Although this theory is still under investigation, evidence shows that people obtain a higher proportion of deep sleep after learning a new task, and show higher concentrations of slow waves in brain areas related to the task. Put another way, your brain evaluates new memories and then preserves and consolidates only the ones that are most relevant to avoid saturating memory pathways. Researchers suggest that deep sleep plays a role in preparing your synapses for the next day. However, your brain cannot take on information forever without rest. Throughout the day, you receive information inputs that strengthen the synapses, or points of communication, in the networks of your brain. Elite athletes value slow-wave sleep as it helps replenish energy stores.ĭeep sleep is important for cognitive function and memory, and it is thought to play a role in language learning, motor skills, and the developing brain. Additionally, slow-wave sleep may be important for regulating glucose metabolism. During deep sleep, your body releases growth hormone and works to build and repair muscles, bones, and tissue, and immune system functioning. While all stages of sleep are necessary for good health, deep sleep offers specific physical and mental benefits. It can be difficult for someone to wake you up, and waking up out of deep sleep may make you feel mentally foggy for up to an hour. During this stage, automatic body functions like breathing and heart rate are also very slow and your muscles are relaxed. Typically you descend into deep sleep within an hour of falling asleep, and experience progressively shorter periods of deep sleep as the night wears on. These waves have a frequency of 0.5 to 2 Hertz and they must make up at least 6 seconds of a 30-second window for that window to count as deep sleep. During deep sleep, electrical activity in the brain appears in long, slow waves called delta waves. Experts believe most of our dreaming happens during REM sleep.ĭeep sleep, also called slow-wave sleep, occurs in the third stage of non-rapid eye movement (NREM) sleep. However, you lack muscle tone and do not move. Your brain activity is similar to that of a person who is awake. REM: As the name suggests, your eyes move quickly beneath your eyelids during REM sleep.Stage 3: Previously divided into stages 3 and 4, stage 3 slow-wave sleep represents the deepest sleep of the sleep cycle, when brain waves are at their slowest in frequency and highest in amplitude.About half of your total sleep every night is spent in this stage Stage 2 sleep lasts longer in each cycle throughout the night.

Your temperature drops and your muscles relax. Stage 2: In this stage of light sleep your breathing and heart rate slow even more.Stage 1: This brief, drowsy stage marks the transition to sleep, when your breathing and heartbeat slow down.However, as the night goes on, you spend more and more time in REM sleep.

In the first half of the night you spend more time in NREM sleep. Adults typically have 4-6 such cycles per night. It usually takes between 90 and 120 minutes to cycle through all four stages, after which the cycle starts again.

Once you fall asleep, your body cycles through three non rapid eye movement (NREM) phases of sleep followed by one rapid eye movement (REM) sleep stage. Deep sleep is the repairing and restorative sleep that is necessary to feel your best each day.īecause of the potential impacts of obtaining insufficient deep sleep, it is important to understand what deep sleep is, the benefits of deep sleep, and the signs of insufficient deep sleep. There are four sleep stages, and each stage has a specific purpose. Like eating and exercising, sleep is crucial for your health.

Deep sleep stage