lowered after recovery sleep.
• They also found that attention suffered during sleep deprivation and didn’t return after recovery sleep.
• This study had essentially concluded that while some sleep debt can be “repaid”, recovery sleep over just a single weekend may not reverse all the effects of sleep lost during the workweek.

In general, it is thought that you can catch up on short-term sleep debt, and may be able to offset some of the effects of long-term sleep debt. Long-term sleep debt, on the other hand, may have some non-reversible side effects.

Is There Evidence That You Can Catch up on Long-Term Sleep Debt?

There is no clear evidence that one can or can’t catch up on long-term sleep debt, this is because most studies have focused on short-term sleep debt.^[5]