The Foundations of Good Quality Sleep

Sleep is crucial to our physical, mental, and emotional well-being. It helps the body create memories, repair tissues, break down food, and fight infections — impacting everything from our hormones, metabolism, and blood pressure to our mood, cognition, and immunity. Most adults require seven to nine hours of sleep each night, while teens, children, and babies need more sleep to support the development of their growing bodies and brains. 

While the amount of sleep we need for optimal health fluctuates throughout life, one thing remains the same: our need for good quality sleep. The type of sleep that leaves us feeling refreshed and ready for the day, comes morning. 

In this blog, we’ll look at the foundations of sleep quality and discuss what you can do to sleep more soundly for improved physical, mental, and emotional wellness. 

A little about sleep architecture 

Sleep is not a uniform, but cycles through different sleep stages:

• Stage 1 NREM (N1 sleep).
• Stage 2 NREM (N2 sleep).
• Stage 3 NREM (N3 sleep) = deep sleep
• Stage 4 REM (rapid eye movement or REM sleep) = dream sleep

While these stages can occur at any time during the night, deep sleep predominantly occurs in the earlier part of the night, within the first 3 hours of falling asleep, and often before midnight, making it so important to not go to sleep too late.

REM sleep on the other hand is more dominant in the 3 hours before the usual waking time (allowing many of us to remember dreams). 

While the body can adapt to a degree to a certain sleep-wake cycle, going to bed late (e.g. going to bed past midnight on the weekend) will take away from the amount of deep sleep available for that night, and you may feel more tired the next day, even if you still caught 7-8h of sleep!

Similarly, waking up very early (e.g. to catch a flight), will shorten or even eliminate REM sleep for that night, which impacts your creativity and clear thinking for the following day. 

Why sleep quality matters

We all need sleep. Not just any kind of sleep, but good quality sleep that’s both restful and restorative. Restorative sleep occurs during deep sleep – the third stage of the sleep cycle and the final stage of non-rapid eye movement (NREM) sleep. 

Although each stage of sleep serves a purpose, deep sleep is especially important for good health. In N3 sleep — the deepest stage of sleep — the body repairs itself, fights infections, and evaluates information learned during the day. If we don’t regularly get enough deep sleep, our memory, attention span, energy levels, and immunity can all suffer. 

Deep sleep is also when the glymphatic system in the brain clears toxins from the central nervous system, suggesting that deep sleep may play a role in neurodegenerative diseases like Alzheimer’s. However, sleep is just one piece of the puzzle; other lifestyle factors such as diet, physical activity, and stress management also affect brain health and impact the function of the glymphatic system.

How much deep sleep do you need? 

For optimal health, about 20 percent of our sleep time should be spent in deep sleep (equal to approximately 1.5h in a 7h sleep window). And while we can’t force our bodies into N3 sleep (as much as we’d like to), increasing the amount of sleep we’re getting overall can help us naturally get deeper, more restorative sleep. 

The foundations of good sleep

For many, establishing healthy bedtime habits is an important first step to getting more quality sleep. This is because our sleep hygiene — the habits and behaviors that influence sleep — impacts our sleep timing and duration, subjective satisfaction with sleep, daytime alertness, and other dimensions of sleep health. Sleep hygiene also affects the following four elements of sleep quality:

1. Sleep latency: the length of time it takes to fall asleep at night
2. Nocturnal awakenings: the number of times we awaken during the night
3. Wake after sleep onset: the amount of time spent awake after going to sleep
4. Sleep efficiency: the ratio of time spent asleep vs. awake while in bed

The good news is that many of the factors impacting your sleep health are modifiable. This means you can change them by improving your sleep environment, adopting healthier sleep habits, and addressing sleep disorders (such as sleep apnea) that keep you from getting the high-quality sleep you need. In some cases, improving your sleep quality could be as simple as keeping your mouth closed while you sleep!

The problem with mouth breathing

Many sleep habits and behaviors — including open-mouth breathing — disrupt our sleep and keep us from getting the deep, restorative rest we need for learning, memory, alertness, and immunity. In fact, open-mouth breathing not only disrupts deep sleep but increases water loss, daytime drowsiness, and mental duress. 

Furthermore, mouth breathing is associated with sleep disorders like obstructive sleep apnea (OSA), poor compliance with continuous positive airway pressure (CPAP) therapy, various dental issues, and conditions such as attention-deficit/hyperactivity disorder (ADHD). Some mouth-breathers can benefit from mouth-taping and breathing exercises, while others may require nasal sprays and treatments for nasal obstruction. 

Examples of poor sleep hygiene

In addition to sleep behaviors that impair sleep quality (like open-mouth breathing), certain sleep hygiene practices can make it harder to fall asleep at night and stay asleep until morning. Examples of poor sleep hygiene practices include watching television in bed, drinking coffee after dinner, eating large meals before bedtime, scrolling through social media in the evening, or constantly changing the sleep and wake up times. 

What does it mean to have good sleep hygiene? 

While poor sleep hygiene can keep us up at night, healthy sleep hygiene helps us fall asleep more easily, sleep soundly throughout the night, and wake feeling rested and refreshed in the morning. Some good sleep hygiene practices include: 

• Sticking to a regular sleep-wake schedule. 
• Avoiding screens in the evening, at least 2h before bed. If screens are unavoidable at night, red light glasses and blue light filters can help offset, but do not eliminate, the negative effects on sleep quality.
• Creating a relaxing nighttime routine that helps you wind down before bed. 
• Napping (if needed) earlier in the day rather than in the afternoon or evening. 
• Avoiding caffeine, alcohol, and nicotine after 3 pm and especially before bed. 
• Sleeping in a cool, dark, quiet, and comfortable sleep environment. 

Many of the lifestyle factors that impact sleep are modifiable, which is good news for those of us who could use a bit more shut-eye! Improving your sleep hygiene — the habits and behaviors that influence the duration and quality of your sleep — is a great place to start.