REM, Light, Deep: How Much of Each Sleep Phase Do I Need?

Walk into any high-street bed shop, and they’ll try to sell you memory Foam for “support” or pocket springs for “comfort” without ever explaining what your body actually needs during sleep. The mattress industry has spent decades marketing firmness levels and spring counts whilst ignoring the fundamental question: does this mattress help you achieve restorative, deep sleep and adequate REM cycles?

This guide explains the science behind sleep stages, why both deep sleep and REM matter (they serve completely different purposes), and what mattress characteristics actually support quality sleep rather than disrupt it. We’ll also explain which John Ryan mattresses our customers report sleeping best on, based on 25+ years of direct feedback.

Understanding sleep architecture: more than just hours

Sleep isn’t a single state where your brain and body shut down for 8 hours. It’s a precisely orchestrated cycle repeating 4 to 6 times per night, with each cycle lasting approximately 90 to 110 minutes.

Your body moves through distinct stages, each with its own purpose. Disrupting these cycles—through an uncomfortable mattress, temperature regulation failure, or partner motion transfer—means you’re not getting restorative sleep regardless of total time in bed.

The complete sleep cycle breakdown

Here’s what most people misunderstand: deep sleep and REM sleep are not the same thing. They occur at different points in the cycle, involve distinct patterns of brain activity, and serve distinct purposes. You need both, and a poor mattress can rob you of either or both.

Deep sleep (Stage 3): when your body repairs itself

Deep sleep is the most physically restorative stage. This is when your body does the actual repair work that makes sleep feel refreshing.

During deep sleep,prioritisesprioritizes physical restoration over mental activity. Your brain produces slow delta waves, your heart rate drops to its lowest point, breathing becomes slow and regular, and blood pressure decreases significantly.

What actually happens during deep sleep

• Tissue repair and growth: Growth hormone releases, triggering muscle repair, bone strengthening, and tissue regeneration
• Immune system reinforcement: Cytokine production increases, strengthening your body’s disease-fighting capabilities
• Energy restoration: Glucose metabolism rebalances, adenosine clears from the brain, preparing you for wakefulness.
• Memory consolidation (declarative): Facts and explicit knowledge transfer from short-term to long-term storage
• Metabolic regulation: Hormones controlling appetite (leptin and ghrelin) rebalance

Deep sleep occurs predominantly in the first half of the night. Your body front-loads deep sleep because physical recovery takes priority. The first sleep cycle might include 30 to 40 minutes of deep sleep, whilst later cycles include progressively less as REM stages lengthen.

How much deep sleep do you actually need?

Adults require approximately 60 to 120 minutes of deep sleep per night, representing 15% to 25% of total sleep time. If you sleep 8 hours but only get 30 minutes of deep sleep, you’ll wake feeling exhausted, even though you hit the recommended duration.

Age significantly affects deep sleep requirements. Children and teenagers need substantially more deep sleep than adults (up to 40% of their sleep time), whilst older adults naturally experience reduced deep sleep, spending more time in Stage 2 light sleep instead.

What disrupts deep sleep

Your mattress plays a direct role in whether you achieve adequate deep sleep:

• Pressure points: Hip, shoulder, or lower back discomfort prevents your body from fully relaxing into deep sleep stages
• Temperature regulation failure: Overheating pulls you out of deep sleep into lighter stages of sleep. Natural fibres breathe better than memory Foam.
• Motion transfer: Partner movement jolts you from deep sleep back to Stage 1 or 2. Pocket springs isolate motion better than continuous coil
• Inadequate support: Spinal misalignment creates unconscious muscle tension, preventing the deep relaxation Stage 3 requires

Alcohol, certain medications (benzodiazepines, opioids), lack of physical activity during the day, and oversleeping past your regular wake time all suppress deep sleep. But an uncomfortable mattress creates a chronic deep sleep deficiency that accumulates night after night.

REM sleep: when your brain processes and consolidates

REM (Rapid Eye Movement) sleep serves purposes completely different from those of deep sleep. Whilst deep sleep focuses on physical restoration, REM sleep handles cognitive functions, emotional regulation, and memory processing.

During REM, your brain activity increases to near-waking levels whilst your body experiences temporary paralysis (atonia). This prevents you from physically acting out dreams. Your eyes dart rapidly beneath closed eyelids, your heart rate and blood pressure increase, and your breathing becomes irregular.

