Sleep is one of the four fundamental pillars (others being exercise, diet, and stress management) of making sure we are healthy and happy. Lack of sleep wreaks havoc on all aspects of our health – impairs our immune system, makes us less resilient to stress, increases the risk of neurodegenerative and other diseases, and can even disrupt our metabolism and increase our chance of gaining weight.
An average healthy adult should aim to get 7–8 hours of continuous uninterrupted sleep every night.
Sleeping less or more than 7–8 hours for extended periods of time is associated with various health issues, such as increased risk of cardiovascular, mental, metabolic and neurodegenerative diseases.
Acute sleep deprivation, meaning sleeping too little for 1 or 2 nights, is not as harmful to our health as chronic lack of sleep, which is sleeping too little for months and years.
Recovering from even a few nights of too little sleep takes several weeks.
One can mitigate sleep loss damages by prioritizing adequate sleep and napping.
However, we are all humans living this unpredictable life, and it is very normal from time to time to get a bad night of sleep. In this article, we will explore whether we can recover from lack of sleep and what it takes to do so.
What is too little sleep?
First, let’s define what is meant by lack of sleep. What is too little sleep? Every person has a different need for sleep depending on their age, health status, genetics, light conditions, everyday activities, and how much the person has slept the previous days.
For example, after a day full of physical activity, when we are sick or in winter, we need to sleep more. On the other hand, if we have slept enough previously, days are full of sunlight, and we are not physically or cognitively active, it is rather normal to need a bit less sleep.
Even though the perfect duration of sleep varies from person to person and day to day, as a rule of thumb, an average healthy adult should aim to get 7–8 hours of continuous uninterrupted sleep every night. Sleeping less or more than that for extended periods is associated with various health issues, such as the increased risk of cardiovascular, mental, metabolic, and neurodegenerative diseases.
Some of the signs that you are getting enough sleep are that you wake up rather easily and feel refreshed within 15–30 min after waking up, that you do not feel exhausted during the daytime, and are easily able to perform all your daily activities without the need to nap, and that you gradually feel tired in the evening few hours before bedtime.
Acute and chronic lack of sleep
It is also important to distinguish between acute and chronic lack of sleep. An acute lack of sleep means that we slept too little for a night or two. This is quite common and happens to most people weekly or monthly. Acute sleep deprivation is not as harmful to our health as a chronic lack of sleep, which is sleeping too little for months and years. Over such extended periods of time, damage to our body can accumulate, which is very hard or even impossible to repair.
How to recover from lack of sleep
A natural question that might arise then is how can you recover from lack of sleep, or at least what can you do to mitigate the damages already done? The first step is to prioritize getting adequate sleep. This means making sure you get 7–8 hours of sleep every night and also that you aim to ensure good sleep quality by following good sleep hygiene advice, such as having a regular sleep schedule, getting enough sunlight in the morning, and avoiding caffeine, alcohol, tobacco and overeating close to bedtime. Taking a nap earlier in the day is also recommended, especially after acute sleep deprivation. In the next paragraphs, we will explore how long it actually takes to recover from lack of sleep.
Recovering from too little sleep takes longer than you think
A 2021 study tested how fast people recovered after two commonly experienced types of sleep loss, namely chronic sleep restriction, in which participants were allowed to sleep only 4 hours a night for 5 consecutive nights, and acute total sleep deprivation – one night without any sleep at all. The study involved 83 healthy adult participants between the ages of 21 and 50 years.
When trying to understand how long it takes to recover from sleep, one has to decide which parameters to measure. As we know, poor sleep impairs pretty much every aspect of our health – immune system, mental health, hormones, metabolism, our cognitive abilities. In this study, researchers decided to test reaction time, vigilance, attention, self-reported vigor, and ability to resist sleep before the sleep deprivation regimens and 4 consecutive recovery days after it. Researchers found that all parameters returned to normal levels during the 4 recovery nights, except vigilance after chronic sleep and vigor after acute sleep deprivation.
Yet another 2021 study supports the findings of previous research, stating that recovery from sleep takes longer than one might think. Here, researchers, had study participants sleep 30% less than they usually do for 10 days, after which a week of recovery sleep followed. Researchers measured cognitive performance and found that even after a full week of recovery sleep when study participants were allowed to sleep as much as they wanted, cognitive performance was diminished and did not reach baseline levels that were measured before sleep restriction.
Longer sleep on weekends is not enough to recover from lack of sleep during weekdays
Another 2021 study investigated the effects of 6 weeks of chronic sleep restriction with weekend recovery on cognitive performance and well-being in high-performing adults. The study involved 15 individuals who were allowed to sleep only 5 hours on weekdays and 8 hours on weekends. Using a battery of 10 cognitive tests covering a range of cognitive domains, researchers showed that such chronic lack of sleep even when allowing longer sleep on weekends led to decreased accuracy across cognitive domains, decreased vigilant attention, and increased speed at the expense of accuracy on a spatial cognition task. Importantly, these cognitive performance deficits were not restored by two nights of 8-hour recovery opportunities at weekends.
In conclusion, even though we can mitigate some damages done by lack of sleep, research says that such recovery takes much longer than one might think.
- Sleep. Effects of six weeks of chronic sleep restriction with weekend recovery on cognitive performance and wellbeing in high-performing adults.
- Sleep. Residual, differential neurobehavioral deficits linger after multiple recovery nights following chronic sleep restriction or acute total sleep deprivation.
- PLOS ONE. Observing changes in human functioning during induced sleep deficiency and recovery periods.