Sleep is an important part of our daily lives, allowing our bodies to rest and recharge. Ever wonder how the body navigates the multiple cycles of sleep? Unpacking the 5 stages of sleep can helps us understand what is happening during our sleep cycles and how it can affect your overall wellbeing.
Sleep is divided into 5 stages. Stage 1 is the lighter sleep cycle, during which we may feel as though we are still awake, as our brain begins to slow its activity. Stages 2 and 3 are considered deep sleep, when brain activity slows down even more, resulting in a period of more restorative rest. Stage 4 return to a lighter sleep cycle, while Stage 5, also known as REM (Rapid Eye Movement) Sleep, is the most active and dream-filled stage of sleep.
During a typical, healthy night’s sleep, these 5 stages of sleep occur in cycles between 90-110 minutes, repeating throughout the night.
Stage 1: Light Sleep Cycle
During Stage 1 of most of sleep cycles, we start to feel a light doze, our muscles are relaxed, and our breathing and heart rate slow down. As the night progresses, the sleep cycle then evolves from a light sleep to a deeper sleep. This stage of sleep is the least restorative and the ideal amount of time spent in this stage is short, usually up to 10 minutes.
Stage 2: ‘Breathing down’
Stage 2 is a deeper sleep period where our body begins to “breathe down” even more, during which our brain waves slower and our body temperatures decreases. It is during this stage of sleep that our breathing, heart rate, and body temperature all come together in unison. This stage usually lasts between 15 and 20 minutes.
The brain also starts to generate very slow wave and fluctuates sporadic bursts of rapid waves, known as “sleep spindles”. These sleep spindles play an important role in consolidating memories, particularly those related to learning.
Light sleepers, those who wake easily or experience very light sleep, may spend a disproportionately long time in this stage.
Stage 3: Deepest Sleep
Stage 3 is the deepest point of your sleep cycle. During this stage, 20-50% of your sleep cycle is made up of slow-wave non-rapid eye movement, also known as delta sleep. This stage is crucial to your physical health including: restoring energy, balancing hormones, restoring and rebuilding current damaged cells, and regeneration of the body in general. It is important for this stage to occur in order to help maintain your overall health.
Brain waves also slow down to about 20% of their awake state. During this deep state of sleep it can be difficult to be awakened due to the complete relaxation of your muscles.
Stage 3 is also the stage during which night terrors, sleepwalking, and sleep talking can occur.
Stage 4: REM Sleep
Stage 4 is when a person enters “REM” or rapid eye movement sleep, and dreams begin. During this stage, heart rate and breathing remain steady, muscles relax even further, and the eyes move rapidly around the face. This stage lasts 30 to 60 minutes and recurs several times during a night’s sleep.
Benefits of REM Sleep
- Brain activity is similar to the awake state
- Heightened learning and memory
- Reduced sensory stress from exercise and injuries
- Heightened concentration
- Regulated emotions
Conclusion
Deuling these five stages of sleep helps us understand why it is important to get the right amount of sleep every night. The stages of somecycles provide an important role, from restoring physical and mental energy to helping us learn and retain memories. Paying attention to your sleep cycles can help you get the best night’s sleep possible.