What actually happens during REM sleep

• Memory consolidation (procedural): Motor skills, habits, and “how-to” knowledge solidify from practice into long-term memory
• Emotional processing: The brain processes emotional experiences, reducing their intensity and integrating them into memory
• Learning enhancement: New information connects to existing knowledge networks, improving understanding and recall
• Brain development: Particularly crucial in infants and children, supporting neural pathway formation
• Mood regulation: REM sleep helps maintain emotional balance and mental wellbeing
• Creative problem-solving: The brain makes novel connections between disparate information during REM

REM sleep occurs predominantly in the second half of the night. Your first REM period might last only 10 minutes, but by your final sleep cycle before waking, REM stages can extend to 60 minutes. This is why being woken early disproportionately reduces REM sleep.

How much REM sleep do you need?

Adults need approximately 90 to 120 minutes of REM sleep per night, representing 20% to 25% of total sleep time. Unlike deep sleep, REM requirements remain relatively stable across adult ages, though infants require dramatically more (up to 50% of their sleep).

Chronic REM deprivation manifests differently from deep sleep deficiency. Whilst lack of deep sleep causes physical fatigue, REM deprivation creates cognitive fog, emotional instability, memory problems, and difficulty concentrating.

What disrupts REM sleep

• Sleep apnea and breathing disorders: Interruptions prevent progression into REM stages
• Alcohol consumption: Suppresses REM in the first half of the night, causing REM rebound later that fragments sleep
• Antidepressants (SSRIs, tricyclics): Many suppress REM sleep as a side effect
• Stress and anxiety: Elevated cortisol prevents smooth progression into REM
• Inconsistent sleep schedules: Irregular bed/wake times disrupt circadian rhythm, affecting REM timing
• Light exposure: Blue light from screens suppresses melatonin, delaying REM onset

Your mattress affects REM sleep less directly than deep sleep, but motion transfer from a partner can wake you during REM stages in the second half of the night. Since REM periods lengthen as the night progresses, disruptions at 5 am to 7 am disproportionately rob you of REM.

How sleep cycles progress through the night

Understanding how cycles change throughout the night explains why mattress characteristics matter differently depending on when disruption occurs.

Early night: Deep sleep dominance (Cycles 1-2)

The first 3 hour prioritiseses deep sleep. The first cycle includes 30 to 40 minutes of Stage 3, with minimal REM (perhaps 10 minutes). The second emphasises deep sleep, but REM begins lengthening to 15 to 20 minutes.

Mattress impact: Pressure-point discomfort is most severe during these cycles. If your mattress causes shoulder pain or hip pressure, you’ll be repeatedly pulled out of deep sleep, sacrificing the physical restoration your body front-loads.

Late night: REM sleep dominance (Cycles 3-5)

Last 4 to 5 hours: Deep sleep shortens to perhaps 5 to 10 minutes per cycle, whilst REM extends progressively. Your final REM period before waking might last 45 to 60 minutes.

Mattress impact: Motion isolation matters most here. Partner movements during late-night cycles disrupt extended REM periods when your brain is performing crucial memory consolidation and emotional processing.

This progression explains why waking at different times feels different. Being woken at 2 am during deep sleep creates profound grogginess (sleep inertia) lasting 30 to 60 minutes. Being woken at 6 am during REM feels less physically disorienting but robs you of crucial cognitive processing time.

What mattress characteristics actually support deep sleep and REM

Now that you understand what happens during sleep stages, let’s address how mattress construction either facilitates or disrupts these processes. This isn’t about firmness marketing or spring count claims. It’s about physical characteristics that create the conditions your body needs to cycle through stages properly.

Pressure relief: essential for deep sleep entry

Deep sleep requires complete muscular relaxation. If your mattress creates pressure points at the shoulders, hips, or lower back, your body cannot fully relax into Stage 3. Unconscious micro-adjustments pull you back into lighter sleep stages.

What creates proper pressure relief:

• Adequate upholstery GSM: Total comfort layer weight determines cushioning depth. 1500 GSM is minimum; 3000+ GSM provides substantial pressure relief for side sleepers
• Natural fibre resilience: Wool, mohair, and Horsetail resist permanent compression better than polyester, maintaining pressure relief over the years
• Appropriate spring gauge for body weight: Heavier sleepers need firmer springs (1.6mm+) to prevent bottoming out, which creates pressure points
• Two-sided construction: Allows rotation to fresh surfaces, preventing permanent body impressions that gradually worsen pressure points

Temperature regulation: prevents sleep stage interruption

Core body temperature naturally drops during sleep. Overheating disrupts this process, pulling you from deep sleep into lighter stages or brief awakenings. Memory Foam’s heat retention is particularly problematic.

