The Science Behind the Stages of Sleep
Do you spend your nights tossing and turning, dreaming of a restorative night’s rest?
Sleep is one of the most powerful wellness tools we can utilize to support ourselves to thrive, yet there are so many contributing factors that can impact our ability to enjoy a restful night’s sleep. During sleep, our body moves through 4 to 6 sleep cycles, transitioning between different phases that each serve an essential function in rejuvenating both the mind and body.
We’re unpacking how you can optimize your sleep quality for improved muscle repair, hormonal function, energy restoration, emotional balance, memory consolidation, and so much more.
The Science of Sleep
Sleep is a highly regulated biological process that occurs in four distinct stages, each governed by complex interactions between the brain, nervous system, and endocrine system.
These stages play a fundamental role in restoring physiological functions, consolidating memories, and maintaining physical, cognitive, hormonal, and emotional health.
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N1 (Light Sleep) (1-5 minutes): This is the first stage of sleep, lasting only a few minutes as your body shifts from wakefulness to sleep. During this phase, muscles start to relax, and brain wave activity begins to slow.
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N2 (Deeper Light Sleep) (10-25 minutes per cycle): In this stage, your heart rate and breathing regulate, and your body temperature drops. This is the longest phase of the sleep cycle (making up about 50% of total sleep time) and plays a key role in preparing the body for deep sleep.
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N3 (Deep Sleep) (20-40 minutes per cycle): Also known as ‘slow-wave sleep’, this is the most restorative phase. During deep sleep, the body repairs muscles, strengthens the immune system and releases growth hormones. This phase is essential for physical recovery. As the night progresses, the length of these cycles gradually shortens.
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REM (Rapid Eye Movement) Sleep (10-60 minutes per cycle): This is the ‘dreaming stage’, occurring about 90 minutes after you first fall asleep. During REM sleep, the brain is highly active, and key cognitive processes take place, such as memory consolidation and emotional regulation. REM sleep cycles lengthen as the night progresses, with the longest periods occurring in the early morning hours.
Sleep at Different Ages
If you notice your sleep quality changing as you age, you’re correct. Our sleep changes due to shifts in brain development, hormone production, and overall physiological changes.
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Infants and children need more time in deep and REM sleep to support rapid growth, neural development and learning.
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In adulthood, sleep patterns stabilize. Quality sleep (7-9) hours per night is essential for maintaining hormonal health, cognitive function, energy levels, and overall wellbeing.
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During later life, deep sleep naturally declines. Older adults tend to spend more time in lighter sleep stages and may wake more frequently during the night. This is due to changes in circadian rhythms and a decrease in the production of sleep-promoting hormones like melatonin. Sleep disturbances can also become more common.
Sleep And Menopause
For perimenopausal and menopausal women, hormonal fluctuations can significantly impact sleep quality and quantity. Declining oestrogen and progesterone levels can lead to night sweats, increased awakenings, and difficulty falling or staying asleep.
Additionally, reduced progesterone levels can heighten stress and anxiety, making it harder to relax before bed. You can support hormonal health for improved sleep with simple lifestyle changes like the ones we’ve listed below.
Want deeper sleep? Try our founder Jess’ expert tips.
We spoke to our Founder, Jess, about the rituals and routines she swears by for quality shut-eye.
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Stick to a sleep schedule:
“Your body thrives on routine. I make an effort to go to bed and wake up at the same time every day, even on weekends. This helps regulate your circadian rhythm, making it easier to drift off.” -
Power down before bed:
“Blue light from screens can interfere with melatonin production, the sleep hormone. I always recommend switching off devices at least two hours before bed and make it a strict rule to switch off my social media by 8:30pm every night!” -
Create a sleep sanctuary:
“A cool, dark, and quiet room encourages your body to wind down and that it’s time to rest. I make a soothing chamomile tea, and take a lavender and Epsom salt bubble bath.” -
Nourish your body with targeted support:
“A quality sleep supplement with science-backed ingredients makes all the difference. I personally love magnesium (look for one with multiple forms) for nervous system relaxation, and passionflower and lavender to help quiet the mind before bed.” -
Move your body during the morning:
“Exercise is essential as it helps to regulate your sleep-wake cycle. Most mornings, I take a gentle walk in morning sunlight (helps to regulate your circadian rhythm), and a 20 minute yoga flow from the JSHealth App. Depending on how I feel, add strength training two times per week.” -
Be mindful of caffeine intake:
“I truly adore my morning coffee, but I always recommend avoiding caffeine in the afternoon and evening, as it can interfere with your ability to fall asleep. Savour your 1-2 coffees before midday, the JSHealth way!” -
Practice a bedtime ritual:
“The way you wind down before bed matters. Try a warm bath, a short meditation, or some deep belly breathing to transition your body into rest mode.”
Read Jess’ full Soothing Nighttime Routine here. -
Support your blood sugar levels:
“Blood sugar imbalances can also impact sleep quality. That’s why it’s so important to incorporate quality protein with every meal (including dinner), and healthy fats to prevent nighttime wake-ups due to energy dips.”