Select Page

The Sleep Cycles: Why Your Brain Needs Rest in Order to Reset

October 26, 2017 | Sleep Better

As a human being, you are an intricate ensemble of entwined systems that rely on sleep cycles in order to function properly. Like components within complex machinery, your body and brain require significant downtime for “maintenance” that enables their optimal performance. Sleep is a crucial biological intermission wherein this upkeep takes place, and it must occur in order for the show to go on.

There are five sleep stages which occur in succession several times throughout the night, repeating roughly every 90 minutes or so. The most obvious distinction between them is that the first four are non-REM (Rapid Eye Movement) sleep, while the fifth phase is the definitive REM state. Regardless, all are critical to the well-being of your respiratory, digestive, endocrine, immune and central nervous systems.


Drifting Off

This transitional phase of sleep is relatively short, lasting anywhere from 5 to 10 minutes. As your heart rate, breathing and muscle activity slows down, your brain enters what is known as Alpha state, then slips into Theta state. This initial part of the sleep cycle is often accompanied by muscle spasms and/or a sense of falling known as hypnic myoclonia – thus the term “falling asleep.”


A Light Snooze

Nearly half of your time asleep is spent in this state, as your heart rate and core body temperature continue to decrease. This phase triggers what is known as the body’s Circadian rhythm sleep cycle, which determines when and for how long you will sleep.


Double Deep Sleep Cycles

Sleep stages three and four are extensions of one another, distinguished by core body temperature that can dip as low as one degree below normal — down to 97.6 degrees or so. These periods of deep sleep are when your brain wave activity slows down to the Delta frequency — meaning that you are in the phases of sleep that are the most difficult to awaken from.

Muscle spasms and general mobility tend to cease here, and although this is an NREM state of sleep it is often distinguished by nightmares and bedwetting in children as well as sleepwalking in adults. During these stages, your brain releases human growth hormone which increases blood flow to your dense tissues and extremities.

This serves to repair muscles and joints that are exerted throughout the day. Meanwhile, the release of additional hormones called leptin and ghrelin regulate the hunger cravings you’ll experience the following day so that you don’t over-eat.


Cue the Music

The final stage of your sleep cycle is known as the REM phase, wherein your brain waves spike to near-waking levels of activity. Here, your brain begins to re-energize itself and your body with a high degree of neuroactivity.

Most dreaming occurs during phase five, as your eyes oscillate back and forth behind your eyelids. During REM sleep, however, your body stays immobile due to your brain’s release of glycine and gamma-aminobutyric acid (GABA) that “paralyze” your skeletal muscles so that you do not act out your dreams.

After spending 20% or more of your time in this phase, your sleep cycle either resets or you wake up as your body temperature returns to its normal level of 98.6 degrees.


Benefits of Monitoring Your Sleep Patterns

There are a number of significant health problems related to insufficient sleep. These include obesity, cardiovascular disease, depression, diabetes, high blood pressure and stroke among others.

Lack of sleep can also cause you to become accident-prone – endangering yourself and those around you, and you can even become more susceptible to the neurodegenerative conditions of Parkinson’s disease.

Fortunately, there are wearable tech garments that are both sophisticated enough to monitor all of your biometric activity throughout the night and comfortable enough to sleep in. By monitoring your heart rate, body temperature, breathing and physical movement while you sleep, you can determine if you are resting well or if you have sleeping issues that you should be concerned about.

a. The Heart of the Matter

Wearable tech with built-in ECG (electrocardiogram) sensors can give you a clear picture of what is happening with your heart rate while you sleep. This biometrics is recorded while you sleep and can be viewed on your tablet or device as soon as you awake.

This information is crucial to understanding whether or not your heart rate is gradually slowing as it should during phases one and two, and staying evenly slow during phases three and four so that you are experiencing the regenerative benefits of deep sleep.

b. Keep it Cool

Measuring your body’s temperature fluctuations during sleep cycles can also indicate whether or not you are resting well. Comfy garments with tiny built-in components can detect the drop in your temperature during phase two, which then indicates a smooth transition into the deep sleep phases three and four.

Lack of body temperature drop can mean that your muscle tissues may not be receiving the regenerative blood flow needed in order to recover from daily activity.

c. Breath is Life

Similar to body temperature, measuring your breathing patterns throughout the night can determine if your rest is peaceful or otherwise. Strained and irregular breathing can indicate serious issues like sleep apnea or other cardiovascular issues. Your wearable tech can give you detailed reports on exactly how you are breathing while sleeping.

d. Unnecessary Movement

Understanding how your body responds to increased brain activity during the fifth sleep cycle (REM) can be invaluable to your health. Your wearable tech garments have built-in sensors that can measure your physical movement during the night. Abnormal levels of activity can indicate sleepwalking and/or the acting out of your dreams – both of which can be dangerous to you and those around you. Also, non-paralyzed REM Sleep Disorder is an indication of the possible onset of Parkinson’s or other neurodegenerative diseases.

Getting enough good sleep is a fundamental component of health, providing your brain with ample time to replenish your body while recharging itself. Measuring your sleep cycles with smart garments gives you invaluable insight as to exactly what is happening during each of the five sleep stages.


This article is not intended to substitute for informed medical advice. You should not use this information to diagnose or treat a health problem or condition. Always check with your doctor before changing your diet, altering your sleep habits, taking supplements, or starting a new fitness routine.