Materials that regulate temperature properly:

• Natural Wool: Wicks moisture away from skin, breathes freely, provides insulation without trapping heat
• Cotton: Highly breathable, absorbs perspiration, allows air circulation through mattress layers
• Mohair: Even better temperature regulation than Wool, naturally moisture-wicking
• Horsehair/Horsetail: Coarse fibres create air channels, preventing heat accumulation
• Calico pocket springs: Individual fabric pockets allow air circulation between springs

Materials that trap heat and disrupt sleep:

• Memory Foam: Dense cell structure traps body heat, causing overheating, particularly in Stages 2 and 3
• Synthetic polyester batting: Doesn’t breathe like natural fibres, accumulates moisture
• Solid Foam bases: Block air circulation from beneath the mattress

Motion isolation: protects REM sleep for couples

Partner movement becomes most disruptive during the late-night REM period, when brain activity is high, but the paralysed are paralysed. Being jostled out of a 45-minute REM stage at 55:30 amrobs you of crucial memory consolidation.

Spring systems and motion transfer:

Spinal support: enables muscular relaxation for deep sleep

Deep sleep requires zero muscular effort to maintain posture. If your mattress allows spinal misalignment, your body unconsciously maintains muscle tension, preventing full relaxation into Stage 3.

Proper support requires:

• Sufficient spring firmness for body weight: Spring gauge matched to weight ensures spine doesn’t sag into mattress
• Consistent support across the surface: No dead zones or sagging areas that create uneven spinal alignment
• Edge support integrity: Prevents roll-off feeling that unconsciously increases muscle tension
• Sleeping position compatibility: Side sleepers need more give for shoulders/hips; back/stomach sleepers need firmer overall support.

Real customer experiences: what actually helped sleep quality

After 25+ years of manufacturing mattresses, we’ve heard countless reports of improved sleep quality. Here are two representative experiences from customers who specifically mentioned sleep stages and feeling more rested:

Sarah’s experience: Artisan Naturals

Background: Sarah, a 42-year-old teacher from Leeds, replaced a 7-year-old memory Foam mattress. She reported sleeping 7 to 8 hours nightly but waking unrefreshed, with persistent lower back stiffness and feeling mentally foggy by midday.

Her feedback after 6 weeks on the Artisan Naturals: realisen’t realise how much my old mattress was affecting my sleep quality until I switched. The memory Foam always felt too warm. I’d wake up hot several times a night, realising it. Now I’m sleeping straight through those first deep sleep hours, as my sleep tracker confirms. I’m getting 90+ minutes of deep sleep versus the 45 to 50 minutes I was averaging before.

“The natural fibres make an enormous difference to temperature. I used to wake up around 2 am too warm, which I now understand was pulling me out of deep sleep. That doesn’t happen anymore. The mohair and Wool layers somehow keep me at exactly the right temperature all night.

“But the biggest change is how I feel mentally. I’m not getting more total hours of sleep, but I wake up sharper, more alert, like my brain actually processed things overnight instead of just treading water. My husband says I’m less irritable in mornings, which probably means I’m getting proper REM sleep in those final hours before the alarm.”

Technical context: The Artisan Naturals provides 3,950 GSM total upholstery, including 1,200 GSM British fleeceWooll and 1,500 GSM mohair. Natural fibres regulate temperature far better than memory Foam, preventing the thermal disruptions that pull sleepers out of deep sleep stages. The calico pocket springs also reduce motion transfer compared to her previous Foam mattress, protecting late-night REM cycles.

James’s experience: Artisan Bespoke 004

Background: James, a 38-year-old software developer from Manchester, is a side sleeper who weighs 15 stone. He and his wife were sleeping on a high-street pocket spring mattress that was only 4 years old, but had developed permanent impressions where they each slept.

His feedback after 3 months on the Artisan Bespoke 004:

“Our previous mattress wasn’t terrible, but I’d wake up with shoulder pain about 4 or 5 times a week, and I’d always need at least two coffees before feeling properly awake. Looking back, I was probably being pulled out of deep sleep by pressure points without fully waking, so I wasn’t getting proper restoration.

