Learn why it's key to clock quality Zzzs.

Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.
Advertisement

Most of us have heard the saying that healthy adults need seven to nine hours of sleep per night. Yet when it comes to the sleep that we bank, quality often trumps quantity. While getting the recommended number of hours of sleep per night might seem like enough to keep our physical and mental wellness in check, how well we actually sleep during that time plays a much bigger role.

To help debunk the mystery surrounding what counts as good quality sleep, we've enlisted the help of experts to weigh in on sleep quality vs. sleep quantity—and why you need both for optimal health. Here's why sleep quality is just as important—if not more important—than sleep quantity, and the steps you can take to get it.

Related Items

Understanding Sleep Stages

Many doctors have a simple definition of good sleep quality: sleep that is restful and restorative. That sounds like a subjective characterization, but there are objective factors to qualify nightly sleep, too. To understand how sleep architecture is structured, think of it as cycles of sleep that each last about 90 minutes. Throughout each of these cycles, we go through a series of sleep stages that all contribute to sleep quality, explains Bruce Forman, PhD, a Florida-based psychologist.

 It starts with non rapid eye movement sleep, known as non-REM or NREM sleep. The first stage is a light sleep where dozing off begins. Then, we enter the second stage of light sleep, where we may be able to respond to someone speaking to us or claim we're not really asleep. In the third stage of non-REM (which can actually be divided into two stages, one even deeper than the next), we enter deep sleep, which is more commonly known as slow-wave sleep. Your brainwave activity during these deep-sleep stages is literally slower—about 10 times slower—than it is when you're awake, writes Matthew Walker, PhD, professor of psychology and neuroscientist, and director of UC Berkeley's Sleep and Neuroimaging Lab, in his book Why We Sleep: Unlocking the Power of Sleep and Dreams

By the time we reach the final stage of the cycle, we're in our deepest sleep yet. At this point we experience rapid eye movement sleep, or REM sleep. "This is the time when we dream," Forman says. "Oddly enough, our brains are just as active during REM sleep as they are while awake." According to Walker, REM sleep brainwave activity is nearly identical to that of a brain at its most awake and alert.

Getting a healthy balance of both REM sleep and non-REM sleep (the other three stages of the cycle) is how we end up having that glorious sleep that makes us wake up feeling refreshed.

RELATED: Why You're Always So Tired—and What You Can Do About It

Why We Need Both REM and NREM Sleep

A balanced amount of REM and NREM sleep is essential for both physical and mental health. Forman explains that when the balance is off, it can result in cognitive decline, exhaustion, and even accident proneness. "It is also a risk factor in health issues such as hypertension, obesity, and diabetes, as well as mood disorders," he says.

Plus, each sleep stage plays an important role in taking care of our brains and bodies. "During REM sleep, our breathing and heart rate changes," explains Ruth Varkovitzky, PhD, licensed clinical psychologist and owner of Renewal Psychology. "This important stage of sleep helps with consolidation of learning as well as emotional processing." 

Meanwhile, during NREM sleep, our brains slow down and our sleep is the deepest. "During non-REM sleep, our body is working hard to strengthen our immune system," she continues, "rebuild bone and muscle, and repair and regenerate tissues."

RELATED: Nightly Techniques to Help You Fall Asleep Fast, According to Sleep Experts

Sleep Quality Is Even More Important Than Quantity

According to Varkovitzky, sleep quality matters much more than sleep quantity—particularly when sleeping in a defined period of time. "Sleep quality is often represented by having consolidated sleep," she says. "In other words, sleeping in one big chunk, instead of having little pieces of sleep spread throughout the day or night."

While brief awakenings are normal, Varkovitzky says the human body can get more rest and feel more recharged from one continuous span of sleep. "Having an extended sleep period allows us to naturally move through all the stages of sleep, including REM sleep as well as non-REM sleep," she says. "The ability to go through this cycle multiple times is important for sleep quality, which is another reason consolidation of sleep to one span is essential." 

Not only do you need to go through each cycle multiple times, but each time the cycle repeats, the ratio of non-REM to REM sleep changes, with a higher proportion of non-REM sleep at the beginning of the night and a higher proportion of REM sleep taking over in the morning hours. The brain craves different sleep types at different parts of the night, so shortchanging at either end can seriously disrupt quality sleep.

To further prove that good sleep should be measured by quality instead of quantity, Forman explains that too much sleep can also be detrimental to our health. According to his experience treating insomnia and other sleep disorders, most adults average about seven to seven and a half hours of sleep per night. "As sleep increases beyond this amount, mortality risk increases," he says.

How to Improve Sleep Quality

Since sleep quality is directly linked to better health, satisfaction, and overall happiness, it's important to make quality just as big of a priority as quantity. Sleep quality often relies heavily on healthy sleep habits and hygiene; what you do over the course of the day, and how you wind down to get ready for sleep at night, can significantly impact how well you sleep. Two of the key areas to focus on are light and temperature, Forman says: "Since light and temperature regulate sleep, we should be mindful that cool temperatures and darkness stimulate sleepiness."

Forman also suggests limiting the use of your bed to sleep and sex. "Other activities such as watching TV or using electronic devices should be avoided so that the brain associates lying in bed in the dark with sleep," he continues. Another great thing you can do to promote a healthy sleep schedule (and in turn, quality sleep) is to wake up at the same time every day.

Varkovitzky recommends staying active in the daytime, taking a warm shower or bath before bed, and keeping a quiet and relaxing sleep environment to boost sleep quality as well. If you can, she also suggests steering clear of naps (especially later in the day), which can disrupt the idea of consolidated sleep.

While sleep quantity—getting enough sleep—matters, sleep quality is arguably even more important. As you continue to make good quality sleep a priority in life, simple lifestyle changes can go a long way. However, it's always best to consult with a doctor first if you're experiencing ongoing sleep problems.

RELATED: Our Sleep Needs Change as We Age—Here's How to Sleep Well in Your 20s, 30s, 40s, and 50s