It’s no accident that we spend a third of our lives asleep. Like the rest of the animal kingdom, we humans need sleep for our overall health and well being. Restorative sleep is particularly important during our nights of sleep.
What is restorative sleep?
Many people recognise that sleep is important to health.
In fact, our bodies need to sleep in order to perform rejuvenating functions like muscle growth, protein synthesis, and tissue repair. We also need sleep for mental functions that involve learning and memory. In addition, sleep appears to play an important role in helping us manage stress and emotions. Although important restorative functions occur during all stages of sleep, the phases of deep sleep and REM sleep are the two sleep stages during which our bodies and minds undergo the most renewal. Together, deep sleep and REM sleep are often collectively referred as “restorative sleep.”
So what happens during deep sleep and REM sleep, these phases that make up our restorative sleep?
Deep Sleep: growth and healing
During deep sleep, our breathing rate and blood pressure decrease, and we enter what sleep experts call slow-wave sleep, when our brain waves become slow and large. This sleep phase is important for physical and emotional restoration. During deep sleep, the body releases growth hormones for healing and growth, which aid in cell repair and healthy new cell growth in tissues and organs throughout the body. It’s also during deep sleep that the immune system strengthens and renews itself.
The drive to catch up
If you lose one whole night of sleep, your body will try to make up its deep sleep the next night by increasing the amount of deep sleep you get. If you’re only partially sleep deprived (for example, getting 6 hours a night instead of 7 or 8), you won’t necessarily get more deep sleep the next night, but recent research suggests that the deep sleep you do get may be “deeper.”
These natural catch-up efforts are a sign of how important deep sleep is to your health and daytime functioning, as your body works hard to make that you get enough of it.
REM: important for memory
REM (Rapid Eye Movement) sleep is a mentally active phase of sleep when our most vivid dreams occur.
During REM sleep, our bodies function in many ways that are similar to when we’re awake. Our minds are active, our breathing and heart rate increase and become more variable than in other sleep stages. However, during REM sleep, most of our muscles shut down, severely restricting movement during this phase. REM sleep is essential for memory formation and storage, as well as for emotional processing. Studies have shown that REM sleep helps us to learn and develop new skills.
When is sleep most restorative?
Deep sleep occurs mostly within the first third of the night, while REM sleep occurs mostly within the final third of the night. This means that in order to get the restorative sleep your body needs from both deep sleep and REM sleep, you should sleeping regularly for between 7 to 9 hours a night on a consistent schedule that includes regular bed times and wake times.
Both deep sleep and REM sleep can be affected by the habits and activities we engage in during the waking day, such as drinking caffeine or alcohol, or by exercising. Be sure to keep an eye out for any sleep stealers among your daily habits that could be chipping away at your restorative sleep.
Sleep well, and feel better through the power of restorative sleep.