“The Artisan Bespoke 004 has 3,600 GSM of natural fibre, the salesperson helpfully advised us over the phone of the exact breakdown, which no one had ever done before. The Horsetail layer is firmer than I expected, but it provides supportive cushioning that keeps my shoulders from being the only pressure points. I don’t wake up with shoulder stiffness anymore, which means I’m staying in deep sleep properly during those first cycles.

“The other major change: my wife’s movements don’t wake me up anymore. She gets up to use the bathroom around 4 am most nights, and I used always to wake when she got back into bed. Now I don’t even notice. Since that’s right when REM sleep is longest, I think I was losing a lot of memory consolidation and dream sleep before. I feel mentally sharper during the day, better able to focus on complex coding problems.

“We’ve had it three months, and there’s zero sign of body impressions forming. The two-sided construction means we can flip and rotate it, unlike our previous mattress. Knowing we won’t have the same sagging problem in a few years makes the higher price worth it—we’re actually sleeping better, not just buying something that’ll need replacing sooner.”

Technical context: The Artisan Bespoke 004’s 100% natural fibre construction (3,600 GSM total) with 1,200 GSM Horsetail provides substantial pressure relief for side sleepers whilst maintaining proper spinal support. The calico pocket spring system offers superior motion isolation, protecting REM sleep during late-night partner movements. Two-sided construction prevents the permanent impressions that gradually degrade both pressure relief and spinal support.

John Ryan mattresses are designed for restorative sleep

Based on 25+ years of customer feedback specifically about sleep quality, energy levels, and waking refreshed, two models consistently receive reports about improved deep sleep and REM cycles:

Origins Natural Comfort (£1,295 King)

The Origins Natural Comfort provides the specifications necessary for proper sleep stage progression at an accessible price point.

• 1,600 calico pocket springs (1.28mm gauge) – Superior motion isolation protects REM sleep from partner disturbance
• 3,950 GSM total upholstery – Substantial cushioning prevents pressure point disruption of deep sleep
• 1,200 GSM British fleece Wool – Natural temperature regulation prevents overheating that interrupts sleep stages
• 1,500 GSM pure mohair – Exceptional breathability and moisture wickingmaintains optimal sleep temperature
• 1,250 GSM rebound polyester – Provides resilient support layer
• 85% natural fibre content – Dramatically better breathability than synthetic Foam mattresses
• Two-sided construction – Prevents body impressions that gradually create pressure points over the years
• Hand side-stitched edges – Maintains usable sleep surface across entire mattress

Price: £1,295 for a King size

Who does this suit for sleep quality:

• Sleepers up to 16 stone seeking pressure relief without bottoming out
• Anyone replacing memory Foam who overheats and disrupts sleep stages
• Couples needing motion isolation to protect late-night REM cycles
• Side sleepers requiring shoulder and hip cushioning for uninterrupted deep sleep
• People waking unrefreshed despite 7 to 8 hours, indicating poor sleep stage distribution

Why customers report better sleep: The combination of natural temperature regulation and substantial pressure relief creates conditions for uninterrupted progression through sleep cycles. Wool and mohair prevent thermal disruptions common with synthetic materials, whilst the 3,950 GSM total upholstery eliminates pressure points that pull you from deep sleep. Calico pocket springs isolate partner movement, protecting extended REM periods in the second half of the night.

Expected lifespan: 12 to 15 years with proper rotation and flipping. Cost per night: approximately £0.24 over 15 years.

Artisan Bespoke 004 (£2,860 King)

The Artisan Bespoke 004 represents premium specifications specifically engineered for sleep quality rather than marketing claims.

• 1,600 calico pocket springs (1.6mm firm gauge available) – Exceptional motion isolation with proper support for heavier sleepers
• 3,600 GSM total upholstery – 100% natural fibre construction for optimal temperature regulation
• 1,200 GSM British fleece Wool/Cotton blend – Natural moisture wicking prevents sleep disruption from overheating
• 200 GSM soft Bamboo – Additional breathability and natural antimicrobial properties
• 1,200 GSM pure Horsetail – Firm, resilient support layer prevents excessive sinking whilst cushioning pressure points
• 1,000 GSM bonded British fleece Wool and Cotton – Maintains loft and support over the ears
• 100% natural fibre content – Zero synthetic materials means maximum breathability and temperature regulation
• Two-sided, fully turnable construction – Distributes wear across four surfaces, maintaining sleep quality for 15+ years
• Hand side-stitched for edge support – Prevents roll-off tension that increases muscle activation during sleep

Price: £2,860 for King size (custom spring tensions available)

