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What Is Restorative Sleep?

Achieving the recommended amount of sleep per night is vital for promoting health and staying at the top of your game. Regularly getting between 7-9 hours of sleep per night is associated with several health benefits, including supporting the immune system, reducing the risk of conditions including heart disease and diabetes, improving mood, decision-making, and mental clarity, and maintaining a healthy weight. 

Getting enough sleep is often easier said than done with many factors, from stress to caffeine, certain medications, and uncontrolled health or sleep conditions contributing to disrupted sleep. The CDC reports that around 1 in 3 US adults state that they don’t sleep enough on a daily basis. 

While getting more hours in bed is not always realistic given the demands of life, focusing on getting quality restorative sleep can provide countless benefits to your body, and make you feel more rested. This article explores what restorative sleep is, how to maximize your chances to achieve it regularly, and the many benefits you’ll gain from prioritizing restorative sleep.

What is Restorative Sleep?

Many of the positive benefits of sleep are due to what experts call “restorative sleep,” which WHOOP defines as the combination of deep sleep (SWS) and REM sleep.

Every day, you experience a normal depletion of cellular components that are used for key biological processes. During sleep, the body is able to replenish stores of these components and undergo repair and healing that is necessary for optimal function. Research indicaties that growth hormone release, tissue growth, protein production, and muscle repair all take place during sleep.

What Makes Sleep Restorative?

Restorative sleep refers to how much time you spend in deep (slow wave sleep) and REM (rapid eye movement) sleep each night. Deep sleep is known as the physically restorative stage of sleep, and is when many of the body's regenerative processes happen. REM sleep is known as the mentally restorative stage of sleep, where most of our dreams occur, and short-term memories are converted into long-term memories. Together, maximizing restorative sleep improves your recovery, your cognitive function and ability to focus during the day, as well as support vital body processes.

The optimal amount of restorative sleep for most people is about 40-50% of the total time asleep in these restorative stages.

Not all sleep qualifies as restorative. This is why it’s possible to sleep for 7 or 8 hours a night and still wake up not feeling well-rested. Sleep can be divided into the following two categories: 

Restorative Sleep

Restorative sleep allows you to wake up feeling like your sleep was both restful and refreshing. There are four stages to sleep, beginning with what we at WHOOP refer to as “awake sleep” (aka Stage 1) as you fall asleep.

The second stage you enter is “light sleep” (Stage 2), which is a deeper period of sleep than the first stage, but is still considered to be light sleep. SWS and REM (Stages 3 and 4) are the periods of sleep where restorative sleep occurs. 

SWS is the deepest period of sleep. This is when physiological repair and growth takes place. Stage 3 sleep also promotes immune health. The fourth stage of sleep is referred to as REM, or rapid eye movement, sleep. During the REM cycle, memory processing and cellular regeneration occur. REM sleep also supports learning and cognitive function. The deep sleep experienced during Stage 3 and REM sleep is essential for mental and physical restoration. 

Non-Restorative Sleep

Non-restorative sleep is the opposite of restorative sleep. It’s characterized by feeling unrefreshed and unrested in the morning, even after getting the recommended amount of sleep. The effects of non-restorative sleep can interrupt daily activities, manifesting as trouble remembering information, difficulty concentrating and making decisions, feeling extremely fatigued, and falling asleep during the day. Non-restorative sleep has also been linked to mental health conditions including depression and diminished quality of life.

That said, light sleep still serves a vital function, especially as we age, and deep sleep occurs less often. Even in light sleep, your heart rate and respiratory rate slow. As we age, we tend to get more light sleep and less deep sleep, losing about 10-12 minutes per decade of age as our bodies produce lower levels of growth hormone and melatonin

But every stage of sleep is important for physical and mental health. As brain activity slows during light sleep we experience short bursts of activity that help us resist being woken up by external stimuli. Light sleep suppresses our senses and prevents us from moving so we can remain asleep. It’s also important for memory, learning and motor skills. Getting sufficient light sleep is essential to meeting your overall sleep needs

What Causes Non-Restorative Sleep?

When the body spends too much time in the first two stages of light sleep and not enough in the deeper sleep periods, the key processes underlying healing and restoration are unable to take place. 

Certain factors can increase the likelihood that you will experience non-restorative sleep. These include health issues like lung disease, chronic fatigue syndrome, anxiety, and chronic pain. Sleep conditions including insomnia, narcolepsy, and sleep apnea have also been associated with non-restorative sleep. Taking certain medications, dealing with excess stress, and not following a consistent sleep routine can also be contributing factors to non-restorative sleep.

