Sleep Debt: The Hidden Cost of Insufficient Rest

Sleep is an essential part of overall health, and getting enough restful sleep on a regular basis offers a plethora of benefits. Quality sleep helps boost energy levels and immune function, and supports cognitive processes like memory consolidation. Not getting enough sleep can have serious consequences and interfere with work, school, and driving.   

Sleep debt, also called a sleep deficit, is the difference between the amount of sleep someone needs and the amount they actually get. For example, if your body needs eight hours of sleep per night but you only get six, you have accumulated two hours of sleep debt. However, through healthy sleep practices and lifestyle accommodations, you can recover from sleep debt and regain the benefits of quality rest.

What Are the Effects of Sleep Debt?

For many people, getting enough sleep can be a challenge. More than one-third of Americans get less than seven hours of sleep Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source every night. Losing sleep is even more common in people who work in the medical field or other jobs that require shift work.

Being in a prolonged state of sleep debt or sleep deprivation on a regular basis increases the risk of diabetes, hypertension, heart disease, and stroke. Sleep deprivation is also linked to reduced immune function, metabolic dysregulation and weight gain, and a greater risk of falls and accidents. Prolonged sleep deprivation also affects memory and cognitive functions.

Since sleep debt is cumulative, going to sleep 30 or 60 minutes later than usual for a few days can quickly add up. The most common activities that cause Americans to miss sleep are work hours, commuting, socializing, relaxing, and watching TV.

Those with accumulated sleep debt may not always experience increased levels of tiredness or fatigue. Research has demonstrated that people can cognitively adapt to chronic sleep restriction Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source without feeling particularly sleepy, even though their body is showing significant declines in physical and mental performance.

How to Avoid Sleep Debt

Learning how much sleep your body needs and prioritizing sleep is the best way to avoid the accumulation of sleep debt and its health consequences. While the amount of sleep each person needs can vary, research shows that most adults need at least seven hours Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source of sleep per night. Children and teenagers need even more sleep to support their bodies as they grow and develop.

It may seem like sacrificing a little sleep to study or work a few more hours helps you get more done, but getting sufficient sleep improves cognitive performance and allows you to be more efficient during the day. There are a number of ways to improve your sleep hygiene and reduce the chances of accumulating sleep debt.

• Keep a set sleep schedule: Maintaining a set sleep schedule allows you to prioritize sleep and make sure you are getting sufficient rest. If you need to change your sleep schedule, do it slowly by adjusting it in increments of 15 to 30 minutes.
• Develop a nightly routine: Having a nightly routine allows your body to relax and prepare for quality sleep. Set an alarm for 30 minutes to an hour before bed to remind you to dim the lights, turn off electronics, and find a relaxing activity.
• Consider daytime habits: If you are chronically sleep deprived, rethink any daytime activities that may be contributing to sleep issues. Make sure you are getting enough sunlight and exercise during the day, not drinking caffeine too close to bedtime, and restricting activities in your bed to just sleep and sex. Limiting screen time prior to sleeping may also help reduce sleep issues.
• Improve the bedroom environment: Optimize your bedroom environment for sleep. Keep the temperature comfortable for sleeping, block out any lights or noises that might keep you awake, and consider replacing your mattress, pillow, or sheets if they are old or uncomfortable.

Recovering From Sleep Debt

Sometimes losing sleep is unavoidable. Whether sleep deprivation is due to a demanding work schedule or a late night with family or friends, it is important to have a plan for recovering from lost sleep. 

Taking a nap is often the first remedy that comes to mind if you are sleep deprived. A brief, 10 to 20 minute nap Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source may help you feel more refreshed during the day. A mid-afternoon nap can increase working memory, learning, and mental acuity for a few hours.

Sleeping in on the weekends Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source to catch up on sleep is another common approach. Unfortunately, it is unclear if sleeping in actually compensates for sleep debt or if it simply helps the body to return to its normal sleep patterns. One study found that sleeping in on weekends does not reverse the metabolic dysregulation Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source and potential weight gain associated with regular sleep loss.

While both napping and sleeping in on weekends may help ease symptoms like fatigue or daytime sleepiness, they are often not enough to adequately recover from sleep debt. The accumulating effects of sleep loss is a debt that takes longer to repay. Research has shown that it can take up to four days to recover from one hour of lost sleep and up to nine days to completely eliminate sleep debt Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source . A full recovery from sleep debt returns our body to its baseline, reducing the negative effects associated with sleep loss.

A full recovery from sleep restriction can take even more time, according to a study that examined the recovery process Trusted Source PLOS ONE PLOS ONE is an inclusive journal community working together to advance science for the benefit of society, now and in the future. Founded with the aim of accelerating the pace of scientific advancement and demonstrating its value, we believe all rigorous science needs to be published and discoverable, widely disseminated and freely accessible to all. View Source of a prolonged period of restricted sleep. When given a cognitive functioning test, participants displayed worse performance during the 10-day sleep restriction period, then showed a gradual yet incomplete recovery in the final phase of the study, when participants could sleep as often as they liked. Results showed that even a full week of opportunity to recover after the 10-night span of restricted sleep was not enough to restore optimal brain function. 

Tips for Catching Up on Sleep 

These techniques can be useful to properly catch up on sleep and eliminate sleep debt.

• Stay consistent: Build time into your schedule for sleep and try to set your bedtime and morning alarm at the same times every day, even on weekends. Maintaining a consistent sleep schedule is important for resyncing circadian rhythms.
• Keep a diary: A sleep diary can help you track your sleep habits and identify patterns or practices that are affecting your sleep. 
• Try an afternoon nap: While napping is not a replacement for lost sleep, it can help you feel more rested during the day. Naps may be particularly helpful for shift workers or people who have trouble maintaining a consistent sleep schedule. Even a short power nap can refresh the body and brain.
• Give it time: Remember that it can take days to recover from a sleep debt. Increase your sleep time slowly, by 15 to 30 minutes at a time, until you reach the optimal amount of sleep for your body. Focus on improving your sleep hygiene and consistently getting enough sleep, and your body will do the rest.
• Talk to your doctor: If sleep debt is interfering with your daytime activities or if you are struggling to recover, it is important to speak with your doctor. A doctor can discuss the possibility of an underlying sleep disorder, like insomnia, and offer personalized tips for improving your sleep.