Who does this suit for sleep quality:

• Sleepers up to 20 stone need firm support without sacrificing pressure relief
• Anyone with temperature sensitivity who wakes from thermal disruption
• Couples where partner movement disrupts sleep—superior motion isolation
• People seeking maximum sleep quality longevity (15+ year lifespan)
• Those replacing premium high-street mattresses that failed to deliver on sleep quality promises
• Environmentally conscious buyers wanting fully natural, biodegradable materials

Why customers report exceptional sleep: The 100% natural construction eliminates the heat retention that disrupts deep sleep progression in synthetic mattresses. Horsetail provides firm, supportive cushioning that prevents pressure points without creating the “stuck” feeling of memory Foam. The substantial 3,600 GSM total creates conditions for deep muscular relaxation essential to Stage 3 sleep, whilst calico pocket springs provide the motion isolation necessary to protect extended REM cycles from partner disturbance.

Expected lifespan: 15 to 18 years with proper maintenance. Cost per night: approximately £0.43 over 18 years, delivering consistent sleep quality throughout rather than gradual degradation.

Beyond the mattress: other factors affecting sleep stages

Whilst your mattress creates the physical foundation for sleep stage progression, other factors significantly affect whether you achieve adequate deep sleep and REM:

Sleep environment factors

• Room temperature: 15°C to 19°C (60°F to 67°F) is optimal. Your body needs to drop core temperature to initiate and maintain deep sleep.
• Light exposure: Complete darkness supports melatonin production. Blue light from screens suppresses melatonin for 2+ hours
• Noise levels: Ambient noise above 40 decibels disrupts sleep stage progression, particularly pulling you from REM
• Air quality: Poor ventilation reduces oxygen levels, affecting sleep quality and stage distribution

Lifestyle factors affecting sleep stages

• Alcohol consumption: Suppresses REM in the first half of the night, causes REM rebound and fragmented sleep in the second half
• Caffeine timing: Half-life of 5 to 6 hours means afternoon coffee still affects bedtime sleep initiation
• Exercise timing: Morning/afternoon exercise promotes deep sleep; evening exercise can delay sleep onset
• Eating schedule: Large meals within 3 hours of bedtime disrupt sleep stage progression through digestive activity
• Consistent sleep schedule: Irregular bed/desynchronises circadian rhythm, affecting both deep sleep and REM timing

A perfect mattress cannot overcome chronic alcohol consumption, blue light exposure at bedtime, or irregular sleep schedules. However, an uncomfortable mattress will sabotage sleep quality and optimise everything else.

Choose specifications over marketing.

The mattress industry has spent decades selling “better sleep” through vague promises about memory Foam contouring, pocket spring support, or orthopaedic firmness. These marketing terms tell you nothing about whether a mattress actually facilitates the sleep stage progression your body requires.

What actually matters:

• Adequate upholstery GSM for pressure relief (prevents deep sleep disruption)
• Natural fibre content for temperature regulation (prevents overheating that interrupts stages)
• Proper spring gauge for body weight (maintains spinal alignment essential to muscular relaxation)
• Motion isolation through pocket springs (protects late-night REM cycles from partner disturbance)
• Two-sided construction (maintains specifications overthe  years rather than gradually degrading)

You can sleep 9 hours and wake exhausted, or sleep 7.5 hours and wake refreshed. The difference is whether you’re achieving 90+ minutes of deep sleep and 90+ minutes of REM, which requires mattress characteristics that support uninterrupted stage progression, not marketing promises about “cloud-like comfort” or “perfect suppospecialisedspecialized in transparent specifications for 25+ years because customers deserve to know what they’re buying. The Origins Natural Comfort and Artisan Bespoke 004 consistently receive feedback about improved sleep quality, specifically because their specifications create proper conditions for deep sleep and REM cycles, not because we’ve marketed them with sleep claims.

If you’re sleeping your recommended hours but waking unrefreshed, your mattress is likely disrupting sleep stages due to pressure points, poor temperature regulation, or inadequate support. Contact us to discuss your specific situation. We’ll specify based on your weight, sleeping position, and temperature sensitivity—not based on whichever model has the best margin this month.

We want to be sure you’re happy with your mattress, which is why we offer a 60-day ‘Love It or Return It’ guarantee. We’ll come and collect the mattress free of charge and offer a full refund if you’re not satisfied within the first 60 days.

For more information on pocket sprung mattresses, get in touch on 0161 437 4419.