The Science Of Sleep Cycles & How To Optimize Yours For Better Health

Learning about the science of sleep cycles and how to regulate them will help you achieve better sleep and improve your overall well-being.

The sleep cycles are regulated by your body's circadian rhythm, a 24-hour cycle primarily influenced by light and darkness. In an ideal world (without any outside influences), your circadian rhythm will trigger your brain and body to be awake during the day when it's light outside and tired when it's dark.

As mentioned, there are three non-REM sleep stages and one REM sleep stage. Each stage has significance for your body and mind, and many factors can contribute to how well you fall and stay asleep.

During this stage, your breathing remains regular, and your muscles start to relax.

N2 sleep makes up about 45% of your total sleep cycle.

Slow-wave sleep is the most difficult stage to wake up from—and if it is interrupted, you'll likely experience some mental fogginess and disorientation8.

REM sleep is considered the deepest stage of sleep. This is when your brain is most active and when you're expected to have the most vivid dreams and nightmares9. REM sleep also contributes to memory consolidation10, which is how the brain converts short-term memories into long-term memories.

Not getting enough sleep can impact your overall health and wellness, leading to sleep deprivation, mood changes, lower reaction times, trouble learning, and fatigue throughout the day. Risk factors for sleep disorders include certain medications, stress, work schedules, or a family history.

Many factors contribute to your ability (or inability) to fall asleep. Fortunately, there's a lot you can do to intervene and set yourself up for a night of restorative sleep.

Stress makes it difficult to sleep—and if you don't sleep, it can increase your stress. A lack of quality sleep can elevate your body's cortisol levels (the stress hormone), further increasing stress and disrupting sleep.

Too much stimulation before bed (e.g., watching television, playing video games, or scrolling on your cell phone) can disrupt the circadian rhythm and wreak havoc on your sleep.

Caffeine and alcohol aren't the only culprits when it comes to messing up your sleep. Certain foods can affect serotonin and melatonin13 activity, and heartburn and GERD14 may interfere with your sleep by waking you up throughout the night.

Even small lifestyle changes can lead to a healthier sleep cycle, which can significantly impact overall well-being.

Giving yourself a bedtime puts your body and mind into the habit of falling asleep and waking up at the same time every day.

Another tip: Keep the bedroom for sleeping, not for television, work, hobbies, or meals.

While some naps are great for restoration, a recent study found that frequent and late naps may be associated with poor sleep quality and increased awakenings throughout the night.

Understanding how the body gets into the various stages of sleep can help you discover how certain habits, sleep disorders, and other factors contribute to your sleep cycle—and you'll be on your way to achieving optimal health and well-being.