Getting more REM and deep sleep comes down to a handful of controllable factors: sleep timing, body temperature, light exposure, exercise, and what you consume. In a healthy adult, deep sleep and REM sleep each make up about 25% of total sleep time. If you’re waking up unrefreshed or a sleep tracker is showing low numbers in either stage, the strategies below target the specific biological processes that drive these restorative phases.
Why REM and Deep Sleep Matter
Deep sleep (also called slow-wave sleep) is when your body does its heaviest physical repair work. Growth hormone release peaks, tissues recover, and the brain clears metabolic waste. REM sleep handles the cognitive side: memory consolidation, emotional processing, and learning. You cycle through both stages multiple times per night, but deep sleep concentrates in the first half of the night while REM periods grow longer toward morning. That pattern matters because the strategies that help each stage differ slightly.
Keep a Consistent Sleep Schedule
Your body distributes REM sleep across the night based on the interaction of two internal forces: sleep pressure (which builds the longer you’re awake) and your circadian clock (which runs on roughly a 24-hour cycle). When these two forces are properly aligned, you get a predictable pattern of lengthening REM episodes as the night progresses. When they’re misaligned, from going to bed at wildly different times, REM episodes become irregular and shorter overall.
Delayed sleep onset specifically increases what researchers call “state instability,” which disrupts the smooth progression of sleep cycles. The fix is straightforward: wake up at the same time every day, including weekends. Your wake time is the single strongest anchor for your circadian clock. A consistent wake time keeps your body’s two sleep-regulating systems in sync, which protects both deep sleep in the early hours and REM sleep in the later hours.
Cool Your Bedroom to 60–67°F
Your core body temperature needs to drop by about 2°F to initiate and maintain sleep. A cool room accelerates that process. The optimal range for most adults is 60 to 67°F (15 to 19°C). This matters for deep sleep in particular because thermoregulation is directly tied to staying in slow-wave sleep stages. When your bedroom is too warm, your body struggles to maintain the lower core temperature that deep sleep requires, and you’re more likely to shift into lighter sleep or wake up entirely.
If you tend to sleep hot, a few adjustments help beyond the thermostat. Breathable bedding materials like cotton or linen wick moisture better than synthetics. Taking a warm shower 60 to 90 minutes before bed seems counterintuitive, but it works: the rapid cooling of your skin afterward drops your core temperature faster. Socks can also help by dilating blood vessels in your feet, which releases heat from your core.
Control Light Exposure, Especially at Night
Light is the most powerful signal your circadian clock receives. Blue light, the wavelength emitted most strongly by phones, tablets, and LED screens, suppresses melatonin production in a dose-dependent way. Research published in the Journal of Applied Physiology found that blue LED light at illuminance levels as low as about 19 lux significantly suppressed melatonin in just 90 minutes of exposure. For reference, a typical phone screen held at normal distance produces 40 to 80 lux. You’re easily clearing that suppression threshold during casual scrolling.
Lower melatonin delays sleep onset and compresses the total time available for both deep and REM sleep. The practical strategy has two parts. First, get bright light exposure early in the day, ideally natural sunlight within the first hour of waking. This sets the start point of your circadian clock and makes your evening melatonin release more robust. Second, dim your environment in the two hours before bed. Switch to warm, low lighting. If you use screens, enable night mode and reduce brightness, though putting them away entirely is more effective.
Time Your Exercise Right
Regular aerobic exercise is one of the most well-supported ways to increase deep sleep. People who exercise consistently tend to spend more time in slow-wave sleep and fall asleep faster. The timing, however, matters. High-intensity exercise less than one hour before bedtime has been shown to delay sleep onset and reduce sleep quality. Harvard Health recommends finishing strenuous physical activity at least two hours before bed.
Moderate exercise, like brisk walking or yoga, doesn’t carry the same late-night penalty and may even be mildly sleep-promoting in the evening. For maximizing deep sleep specifically, morning or afternoon workouts appear to be the sweet spot. The post-exercise rise in core body temperature followed by a gradual cool-down over several hours mirrors the natural thermal drop your body needs to enter deep sleep.
Cut Caffeine at Least 8 Hours Before Bed
Caffeine blocks the receptors for adenosine, the compound that builds sleep pressure throughout the day. That sleep pressure is what drives you into deep sleep during the first few hours of the night. When caffeine interferes with it, deep sleep takes the biggest hit. You might still fall asleep on time but spend less of the night in slow-wave stages.
Caffeine’s half-life varies widely between individuals, ranging from 2 to 12 hours depending on genetics, age, and liver function. The generally recommended cutoff is a minimum of eight hours before bedtime. If you go to bed at 11 p.m., that means no caffeine after 3 p.m. If you’re a slow metabolizer (you can often tell because even afternoon coffee affects your sleep), you may need to push that cutoff earlier, to noon or even 10 a.m.
Limit Alcohol, Especially Before Bed
Alcohol is one of the most common and least recognized sleep disruptors. It acts as a sedative initially, which is why people feel it helps them fall asleep. During the first half of the night, alcohol actually increases deep sleep. The trade-off comes later: it causes a dose-dependent suppression of REM sleep. Once your body metabolizes the alcohol and blood alcohol levels drop in the second half of the night, a REM rebound kicks in, often accompanied by fragmented sleep, vivid dreams, and early morning awakenings.
The net result is less total REM sleep and lower sleep quality overall. Even moderate drinking (two drinks) within a few hours of bed produces measurable REM suppression. If improving REM sleep is your goal, reducing or eliminating evening alcohol is one of the highest-impact changes you can make. At minimum, allow three to four hours between your last drink and bedtime so your body has time to clear the alcohol before your longest REM periods begin.
Manage Stress Before Bed
Elevated cortisol at night directly interferes with both deep and REM sleep. Your cortisol levels are supposed to be at their lowest point in the first half of the night, which is exactly when deep sleep dominates. Stress, anxiety, and mental hyperarousal keep cortisol elevated and shift your sleep architecture toward lighter stages.
Structured wind-down routines lower physiological arousal. What works varies by person, but techniques with clinical support include progressive muscle relaxation (systematically tensing and releasing muscle groups), slow breathing exercises where you extend your exhale longer than your inhale, and journaling or writing a to-do list to externalize racing thoughts. The goal isn’t relaxation as a vague concept. It’s reducing sympathetic nervous system activation so your body can transition smoothly into deep sleep within the first 20 minutes of falling asleep.
Get Enough Total Sleep
This sounds obvious, but it’s worth emphasizing because of how sleep stages are distributed. Deep sleep loads heavily into the first three to four hours. REM sleep loads into the last two to three hours. If you’re consistently getting six hours instead of seven or eight, you’re disproportionately cutting REM sleep. Your body prioritizes deep sleep when time is short, so REM gets sacrificed first.
Most adults need seven to nine hours to cycle through enough complete sleep cycles (typically four to six per night) to get adequate amounts of both stages. If you’re optimizing everything else but shorting your total sleep time, you’ll still see low REM numbers. Protecting that last hour or two of sleep in the morning is one of the simplest ways to recover more REM time.