Why Restorative Sleep is Important to Recovery, Health & Performance

Restorative sleep gives you a leg up both mentally and physically. WHOOP research has found that for every extra 30 minutes spent in deep, slow wave sleep, an individual is able to see a 5-10% increase in mental control the following day.

The same study found that for every 45 minutes of sleep debt a person experiences, they will also go through a 5-10% decrease in mental control the next day. To give your cognition the boost it needs to keep you sharp and alert throughout the day, restorative sleep is a must.

Restorative sleep isn’t just important for mental performance — it also plays a major role in physical performance. Intense workouts take a toll on your body — breaking down muscle fibers that need to be built back stronger for you to experience gains in muscle mass and strength. This muscle repair occurs during restorative sleep, which also contributes to bone and tissue repair, a balanced metabolism, and increased blood flow to the muscles.

How to Know If Your Sleep Was Restorative

Getting restorative sleep can make a big impact on your ability to perform day-to-day activities. That’s why it’s important to be able to recognize whether or not your sleep was restorative. Here are three aspects of your sleep to pay attention to when determining whether it was restorative or non-restorative:

  • Sleep Efficiency — Sleeping through the night is a sign of good sleep continuity, suggesting that you are able to pass through each of the sleep cycles and experience restorative sleep. If you wake up multiple times during the night or feel like your sleep is interrupted, you have poor sleep continuity and are more likely to have non-restorative sleep.
  • Sleep Latency — Sleep onset refers to how long it takes you to actually fall asleep. The average healthy individual has a sleep onset time in the range of 10-20 minutes. Sleep onset times that are shorter and longer than this average can indicate issues with sleep. Falling asleep right away can point to sleep deprivation or an undiagnosed sleep disorder, while taking much longer to fall asleep can contribute to poor sleep quality and non-restorative sleep.
  • Sleep Consistency — Paying attention to how consistent or similar your bedtime and wake times are over the course of several days can help you recognize ways to improve your sleep pattern and schedule, optimize your body’s rest and health, and maximize your energy the following day. Use WHOOP to track your sleep consistency and enjoy the benefits of consistent quality sleep, longterm. 

How to Increase Restorative Sleep

If you feel that you are mostly getting non-restorative sleep, or would like to make sure you get more restorative sleep whenever possible, there are strategies you can take to improve sleep quality and increase time spent in deep sleep. Here are a few techniques to try out for yourself:

  • Prioritize Sleep Consistency and Routine — Going to bed and waking up at the same time every day is a great way to support sleep consistency. Sticking to a regular sleep schedule helps maintain your body’s circadian rhythm, allowing you to cycle through every stage of sleep and get the restful, restorative deep sleep you need. 
  • Engage in Relaxing Activities Before Bed — Boost restorative sleep by focusing on sleep hygiene — which aims to create a relaxing environment and routine around sleep each night. Examples of relaxing activities to try as part of a sleep routine include taking a nightly bath or warm shower, reading or listening to music, walking your dog, practicing deep breathing and meditation, and limiting screen time before bed. To ensure you have an environment conducive to restorative sleep, make sure your room is cool and dark, and that you have a comfortable place to sleep.
  • Exercise Earlier in the Day — Scheduling your fitness sessions for specific times of day can also help improve sleep. Instead of exercising right before bed, consider morning or afternoon sessions. Certain workout types are more effective when performed earlier as well. For example, aerobic and resistance workouts can improve sleep onset when performed in the morning, and afternoon sessions of high-intensity fitness can boost sleep quality at night.

Improve Sleep with WHOOP

If one of your health goals is to improve your sleep and spend more time in deep, restorative sleep each night, WHOOP can offer valuable insights that you can use to enhance your sleep routine.

WHOOP keeps track of your time in bed, hours asleep, sleep need, sleep performance, wake events, sleep efficiency, sleep consistency, and stages of sleep – including how long you spend in restorative sleep every night. You can even view your restorative sleep trends over the course of a week, month, or six months at a time. 

Based on these data points, WHOOP also offers personalized daily sleep recommendations based on your nightly sleep performance. These recommendations can help you improve your recovery, maintain higher daily energy levels, and get all of the benefits of restorative sleep. 

Spend more time in restorative sleep and give both your mental and physical performance a boost by monitoring your sleep with WHOOP.