What are REM sleep cycles?
REM sleep, or rapid eye movement sleep, is a stage of sleep characterized by rapid eye movements, faster breathing, and more brain activity. During REM sleep, we tend to have vivid dreams. REM sleep cycles occur multiple times during the night and are critical for memory consolidation, learning, and overall brain health.
On average, we experience 4-6 REM sleep cycles per night. Each cycle lasts around 90-120 minutes. The first REM cycle is the shortest, while subsequent cycles get progressively longer. As we sleep, we go back and forth between REM and non-REM sleep. Non-REM sleep consists of three stages:
- Stage 1 – Light sleep
- Stage 2 – True sleep
- Stage 3 – Deep sleep
We need both REM and non-REM sleep to function optimally. During non-REM sleep, our body repairs itself, while REM sleep allows our brain to consolidate memories and learn new information. Not getting enough quality REM sleep can impair our cognitive abilities, creativity, and emotional regulation.
How many REM cycles do we need?
Most sleep experts recommend getting at least 3-5 full REM cycles per night. This equates to around 7-9 hours of total sleep for most adults. However, sleep needs can vary significantly between individuals. Some people do fine on just 6 hours, while others need 9 or more.
Here are some general guidelines on REM cycle needs:
- Young children: 11+ hours of sleep, with 5-6 REM cycles
- Teenagers: 8-10 hours of sleep, with 4-5 REM cycles
- Adults: 7-9 hours of sleep, with 3-5 REM cycles
- Elderly: 7-8 hours of sleep, with 3-4 REM cycles
If you routinely wake up before completing a full REM cycle, you may suffer impaired cognitive function during the day. Getting too little REM sleep is linked to difficulties with focus, learning, memory, and mood.
How sleep deprivation impacts REM cycles
If you fail to get adequate total sleep on a regular basis, you miss out on vital REM sleep. Sleep restriction studies have found that cutting back on sleep reduces the amount of time spent in REM.
During prolonged periods of insufficient sleep, you build up a “REM debt.” Your brain tries to make up for this by increasing REM density. This means you spend a higher percentage of the sleep period in REM stage. However, you can’t recoup all the lost REM cycles from sleep deprivation.
Missing out on REM sleep negatively affects brain plasticity – the ability to learn and create new neural pathways in the brain. Multiple studies link poor REM sleep to:
- Impaired learning and memory
- Reduced problem-solving abilities
- Difficulty concentrating and paying attention
- Slower reactions
If continued over months or years, REM sleep deficiency may increase the risk of certain health conditions. For example, some research indicates that lack of REM sleep could promote neurodegeneration and dementia later in life.
Optimizing your REM sleep
Here are some tips to help you get enough high-quality REM sleep cycles each night:
- Follow a consistent sleep schedule, even on weekends
- Avoid screens before bedtime
- Limit daytime naps to 20-30 minutes
- Cut back on stimulants like caffeine and nicotine
- Create a cool, dark sleeping environment
- Use blackout curtains to minimize light
- Try a white noise machine to dampen sounds
- Finish eating 2-3 hours before bed
- Exercise regularly but not too close to bedtime
- Manage stress through meditation, yoga or relaxation techniques
If you continue having issues getting adequate REM sleep, consult your doctor. You may need treatment for an underlying condition like sleep apnea or insomnia.
Tracking your REM cycles
Wondering how many REM cycles you get per night? You can track this data by using a sleep tracking device or app. Many fitness trackers and smartwatches automatically monitor light sleep vs. deep sleep vs. REM sleep.
These consumer devices aren’t as accurate as a medical sleep study. However, they can give you a good idea of your REM sleep patterns. Focus on the total time spent in REM, rather than getting a specific number of cycles.
Here are some options for tracking REM sleep:
- Fitbit trackers and app
- Garmin devices and app
- Apple Watch sleep tracking
- Oura Ring
- Sleep Cycle app
- Dreem headband
Review your data over time to get a sense of your typical REM sleep amount. Note how variables like alcohol, late meals, and stress impact your cycles. If you notice any major decreases in REM sleep, discuss them with your doctor.
Significance of REM sleep for health
REM sleep represents a critical stage for overall wellbeing and brain health. Some key benefits of REM sleep include:
- Memory consolidation – REM helps strengthen and retain memories. The hippocampus replays memories during REM sleep, transferring them to long-term storage.
- Learning enhancement – Getting adequate REM sleep improves your ability to pick up new information and skills. REM sleep facilitates creative problem-solving.
