Understanding the Stages of Sleep

Throughout the night, your body will cycle through a number of stages, each defined by unique brain activity measure on an electroencephalogram (EEG).¹

• N1: The Prelude
• N2: The Deepening
• N3: The Core
• REM: The Dreaming

Let’s take a moment to explore each stage and understand how they contribute to our natural health.

The Prelude: NREM Stage 1 (N1)

As we close our eyes and drift off, we enter the first stage of Non-Rapid Eye Movement (NREM) sleep, known as N1. This is the lightest stage of sleep, lasting for about 5 to 10 minutes. During N1, our body begins to relax, our brain wave activity slows down with the appearance of theta waves, and our heartbeat and breathing start to slow. This stage is a gentle introduction to the world of sleep, where we can be easily awakened. It has been shown that waking from N1 before entering N2 is associated with a burst of creativity², so nodding off for a brief moment may not be a bad thing.

The Deepening: NREM Stage 2 (N2)

The second stage, N2, marks a deeper level of sleep which lasts for about 20 minutes. At this point, our body goes into a state of further relaxation defined by a noticeable decrease in temperature, heart rate, and breathing rate. This stage is crucial for consolidating memories and information from the day. Brain activity will show characteristic patterns called sleep spindles and K-complexes, which play a role in cognitive processing and sleep-based memory consolidation.³

Unfortunately, this stage is also when teeth grinding (bruxism) occurs. Considering N2 makes up about 45% of our total sleep, wearing your prescribed night guard is crucial for looking after your dental health.⁴

The Core: NREM Stage 3 (N3)

N3 is the most restorative stage and you will often hear it referred to as slow-wave sleep or deep sleep. Lasting for about 30 minutes, it’s characterized by delta waves – slow and high-amplitude brain waves. During this stage, the body repairs and regrows tissues, builds muscle and bone, and bolsters the immune system. This is due to the release of human growth hormone, highlighting its importance for physical health and recovery.^5,6

Waking up during this stage can create something of a hangover effect. When researchers assess brain function on waking, those who woke from N3 have impaired cognitive function for upwards of an hour.⁷

The Dreaming: REM Sleep

After about 90 minutes of NREM sleep, we enter the Rapid Eye Movement (REM) stage. This stage is known for vivid dreams due to increased brain activity that resembles being awake (i.e. beta waves). Researchers have even shown that brain metabolism can jump 20% during this stage!⁸ REM sleep plays a vital role in emotional and mental health as it helps us process emotions, further consolidate memories, and facilitate learning. The first REM stage can last up to ten minutes, with longer periods of even upwards of an hour, occurring towards wakening.

The Cycle Repeats

These stages are not a one-time thing, but rather a cyclical process throughout the night. This larger cycle lasts about 90 to 110 minutes as you rotate through N1, N2, N3 and REM. Usually NREM dominates earlier cycles, with REM becoming more prolonged in later cycles.

Understanding the Importance for Natural Health

Each stage has its distinctive role in maintaining our overall health. By providing the mind and body time to rest, recover, and process, sleep is as vital as a balanced diet or regular exercise.

Tips for Better Sleep

• Relaxation techniques: Engage in relaxing activities like reading, meditation, or taking a warm bath before bed.
• Create a sleep-inducing environment: Make your bedroom a sanctuary for sleep by keeping it quiet, cool, and dark.
• Establish a regular sleep schedule: Due to the cyclical nature of hormones and the sleep cycle, going to bed and waking up at the same time every day (even on weekends!) can help you feel more rested.
• Make use of sleep aids as needed: Many over-the-counter sleep aids can cause us to become dependent on their sedating effects. Natural options like GoodNight! are non-habit-forming and dissolve quickly in the mouth to release their sleep-inducing ingredients. This includes the novel herb Lactuca sativa which has been shown to influence all stages of sleep. Check out our article Can't Sleep ? An Innovative Natural Solution to Canada’s Sleep Epidemic for more information about this innovative product!
• Mind your diet: Avoid alcohol, caffeine, or heavy meals close to bedtime.
• Limit screen time: Certain wavelengths of light, like those released from our devices, can interfere with melatonin production at night, impacting our overall sleep quality.
• Get moving: 60 minutes of exercise from 5 to 6 pm was shown to improve slow-wave stability and the overall quality of N3.⁹

Remember that good sleep is not a luxury, it is a fundamental component of a healthy lifestyle.

References

1. Patel, Aakash K., et al. "Physiology, sleep stages." StatPearls [Internet]. StatPearls Publishing, 2022.
2. Lacaux, Célia, et al. "Sleep onset is a creative sweet spot." Science Advances50 (2021): eabj5866.
3. Antony, James W., et al. "Sleep spindles and memory reprocessing." Trends in neurosciences1 (2019): 1-3.
4. Carra, Maria Clotilde. "Obstructive sleep disordered breathing, sleep bruxism and periodontal diseases." L'Orthodontie Francaise3-4 (2019): 301-310.
5. Shah, Neomi, et al. "Sleep and insulin-like growth factors in the Cardiovascular Health Study." Journal of Clinical Sleep Medicine12 (2013): 1245-1251.
6. Carley, David W., and Sarah S. Farabi. "Physiology of sleep." Diabetes spectrum: a publication of the American Diabetes Association1 (2016): 5.
7. Hilditch, Cassie J., and Andrew W. McHill. "Sleep inertia: current insights." Nature and science of sleep(2019): 155-165.
8. Peever, John, and Patrick M. Fuller. "The biology of REM sleep." Current biology 27.22 (2017): R1237-R1248.
9. Park, Insung, et al. "Exercise improves the quality of slow-wave sleep by increasing slow-wave stability." Scientific reports1 (2021): 4410.