- Emotional regulation – REM sleep allows your brain to process emotions. Lack of REM is linked to increased anxiety, irritability, and sensitivity to stress.
- Brain detox – Your brain clears out toxins and waste products during sleep. This glymphatic system activity seems to be most productive during REM sleep.
- Immune function – Certain cytokines and antibodies are boosted during REM sleep, helping you fight infection.
Given these vital benefits, it’s clear that REM sleep is imperative for everyone. Make getting adequate high-quality REM a top priority for maintaining optimal health. Talk to your doctor if you regularly feel unrested and suspect you’re not getting enough REM sleep.
How sleep disorders impair REM
Certain sleep disorders can dramatically reduce REM sleep cycles and duration:
Insomnia
People with insomnia often have trouble staying asleep. They tend to wake frequently which interrupts REM sleep. Studies show those with insomnia get less overall REM sleep and take longer to enter REM cycles.
Sleep apnea
This disorder causes breathing to stop intermittently during sleep. Sleep is extremely fragmented, reducing time spent in restorative stages like REM. Apneic events are most common during REM sleep.
Restless leg syndrome
RLS causes uncomfortable leg sensations that create an irresistible urge to move them. This prevents restful sleep, especially diminishing REM sleep time.
Narcolepsy
People with narcolepsy experience premature entry into REM sleep. This can occur both at night or during wakeful hours, leading to excessive daytime sleepiness.
Depression
Depressed individuals often have shorter REM cycles, lower REM density, and overall less REM sleep. Disruptions to REM sleep may exacerbate mood disorders.
If you suffer from poor sleep, talk to your doctor. Treating any underlying conditions can help restore healthy REM sleep patterns.
Monitoring REM cycles in sleep studies
Sleep clinics use specialized technologies like polysomnography and EEG to precisely track REM cycles during sleep studies. Here’s how it works:
Polysomnography
This test monitors brain waves, heart rate, breathing, and movement during sleep. Sensors on the scalp record electrical activity in the brain to differentiate between sleep stages. Rapid side-to-side eye movements signal the onset of REM sleep.
EEG
An EEG measures neurons firing in the brain during REM cycles. Brainwave frequencies shift dramatically between sleep stages. REM sleep generates fast, desynchronized low-amplitude waves.
EMG
Electromyography sensors detect muscle tension. During REM, the body experiences atonia or temporary paralysis. This loss of muscle tone indicates you’ve entered a REM cycle.
Analyzing this data allows doctors to pinpoint issues with REM duration and quality. They can then recommend tailored treatments to restore healthy REM sleep.
Impact of age on REM sleep
As we age, the structure of sleep changes. Time spent in the deepest stages of non-REM sleep decreases. However, REM sleep remains relatively stable over the lifespan.
Here’s how REM sleep changes as we get older:
Newborns
Babies spend about 50% of total sleep time in the REM stage. Their sleep cycles are shorter, cycling between REM and light non-REM sleep every 50-60 minutes. This high level of REM is critical for incredible rates of learning and development in infancy.
Children
From ages 2-5 years, REM continues to account for about 30% of sleep. Naps can contain heavy concentrations of REM sleep. Getting adequate daytime REM helps kids consolidate learning and sharpen focus.
Adolescents
Puberty brings a shift toward more deep non-REM sleep. However, REM remains at approximately 25% of the overall sleeping period. Teens need this REM sleep for skill acquisition, memory, creativity, and emotional control.
Adults
In healthy adults, roughly 20-25% of nightly sleep goes to REM. The first REM cycle of the night is shortest, averaging around 70-90 minutes. Subsequent REM cycles get progressively longer over the night.
Elderly
Although time in deep sleep decreases, REM sleep remains relatively steady in duration throughout older adulthood. However, sleep tends to get lighter and more fragmented. Maintaining REM quality helps preserve cognitive abilities into old age.
While REM sleep patterns shift across the lifespan, this restorative stage remains vital to learning, memory, and emotional health from infancy through old age.
Conclusion
REM sleep cycles play a critical role in cognitive function, memory formation, learning, creativity, emotional regulation, and brain health. Most adults need about 90-120 minutes of REM sleep, 4-5 times per night, equating to roughly 7-9 hours of total sleep.
Getting adequate high-quality REM sleep is essential for mental and physical wellbeing. If you routinely feel unrested or suspect sleep issues, talk to your doctor. They can recommend lifestyle changes, sleep hygiene tips, or treatments to help you optimize your REM sleep cycles. Consistently getting sufficient REM sleep will allow you to perform at your best during the day.